Maintaining natural habitats is crucial for the preservation of insects and other species that indicate environmental changes. However, the Mpanga/Kipengere Game Reserve and its surrounding farmlands are facing distur...Maintaining natural habitats is crucial for the preservation of insects and other species that indicate environmental changes. However, the Mpanga/Kipengere Game Reserve and its surrounding farmlands are facing disturbance due to human activities, which is putting many wildlife species, particularly larger mammals, at risk. To determine the impact of human activities on butterfly species diversity and abundance in the reserve and its surrounding areas, we conducted a study from November 2021 to October 2023. We collected butterfly data using transect walks and baited traps in two habitat types. Our study yielded 2799 butterfly Individuals ranging in 124 species divided into five families habitat, season, and anthropogenic factors are significant environmental variables influencing species diversity and abundance of butterflies. Therefore, it’s important to protect habitat and dry-season water for the conservation of invertebrates such as butterflies. Our study findings provide essential information for ecological monitoring and future assessment of the Mpanga/Kipengere Game Reserve ecosystem health.展开更多
The change processes and trends of shoreline and tidal flat forced by human activities are essential issues for the sustainability of coastal area,which is also of great significance for understanding coastal ecologic...The change processes and trends of shoreline and tidal flat forced by human activities are essential issues for the sustainability of coastal area,which is also of great significance for understanding coastal ecological environment changes and even global changes.Based on field measurements,combined with Linear Regression(LR)model and Inverse Distance Weighing(IDW)method,this paper presents detailed analysis on the change history and trend of the shoreline and tidal flat in Bohai Bay.The shoreline faces a high erosion chance under the action of natural factors,while the tidal flat faces a different erosion and deposition patterns in Bohai Bay due to the impact of human activities.The implication of change rule for ecological protection and recovery is also discussed.Measures should be taken to protect the coastal ecological environment.The models used in this paper show a high correlation coefficient between observed and modeling data,which means that this method can be used to predict the changing trend of shoreline and tidal flat.The research results of present study can provide scientific supports for future coastal protection and management.展开更多
Under the combined influence of climate change and human activities,vegetation ecosystem has undergone profound changes.It can be seen that there are obvious differences in the evolution patterns and driving mechanism...Under the combined influence of climate change and human activities,vegetation ecosystem has undergone profound changes.It can be seen that there are obvious differences in the evolution patterns and driving mechanisms of vegetation ecosystem in different historical periods.Therefore,it is urgent to identify and reveal the dominant factors and their contribution rates in the vegetation change cycle.Based on the data of climate elements(sunshine hours,precipitation and temperature),human activities(population intensity and GDP intensity)and other natural factors(altitude,slope and aspect),this study explored the spatial and temporal evolution patterns of vegetation NDVI in the Yellow River Basin of China from 1989 to 2019 through a residual method,a trend analysis,and a gravity center model,and quantitatively distinguished the relative actions of climate change and human activities on vegetation evolution based on Geodetector model.The results showed that the spatial distribution of vegetation NDVI in the Yellow River Basin showed a decreasing trend from southeast to northwest.During 1981-2019,the temporal variation of vegetation NDVI showed an overall increasing trend.The gravity centers of average vegetation NDVI during the study period was distributed in Zhenyuan County,Gansu Province,and the center moved northeastwards from 1981 to 2019.During 1981-2000 and 2001-2019,the proportion of vegetation restoration areas promoted by the combined action of climate change and human activities was the largest.During the study period(1981-2019),the dominant factors influencing vegetation NDVI shifted from natural factors to human activities.These results could provide decision support for the protection and restoration of vegetation ecosystem in the Yellow River Basin.展开更多
The gravity recovery and climate experiment(GRACE)has emerged as a crucial source of land water storage information in hydrological analysis and research.Numerous factors contribute to regional terrestrial water stora...The gravity recovery and climate experiment(GRACE)has emerged as a crucial source of land water storage information in hydrological analysis and research.Numerous factors contribute to regional terrestrial water storage(TWS),resulting in a complex mechanism.In the Loess Plateau region,the continuous alteration of natural conditions and profound impact of human activities have posed a serious threat to the natural ecosystem,leading to an escalating trend of TWS reduction.Addressing the specific analysis of how natural conditions and human activities affect TWS represents a pressing issue.This study employed the residual analysis method to discern the contribution rates of natural conditions and human activities,elucidated the spatial and temporal changes associated with each factor,and ascertained their individual influence.The findings indicated that TWS on the Loess Plateau exhibited a downward trend of-4.89 mm·a^(-1)from 2003 to 2017.The combined effects of climate change and human activities accounted for alterations in water resource reserves across most areas of the Loess Plateau,with human activities predominantly driving these changes.Precipitation emerged as the primary natural factor influencing TWS variations,and NDVI demonstrated a positive feedback effect on TWS at approximately 30%.Substantial spatial disparities in TWS existed within the Loess Plateau,with human activities identified as the primary cause for the decreasing trend.Vegetation restoration plays a positive role in saving water resources in the Loess Plateau to some extent,and vegetation growth exceeding the regional load will lead to water shortage.展开更多
The morphology of the Modaomen Estuary(ME)has undergone drastic changes in recent decades,and quantifying the contribution of human activities and natural processes is crucial for estuary management.Using Landsat imag...The morphology of the Modaomen Estuary(ME)has undergone drastic changes in recent decades,and quantifying the contribution of human activities and natural processes is crucial for estuary management.Using Landsat images,chart data,and hydrological and meteorological data,this study analyzed the evolution of the shoreline and subaqueous topography of the ME and attempted to quantify the extent of the contributions of human activities.The results show that local human activities dominated morphological evolution in some periods.From 1973 to 2003,the shoreline advanced rapidly seaward,resulting in approximately half of the water area being converted into land.Human activity is critical to this process,with the direct contribution of local land reclamation projects reaching more than 85%.After 2003,the shoreline remained relatively stable,probably due to a decrease in land reclamation projects.Regarding the evolution of subaqueous topography,the shoals in the estuary were heavily silted and gradually disappeared during 1983–2003,and the waterways narrowed and deepened.The average siltation rate decreased from 15.43 mm/a to-1.02 mm/a,indicating that the ME changed from sedimentation to slight erosion.By detecting variations of sediment load,we found that upstream human activities reduced river sediment,while downstream human activities significantly increased sediment input to the ME,leaving little change in the actual sediment input to the ME for a relatively long period.In addition,based on the empirical relationship between the sediment input and siltation rate,local human activities influenced the shift in the siltation state more than upstream and downstream human activities did.These findings suggest that more attention should be paid to local human activities to improve the estuarine management in the ME.展开更多
