Land use and cover change(LUCC)is the most direct manifestation of the interaction between anthropological activities and the natural environment on Earth's surface,with significant impacts on the environment and ...Land use and cover change(LUCC)is the most direct manifestation of the interaction between anthropological activities and the natural environment on Earth's surface,with significant impacts on the environment and social economy.Rapid economic development and climate change have resulted in significant changes in land use and cover.The Shiyang River Basin,located in the eastern part of the Hexi Corridor in China,has undergone significant climate change and LUCC over the past few decades.In this study,we used the random forest classification to obtain the land use and cover datasets of the Shiyang River Basin in 1991,1995,2000,2005,2010,2015,and 2020 based on Landsat images.We validated the land use and cover data in 2015 from the random forest classification results(this study),the high-resolution dataset of annual global land cover from 2000 to 2015(AGLC-2000-2015),the global 30 m land cover classification with a fine classification system(GLC_FCS30),and the first Landsat-derived annual China Land Cover Dataset(CLCD)against ground-truth classification results to evaluate the accuracy of the classification results in this study.Furthermore,we explored and compared the spatiotemporal patterns of LUCC in the upper,middle,and lower reaches of the Shiyang River Basin over the past 30 years,and employed the random forest importance ranking method to analyze the influencing factors of LUCC based on natural(evapotranspiration,precipitation,temperature,and surface soil moisture)and anthropogenic(nighttime light,gross domestic product(GDP),and population)factors.The results indicated that the random forest classification results for land use and cover in the Shiyang River Basin in 2015 outperformed the AGLC-2000-2015,GLC_FCS30,and CLCD datasets in both overall and partial validations.Moreover,the classification results in this study exhibited a high level of agreement with the ground truth features.From 1991 to 2020,the area of bare land exhibited a decreasing trend,with changes primarily occurring in the middle and lower reaches of the basin.The area of grassland initially decreased and then increased,with changes occurring mainly in the upper and middle reaches of the basin.In contrast,the area of cropland initially increased and then decreased,with changes occurring in the middle and lower reaches.The LUCC was influenced by both natural and anthropogenic factors.Climatic factors and population contributed significantly to LUCC,and the importance values of evapotranspiration,precipitation,temperature,and population were 22.12%,32.41%,21.89%,and 19.65%,respectively.Moreover,policy interventions also played an important role.Land use and cover in the Shiyang River Basin exhibited fluctuating changes over the past 30 years,with the ecological environment improving in the last 10 years.This suggests that governance efforts in the study area have had some effects,and the government can continue to move in this direction in the future.The findings can provide crucial insights for related research and regional sustainable development in the Shiyang River Basin and other similar arid and semi-arid areas.展开更多
Understanding the response of vegetation variation to climate change and human activities is critical for addressing future conflicts between humans and the environment,and maintaining ecosystem stability.Here,we aime...Understanding the response of vegetation variation to climate change and human activities is critical for addressing future conflicts between humans and the environment,and maintaining ecosystem stability.Here,we aimed to identify the determining factors of vegetation variation and explore the sensitivity of vegetation to temperature(SVT)and the sensitivity of vegetation to precipitation(SVP)in the Shiyang River Basin(SYRB)of China during 2001-2022.The climate data from climatic research unit(CRU),vegetation index data from Moderate Resolution Imaging Spectroradiometer(MODIS),and land use data from Landsat images were used to analyze the spatial-temporal changes in vegetation indices,climate,and land use in the SYRB and its sub-basins(i.e.,upstream,midstream,and downstream basins)during 2001-2022.Linear regression analysis and correlation analysis were used to explore the SVT and SVP,revealing the driving factors of vegetation variation.Significant increasing trends(P<0.05)were detected for the enhanced vegetation index(EVI)and normalized difference vegetation index(NDVI)in the SYRB during 2001-2022,with most regions(84%)experiencing significant variation in vegetation,and land use change was determined as the dominant factor of vegetation variation.Non-significant decreasing trends were detected in the SVT and SVP of the SYRB during 2001-2022.There were spatial differences in vegetation variation,SVT,and SVP.Although NDVI and EVI exhibited increasing trends in the upstream,midstream,and downstream basins,the change slope in the downstream basin was lower than those in the upstream and midstream basins,the SVT in the upstream basin was higher than those in the midstream and downstream basins,and the SVP in the downstream basin was lower than those in the upstream and midstream basins.Temperature and precipitation changes controlled vegetation variation in the upstream and midstream basins while human activities(land use change)dominated vegetation variation in the downstream basin.We concluded that there is a spatial heterogeneity in the response of vegetation variation to climate change and human activities across different sub-basins of the SYRB.These findings can enhance our understanding of the relationship among vegetation variation,climate change,and human activities,and provide a reference for addressing future conflicts between humans and the environment in the arid inland river basins.展开更多
Due to the uncertainties posed by climate change,resilience has become an increasingly important variable for evaluating regional ecosystem stability.The assessment of Ecological Network Resilience(ENR)is crucial for ...Due to the uncertainties posed by climate change,resilience has become an increasingly important variable for evaluating regional ecosystem stability.The assessment of Ecological Network Resilience(ENR)is crucial for establishing mitigation strategies and sustainable socioeconomic development in arid regions.Shiyang River Basin is an arid watershed in Northwest China with complex characteristics,its ENR and spatial differentiation characteristics in 2020 were investigated in this work based on the Complex Adaptive System(CAS)theory.The results indicated that the mean Ecological Network Resilience Index(ENRI)value for the Shiyang River Basin was 0.390 in 2020,and the mean values in the southern mountainous,middle oasis,and northern desert regions of the basin were 0.598,0.461,and 0.237,respectively,demonstrating evident spatial differences.Additionally,the ENR of the basin exhibited distinct distribution characteristics across different dimension,whereas the trend of the integrated ENR of the basin was consistent with that of elemental,structural,and functional resilience,indicating the constructed three-region ENR model based on the logical relationship of element-structure-function was suitable for evaluation of the ENR in arid inland river watersheds.Furthermore,strategies for enhancing regional ENR were proposed from the perspective of adapting to climate change.展开更多
