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Thermal influence of ponding and buried warm-oil pipelines on permafrost: a case study of the China-Russia Crude Oil Pipeline 被引量:2
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作者 YanHu Mu MingTang Chai +3 位作者 GuoYu Li Wei Ma Fei Wang YaPeng Cao 《Research in Cold and Arid Regions》 CSCD 2020年第2期59-70,共12页
Buried pipelines are widely used for transporting oil in remote cold regions. However, the warm oil can induce considerable thermal influence on the surrounding frozen soils and result in severe maintenance problems. ... Buried pipelines are widely used for transporting oil in remote cold regions. However, the warm oil can induce considerable thermal influence on the surrounding frozen soils and result in severe maintenance problems. This paper presents a case study of the thermal influence of ponding and buried warm-oil pipelines on permafrost along the China-Russia Crude Oil Pipeline(CRCOP) in Northeast China. Since its operation in 2011, the operation of the warm-oil pipelines has led to rapid warming and thawing of the surrounding permafrost and development of sizable ponding along the pipeline route,which, in return, exacerbates the permafrost degradation. A field study was conducted along a 400-km long segment of the CRCOP in permafrost regions of Northeast China to collect the location and size information of ponding. A two-dimensional heat transfer model coupled with phase change was established to analyze the thermal influence of ponding and the operation of warm-oil pipelines on the surrounding permafrost. In-situ measured ground temperatures from a monitoring site were obtained to validate the numerical model. The simulation results show that ponding accelerates the development of the thaw bulb around the pipeline. The maximum thaw depth below the pipeline increases from 4 m for the case without ponding to 9 m for the case with ponding after 50 years of operation, and ponding directly above the pipe induces the maximum thaw depth. Engineering measures should be adopted to control the size or even eliminate surface water-rich ponding for the long-term performance of buried warm-oil pipelines. 展开更多
关键词 ponding heat transfer modeling oil PIPELINE PERMAFROST thaw DEPTH
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Relationship between ponding and topographic factors along the China-Russia Crude Oil Pipeline in permafrost regions 被引量:1
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作者 MingTang Chai YanHu Mu +2 位作者 GuoYu Li Wei Ma Fei Wang 《Research in Cold and Arid Regions》 CSCD 2019年第6期419-427,共9页
The original landform along the China Russia Crude Oil Pipeline(CRCOP,line 2)was disturbed during installation of pavement for the pipeline.Forest and vegetation coverage is dense,and runoff develops along the pipe.Si... The original landform along the China Russia Crude Oil Pipeline(CRCOP,line 2)was disturbed during installation of pavement for the pipeline.Forest and vegetation coverage is dense,and runoff develops along the pipe.Since the opera tion of the CRCOP(line 2)began in 2018,ponding has appeared on both sides of the pipeline.If there is no drainage,ponding can hardly dissipate,due to the low permeability of the permafrost layer.With the supply of surface flow and the transportation of oil at positive temperatures,ponding promotes an increase in temperature and changes the boundary ther mal conditions of the pipeline.Meanwhile,when the ponding freezes and thaws,frost heave threatens operational safety of the pipeline.Furthermore,the ponding can affect the thermal condition of line 1.In this paper,the distribution of pond ing along the CRCOP was obtained by field investigation.The type and cause of ponding were summarized,and the catch ment and stream order were extracted by the Digital Elevation Model(DEM).According to the statistical results in attri butes for topographic factors,it is known that ponding along the pipeline is relative to elevation,slope,aspect,and the Topographic Wetness Index(TWI).Water easily accumulates at altitudes of 300450 m,slopes within 3°5°,aspect in the northeast or south,TWI within 1316,flow direction in north east south,and flow length within 90150 km.This paper proposes a theoretical basis for the cause and characteristics of ponding along the pipeline. 展开更多
关键词 PERMAFROST Digital Elevation Model(DEM) Topographic Wetness Index(TWI) PIPELINE ponding