Climate change and human activities have changed a number of characteristics of river flow in the Taihu Basin.Based on long-term time series of hydrological data from 1986 to 2015,we analyzed variability in precipitat...Climate change and human activities have changed a number of characteristics of river flow in the Taihu Basin.Based on long-term time series of hydrological data from 1986 to 2015,we analyzed variability in precipitation,water stage,water diversion from the Yangtze River,and net inflow into Taihu Lake with the Mann-Kendall test.The non-stationary relationship between precipitation and water stage was first analyzed for the Taihu Basin and the Wuchengxiyu(WCXY)sub-region.The optimized regional and urban regulation schemes were explored to tackle high water stage problems through the hydrodynamic model.The results showed the following:(1)The highest,lowest,and average Taihu Lake water stages of all months had increasing trends.The total net inflow into Taihu Lake from the Huxi(HX)sub-region and the Wangting Sluice increased significantly.(2)The Taihu Lake water stage decreased much more slowly after 2002;it was steadier and higher after 2002.After the construction of Wuxi urban flood control projects,the average water stage of the inner city was 0.16e0.40 m lower than that of suburbs in the flood season,leading to the transfer of flooding in inner cities to suburbs and increasing inflow from HX into Taihu Lake.(3)The regional optimized schemes were more satisfactory in not increasing the inner city flood control burden,thereby decreasing the average water stage by 0.04e0.13 m,and the highest water stage by 0.04e0.09 m for Taihu Lake and the sub-region in the flood season.Future flood control research should set the basin as the basic unit.Decreasing diversion and drainage lines along the Yangtze River can take an active role in flood control.展开更多
Changing climatic conditions and extensive human activities have influenced the global water cycle.In recent years,significant changes in climate and land use have degraded the watershed ecosystem of the Ebinur Lake B...Changing climatic conditions and extensive human activities have influenced the global water cycle.In recent years,significant changes in climate and land use have degraded the watershed ecosystem of the Ebinur Lake Basin in Xinjiang,Northwest China.In this paper,variations of runoff,temperature,precipitation,reference evapotranspiration,lake area,socio-economic water usage,groundwater level and water quality in the Ebinur Lake Basin from 1961 to 2015 were systematically analyzed by the Mann-Kendall test methods(M-K)mutation test,the cumulative levelling method,the climate-sensitive method and land-use change index.In addition,we evaluated the effects of human activities on land use change and water quality.The results reveal that there was a significant increase in temperature and precipitation from 1961 to 2015,despite a decrease in reference evapotranspiration.The Wenquan station was not significantly affected by human activities as it is situated at a higher altitude.Runoff at this station increased significantly with climate warming.In contrast,runoff at the Jinghe station was severely affected by numerous human activities.Runoff decreased without obvious fluctuations.The contributions of climate change to runoff variation at the Jinghe and Wenquan stations were 46.87%and 58.94%,respectively;and the contributions of human activities were 53.13%and 41.06%,respectively.Land-use patterns in the basin have changed significantly between 1990 and 2015:urban and rural constructed lands,saline-alkali land,bare land,cultivated land,and forest land have expanded,while areas under grassland,lake,ice/snow and river/channel have declined.Human activities have dramatically intensified land degradation and desertification.From 1961 to 2015,both the inflow into the Ebinur Lake and the area of the lake have declined year by year;groundwater levels have dropped significantly,and the water quality has deteriorated during the study period.In the oasis irrigation area below the runoff pass,human activities mainly influenced the utilization mode and quantity of water resources.Changes in the hydrology and quantity of water resources were driven primarily by the continuous expansion of cultivated land and oasis,as well as the growth of population and the construction of hydraulic engineering projects.After 2015,the effects of some ecological protection projects were observed.However,there was no obvious sign of ecological improvement in the basin,and some environmental problems continue to persist.On this basis,this study recommends that the expansion of oasis should be limited according to the carrying capacity of the local water bodies.Moreover,in order to ensure the ecological security of the basin,it is necessary to determine the optimal oasis area for sustainable development and improve the efficiency of water resources exploitation and utilization.展开更多
Central Asia is located in the hinterland of Eurasia,comprising Kazakhstan,Uzbekistan,Kyrgyzstan,Turkmenistan,and Tajikistan;over 93.00%of the total area is dryland.Temperature rise and human activities have severe im...Central Asia is located in the hinterland of Eurasia,comprising Kazakhstan,Uzbekistan,Kyrgyzstan,Turkmenistan,and Tajikistan;over 93.00%of the total area is dryland.Temperature rise and human activities have severe impacts on the fragile ecosystems.Since the 1970s,nearly half the great lakes in Central Asia have shrunk and rivers are drying rapidly owing to climate changes and human activities.Water shortage and ecological crisis have attracted extensive international attention.In general,ecosystem services in Central Asia are declining,particularly with respect to biodiversity,water,and soil conservation.Furthermore,the annual average temperature and annual precipitation in Central Asia increased by 0.30℃/decade and 6.9 mm/decade in recent decades,respectively.Temperature rise significantly affected glacier retreat in the Tianshan Mountains and Pamir Mountains,which may intensify water shortage in the 21st century.The increase in precipitation cannot counterbalance the aggravation of water shortage caused by the temperature rise and human activities in Central Asia.The population of Central Asia is growing gradually,and its economy is increasing steadily.Moreover,the agricultural land has not been expended in the last two decades.Thus,water and ecological crises,such as the Aral Sea shrinkage in the 21st century,cannot be attributed to agriculture extension any longer.Unbalanced regional development and water interception/transfer have led to the irrational exploitation of water resources in some watersheds,inducing downstream water shortage and ecological degradation.In addition,accelerated industrialization and urbanization have intensified this process.Therefore,all Central Asian countries must urgently reach a consensus and adopt common measures for water and ecological protection.展开更多
The Luanhe River Delta is located in the center of the Circum-Bohai Sea Economic Zone.It enjoys rapid economic and social development while suffering relatively water scarcity.The overexploitation of groundwater in th...The Luanhe River Delta is located in the center of the Circum-Bohai Sea Economic Zone.It enjoys rapid economic and social development while suffering relatively water scarcity.The overexploitation of groundwater in the Luanhe River Delta in recent years has caused the continuous drop of groundwater level and serious environmental and geological problems.This study systematically analyzes the evolution characteristics of the population,economy,and groundwater exploitation in the Luanhe River Delta and summarizes the change patterns of the groundwater flow regime in different aquifers in the Luanhe River Delta according to previous water resource assessment data as well as the latest groundwater survey results.Through comparison of major source/sink terms and groundwater resources,the study reveals the impacts of human activities on the groundwater resources and ecological environment in the study area over the past 30 years from 1990 to 2020.The results are as follows.The average annual drop rate of shallow groundwater and the deep groundwater in the centers of depression cones is 0.4 m and 1.64 m,respectively in the Luanhe River Delta in the past 30 years.The depression cones of shallow and deep groundwater in the study area cover an area of 545.32 km^(2)and 548.79 km^(2),respectively,accounting for more than 10%of the total area of the Luanhe River Delta.Overexploitation of groundwater has further aggravated land subsidence.As a result,two large-scale subsidence centers have formed,with a maximum subsidence rate of up to 120 mm/a.The drop of groundwater level has induced some ecological problems in the Luanhe River Delta area,such as the zero flow and water quality deterioration of rivers and continuous shrinkage of natural wetlands and water.Meanwhile,the proportion of natural wetland area to the total wetland area has been decreased from 99%to 8%and the water area from 1776 km^(2)to 263 km^(2).These results will provide data for groundwater overexploitation control,land subsidence prevention,and ecological restoration in plains and provide services for water resources management and national land space planning.展开更多