Based on 35 a meteorological data and main crops planting data in Shiyang River basin meteorological station,the agricultural climate change,agricultural production,hydrology change and the influences on the crops lay...Based on 35 a meteorological data and main crops planting data in Shiyang River basin meteorological station,the agricultural climate change,agricultural production,hydrology change and the influences on the crops layout,planting in the basin were discussed.The results showed that the linear inclined rates of ≥0 ℃,10 ℃ accumulated temperature increase in the north-central part were bigger than in the south,and the heat resources increased evidently.The annual precipitation increased in the linear inclined rate which was 4.719 mm/10 a,and the annual runoff decreased in 0.274×109 m3/10 a velocity.The climate productivity increased in 134.62 kg/(hm2·10 a) velocity.In late spring and early summer,the regional drought increased evidently,and the frostless period prolonged.The sand storm decreased evidently.The gale in the south increased and decreased in the north-central part.The agricultural climate change made that the spring wheat planting zone advanced to the high-altitude area.The seeding date advanced,and the growth period shortened.It didn't favor for the yield formation.However,it was favorable to improve the yield and quality of thermophilous crops such as the corn,cotton and wine grape and so on.展开更多
Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods f...Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods for measuring oasis ecosystem risk were established using reliability theory. These indicators are linked to water resource, which is the key restricting factor in arid area oasis ecosystems. They have clear meanings and can also be compared in different arid area oases. A case study in the Liangzhou oasis of the Shiyang River Basin in China shows how to calculate these ecosystem risk indicators. The results of the case study are as follows： the reliability indicator, risk indicator, stability indicator, and integrated loss indicator of the Liangzhou oasis are 0.686, 0.314, 0.743, and 0.301, respectively. This means that the reliability degree of the oasis＇s ecosystem safety is 68.6%; the degree of risk that it is unsafe is 31.4%; the stability degree is 74.3%; and 30.1% of the oasis＇s area is supported by over-exploiting underground water and damaging the lower reaches of the ecosystem. This result can be used as a guide in controlling and managing ecosystem risk in the research area.展开更多
Glacier runoff in mountain areas of the Shiyang River Basin(SRB), Qilian Mountain, western China is important for the river and water supply downstream. Small glaciers with area of less than 1km2 are dominant(87%) in ...Glacier runoff in mountain areas of the Shiyang River Basin(SRB), Qilian Mountain, western China is important for the river and water supply downstream. Small glaciers with area of less than 1km2 are dominant(87%) in the SRB. A modified monthly degree-day model was applied to quantify the glacier mass balance, area, and changes in glacier runoff in the SRB during 1961–2050. The comparison between the simulated and observed snow line altitude, annual glacier runoff, and mass balance from1961 to 2008 suggests that the degree-day model may be used to analyze the long-term change of glacier mass balance and runoff in the SRB. The glacier accumulation shows a significant(p<0.01) decreasing trend of-0.830 mm a-1. The mass balance also shows a significant(p<0.01) decreasing trend of-5.521 mm a-1. The glacier total runoff has significantly(p<0.05)increased by 0.079 × 105 m3 from 1961 to 2008. The monthly precipitation and air temperature are projected to significant(p<0.005) increase during2015 to 2050 under three different scenarios. The ablation is projected to significant(p<0.001) increase,while the accumulation has no significant(p=0.05)trend. The mass balance is projected to decrease, theglacier area is projected to decrease, and the glacier runoff depth is projected to increase. However, the glacier total runoff is projected to decrease. These results indicate that the glacier total runoff over glacier areas observed in 1970 reached its peak in the 2000 s. This will exacerbate the contradiction between water supply and downstream water demands in the SRB.展开更多
The research on the present situation of soil and water development and utilization in Shiyang River Basin shows that water resources and eco-environment situation in this area are near the edge of collapse. Since the...The research on the present situation of soil and water development and utilization in Shiyang River Basin shows that water resources and eco-environment situation in this area are near the edge of collapse. Since the water crises occurred in the 1970s, problems caused by continuous decrease of water resources have been becoming serious year by year and eco-environment crisis occurred as a consequence. Up to now, 10 380ha of irrigated lands have been abandoned due to sand coverage and water shortage in the basin. Ground water was over exploded in Wuwei and Minqin because of water shortage. Ground water table in many places dropped under 5m （which is the ecology water table level）, thus about 3000ha ofElaeagnus angustifolia forest come to dead and another 5800ha become feeble, and wind-drift sand near the oasis become alive. According to the current situation, if water utilization scope was not enlarged, a water transfer volume of 600×10^6m^3/a from other areas will be suitable to keep water resources and eco-environment safety in the basin, and also 70×10^6m^3/a will be left as spare water. Under this condition the water resources and eco-environment of the basin can reach the critical safety line of 2.032×10^6m^3/a; or if 180×10^6m^3 of water can be transferred from other areas, the water resources can reach the safety warning line of 1.732×10^9m^3/a.展开更多