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Ranking the Suitability of Sub-watersheds for Ponding-Based Methods of Managed Aquifer Recharge in Lower Yom River Basin, Thailand
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作者 Kriengsak Srisuk Sumrit Chusanatus +3 位作者 Sitisak Munyou Laa Archwichai Kewaree Pholkern Penlada Boonsongka 《Journal of Geological Resource and Engineering》 2014年第3期158-166,共9页
The study area is located in the Lower Yom River Basin covering an area of about 970 km^2 in the lower part of Northern Thailand, which is underlain by sequences of unconsolidated alluvial deposits derived from the Yo... The study area is located in the Lower Yom River Basin covering an area of about 970 km^2 in the lower part of Northern Thailand, which is underlain by sequences of unconsolidated alluvial deposits derived from the Yom and Nan River floodplains. Groundwater has been heavily exploited largely for agriculture from the shallow gravel, sand and silt aquifer in the basin. Drastically declining water levels, up to 10 m in some areas, has been observed within the past decade, creating difficulties with lift irrigation for the local farmers. Therefore, the Department of Groundwater Resources, Thailand, considers that groundwater artificial recharge may be useful for recovering the static water levels within the most hydrogeological suitable areas. The objective of the paper is to rank the suitability of sub-watershed in the Lower Yom River Basin for conducting a pilot-scale testing of MAR (managed aquifer recharge) by ponding system. Hydrogeological and non-hydrogeological parameters were used to formulate the site selection criteria. Boolean logic and Fuzzy logic were used for delineating the 19 sub-watersheds in the Lan Ba watershed. Detailed hydrogeological investigations were conducted in the 10 most prospective sub-watersheds. Of these, the Nong Na 3 sub-watershed covering an area of about 500 hectares was determined to be the most appropriate site for the MAR pilot construction and testing. 展开更多
关键词 MAR ponding system Boolean logic Fuzzy logic suitability of sub-watersheds Lower Yom River Basin.
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Arctic summer sea ice phenology including ponding from 1982 to 2017
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作者 Xiaoli Chen Chunxia Zhou +3 位作者 Lei Zheng Mingci Li Yong Liu Tingting Liu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2022年第9期169-181,共13页
Information on the Arctic sea ice climate indicators is crucial to business strategic planning and climate monitoring.Data on the evolvement of the Arctic sea ice and decadal trends of phenology factors during melt se... Information on the Arctic sea ice climate indicators is crucial to business strategic planning and climate monitoring.Data on the evolvement of the Arctic sea ice and decadal trends of phenology factors during melt season are necessary for climate prediction under global warming.Previous studies on Arctic sea ice phenology did not involve melt ponds that dramatically lower the ice surface albedo and tremendously affect the process of sea ice surface melt.Temporal means and trends of the Arctic sea ice phenology from 1982 to 2017 were examined based on satellite-derived sea ice concentration and albedo measurements.Moreover,the timing of ice ponding and two periods corresponding to it were newly proposed as key stages in the melt season.Therefore,four timings,i.e.,date of snow and ice surface melt onset(MO),date of pond onset(PO),date of sea ice opening(DOO),and date of sea ice retreat(DOR);and three durations,i.e.,melt pond formation period(MPFP,i.e.,MO–PO),melt pond extension period(MPEP,i.e.,PO–DOR),and seasonal loss of ice period(SLIP,i.e.,DOO–DOR),were used.PO ranged from late April in the peripheral seas to late June in the central Arctic Ocean in Bootstrap results,whereas the pan-Arctic was observed nearly 4 days later in NASA Team results.Significant negative trends were presented in the MPEP in the Hudson Bay,the Baffin Bay,the Greenland Sea,the Kara and Barents seas in both results,indicating that the Arctic sea ice undergoes a quick transition from ice to open water,thereby extending the melt season year to year.The high correlation coefficient between MO and PO,MPFP illustrated that MO predominates the process of pond formation. 展开更多