Yulin is a typical ecological fragile area in China, and its vegetation ecosystem is so fragile that could be vulnerable to climate change and human activities. Spatial and temporal change of vegetation Normalized Dif...Yulin is a typical ecological fragile area in China, and its vegetation ecosystem is so fragile that could be vulnerable to climate change and human activities. Spatial and temporal change of vegetation Normalized Difference Vegetation Index (NDVI) and its relationship with climate change and human activities were analyzed based on MODIS NDVI data from 2000 to 2015, as well as annual temperature and precipitation data from 2000 to 2014, and linear trend analysis, correlation and buffer analysis were used. Result showed: 1) NDVI value was small and vegetation cover was low, but NDVI had a linear growth rate of 0.0096/annum from 2000 to 2015 in Yulin area. The area of growth trend accounted for 97.06% of the total area, while the area with decreased rate was small, which mainly had correlation with human activities, and was distributed in the southwest mountain area, urban neighborhood, and river valley in the middle and east of Yulin area. 2) Correlation analysis between NDVI and temperature, precipitation, respectively, reflected that negative correlation was between NDVI and temperature, while positive correlation was between NDVI and precipitation. Furthermore, the role of precipitation was higher than that of temperature in the process of interaction between NDVI and temperature, precipitation. 3) NDVI change process in the range of human activities indicated that the intensity of human activities in buffer_city area was higher than that in buffer_county area. Buffer_city area was divided into within 5 km area with dramatic impact by human activities, and from 5 km to 9 km area with less impact by human activities, and outside 9 km area with mini-affected by human activities.展开更多
This work analyzes and discusses the influence of human activities on the meteorological conditions related to winter haze events in Beijing,Tianjin,and Hebei(i.e.,the Jing-Jin-Ji region)during 1961-2016,using the res...This work analyzes and discusses the influence of human activities on the meteorological conditions related to winter haze events in Beijing,Tianjin,and Hebei(i.e.,the Jing-Jin-Ji region)during 1961-2016,using the results of two numerical simulation experiments based on the Community Atmosphere Model version 5.1.1(http://www.cesm.ucar.edu/models/cesm1.0/cam/docs/ug5_1_1/book1.html)used in the international Climate Variability and Predictability Programme(CLIVAR)Climate of the 20th Century Detection and Attribution Project(C20C+D&A).The results show that,under the influence of human activities,the changes in dynamical and thermal meteorological conditions related to winter haze events in the Jing–Jin–Ji region are conducive to the formation and accumulation of haze,and prevent the diffusion of pollutants.The dynamical conditions mainly include the obvious weakening of the East Asian winter monsoon(EAWM)and the enhancement of the near-surface anomalous southerly wind.The thermal conditions include the obvious increase in surface temperature,and the enhancement of water vapor transport and near-surface inversion.The relative contribution of dynamical and thermal conditions to the variation of haze days in the Jing-Jin-Ji region is analyzed using statistical methods.The results show that the contribution of human activities to the increase of haze days in the Jing-Jin-Ji region is greater than that of natural forcing for the study period.To be specific,the dynamical meteorological factors contribute more to the haze days than the thermal meteorological factors.The contribution of thermal meteorological factors is basically the same in both scenarios.展开更多
The Three-River Headwater Region(TRHR)of China is a typical representative of the alpine environment in the Central Asian plateau and the alpine grassland in the world.Grassland degradation is one of its serious eco-l...The Three-River Headwater Region(TRHR)of China is a typical representative of the alpine environment in the Central Asian plateau and the alpine grassland in the world.Grassland degradation is one of its serious eco-logical problems.The purpose of this study is to quantify the joint impacts of climate and human activities on grassland changes in TRHR after two phases of Ecological Conservation and Construction Project(Ecological Project).Grassland vegetation coverage is selected as an indicator for analyzing grassland changes.We adopt Sen+Mann-Kendall trend analysis,residual trend analysis and correlation analysis methods to analyze the trends in spatial-temporal changes and driving factors of grassland in TRHR from 2000 to 2019.The results show that:(1)The grassland has been mainly restored,and the degraded grassland area only accounts for 1.66%of TRHR.After the implementation of the first phase of the Ecological Project,the percentage of restored grassland area has significantly increased from 8.82%to 24.57%,and slightly decreased during the second phase.(2)The establish-ment of national nature reserves and the implementation of the Ecological Project have changed the situation that“the grassland inside the reserve is worse than that outside the reserve”.(3)Grassland restoration is mainly af-fected by the joint effects of climate and human activities.Nevertheless,grassland degradation is mainly affected by human activities such as overgrazing and grassland reclamation.All of these findings can enrich our under-standing of grassland restoration in TRHR.Artificial measures have certain limitations in promoting grassland restoration.Natural restoration should be considered when human beings strengthen ecological conservation and transform their production and life styles.展开更多
This study was proposed to explore the impact of human activities on the environment in Mhondongori. In this community, there are natural resources that include minerals, natural forest, wetlands, rivers and beautiful...This study was proposed to explore the impact of human activities on the environment in Mhondongori. In this community, there are natural resources that include minerals, natural forest, wetlands, rivers and beautiful mountains. However, over the past two decades, the environmental quality of the community has deteriorated demonstrating irresponsible use of natural resources by humans. Indeed, if such poor natural resource management continues at the current rate, this would ultimately lead to extinction. Qualitative research design and convenience sampling methods were used. The study involved six participants who provided the data. An interview guide and observation techniques were used to collect data. Using content analysis data was classified into themes and a scorecard was used to determine the human activities on the environment and their impact. The results revealed that in Mhondongori, human activities that affected the environment were mining, veld fire, cutting down trees, overgrazing, excessive communal hunting and fishing, littering, water and air pollution. The impacts were the degradation of land, permanent scars on the landscape, deforestation, destruction of wildlife habitats, disappearance of wetlands, destruction of trees, grass, seed bank and seedlings, pollution of streets, bushes and rivers, disruption of migration and hibernation of animals. To conserve the environment, it was recommended that community leadership must develop appropriate environmental management strategies to mitigate these unfavourable impacts and that the state must empower Mhondongori leadership through reasonable legislative and other measures that would prevent environmental degradation.展开更多
Mid and high latitude wetlands are becoming fragmented and losing ecosystem functions at a much faster rate than many other ecosystems.This is due in part to increasing human activities and climate change.In this stud...Mid and high latitude wetlands are becoming fragmented and losing ecosystem functions at a much faster rate than many other ecosystems.This is due in part to increasing human activities and climate change.In this study,we analyzed wetland distribution and spatial pattern changes for the Heilongjiang River Basin over the past 100 yr.We identified the driving factors and quantified the relative importance of each factor based on landscape pattern metrics and machine learning algorithms.Our results show that wetlands have been fragmented into smaller and regular patches with dominant factors that varied at different periods.Geographic features play the most important role in patterns of wetland change for the entire basin(with 50%-60%of relative importance).Human activities are more important than climate change at the century scale,but less important when magnified at the decadal scale.In the early 1900s,human activities were relatively low and localized and remained that way in the subsequent decades.Thus,the effect of human activities on wetland area of the entire basin is weaker when examined at the magnified decadal scale.The results also show that human activities are more important on the Chinese side of the Heilongjiang River Basin,in the ZeyaBureya Plain on the Russian side,and at lower altitudes(0-100 m).Revealing the spatial and temporal processes and driving factors over the past 100 yr helps researchers and policymakers understand and anticipate wetland change and design effective conservation and restoration policies.展开更多
Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues.However,whether human-induced activities could change the coastal land use gradient pattern,an import...Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues.However,whether human-induced activities could change the coastal land use gradient pattern,an important coastal zonal characteristic along the sea-land direction,remains unclear.Manila Bay was selected as the study area in this work.According to the distance of the land use and land cover(LULC)to the coastline,we clustered the typical coastal land use sequence patterns(CLUSPs)along the sea-land direction between 1988 and 2016 in Manila Bay and found the following.(1)Four typical CLUSPs,including the natural CLUSP dominated by forest land and grassland,the agricultural CLUSP dominated by dry farm and paddy field,the urbanised CLUSP dominated by construction land and the fishery CLUSP dominated by fishing farm,were mined in 1988.Three typical CLUSPs(a natural CLUSP,an intermediate CLUSP between the agricultural and urbanised CLUSPs,and a fishery CLUSP)were mined in 2016.(2)Affected by the dominant LULC,these typical CLUSPs showed a regular spatial pattern along the sea-land direction.For example,the typical natural CLUSP showed a landward pattern due to the long distance between the forest land and grassland and the coastline.(3)However,influenced by urban and aquaculture expansion,the land intensification of the CLUSP exhibited an obvious increase and caused the decrease of the CLUSP diversity from 1988 to 2016.The increase in the area of LULC coverage showed no obvious correlation with its distance from the coastline(DFC),but the net increase rate of LULC coverage had a significant negative correlation with the DFC.Therefore,human-induced activities have a large impact on the gradient pattern of coastal land use along the sea-land direction.展开更多
When various urban functions are integrated into one location,they form a mixture of functions.The emerging big data promote an alternative way to identify mixed functions.However,current methods are largely unable to...When various urban functions are integrated into one location,they form a mixture of functions.The emerging big data promote an alternative way to identify mixed functions.However,current methods are largely unable to extract deep features in these data,resulting in low accuracy.In this study,we focused on recognizing mixed urban functions from the perspective of human activities,which are essential indicators of functional areas in a city.We proposed a framework to comprehensively extract deep features of human activities in big data,including activity dynamics,mobility interactions,and activity semantics,through representation learning methods.Then,integrating these features,we employed fuzzy clustering to identify the mixture of urban functions.We conducted a case study using taxiflow and social media data in Beijing,China,in whichfive urban functions and their correlations with land use were recognized.The mixture degree of urban functions in each location was revealed,which had a negative correlation with taxi trip distance.The results confirmed the advantages of our method in understanding mixed urban functions by employing various representation learning methods to comprehensively depict human activities.This study has important implications for urban planners in understanding urban systems and developing better strategies.展开更多
Animals must strike a balance between anti-predation behavior and other essential behaviors,such as foraging.Within the same species,strategies may vary on individuals’risk-taking preferences,and in this process the ...Animals must strike a balance between anti-predation behavior and other essential behaviors,such as foraging.Within the same species,strategies may vary on individuals’risk-taking preferences,and in this process the environment is a determinant,in addition to predator regime.The Crested Ibis(Nipponia nippon)exhibits such tendency.This is an endangered species,once inhabiting exclusively in China’s Qinling Mountain.This used to be the sole remaining wild population.However,over recent decades,this population has expanded.A portion has relocated to breed in the lower plain area,which is characterized by elevated level of human activities and landscape complexity.We used flight initiation distance(FID)as an indicator of the ibises’risk-taking preference,particularly their response to human proximity.Additionally,we examined the environmental factors influencing their foraging site selection,including altitude,terrain openness,human activity intensity and human construction.Our findings revealed a significantly shorter FID among individuals relocating to plain habitats,indicating a higher tolerance of human proximity.The results showed that FID decreased with distance to the nearest human settlement.Another finding is that FID was independent of instant human activity intensity and environmental factors(altitude and terrain openness).These different may arise from various combinations of human activity,predation risk,and food abundance within the two habitats.These results provide insights into the in situ conservation of the threatened species within the context of global urbanization.展开更多
Human activities in a transborder watershed are complex under the influence of domestic policies,international relations,and global events.Understanding the forces driving human activity change is important for the de...Human activities in a transborder watershed are complex under the influence of domestic policies,international relations,and global events.Understanding the forces driving human activity change is important for the development of transborder watershed.In this study,we used global historical land cover data,the hemeroby index model,and synthesized major historical events to analyze how human activity intensity changed in the Heilongjiang River(Amur River in Russia)watershed(HLRW).The results showed that there was a strong spatial heterogeneity in the variation of human activity intensity in the HLRW over the past century(1900-2016).On the Chinese side,the human activity intensity change shifted from the plain areas for agricultural reclamation to the mountainous areas for timber extraction.On the Russian side,human activity intensity changes mostly concentrated along the Trans-Siberian Railway and the Baikal-Amur Mainline.Localized variation of human activity intensity tended to respond to regional events while regionalized variation tends to reflect national policy change or broad international events.The similarities and differences between China and Russia in policies and positions in international events resulted in synchronous and asynchronous changes in human activity intensity.Meanwhile,policy shifts were often confined by the natural features of the watershed.These results reveal the historical origins and fundamental connotations of watershed development and contribute to formulating regional management policies that coordinate population,eco-nomic,social,and environmental activities.展开更多
RFID-based human activity recognition(HAR)attracts attention due to its convenience,noninvasiveness,and privacy protection.Existing RFID-based HAR methods use modeling,CNN,or LSTM to extract features effectively.Still...RFID-based human activity recognition(HAR)attracts attention due to its convenience,noninvasiveness,and privacy protection.Existing RFID-based HAR methods use modeling,CNN,or LSTM to extract features effectively.Still,they have shortcomings:1)requiring complex hand-crafted data cleaning processes and 2)only addressing single-person activity recognition based on specific RF signals.To solve these problems,this paper proposes a novel device-free method based on Time-streaming Multiscale Transformer called TransTM.This model leverages the Transformer's powerful data fitting capabilities to take raw RFID RSSI data as input without pre-processing.Concretely,we propose a multiscale convolutional hybrid Transformer to capture behavioral features that recognizes singlehuman activities and human-to-human interactions.Compared with existing CNN-and LSTM-based methods,the Transformer-based method has more data fitting power,generalization,and scalability.Furthermore,using RF signals,our method achieves an excellent classification effect on human behaviorbased classification tasks.Experimental results on the actual RFID datasets show that this model achieves a high average recognition accuracy(99.1%).The dataset we collected for detecting RFID-based indoor human activities will be published.展开更多
文摘Maintaining natural habitats is crucial for the preservation of insects and other species that indicate environmental changes. However, the Mpanga/Kipengere Game Reserve and its surrounding farmlands are facing disturbance due to human activities, which is putting many wildlife species, particularly larger mammals, at risk. To determine the impact of human activities on butterfly species diversity and abundance in the reserve and its surrounding areas, we conducted a study from November 2021 to October 2023. We collected butterfly data using transect walks and baited traps in two habitat types. Our study yielded 2799 butterfly Individuals ranging in 124 species divided into five families habitat, season, and anthropogenic factors are significant environmental variables influencing species diversity and abundance of butterflies. Therefore, it’s important to protect habitat and dry-season water for the conservation of invertebrates such as butterflies. Our study findings provide essential information for ecological monitoring and future assessment of the Mpanga/Kipengere Game Reserve ecosystem health.