The Shiyang River Basin is an area of China that is severly affected by aeolian desertification.Thus,we established an aeolian desertified land classification system for visual interpretation,which classified the Aeol...The Shiyang River Basin is an area of China that is severly affected by aeolian desertification.Thus,we established an aeolian desertified land classification system for visual interpretation,which classified the Aeolian Desertified Land(ADL)into Slight(SL),Moderate(M),Severe(S)and Extremely Severe(ES)according to the severity.Imagery of Landsat series(acquired in 1975,1990,2000 and 2010)were employed to monitor the status,trend and spatial pattern of aeolian desertification,especially to map the overall spatial pattern of ADL dynamics by proposing a new Dynamic Index(DI)in the Shiyang River Basin from 1975 to 2010.The results show a generally decreasing trend from 1975 to 2010.However,the ES ADL kept increasing throughout the whole study period.Moreover,the area of ADLs with different severity increased with increasing severity,this S and ES ADLs dominated characteristics of aeolian desertification was contrary to those sandy lands in eastern China where was dominated by SL and M ADLs.Among the three sub-periods of 1975−1990,1990−2000 and 2000−2010,the first two were the restoration stage,while the last one was the expansion stage of aeolian desertification.Moreover,all these new ADLs occurred in Minqin County during 2000−2010,indicating a detrimental increase of aeolian desertification in Minqin,and the concentration of ADLs toward the lower reaches of the Shiyang River Basin.The DI works well to identify areas with desertification changes no matter the sub-periods.Moreover,DI results disclosed a stable status of aeolian desertification,and the DI decreased with increasing ADL severity.These results indicate that it will be difficult to control the expansion of aeolian desertification in Minqin County over an extended period of time.Thus,we suggest effective and long-lasting aeolian desertification control programs in the Shiyang River Basin,especially in Minqin,and SL and MADLs should have priority in facilitating a quick reversal of aeolian desertification.展开更多
Meteorological data of 5 weather stations in the Shiyang River Basin on the eastern section of Hexi Corridor from 1961 to 2014 were analyzed using statistical analysis techniques such as linear trend and variance sign...Meteorological data of 5 weather stations in the Shiyang River Basin on the eastern section of Hexi Corridor from 1961 to 2014 were analyzed using statistical analysis techniques such as linear trend and variance signifi cance test. The results showed that as the low temperature rose generally, temperature in stations nearby desert showed higher increase rate; annual extreme maximum temperature in stations nearby mountains showed more signifi cant increase, and annual extreme minimum temperature in stations nearby desert showed more signifi cant increase, and the increase tendency of extreme minimum temperature was more obvious than that of extreme maximum temperature; annual extreme maximum temperature in stations in desert showed higher instability; instability of annual extreme minimum temperature in all sampling points increased, and showed no obvious regularity between desert and mountain.展开更多
Agricultural water allocation system based on priority rights has caused regional conflicts and downstream ecological degradation. It is the urgent need to introduce the concept of the initial water rights and establi...Agricultural water allocation system based on priority rights has caused regional conflicts and downstream ecological degradation. It is the urgent need to introduce the concept of the initial water rights and establish benefits compensation mechanism to resolve such problems. This paper takes the Shiyang River basin as an example to calculate the opportunity cost of 0.97×10^8 m^3 of agricultural water encroached by the middle reach based on initial water right allocation system under which water is allocated in accordance with the ratio between agricultural population of two different regions concerning the downstream ecological reconstruction needs with Bio-economic model （BEM）. The results suggest that the total economic loss of Minqin County for ecological reconstruction amounts to 2.5 7×10^8 yuan, of which 1.68×10^8 yuan is ecological compensation, representing the economic loss Minqin suffered for ecological reconstruction which shouM burden beneficial groups of ecological reconstruction and 0.89 ×10^8 yuan is the economic loss Minqin suffered due to Liangzhou＇s encroachment behavior which should be compensated by Liangzhou.展开更多
On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic be...On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic benefits, production efficiency, ecological stabilities and developmental conditions of the Wuwei Oasis agricultural ecosystem in the middle reaches of the river basin and the Minqin Oasis agricultural ecosystem in the lower reaches. Under a same management level and investment of . material and energy, primary productiveness and economic benefits of the former are higher than those of the latter. Construction directions of Wuwei and Minqin oases should be different in order to alleviate the water- use contradiction between the middle and lower reaches. The construction objective of Wuwei Oasis should be efficient irrigated farming production system and Minqin Oasis should become a mixed forestry-pastoral-farming ecosystem taking ecological protection as its major function.展开更多
In recent years, the population size and scale of the Shiyang River Basin unceasingly expanding lead to a series of ecological environment: surface water reducing, land desertification and Ground water levels fall, et...In recent years, the population size and scale of the Shiyang River Basin unceasingly expanding lead to a series of ecological environment: surface water reducing, land desertification and Ground water levels fall, etc. Research evolution characteristics of population distribution and migration growth of Shiyang River Basin contribute to river water resources and the industrial development of the comprehensive management. The article using the distribution of population structure index, population distribution center of gravity model and the population migration growth analysis model analyzes the distribution of the population evolution characteristics and population migration growth characteristics of Shiyang River Basin in 2000 to 2010. The results show that: 1) Considering Shiyang River Basin, population density is generally low, population distribution difference is bigger and concentration distribution in the middle corridor plain and three big population distribution center of Minqin oasis area, presenting a “point-areas-ribbon” structure characteristics. 2) The population distribution trend of Shiyang River Basin is constantly concentration, but the change is slow;the population distribution of Minqin is in the highest concentration degree, but the trend has been declining. 3) The focus of population density in river basin locates in Liangzhou district of Daliu country;in ten years, it migrates about 1209 m to southwest Wuwei City direction, but migration along the direction things is bigger than the north and south direction. The focus of population density and the basin geometry center is far away. 4) For ten years, at the township for basic statistics unit, each level population migration change within the overall is not significant: township level > prefecture-level cities level > counties level. 5) For ten years, there are significant changes in population migration between watershed township units, Wuwei City and Gulang Town are the two main concentrations of population centers.展开更多