关键词 Arctic sea ice sea ice phenology melt timings and durations melt ponds remote sensing
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Infiltration,runoff,and slope stability behaviors of infinite slope with macropores based on an improved Green–Ampt model
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作者 LI Shanghui WU Guoxiong +2 位作者 QUE Yun JIANG Zhenliang CHENG Gaoyun 《Journal of Mountain Science》 SCIE CSCD 2024年第7期2220-2235,共16页
Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is unclear.This paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e... Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is unclear.This paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e.,matrix and macropore)and ponding condition,and proposed the infiltration equations,infiltration–runoff coupled model,and safety factor calculation method.Results show that the infiltration processes of macropore slope can be divided into three stages,and the proposed model is rational by a comparative analysis.The wetting front depth of the traditional unsaturated slope is 17.2%larger than that of the macropore slope in the early rainfall stage and 27%smaller than that of the macropore slope in the late rainfall stage.Then,macropores benefit the slope stability in the early rainfall but not in the latter.Macropore flow does not occur initially but becomes pronounced with increasing rainfall duration.The equal depth of the wetting front in the two domains is regarded as the onset criteria of macropore flow.Parameter analysis shows that macropore flow is delayed by increasing proportion of macropore domain(ω_(f)),whereas promoted by increasing ratio of saturated permeability coefficients between the two domains(μ).The increasing trend of ponding depth is sharp at first and then grows slowly.Finally,when rainfall duration is less than 3 h,ωf andμhave no significant effect on the safety factor,whereas it decreases with increasingωf and increases with increasingμunder longer duration(≥3 h).With the increase ofω_(f),the slope maximum instability time advances by 10.5 h,and with the increase ofμ,the slope maximum instability time delays by 3.1 h. 展开更多
关键词 Macropore slope Green–Ampt infiltration model Equivalent wetting front ponding response time Slope stability
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Assessment of Retention Ponds and Its Impacts on Health of Residents in Mogadishu, Somalia: Mixed Methods
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作者 Mohamed Ahmed Kullane Mohamed Ibrahim Abdi-Soojeede 《Journal of Water Resource and Protection》 CAS 2024年第4期293-307,共15页
The purpose of this study was to evaluate the effects of retention ponds on the environment and population health by analyzing water samples from various ponds in Mogadishu, to determine the prevalence of waterborne i... The purpose of this study was to evaluate the effects of retention ponds on the environment and population health by analyzing water samples from various ponds in Mogadishu, to determine the prevalence of waterborne illnesses that occur during the rainy season in Mogadishu, and to find out what experts thought about the effects of retention ponds on the environment as well as population health in Mogadishu. Methods: Mixed designs were used in the study. The first design is an exploratory study where samples are taken from different retention ponds in Mogadishu. The second design involves gathering secondary data from the online FSNAU Dashboard regarding the incidence of rainfall and waterborne illnesses including malaria and cholera. Additionally, a cross-sectional survey of expert opinions using questionnaires was the third design. The 10 water samples were taken from retention ponds in Mogadishu as part of the sample size. Data on the fourth month was also gathered using the FNSAU dashboard, and seventy sample sizes were used for the expert self-administered questionnaire for the third design. Excel was used for data analysis in the initial design. While BMI SPSS versions 22 were used to analyze the data from the Self-administered Questionnaire, additional methods were utilized to compute descriptive statistics, such as mean and standard deviation, and to analyze demographic data in a frequency table. Findings: The results show that three samples had unsatisfactory scores (Grade D): Yaqshid (Warshadda Bastada) had a WQI