基金supported by the National Natural Science Foundation of China (41602205, 42293261)the China Geological Survey Program (DD20189506, DD20211301)+2 种基金the Special Investigation Project on Science and Technology Basic Resources of the Ministry of Science and Technology (2021FY101003)the Central Guidance for Local Scientific and Technological Development Fund of 2023the Project of Hebei University of Environmental Engineering (GCY202301)
文摘The change processes and trends of shoreline and tidal flat forced by human activities are essential issues for the sustainability of coastal area,which is also of great significance for understanding coastal ecological environment changes and even global changes.Based on field measurements,combined with Linear Regression(LR)model and Inverse Distance Weighing(IDW)method,this paper presents detailed analysis on the change history and trend of the shoreline and tidal flat in Bohai Bay.The shoreline faces a high erosion chance under the action of natural factors,while the tidal flat faces a different erosion and deposition patterns in Bohai Bay due to the impact of human activities.The implication of change rule for ecological protection and recovery is also discussed.Measures should be taken to protect the coastal ecological environment.The models used in this paper show a high correlation coefficient between observed and modeling data,which means that this method can be used to predict the changing trend of shoreline and tidal flat.The research results of present study can provide scientific supports for future coastal protection and management.
基金This work was supported by grants from the National Natural Science Foundation of China(42101306,4217107)the Natural Science Foundation of Shandong Province(ZR2021MD047),the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA2002040203)+2 种基金the Open Fund of the Key Laboratory of National Geographic Census and Monitoring,Ministry of Natural Resources(MNR)(2020NGCM02)the Open Fund of the Key Laboratory of Urban Land Resources Monitoring and Simulation,Ministry of Natural Resources(KF-2020-05-001)the Major Project of the High Resolution Earth Observation System of China(GFZX0404130304).
文摘Under the combined influence of climate change and human activities,vegetation ecosystem has undergone profound changes.It can be seen that there are obvious differences in the evolution patterns and driving mechanisms of vegetation ecosystem in different historical periods.Therefore,it is urgent to identify and reveal the dominant factors and their contribution rates in the vegetation change cycle.Based on the data of climate elements(sunshine hours,precipitation and temperature),human activities(population intensity and GDP intensity)and other natural factors(altitude,slope and aspect),this study explored the spatial and temporal evolution patterns of vegetation NDVI in the Yellow River Basin of China from 1989 to 2019 through a residual method,a trend analysis,and a gravity center model,and quantitatively distinguished the relative actions of climate change and human activities on vegetation evolution based on Geodetector model.The results showed that the spatial distribution of vegetation NDVI in the Yellow River Basin showed a decreasing trend from southeast to northwest.During 1981-2019,the temporal variation of vegetation NDVI showed an overall increasing trend.The gravity centers of average vegetation NDVI during the study period was distributed in Zhenyuan County,Gansu Province,and the center moved northeastwards from 1981 to 2019.During 1981-2000 and 2001-2019,the proportion of vegetation restoration areas promoted by the combined action of climate change and human activities was the largest.During the study period(1981-2019),the dominant factors influencing vegetation NDVI shifted from natural factors to human activities.These results could provide decision support for the protection and restoration of vegetation ecosystem in the Yellow River Basin.
基金financial support from the Natural Science Basic Research Plan of Shaanxi Province(2023-JC-YB-275)the National Natural Science Foundation of China(42071144,41971218)+1 种基金the Fundamental Research Funds for the Central Universities,Shaanxi Normal University(2021CBWY003)the Special Scientific Research Project of Shaanxi Normal University(22YDYLZ002)。
文摘The gravity recovery and climate experiment(GRACE)has emerged as a crucial source of land water storage information in hydrological analysis and research.Numerous factors contribute to regional terrestrial water storage(TWS),resulting in a complex mechanism.In the Loess Plateau region,the continuous alteration of natural conditions and profound impact of human activities have posed a serious threat to the natural ecosystem,leading to an escalating trend of TWS reduction.Addressing the specific analysis of how natural conditions and human activities affect TWS represents a pressing issue.This study employed the residual analysis method to discern the contribution rates of natural conditions and human activities,elucidated the spatial and temporal changes associated with each factor,and ascertained their individual influence.The findings indicated that TWS on the Loess Plateau exhibited a downward trend of-4.89 mm·a^(-1)from 2003 to 2017.The combined effects of climate change and human activities accounted for alterations in water resource reserves across most areas of the Loess Plateau,with human activities predominantly driving these changes.Precipitation emerged as the primary natural factor influencing TWS variations,and NDVI demonstrated a positive feedback effect on TWS at approximately 30%.Substantial spatial disparities in TWS existed within the Loess Plateau,with human activities identified as the primary cause for the decreasing trend.Vegetation restoration plays a positive role in saving water resources in the Loess Plateau to some extent,and vegetation growth exceeding the regional load will lead to water shortage.
基金The National Natural Science Foundation of China under contract Nos 41876205,42106169 and 41890851the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)under contract Nos GML2019ZD0305 and GML2019ZD0303the Project of State Key Laboratory of Tropical Oceanography under contract Nos LTOZZ2102 and LTOZZ2202.
文摘The morphology of the Modaomen Estuary(ME)has undergone drastic changes in recent decades,and quantifying the contribution of human activities and natural processes is crucial for estuary management.Using Landsat images,chart data,and hydrological and meteorological data,this study analyzed the evolution of the shoreline and subaqueous topography of the ME and attempted to quantify the extent of the contributions of human activities.The results show that local human activities dominated morphological evolution in some periods.From 1973 to 2003,the shoreline advanced rapidly seaward,resulting in approximately half of the water area being converted into land.Human activity is critical to this process,with the direct contribution of local land reclamation projects reaching more than 85%.After 2003,the shoreline remained relatively stable,probably due to a decrease in land reclamation projects.Regarding the evolution of subaqueous topography,the shoals in the estuary were heavily silted and gradually disappeared during 1983–2003,and the waterways narrowed and deepened.The average siltation rate decreased from 15.43 mm/a to-1.02 mm/a,indicating that the ME changed from sedimentation to slight erosion.By detecting variations of sediment load,we found that upstream human activities reduced river sediment,while downstream human activities significantly increased sediment input to the ME,leaving little change in the actual sediment input to the ME for a relatively long period.In addition,based on the empirical relationship between the sediment input and siltation rate,local human activities influenced the shift in the siltation state more than upstream and downstream human activities did.These findings suggest that more attention should be paid to local human activities to improve the estuarine management in the ME.
基金supported by the National Key Research and Development Project(Grants No.2018YFC0407900 and 2017YFC1502403)the Special Public Sector Research Program of the Ministry of Water Resources of China(Grant No.201501014)the National Natural Science Foundation of China(Grants No.51779071 and 51579065).