Pollen analyses of 85 samples from the San-jiaocheng section well along the margin of a palaeolake at the end of the Shiyang River, NW China, show that Picea and Sabina dominate the pollen assemblage. Together they re...Pollen analyses of 85 samples from the San-jiaocheng section well along the margin of a palaeolake at the end of the Shiyang River, NW China, show that Picea and Sabina dominate the pollen assemblage. Together they reach as high as 40%-60%, with the percentage of Picea varying inversely with that of Sabina. Similar results were obtained from another section in the Shiyang River drainage. Using modern ecological habitat relationship analogues, pol-len transport characteristics, and the overall pollen assem-blage, we propose that both Picea and Sabina pollen were transported by the river from the mountains at the upper reaches of the Shiyang River, and that the assemblage is more indicative of changes in upland vegetation than of local conditions near the section. This interpretation is supported by pollen data derived from surface samples, water samples, and riverbed samples. Using a moisture indicator (the Picea to Sabina ratio) and calculated pollen concentrations, we identify a series of展开更多
To improve the accuracy of runoff forecasting,an uncertain multiple linear regression(UMLR) model is presented in this study. The proposed model avoids the transfer of random error generated in the independent variabl...To improve the accuracy of runoff forecasting,an uncertain multiple linear regression(UMLR) model is presented in this study. The proposed model avoids the transfer of random error generated in the independent variable to the dependent variable, as this affects prediction accuracy. On this basis, an inexact two-stage stochastic programming(ITSP) model is used for crop planting structure optimization(CPSO) with the inputs that are interval flow values under different probabilities obtained from the UMLR model. The developed system, in which the UMLR model for runoff forecasting and the ITSP model for crop planting structure optimization are integrated, is applied to a real case study. The aim of the developed system is to optimize crops planting area with limited available water resources base on the downstream runoff forecasting in order to obtain the maximum system benefit in the future. The solution obtained can demonstrate the feasibility and suitability of the developed system, and help decision makers to identify reasonable crop planting structure under multiple uncertainties.展开更多
Last century 50 - 70 years, the dam construction of Shiyang Inland River Basin (SIRB) profound impact on the distribution of water resources and arable land in the basin. Through data collection, field surveys and rem...Last century 50 - 70 years, the dam construction of Shiyang Inland River Basin (SIRB) profound impact on the distribution of water resources and arable land in the basin. Through data collection, field surveys and remote sensing image interpretation, we analysis the use of land and water resources change process in the middle and lower reaches of SIRB in recent decades. The results show: (1) The cultivated area of SIRB has been an upward trend in recent decades, The whole basin cultivated area has increased total 229,000 hm<sup>2</sup> from 1973 to 2010 and mainly in the middle and lower reaches. Midstream increased by 149,700 hm<sup>2</sup> accounting for 65.36 percent of total, downstream increased by 70,000 hm<sup>2</sup> accounting for 30.70 percent of total. (2) The amount of surface water resources of downstream reduce significantly gradually since dam construction, and the water table sharp decline. While the volume of surface water resources come downstream from the 1950s accounted for 30 to 40 percent of the total gradually reduced to less than 10% in 2012;(3) since the arable land area of middle and lower reaches of SIRB basin substantial increase, so the surface water resource does not meet irrigation needs. Agricultural irrigation relies heavily on exploitation of groundwater to supplement, resulting in Regional Groundwater Depth dropped rapidly, and forming several huge funnel groundwater settlements. 20 years from 1981 to 2001 the groundwater level of midstream dropped from around 5m to around 10m in Wuwei, and in Minqin dam-region of downstream along faster rate of decline in 20 years fell from 8.52 m to 22.68 m. Dam construction project has changed the pattern of the basin water cycle, the middle reaches closure a large number of surface water resources led to downstream sharp decline. Downstream continued exploitation of groundwater formed a few huge funnel groundwater settlements, it caused serious ecological problems. The basin should adjust the industrial structure and develop water saving irrigation, promote a virtuous cycle of water resources, to achieve sustainable development, seek a sustainable development ways conversion natural oasis to artificial oasis efficiency in arid zone.展开更多
As an important and typical arid inland region in China,Shiyang River Basin plays an important role in maintaining the sustainable development of eco-environment,whose ecological land suitability restricts the develop...As an important and typical arid inland region in China,Shiyang River Basin plays an important role in maintaining the sustainable development of eco-environment,whose ecological land suitability restricts the development of the local human activities.Therefore,Shiyang River Basin was selected as the case study,the minimum cumulative resistance(MCR)model and GIS technique were integrated to create land suitability evaluation map.We calculated the MCR value of ecological source and living source,and divided the whole basin into five partitions according to the difference between ecological source and living source,and analyzed the patterns and characteristics of the ecological land suitability evaluation(ELSE)regions,respectively.The results showed that:1)The suitable ecological land includes prohibited development region and restricted development region,which accounts for 15.45%and 23.35%of the total land area of the Shiyang River Basin,respectively.These two regions mainly distributed high altitude region in the southern Qilian Mountain and low altitude region where had high density of rivers.2)The protection of ecological land requires not only conserving existing ecological land but also focusing on ecological buffer belts around ecological sources and improving ecological land service ability.3)Ecological networks should be constructed through artificial planting trees around the boundary of oasis and ecological restoration region.Buffer greenbelts should also be established between optimized development region and ecological restoration region.展开更多
基金supported by the Central Government to Guide Local Technological Development(23ZYQH0298)the Science and Technology Project of Gansu Province(20JR10RA656,22JR5RA416)the Science and Technology Project of Wuwei City(WW2202YFS006).