of 80.85, Boondheer (Bondher Pond) had a WQI of 80.64, and Wartanabad (Xamar Jadiid Pond) had a WQI of 80.89. The remaining samples were all rated as fair (grade), which indicates that they ranged from 50 to 75. The months with the largest rainfall already occurred in December, November, and October, when the prevalence of diseases during the rainy season was highest for cholera cases. Although October and December saw a significant number of malaria cases, November did not. Retention ponds’ overall effects on residential environments were evaluated, and the results showed that the standard deviation was 0.802 and the cumulative average mean scores were 4.41 overall. This indicates that the respondents were in agreement that retention ponds in Mogadishu, Somalia, had an effect on residential areas. Recommendation: The study suggested that in order to identify retention pond contamination and create treatment units for its management, the Ministry of Health forms a district-level public health committee. All districts must have a sewer system installed by the local government, and retention ponds must be made easier in order to move waste outside of the city. 展开更多
关键词 RETENTION PONDS CONTAMINATION Water Quality Index Waterborne Diseases Mogadishu SOMALIA
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Land Use and Gully Dynamics in the Kourfa Watershed, Matankari (Southwest Niger)
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作者 Bachirou Hamadou Younoussa Tahirou Hassane Yaou +4 位作者 Bouba Hassane Abass Kadade Sabou Abdoulkader Moussa Issaka Amadou Abdourhamane Toure Zibo Garba 《Journal of Geographic Information System》 2024年第4期306-320,共15页
The main consequences of climate change in the Sahel have been the metamorphosis of surface conditions. These metamorphoses have resulted in surface degradation, of which silting up of watersheds is the main phenomeno... The main consequences of climate change in the Sahel have been the metamorphosis of surface conditions. These metamorphoses have resulted in surface degradation, of which silting up of watersheds is the main phenomenon. The objective of this study is to assess the environmental trends of the Kourfa pond watershed. The study is based on diachronic mapping with Landsat satellite images and Google Earth images, over the period 1986 to 2021. The study reveals that vegetation (whose rate of regression doubled between 1986 and 2021) has decreased to the benefit of crop areas (whose rate of increase multiplied by 3.61 between 1986 and 2021). Bare soil and encrusted areas have also decreased, with regression rates almost double than those of 1986. In addition, the Kourfa waterholes have experienced two types of changes over 35 years: one progressive between 2011 and 2016 and the other regressive between 2001 and 2021 compared to 1986. The ravine network has been multiplied by a factor of 2.4, with density more than doubled and the connectivity of the hydrographic networks has risen from 2 to 4, with significant bank recession. This dynamic of the Kourfa pond is linked to the high drainage, the increasing complexity of the gully network and the erosion due to the retreat of the watershed banks, all of which contribute to the silting-up of the Kourfa watershed. 展开更多
关键词 Kourfa Pond DYNAMICS WATERSHED Dosso NIGER
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Microscopic analysis on eukaryotic algae and cyanobacteria in nine seasonal lakes and ponds in Vestfjella,Dronning Maud Land,Antarctica
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作者 Lauri ARVOLA Matti LEPPÄRANTA LI Zhijun 《Advances in Polar Science》 CSCD 2024年第2期206-218,共13页
Antarctic continental lakes and ponds are among the most impoverished aquatic environments on earth but many of them support flourishing populations of cyanobacteria,eukaryotic algae,protozoans,and some multicellular ... Antarctic continental lakes and ponds are among the most impoverished aquatic environments on earth but many of them support flourishing populations of cyanobacteria,eukaryotic algae,protozoans,and some multicellular animals.In this study,we present results of a microscopic analysis of cyanobacteria and eukaryotic algae from nine diverse types of Antarctic continental water bodies during one austral summer.The results supplement and enlarge our previous studies on the limnological characteristics of the epiglacial