文摘Climate change and human activities have changed a number of characteristics of river flow in the Taihu Basin.Based on long-term time series of hydrological data from 1986 to 2015,we analyzed variability in precipitation,water stage,water diversion from the Yangtze River,and net inflow into Taihu Lake with the Mann-Kendall test.The non-stationary relationship between precipitation and water stage was first analyzed for the Taihu Basin and the Wuchengxiyu(WCXY)sub-region.The optimized regional and urban regulation schemes were explored to tackle high water stage problems through the hydrodynamic model.The results showed the following:(1)The highest,lowest,and average Taihu Lake water stages of all months had increasing trends.The total net inflow into Taihu Lake from the Huxi(HX)sub-region and the Wangting Sluice increased significantly.(2)The Taihu Lake water stage decreased much more slowly after 2002;it was steadier and higher after 2002.After the construction of Wuxi urban flood control projects,the average water stage of the inner city was 0.16e0.40 m lower than that of suburbs in the flood season,leading to the transfer of flooding in inner cities to suburbs and increasing inflow from HX into Taihu Lake.(3)The regional optimized schemes were more satisfactory in not increasing the inner city flood control burden,thereby decreasing the average water stage by 0.04e0.13 m,and the highest water stage by 0.04e0.09 m for Taihu Lake and the sub-region in the flood season.Future flood control research should set the basin as the basic unit.Decreasing diversion and drainage lines along the Yangtze River can take an active role in flood control.
基金supported by the Scientific Research Foundation for High-Level Talents of Shihezi University(RCZK2018C41,CXRC201801,RCZK2018C22)the National Natural Science Foundation of China(41661040,U1803244)the Scientific and Technological Research Projects of Xinjiang Production and Construction Corps,China(2021AB021)。
文摘Changing climatic conditions and extensive human activities have influenced the global water cycle.In recent years,significant changes in climate and land use have degraded the watershed ecosystem of the Ebinur Lake Basin in Xinjiang,Northwest China.In this paper,variations of runoff,temperature,precipitation,reference evapotranspiration,lake area,socio-economic water usage,groundwater level and water quality in the Ebinur Lake Basin from 1961 to 2015 were systematically analyzed by the Mann-Kendall test methods(M-K)mutation test,the cumulative levelling method,the climate-sensitive method and land-use change index.In addition,we evaluated the effects of human activities on land use change and water quality.The results reveal that there was a significant increase in temperature and precipitation from 1961 to 2015,despite a decrease in reference evapotranspiration.The Wenquan station was not significantly affected by human activities as it is situated at a higher altitude.Runoff at this station increased significantly with climate warming.In contrast,runoff at the Jinghe station was severely affected by numerous human activities.Runoff decreased without obvious fluctuations.The contributions of climate change to runoff variation at the Jinghe and Wenquan stations were 46.87%and 58.94%,respectively;and the contributions of human activities were 53.13%and 41.06%,respectively.Land-use patterns in the basin have changed significantly between 1990 and 2015:urban and rural constructed lands,saline-alkali land,bare land,cultivated land,and forest land have expanded,while areas under grassland,lake,ice/snow and river/channel have declined.Human activities have dramatically intensified land degradation and desertification.From 1961 to 2015,both the inflow into the Ebinur Lake and the area of the lake have declined year by year;groundwater levels have dropped significantly,and the water quality has deteriorated during the study period.In the oasis irrigation area below the runoff pass,human activities mainly influenced the utilization mode and quantity of water resources.Changes in the hydrology and quantity of water resources were driven primarily by the continuous expansion of cultivated land and oasis,as well as the growth of population and the construction of hydraulic engineering projects.After 2015,the effects of some ecological protection projects were observed.However,there was no obvious sign of ecological improvement in the basin,and some environmental problems continue to persist.On this basis,this study recommends that the expansion of oasis should be limited according to the carrying capacity of the local water bodies.Moreover,in order to ensure the ecological security of the basin,it is necessary to determine the optimal oasis area for sustainable development and improve the efficiency of water resources exploitation and utilization.
基金This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences:the Pan-Third Pole Environment Study for a Green Silk Road(XDA20060303)the CAS''Light of West China''Program(2018-XBQNXZ-B-017)the''High-level Talents Program''of Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences(Y871171).Special thanks are given to the Philosophy and Social Science Major Research Project"Research on the Major Risk Prevention System in the Development of Artificial Intelligence"(20JZD026)funded by the Ministry of Education of the People's Republic of China.
文摘Central Asia is located in the hinterland of Eurasia,comprising Kazakhstan,Uzbekistan,Kyrgyzstan,Turkmenistan,and Tajikistan;over 93.00%of the total area is dryland.Temperature rise and human activities have severe impacts on the fragile ecosystems.Since the 1970s,nearly half the great lakes in Central Asia have shrunk and rivers are drying rapidly owing to climate changes and human activities.Water shortage and ecological crisis have attracted extensive international attention.In general,ecosystem services in Central Asia are declining,particularly with respect to biodiversity,water,and soil conservation.Furthermore,the annual average temperature and annual precipitation in Central Asia increased by 0.30℃/decade and 6.9 mm/decade in recent decades,respectively.Temperature rise significantly affected glacier retreat in the Tianshan Mountains and Pamir Mountains,which may intensify water shortage in the 21st century.The increase in precipitation cannot counterbalance the aggravation of water shortage caused by the temperature rise and human activities in Central Asia.The population of Central Asia is growing gradually,and its economy is increasing steadily.Moreover,the agricultural land has not been expended in the last two decades.Thus,water and ecological crises,such as the Aral Sea shrinkage in the 21st century,cannot be attributed to agriculture extension any longer.Unbalanced regional development and water interception/transfer have led to the irrational exploitation of water resources in some watersheds,inducing downstream water shortage and ecological degradation.In addition,accelerated industrialization and urbanization have intensified this process.Therefore,all Central Asian countries must urgently reach a consensus and adopt common measures for water and ecological protection.
基金This research is jointly funded by the“Project of Hydrogeological survey of Luanhe River Basin”of China Geological Survey(No.DD20190338)General Project of National Natural Science Foundation of China(No.41972196)+1 种基金Youth Fund of the National Natural Science Foundation of China(No.41907149)China Postdoctoral Foundation(No.2018M631732).
文摘The Luanhe River Delta is located in the center of the Circum-Bohai Sea Economic Zone.It enjoys rapid economic and social development while suffering relatively water scarcity.The overexploitation of groundwater in the Luanhe River Delta in recent years has caused the continuous drop of groundwater level and serious environmental and geological problems.This study systematically analyzes the evolution characteristics of the population,economy,and groundwater exploitation in the Luanhe River Delta and summarizes the change patterns of the groundwater flow regime in different aquifers in the Luanhe River Delta according to previous water resource assessment data as well as the latest groundwater survey results.Through comparison of major source/sink terms and groundwater resources,the study reveals the impacts of human activities on the groundwater resources and ecological environment in the study area over the past 30 years from 1990 to 2020.The results are as follows.The average annual drop rate of shallow groundwater and the deep groundwater in the centers of depression cones is 0.4 m and 1.64 m,respectively in the Luanhe River Delta in the past 30 years.The depression cones of shallow and deep groundwater in the study area cover an area of 545.32 km^(2)and 548.79 km^(2),respectively,accounting for more than 10%of the total area of the Luanhe River Delta.Overexploitation of groundwater has further aggravated land subsidence.As a result,two large-scale subsidence centers have formed,with a maximum subsidence rate of up to 120 mm/a.The drop of groundwater level has induced some ecological problems in the Luanhe River Delta area,such as the zero flow and water quality deterioration of rivers and continuous shrinkage of natural wetlands and water.Meanwhile,the proportion of natural wetland area to the total wetland area has been decreased from 99%to 8%and the water area from 1776 km^(2)to 263 km^(2).These results will provide data for groundwater overexploitation control,land subsidence prevention,and ecological restoration in plains and provide services for water resources management and national land space planning.