文摘Land use and cover change(LUCC)is the most direct manifestation of the interaction between anthropological activities and the natural environment on Earth's surface,with significant impacts on the environment and social economy.Rapid economic development and climate change have resulted in significant changes in land use and cover.The Shiyang River Basin,located in the eastern part of the Hexi Corridor in China,has undergone significant climate change and LUCC over the past few decades.In this study,we used the random forest classification to obtain the land use and cover datasets of the Shiyang River Basin in 1991,1995,2000,2005,2010,2015,and 2020 based on Landsat images.We validated the land use and cover data in 2015 from the random forest classification results(this study),the high-resolution dataset of annual global land cover from 2000 to 2015(AGLC-2000-2015),the global 30 m land cover classification with a fine classification system(GLC_FCS30),and the first Landsat-derived annual China Land Cover Dataset(CLCD)against ground-truth classification results to evaluate the accuracy of the classification results in this study.Furthermore,we explored and compared the spatiotemporal patterns of LUCC in the upper,middle,and lower reaches of the Shiyang River Basin over the past 30 years,and employed the random forest importance ranking method to analyze the influencing factors of LUCC based on natural(evapotranspiration,precipitation,temperature,and surface soil moisture)and anthropogenic(nighttime light,gross domestic product(GDP),and population)factors.The results indicated that the random forest classification results for land use and cover in the Shiyang River Basin in 2015 outperformed the AGLC-2000-2015,GLC_FCS30,and CLCD datasets in both overall and partial validations.Moreover,the classification results in this study exhibited a high level of agreement with the ground truth features.From 1991 to 2020,the area of bare land exhibited a decreasing trend,with changes primarily occurring in the middle and lower reaches of the basin.The area of grassland initially decreased and then increased,with changes occurring mainly in the upper and middle reaches of the basin.In contrast,the area of cropland initially increased and then decreased,with changes occurring in the middle and lower reaches.The LUCC was influenced by both natural and anthropogenic factors.Climatic factors and population contributed significantly to LUCC,and the importance values of evapotranspiration,precipitation,temperature,and population were 22.12%,32.41%,21.89%,and 19.65%,respectively.Moreover,policy interventions also played an important role.Land use and cover in the Shiyang River Basin exhibited fluctuating changes over the past 30 years,with the ecological environment improving in the last 10 years.This suggests that governance efforts in the study area have had some effects,and the government can continue to move in this direction in the future.The findings can provide crucial insights for related research and regional sustainable development in the Shiyang River Basin and other similar arid and semi-arid areas.
基金National Natural Science Foundation of China(42230720).
文摘Understanding the response of vegetation variation to climate change and human activities is critical for addressing future conflicts between humans and the environment,and maintaining ecosystem stability.Here,we aimed to identify the determining factors of vegetation variation and explore the sensitivity of vegetation to temperature(SVT)and the sensitivity of vegetation to precipitation(SVP)in the Shiyang River Basin(SYRB)of China during 2001-2022.The climate data from climatic research unit(CRU),vegetation index data from Moderate Resolution Imaging Spectroradiometer(MODIS),and land use data from Landsat images were used to analyze the spatial-temporal changes in vegetation indices,climate,and land use in the SYRB and its sub-basins(i.e.,upstream,midstream,and downstream basins)during 2001-2022.Linear regression analysis and correlation analysis were used to explore the SVT and SVP,revealing the driving factors of vegetation variation.Significant increasing trends(P<0.05)were detected for the enhanced vegetation index(EVI)and normalized difference vegetation index(NDVI)in the SYRB during 2001-2022,with most regions(84%)experiencing significant variation in vegetation,and land use change was determined as the dominant factor of vegetation variation.Non-significant decreasing trends were detected in the SVT and SVP of the SYRB during 2001-2022.There were spatial differences in vegetation variation,SVT,and SVP.Although NDVI and EVI exhibited increasing trends in the upstream,midstream,and downstream basins,the change slope in the downstream basin was lower than those in the upstream and midstream basins,the SVT in the upstream basin was higher than those in the midstream and downstream basins,and the SVP in the downstream basin was lower than those in the upstream and midstream basins.Temperature and precipitation changes controlled vegetation variation in the upstream and midstream basins while human activities(land use change)dominated vegetation variation in the downstream basin.We concluded that there is a spatial heterogeneity in the response of vegetation variation to climate change and human activities across different sub-basins of the SYRB.These findings can enhance our understanding of the relationship among vegetation variation,climate change,and human activities,and provide a reference for addressing future conflicts between humans and the environment in the arid inland river basins.