and supraglacial lakes and ponds in Dronning Maud Land,an area that has received little attention from limnologists.The taxon with highest frequency among the samples(n=79)was Mesotaenium cf.berggrenii,a eukaryotic Zygnematophyceae,which occurred in 82%of the samples with a maximum cell density of 68 cells·mL^(-1).The taxa with second and third highest frequency were the prokaryotes Gloeocapsopsis(60%)and Leptolyngbya(41%),followed by Chlamydomonas(34%)and Cyanothece(29%).The number of taxa varied between 7-21 among the lakes and ponds,being highest in a supraglacial lake,and lowest in an epiglacial lake.The results did not reveal any obvious correlation between the abundance of any taxa and the water chemistry,but water bodies with inorganic sediments had higher cell densities and biomasses than those without sediment.This suggests the importance of sediment in supporting biological diversity in these ultraoligotrophic lakes and ponds. 展开更多
关键词 Antarctic continental lakes Antarctic continental ponds CYANOBACTERIA algae protozoa rotifers TARDIGRADA
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Evaluation of Human Impacts on Bartlett Pond Ecosystem, Laredo, Southern Texas, USA, through Empirical Modeling
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作者 Maya P. Bhatt Amede Rubio +6 位作者 Ganesh B. Malla Cristobal Lopez Virginia Morales Erick Vazquez Cano David Marquez Orlando Berumen Alvarez Alfred Addo-Mensah 《Journal of Environmental Protection》 2024年第4期497-526,共30页
The trace elements chemistry of Bartlett Pond, a small shallow wetland pond in Laredo, Southern Texas, was sampled to evaluate the dynamics of trace elements impacts on water quality and ecosystems ecology of the pond... The trace elements chemistry of Bartlett Pond, a small shallow wetland pond in Laredo, Southern Texas, was sampled to evaluate the dynamics of trace elements impacts on water quality and ecosystems ecology of the pond. Two types of fish (bass and tilapia) were also sampled to see the trace element accumulation in different parts of their body. The concentrations of trace elements in water samples were found in the following order: Fe &Gt;Sb > Pb > As &Gt;Co > Tl > Cr > Cd within Bartlett Pond. Overall, the water quality of the pond is unacceptable for drinking and any other purposes as trace element concentrations (e.g. As, Cd, Co, Cr, Pb, Fe, Sb and Tl) are exceedingly higher (several fold) than the WHO and US EPA guidelines. Predictive and correlation analysis shows that most trace elements exhibit a strong positive correlation among them indicating the same anthropogenic sources and biogeochemical processes regulate these trace elements within the pond. Distributions of the trace elements in water exhibit different shapes mostly as positively skewed distribution for As, Cd, Co, Cr, and Tl, symmetrical distribution for Fe and almost symmetrical distribution for Pb and Sb. Concentrations of As, Co and Tl accumulated much higher in different parts of the Bass than Tilapia fish. The concentrations of As, Tl, Co, and Sb appeared significantly higher in different parts of the body of both Bass and Tilapia than the maximum SRM certified values. Accumulation of these contaminants in fish tissues pose increased health risks to humans who consume these contaminated fish although fishing is prohibited. Anthropogenic activities in the region primarily degrade the whole pond ecosystem ecology of the Bartlett Pond and waters of this pond to be not recommended for any use. These findings may be useful for the scientific community and concerned authorities to improve understanding about these precious natural resources and conservation of the ecosystem ecology. 展开更多
关键词 Trace Elements Bartlett Pond Laredo Southern Texas WETLANDS Ecosystem Ecology
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Nitrogen and Phosphorus Removal from Lake Kinneret Inputs
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作者 Moshe Gophen 《Open Journal of Ecology》 2024年第2期165-182,共18页