文摘Yulin is a typical ecological fragile area in China, and its vegetation ecosystem is so fragile that could be vulnerable to climate change and human activities. Spatial and temporal change of vegetation Normalized Difference Vegetation Index (NDVI) and its relationship with climate change and human activities were analyzed based on MODIS NDVI data from 2000 to 2015, as well as annual temperature and precipitation data from 2000 to 2014, and linear trend analysis, correlation and buffer analysis were used. Result showed: 1) NDVI value was small and vegetation cover was low, but NDVI had a linear growth rate of 0.0096/annum from 2000 to 2015 in Yulin area. The area of growth trend accounted for 97.06% of the total area, while the area with decreased rate was small, which mainly had correlation with human activities, and was distributed in the southwest mountain area, urban neighborhood, and river valley in the middle and east of Yulin area. 2) Correlation analysis between NDVI and temperature, precipitation, respectively, reflected that negative correlation was between NDVI and temperature, while positive correlation was between NDVI and precipitation. Furthermore, the role of precipitation was higher than that of temperature in the process of interaction between NDVI and temperature, precipitation. 3) NDVI change process in the range of human activities indicated that the intensity of human activities in buffer_city area was higher than that in buffer_county area. Buffer_city area was divided into within 5 km area with dramatic impact by human activities, and from 5 km to 9 km area with less impact by human activities, and outside 9 km area with mini-affected by human activities.
基金This study was jointly supported by the National Key Research and Development Program of China(2017YF0603703 and 2017YF0605004)the Atmospheric Pollution Control of the Prime Minister Fund of China(DQGG0104).
文摘This work analyzes and discusses the influence of human activities on the meteorological conditions related to winter haze events in Beijing,Tianjin,and Hebei(i.e.,the Jing-Jin-Ji region)during 1961-2016,using the results of two numerical simulation experiments based on the Community Atmosphere Model version 5.1.1(http://www.cesm.ucar.edu/models/cesm1.0/cam/docs/ug5_1_1/book1.html)used in the international Climate Variability and Predictability Programme(CLIVAR)Climate of the 20th Century Detection and Attribution Project(C20C+D&A).The results show that,under the influence of human activities,the changes in dynamical and thermal meteorological conditions related to winter haze events in the Jing–Jin–Ji region are conducive to the formation and accumulation of haze,and prevent the diffusion of pollutants.The dynamical conditions mainly include the obvious weakening of the East Asian winter monsoon(EAWM)and the enhancement of the near-surface anomalous southerly wind.The thermal conditions include the obvious increase in surface temperature,and the enhancement of water vapor transport and near-surface inversion.The relative contribution of dynamical and thermal conditions to the variation of haze days in the Jing-Jin-Ji region is analyzed using statistical methods.The results show that the contribution of human activities to the increase of haze days in the Jing-Jin-Ji region is greater than that of natural forcing for the study period.To be specific,the dynamical meteorological factors contribute more to the haze days than the thermal meteorological factors.The contribution of thermal meteorological factors is basically the same in both scenarios.
基金This research is jointly funded by Key Technologies Research and De-velopment Program of China(Grant No.2017YFC0404503)funding project for basic scientific research operations of China’s Central Public Welfare Scientific Research Institutes(AR2117).
文摘The Three-River Headwater Region(TRHR)of China is a typical representative of the alpine environment in the Central Asian plateau and the alpine grassland in the world.Grassland degradation is one of its serious eco-logical problems.The purpose of this study is to quantify the joint impacts of climate and human activities on grassland changes in TRHR after two phases of Ecological Conservation and Construction Project(Ecological Project).Grassland vegetation coverage is selected as an indicator for analyzing grassland changes.We adopt Sen+Mann-Kendall trend analysis,residual trend analysis and correlation analysis methods to analyze the trends in spatial-temporal changes and driving factors of grassland in TRHR from 2000 to 2019.The results show that:(1)The grassland has been mainly restored,and the degraded grassland area only accounts for 1.66%of TRHR.After the implementation of the first phase of the Ecological Project,the percentage of restored grassland area has significantly increased from 8.82%to 24.57%,and slightly decreased during the second phase.(2)The establish-ment of national nature reserves and the implementation of the Ecological Project have changed the situation that“the grassland inside the reserve is worse than that outside the reserve”.(3)Grassland restoration is mainly af-fected by the joint effects of climate and human activities.Nevertheless,grassland degradation is mainly affected by human activities such as overgrazing and grassland reclamation.All of these findings can enrich our under-standing of grassland restoration in TRHR.Artificial measures have certain limitations in promoting grassland restoration.Natural restoration should be considered when human beings strengthen ecological conservation and transform their production and life styles.
文摘This study was proposed to explore the impact of human activities on the environment in Mhondongori. In this community, there are natural resources that include minerals, natural forest, wetlands, rivers and beautiful mountains. However, over the past two decades, the environmental quality of the community has deteriorated demonstrating irresponsible use of natural resources by humans. Indeed, if such poor natural resource management continues at the current rate, this would ultimately lead to extinction. Qualitative research design and convenience sampling methods were used. The study involved six participants who provided the data. An interview guide and observation techniques were used to collect data. Using content analysis data was classified into themes and a scorecard was used to determine the human activities on the environment and their impact. The results revealed that in Mhondongori, human activities that affected the environment were mining, veld fire, cutting down trees, overgrazing, excessive communal hunting and fishing, littering, water and air pollution. The impacts were the degradation of land, permanent scars on the landscape, deforestation, destruction of wildlife habitats, disappearance of wetlands, destruction of trees, grass, seed bank and seedlings, pollution of streets, bushes and rivers, disruption of migration and hibernation of animals. To conserve the environment, it was recommended that community leadership must develop appropriate environmental management strategies to mitigate these unfavourable impacts and that the state must empower Mhondongori leadership through reasonable legislative and other measures that would prevent environmental degradation.
基金supported by the Joint Fund of National Natural Science Foundation of China(Nos.42101107 and 42271100).