基金Under the Major Special Science and Technology Project of Gansu Province(No.23ZDKA0004)。
文摘Due to the uncertainties posed by climate change,resilience has become an increasingly important variable for evaluating regional ecosystem stability.The assessment of Ecological Network Resilience(ENR)is crucial for establishing mitigation strategies and sustainable socioeconomic development in arid regions.Shiyang River Basin is an arid watershed in Northwest China with complex characteristics,its ENR and spatial differentiation characteristics in 2020 were investigated in this work based on the Complex Adaptive System(CAS)theory.The results indicated that the mean Ecological Network Resilience Index(ENRI)value for the Shiyang River Basin was 0.390 in 2020,and the mean values in the southern mountainous,middle oasis,and northern desert regions of the basin were 0.598,0.461,and 0.237,respectively,demonstrating evident spatial differences.Additionally,the ENR of the basin exhibited distinct distribution characteristics across different dimension,whereas the trend of the integrated ENR of the basin was consistent with that of elemental,structural,and functional resilience,indicating the constructed three-region ENR model based on the logical relationship of element-structure-function was suitable for evaluation of the ENR in arid inland river watersheds.Furthermore,strategies for enhancing regional ENR were proposed from the perspective of adapting to climate change.
基金Supported by The Special Project of Public Welfare Industry(Meteorology) Science Research(GYHY200806021)
文摘Based on 35 a meteorological data and main crops planting data in Shiyang River basin meteorological station,the agricultural climate change,agricultural production,hydrology change and the influences on the crops layout,planting in the basin were discussed.The results showed that the linear inclined rates of ≥0 ℃,10 ℃ accumulated temperature increase in the north-central part were bigger than in the south,and the heat resources increased evidently.The annual precipitation increased in the linear inclined rate which was 4.719 mm/10 a,and the annual runoff decreased in 0.274×109 m3/10 a velocity.The climate productivity increased in 134.62 kg/(hm2·10 a) velocity.In late spring and early summer,the regional drought increased evidently,and the frostless period prolonged.The sand storm decreased evidently.The gale in the south increased and decreased in the north-central part.The agricultural climate change made that the spring wheat planting zone advanced to the high-altitude area.The seeding date advanced,and the growth period shortened.It didn't favor for the yield formation.However,it was favorable to improve the yield and quality of thermophilous crops such as the corn,cotton and wine grape and so on.
基金Project supported by the China Scholarship Council and the National Basic Research Program (973) of China (No. 2002CCA00300).
文摘Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods for measuring oasis ecosystem risk were established using reliability theory. These indicators are linked to water resource, which is the key restricting factor in arid area oasis ecosystems. They have clear meanings and can also be compared in different arid area oases. A case study in the Liangzhou oasis of the Shiyang River Basin in China shows how to calculate these ecosystem risk indicators. The results of the case study are as follows： the reliability indicator, risk indicator, stability indicator, and integrated loss indicator of the Liangzhou oasis are 0.686, 0.314, 0.743, and 0.301, respectively. This means that the reliability degree of the oasis＇s ecosystem safety is 68.6%; the degree of risk that it is unsafe is 31.4%; the stability degree is 74.3%; and 30.1% of the oasis＇s area is supported by over-exploiting underground water and damaging the lower reaches of the ecosystem. This result can be used as a guide in controlling and managing ecosystem risk in the research area.
基金supported by the Global Change Research Program of China (Grant No. 2013CBA01806)the China National Natural Science Foundation (Grants Nos. 41130641, 41130638, and 41271090)Shanxi key science and technology innovation team (2014KCT-27)
文摘Glacier runoff in mountain areas of the Shiyang River Basin(SRB), Qilian Mountain, western China is important for the river and water supply downstream. Small glaciers with area of less than 1km2 are dominant(87%) in the SRB. A modified monthly degree-day model was applied to quantify the glacier mass balance, area, and changes in glacier runoff in the SRB during 1961–2050. The comparison between the simulated and observed snow line altitude, annual glacier runoff, and mass balance from1961 to 2008 suggests that the degree-day model may be used to analyze the long-term change of glacier mass balance and runoff in the SRB. The glacier accumulation shows a significant(p<0.01) decreasing trend of-0.830 mm a-1. The mass balance also shows a significant(p<0.01) decreasing trend of-5.521 mm a-1. The glacier total runoff has significantly(p<0.05)increased by 0.079 × 105 m3 from 1961 to 2008. The monthly precipitation and air temperature are projected to significant(p<0.005) increase during2015 to 2050 under three different scenarios. The ablation is projected to significant(p<0.001) increase,while the accumulation has no significant(p=0.05)trend. The mass balance is projected to decrease, theglacier area is projected to decrease, and the glacier runoff depth is projected to increase. However, the glacier total runoff is projected to decrease. These results indicate that the glacier total runoff over glacier areas observed in 1970 reached its peak in the 2000 s. This will exacerbate the contradiction between water supply and downstream water demands in the SRB.
文摘The research on the present situation of soil and water development and utilization in Shiyang River Basin shows that water resources and eco-environment situation in this area are near the edge of collapse. Since the water crises occurred in the 1970s, problems caused by continuous decrease of water resources have been becoming serious year by year and eco-environment crisis occurred as a consequence. Up to now, 10 380ha of irrigated lands have been abandoned due to sand coverage and water shortage in the basin. Ground water was over exploded in Wuwei and Minqin because of water shortage. Ground water table in many places dropped under 5m （which is the ecology water table level）, thus about 3000ha ofElaeagnus angustifolia forest come to dead and another 5800ha become feeble, and wind-drift sand near the oasis become alive. According to the current situation, if water utilization scope was not enlarged, a water transfer volume of 600×10^6m^3/a from other areas will be suitable to keep water resources and eco-environment safety in the basin, and also 70×10^6m^3/a will be left as spare water. Under this condition the water resources and eco-environment of the basin can reach the critical safety line of 2.032×10^6m^3/a; or if 180×10^6m^3 of water can be transferred from other areas, the water resources can reach the safety warning line of 1.732×10^9m^3/a.