The Hula Valley was drained in 1957. The land use was modified from natural wetland and old shallow lake ecosystems to agricultural development. About half of the drained land area was utilized for aquaculture. Popula... The Hula Valley was drained in 1957. The land use was modified from natural wetland and old shallow lake ecosystems to agricultural development. About half of the drained land area was utilized for aquaculture. Population size was enhanced and the diary was developed intensively resulting in the enhancement of domestic and husbandry sewage production that increased as well. The natural intact Hula Valley-Lake Kinneret ecosystem was heavily anthropogenically interrupted: The Hula was drained and Kinneret became a national source for domestic water supply. Some aspects of the environmental and water quality protection policy of the system are presented. The causation and operational management implications for the reduction of Nitrogen and Phosphorus migration from the Hula Valley are discussed. Drastic (81%) restriction of aquaculture accompanied by sewage totally removed achieved a reasonable improvement in pollution control which was also supported by the Hula Project. The implications of anthropogenic intervention in the process of environmental management design are presented. 展开更多
关键词 Hula Valley JORDAN Kinneret NITROGEN PHOSPHORUS Peat Soil Fish Ponds Sewage Removal
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Spatial distribution and ecological risk of heavy metals and their source apportionment in soils from a typical mining area, Inner Mongolia, China
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作者 XIE Shicheng LAN Tian +5 位作者 XING An CHEN Chen MENG Chang WANG Shuiping XU Mingming HONG Mei 《Journal of Arid Land》 SCIE CSCD 2023年第10期1196-1215,共20页
Determining the distributions and sources of heavy metals in soils and assessing ecological risks are fundamental tasks in the control and management of pollution in mining areas.In this study,we selected 244 sampling... Determining the distributions and sources of heavy metals in soils and assessing ecological risks are fundamental tasks in the control and management of pollution in mining areas.In this study,we selected 244 sampling sites around a typical lead(Pb)and zinc(Zn)mining area in eastern Inner Mongolia Autonomous Region of China and measured the content of six heavy metals,including cuprum(Cu),Zn,Pb,arsenic(As),cadmium(Cd),and chromium(Cr).The ecological risk of heavy metals was comprehensively evaluated using the Geo-accumulation index,Nemerow general pollution index,and potential ecological risk index.The heavy metals were traced using correlation analysis and principal component analysis.The results showed that the highest content of heavy metals was found in 0–5 cm soil layer in the study area.The average content of Zn,As,Pb,Cu,Cr,and Cd was 670,424,235,162,94,and 4 mg/kg,respectively,all exceeding the risk screening value of agricultural soil in China.The areas with high content of soil heavy metals were mainly distributed near the tailings pond.The study area was affected by a combination of multiple heavy metals,with Cd and As reaching severe pollution levels.The three pathways of exposure for carcinogenic and noncarcinogenic risks were ranked as inhalation>oral ingestion>dermal absorption.The heavy metals in the study area posed certain hazards to human health.Specifically,oral ingestion of these heavy metals carried carcinogenic risks for both children and adults,as well as noncarcinogenic risks for children.There were differences in the sources of different heavy metals.The tailings pond had a large impact on the accumulation of Cd,Zn,and Pb.The source of Cr was the soil parent material,the source of As was mainly the soil matrix,and the source of Cu was mainly the nearby Cu ore.The purpose of this study is to more accurately understand the extent,scope,and source of heavy metals pollution near a typical mining area,providing effective help to solve the problem of heavy metals pollution. 展开更多
关键词 heavy metal ecological risk Geo-accumulation index Nemerow general pollution index tailings pond mining area
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Dynamic Behaviour of Pond Ash Mixed with Coir and Crumb Rubber
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作者 Ashish Malik Sanjay Kumar Singh 《Journal of Renewable Materials》 SCIE EI 2023年第3期1271-1291,共21页