文摘Mid and high latitude wetlands are becoming fragmented and losing ecosystem functions at a much faster rate than many other ecosystems.This is due in part to increasing human activities and climate change.In this study,we analyzed wetland distribution and spatial pattern changes for the Heilongjiang River Basin over the past 100 yr.We identified the driving factors and quantified the relative importance of each factor based on landscape pattern metrics and machine learning algorithms.Our results show that wetlands have been fragmented into smaller and regular patches with dominant factors that varied at different periods.Geographic features play the most important role in patterns of wetland change for the entire basin(with 50%-60%of relative importance).Human activities are more important than climate change at the century scale,but less important when magnified at the decadal scale.In the early 1900s,human activities were relatively low and localized and remained that way in the subsequent decades.Thus,the effect of human activities on wetland area of the entire basin is weaker when examined at the magnified decadal scale.The results also show that human activities are more important on the Chinese side of the Heilongjiang River Basin,in the ZeyaBureya Plain on the Russian side,and at lower altitudes(0-100 m).Revealing the spatial and temporal processes and driving factors over the past 100 yr helps researchers and policymakers understand and anticipate wetland change and design effective conservation and restoration policies.
基金The Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences under contract No.ISEE2020YB06the National Natural Science Foundation of China under contract Nos 41830648 and 41801353+3 种基金the Chongqing Postdoctoral Innovation Fund under contract No.cstc2020jcyj-bshX0103the Grant from the State Key Laboratory of Resources and Environmental Information Systemthe Open Project Programme of the Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions under contract No.GTYR201906the Open Project Programme of Chongqing Key Laboratory of Karst Environment under contract No.Cqk201903.
文摘Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues.However,whether human-induced activities could change the coastal land use gradient pattern,an important coastal zonal characteristic along the sea-land direction,remains unclear.Manila Bay was selected as the study area in this work.According to the distance of the land use and land cover(LULC)to the coastline,we clustered the typical coastal land use sequence patterns(CLUSPs)along the sea-land direction between 1988 and 2016 in Manila Bay and found the following.(1)Four typical CLUSPs,including the natural CLUSP dominated by forest land and grassland,the agricultural CLUSP dominated by dry farm and paddy field,the urbanised CLUSP dominated by construction land and the fishery CLUSP dominated by fishing farm,were mined in 1988.Three typical CLUSPs(a natural CLUSP,an intermediate CLUSP between the agricultural and urbanised CLUSPs,and a fishery CLUSP)were mined in 2016.(2)Affected by the dominant LULC,these typical CLUSPs showed a regular spatial pattern along the sea-land direction.For example,the typical natural CLUSP showed a landward pattern due to the long distance between the forest land and grassland and the coastline.(3)However,influenced by urban and aquaculture expansion,the land intensification of the CLUSP exhibited an obvious increase and caused the decrease of the CLUSP diversity from 1988 to 2016.The increase in the area of LULC coverage showed no obvious correlation with its distance from the coastline(DFC),but the net increase rate of LULC coverage had a significant negative correlation with the DFC.Therefore,human-induced activities have a large impact on the gradient pattern of coastal land use along the sea-land direction.
基金supported by the National Natural Science Foundation of China[grant number 41971331].
文摘When various urban functions are integrated into one location,they form a mixture of functions.The emerging big data promote an alternative way to identify mixed functions.However,current methods are largely unable to extract deep features in these data,resulting in low accuracy.In this study,we focused on recognizing mixed urban functions from the perspective of human activities,which are essential indicators of functional areas in a city.We proposed a framework to comprehensively extract deep features of human activities in big data,including activity dynamics,mobility interactions,and activity semantics,through representation learning methods.Then,integrating these features,we employed fuzzy clustering to identify the mixture of urban functions.We conducted a case study using taxiflow and social media data in Beijing,China,in whichfive urban functions and their correlations with land use were recognized.The mixture degree of urban functions in each location was revealed,which had a negative correlation with taxi trip distance.The results confirmed the advantages of our method in understanding mixed urban functions by employing various representation learning methods to comprehensively depict human activities.This study has important implications for urban planners in understanding urban systems and developing better strategies.
基金supported by National Natural Science Foundation of China(No.32270554 to CD)。
文摘Animals must strike a balance between anti-predation behavior and other essential behaviors,such as foraging.Within the same species,strategies may vary on individuals’risk-taking preferences,and in this process the environment is a determinant,in addition to predator regime.The Crested Ibis(Nipponia nippon)exhibits such tendency.This is an endangered species,once inhabiting exclusively in China’s Qinling Mountain.This used to be the sole remaining wild population.However,over recent decades,this population has expanded.A portion has relocated to breed in the lower plain area,which is characterized by elevated level of human activities and landscape complexity.We used flight initiation distance(FID)as an indicator of the ibises’risk-taking preference,particularly their response to human proximity.Additionally,we examined the environmental factors influencing their foraging site selection,including altitude,terrain openness,human activity intensity and human construction.Our findings revealed a significantly shorter FID among individuals relocating to plain habitats,indicating a higher tolerance of human proximity.The results showed that FID decreased with distance to the nearest human settlement.Another finding is that FID was independent of instant human activity intensity and environmental factors(altitude and terrain openness).These different may arise from various combinations of human activity,predation risk,and food abundance within the two habitats.These results provide insights into the in situ conservation of the threatened species within the context of global urbanization.
基金Under the auspices of National Key Research and Development Program of China(No.2017YFA0604403)National Natural Science Foundation of China(No.41801108)。
文摘Human activities in a transborder watershed are complex under the influence of domestic policies,international relations,and global events.Understanding the forces driving human activity change is important for the development of transborder watershed.In this study,we used global historical land cover data,the hemeroby index model,and synthesized major historical events to analyze how human activity intensity changed in the Heilongjiang River(Amur River in Russia)watershed(HLRW).The results showed that there was a strong spatial heterogeneity in the variation of human activity intensity in the HLRW over the past century(1900-2016).On the Chinese side,the human activity intensity change shifted from the plain areas for agricultural reclamation to the mountainous areas for timber extraction.On the Russian side,human activity intensity changes mostly concentrated along the Trans-Siberian Railway and the Baikal-Amur Mainline.Localized variation of human activity intensity tended to respond to regional events while regionalized variation tends to reflect national policy change or broad international events.The similarities and differences between China and Russia in policies and positions in international events resulted in synchronous and asynchronous changes in human activity intensity.Meanwhile,policy shifts were often confined by the natural features of the watershed.These results reveal the historical origins and fundamental connotations of watershed development and contribute to formulating regional management policies that coordinate population,eco-nomic,social,and environmental activities.
基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDC02040300)for this study.
文摘RFID-based human activity recognition(HAR)attracts attention due to its convenience,noninvasiveness,and privacy protection.Existing RFID-based HAR methods use modeling,CNN,or LSTM to extract features effectively.Still,they have shortcomings:1)requiring complex hand-crafted data cleaning processes and 2)only addressing single-person activity recognition based on specific RF signals.To solve these problems,this paper proposes a novel device-free method based on Time-streaming Multiscale Transformer called TransTM.This model leverages the Transformer's powerful data fitting capabilities to take raw RFID RSSI data as input without pre-processing.Concretely,we propose a multiscale convolutional hybrid Transformer to capture behavioral features that recognizes singlehuman activities and human-to-human interactions.Compared with existing CNN-and LSTM-based methods,the Transformer-based method has more data fitting power,generalization,and scalability.Furthermore,using RF signals,our method achieves an excellent classification effect on human behaviorbased classification tasks.Experimental results on the actual RFID datasets show that this model achieves a high average recognition accuracy(99.1%).The dataset we collected for detecting RFID-based indoor human activities will be published.