基金The National Key R&D Program of China(2016YFC0500909)the International Partnership Program of Chinese Academy of Sciences(No.131B62KYSB20170031).
文摘The Shiyang River Basin is an area of China that is severly affected by aeolian desertification.Thus,we established an aeolian desertified land classification system for visual interpretation,which classified the Aeolian Desertified Land(ADL)into Slight(SL),Moderate(M),Severe(S)and Extremely Severe(ES)according to the severity.Imagery of Landsat series(acquired in 1975,1990,2000 and 2010)were employed to monitor the status,trend and spatial pattern of aeolian desertification,especially to map the overall spatial pattern of ADL dynamics by proposing a new Dynamic Index(DI)in the Shiyang River Basin from 1975 to 2010.The results show a generally decreasing trend from 1975 to 2010.However,the ES ADL kept increasing throughout the whole study period.Moreover,the area of ADLs with different severity increased with increasing severity,this S and ES ADLs dominated characteristics of aeolian desertification was contrary to those sandy lands in eastern China where was dominated by SL and M ADLs.Among the three sub-periods of 1975−1990,1990−2000 and 2000−2010,the first two were the restoration stage,while the last one was the expansion stage of aeolian desertification.Moreover,all these new ADLs occurred in Minqin County during 2000−2010,indicating a detrimental increase of aeolian desertification in Minqin,and the concentration of ADLs toward the lower reaches of the Shiyang River Basin.The DI works well to identify areas with desertification changes no matter the sub-periods.Moreover,DI results disclosed a stable status of aeolian desertification,and the DI decreased with increasing ADL severity.These results indicate that it will be difficult to control the expansion of aeolian desertification in Minqin County over an extended period of time.Thus,we suggest effective and long-lasting aeolian desertification control programs in the Shiyang River Basin,especially in Minqin,and SL and MADLs should have priority in facilitating a quick reversal of aeolian desertification.
基金Sponsored by Preliminary Project of State 973 Program(2014CB460611)National Natural Science Foundation of China(41261102)
文摘Meteorological data of 5 weather stations in the Shiyang River Basin on the eastern section of Hexi Corridor from 1961 to 2014 were analyzed using statistical analysis techniques such as linear trend and variance signifi cance test. The results showed that as the low temperature rose generally, temperature in stations nearby desert showed higher increase rate; annual extreme maximum temperature in stations nearby mountains showed more signifi cant increase, and annual extreme minimum temperature in stations nearby desert showed more signifi cant increase, and the increase tendency of extreme minimum temperature was more obvious than that of extreme maximum temperature; annual extreme maximum temperature in stations in desert showed higher instability; instability of annual extreme minimum temperature in all sampling points increased, and showed no obvious regularity between desert and mountain.
基金supported by the "100 Talents Pro-gramme" of Chinese Academy of Sciences.
文摘Agricultural water allocation system based on priority rights has caused regional conflicts and downstream ecological degradation. It is the urgent need to introduce the concept of the initial water rights and establish benefits compensation mechanism to resolve such problems. This paper takes the Shiyang River basin as an example to calculate the opportunity cost of 0.97×10^8 m^3 of agricultural water encroached by the middle reach based on initial water right allocation system under which water is allocated in accordance with the ratio between agricultural population of two different regions concerning the downstream ecological reconstruction needs with Bio-economic model （BEM）. The results suggest that the total economic loss of Minqin County for ecological reconstruction amounts to 2.5 7×10^8 yuan, of which 1.68×10^8 yuan is ecological compensation, representing the economic loss Minqin suffered for ecological reconstruction which shouM burden beneficial groups of ecological reconstruction and 0.89 ×10^8 yuan is the economic loss Minqin suffered due to Liangzhou＇s encroachment behavior which should be compensated by Liangzhou.
文摘On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic benefits, production efficiency, ecological stabilities and developmental conditions of the Wuwei Oasis agricultural ecosystem in the middle reaches of the river basin and the Minqin Oasis agricultural ecosystem in the lower reaches. Under a same management level and investment of . material and energy, primary productiveness and economic benefits of the former are higher than those of the latter. Construction directions of Wuwei and Minqin oases should be different in order to alleviate the water- use contradiction between the middle and lower reaches. The construction objective of Wuwei Oasis should be efficient irrigated farming production system and Minqin Oasis should become a mixed forestry-pastoral-farming ecosystem taking ecological protection as its major function.
文摘In recent years, the population size and scale of the Shiyang River Basin unceasingly expanding lead to a series of ecological environment: surface water reducing, land desertification and Ground water levels fall, etc. Research evolution characteristics of population distribution and migration growth of Shiyang River Basin contribute to river water resources and the industrial development of the comprehensive management. The article using the distribution of population structure index, population distribution center of gravity model and the population migration growth analysis model analyzes the distribution of the population evolution characteristics and population migration growth characteristics of Shiyang River Basin in 2000 to 2010. The results show that: 1) Considering Shiyang River Basin, population density is generally low, population distribution difference is bigger and concentration distribution in the middle corridor plain and three big population distribution center of Minqin oasis area, presenting a “point-areas-ribbon” structure characteristics. 2) The population distribution trend of Shiyang River Basin is constantly concentration, but the change is slow;the population distribution of Minqin is in the highest concentration degree, but the trend has been declining. 3) The focus of population density in river basin locates in Liangzhou district of Daliu country;in ten years, it migrates about 1209 m to southwest Wuwei City direction, but migration along the direction things is bigger than the north and south direction. The focus of population density and the basin geometry center is far away. 4) For ten years, at the township for basic statistics unit, each level population migration change within the overall is not significant: township level > prefecture-level cities level > counties level. 5) For ten years, there are significant changes in population migration between watershed township units, Wuwei City and Gulang Town are the two main concentrations of population centers.
基金. This work was supported by the National Natural Science Foundation of China (Grant Nos. 49731010 and 49871072).
文摘Pollen analyses of 85 samples from the San-jiaocheng section well along the margin of a palaeolake at the end of the Shiyang River, NW China, show that Picea and Sabina dominate the pollen assemblage. Together they reach as high as 40%-60%, with the percentage of Picea varying inversely with that of Sabina. Similar results were obtained from another section in the Shiyang River drainage. Using modern ecological habitat relationship analogues, pol-len transport characteristics, and the overall pollen assem-blage, we propose that both Picea and Sabina pollen were transported by the river from the mountains at the upper reaches of the Shiyang River, and that the assemblage is more indicative of changes in upland vegetation than of local conditions near the section. This interpretation is supported by pollen data derived from surface samples, water samples, and riverbed samples. Using a moisture indicator (the Picea to Sabina ratio) and calculated pollen concentrations, we identify a series of
基金supported by the National Key Research and Development Plan of China (2016YFC0400207)the National Natural Science Foundation of China (51439006)the National High Technology Research and Development Program of China (2013AA102904)
文摘To improve the accuracy of runoff forecasting,an uncertain multiple linear regression(UMLR) model is presented in this study. The proposed model avoids the transfer of random error generated in the independent variable to the dependent variable, as this affects prediction accuracy. On this basis, an inexact two-stage stochastic programming(ITSP) model is used for crop planting structure optimization(CPSO) with the inputs that are interval flow values under different probabilities obtained from the UMLR model. The developed system, in which the UMLR model for runoff forecasting and the ITSP model for crop planting structure optimization are integrated, is applied to a real case study. The aim of the developed system is to optimize crops planting area with limited available water resources base on the downstream runoff forecasting in order to obtain the maximum system benefit in the future. The solution obtained can demonstrate the feasibility and suitability of the developed system, and help decision makers to identify reasonable crop planting structure under multiple uncertainties.
文摘Last century 50 - 70 years, the dam construction of Shiyang Inland River Basin (SIRB) profound impact on the distribution of water resources and arable land in the basin. Through data collection, field surveys and remote sensing image interpretation, we analysis the use of land and water resources change process in the middle and lower reaches of SIRB in recent decades. The results show: (1) The cultivated area of SIRB has been an upward trend in recent decades, The whole basin cultivated area has increased total 229,000 hm<sup>2</sup> from 1973 to 2010 and mainly in the middle and lower reaches. Midstream increased by 149,700 hm<sup>2</sup> accounting for 65.36 percent of total, downstream increased by 70,000 hm<sup>2</sup> accounting for 30.70 percent of total. (2) The amount of surface water resources of downstream reduce significantly gradually since dam construction, and the water table sharp decline. While the volume of surface water resources come downstream from the 1950s accounted for 30 to 40 percent of the total gradually reduced to less than 10% in 2012;(3) since the arable land area of middle and lower reaches of SIRB basin substantial increase, so the surface water resource does not meet irrigation needs. Agricultural irrigation relies heavily on exploitation of groundwater to supplement, resulting in Regional Groundwater Depth dropped rapidly, and forming several huge funnel groundwater settlements. 20 years from 1981 to 2001 the groundwater level of midstream dropped from around 5m to around 10m in Wuwei, and in Minqin dam-region of downstream along faster rate of decline in 20 years fell from 8.52 m to 22.68 m. Dam construction project has changed the pattern of the basin water cycle, the middle reaches closure a large number of surface water resources led to downstream sharp decline. Downstream continued exploitation of groundwater formed a few huge funnel groundwater settlements, it caused serious ecological problems. The basin should adjust the industrial structure and develop water saving irrigation, promote a virtuous cycle of water resources, to achieve sustainable development, seek a sustainable development ways conversion natural oasis to artificial oasis efficiency in arid zone.
基金Under the auspices of National Natural Science Foundation of China(No.41861040,41761047)。
文摘As an important and typical arid inland region in China,Shiyang River Basin plays an important role in maintaining the sustainable development of eco-environment,whose ecological land suitability restricts the development of the local human activities.Therefore,Shiyang River Basin was selected as the case study,the minimum cumulative resistance(MCR)model and GIS technique were integrated to create land suitability evaluation map.We calculated the MCR value of ecological source and living source,and divided the whole basin into five partitions according to the difference between ecological source and living source,and analyzed the patterns and characteristics of the ecological land suitability evaluation(ELSE)regions,respectively.The results showed that:1)The suitable ecological land includes prohibited development region and restricted development region,which accounts for 15.45%and 23.35%of the total land area of the Shiyang River Basin,respectively.These two regions mainly distributed high altitude region in the southern Qilian Mountain and low altitude region where had high density of rivers.2)The protection of ecological land requires not only conserving existing ecological land but also focusing on ecological buffer belts around ecological sources and improving ecological land service ability.3)Ecological networks should be constructed through artificial planting trees around the boundary of oasis and ecological restoration region.Buffer greenbelts should also be established between optimized development region and ecological restoration region.