An experimental program was conducted to determine the dynamic properties of pond ash(PA)and pond ash mixed with admixtures like crumb rubber(CR)and coir fiber(CF)which are wastes of different industries.Additives CR ... An experimental program was conducted to determine the dynamic properties of pond ash(PA)and pond ash mixed with admixtures like crumb rubber(CR)and coir fiber(CF)which are wastes of different industries.Additives CR and CF were mixed separately with pond ash in a percentage ranging from 0%–20%at an interval of 5%and 0%–2%at an interval of 0.5%by weight of pond ash,respectively.Dynamic properties(Shear modulus,Number of cycles to initiate liquefaction,Degradation index and Damping ratio)for pond ash mixes were determined using strain-controlled cyclic tri-axial apparatus.The shear strain was kept constant at 1.2%and the frequency varied from 0.4 to 1 Hz.Liquefaction resistance improves when crumb rubber is added to pond ash,however adding Coir fiber to pond ash has essentially no effect on the number of cycles required to initiate liquefaction.The dynamic shear modulus decreases when crumb rubber was mixed in pond ash whereas when coir fiber is added to pond ash,the dynamic shear modulus increases significantly.A mix of PA,CR,and CF was also tried to balance the number of cycles required to initiate liquefaction and shear modulus.The mixed sample in the proportion of PA(84%)+CR(15)+CF(1%)can be termed a balanced mix as the number of cycles to initiate liquefaction was more than all PA-CF mixes and also the shear modulus was more than all PA-CR mixes.Damping ratio increases with increasing frequency of loading(0.4 to 1 Hz). 展开更多
关键词 Pond ash COIR crumb rubber cyclic loading LIQUEFACTION
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Chemical weathering profile in the V–Ti–Fe mine tailings pond:a basalt-weathering analog
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作者 Xiaolin Zhang Yinger Deng +2 位作者 Liang Tang Zhengmeng Hou Jinsong Yang 《Acta Geochimica》 EI CAS CSCD 2023年第6期1035-1050,共16页
The(ultra-)mafic mine tailings pond revealed a weathering discrepancy in the tailings profile,which provided a valuable analog to assess the role of carbonate and silicate weathering of the basalt.In this study,drill-... The(ultra-)mafic mine tailings pond revealed a weathering discrepancy in the tailings profile,which provided a valuable analog to assess the role of carbonate and silicate weathering of the basalt.In this study,drill-cores samples were selected from the Wanniangou V–Ti–Fe mine tailings pond(Sichuan province,China)to investigate the mineralogicand geochemical characteristics in the tailings profile.The results reveal(1)the tailings pond profile consist of upper and lower layers.The upper layer is composed of carbonate weathering(1.4%),which was formed in the initial stages of tailings exposure and represented a minimal weathering degree.(2)The lower layer was primarily observed at the aquifer zone of the tailings pond,and was consistent with 0.45%carbonate weathering and 48.4%silicate weathering.(3)The weathering discrepancy in the tailings profile could be due to the sulfide oxidation and aerobic/flowing aquifer,which facilitate the water-tailings reactions.The tailings profile provides an analog to studying basalt weathering,as it spans both carbonate and silicate weathering.This research reinforces the idea that silicate weathering is predominant in basaltic areas and plays a crucial role in regulating atmospheric CO_(2)(carbon dioxide)levels on Earth. 展开更多
关键词 V–Ti–Fe mine Tailings pond profile Drill core Basalt weathering
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Carbon isotope ratios of n-alkanoic acids: new organic proxies for paleo-productivity in Antarctic ponds
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作者 CHEN Xin JIN Jing +5 位作者 NIE Yaguang ZHANG Jifeng DONG Liang HUANG Xianyu Steven D()EMSLIE LIU Xiaodong 《Advances in Polar Science》 CSCD 2023年第4期304-317,共14页
Primary productivity in the Antarctic aquatic environment with simple ecosystems is sensitive to climate and environmental fluctuations.We investigatedδ13C values for n-alkanoic acids derived from phototrophic organi... Primary productivity in the Antarctic aquatic environment with simple ecosystems is sensitive to climate and environmental fluctuations.We investigatedδ13C values for n-alkanoic acids derived from phototrophic organisms in a lacustrine sediment core(IIL3)to indicate primary productivity in ponds on Inexpressible Island in the western Ross Sea,Antarctica.Short-chain n-alkanoic acids(C14–C18)were abundant in the IIL3 sediment profile.The carbon isotope ratios of short-chain n-alkanoic acids in the sediment samples and floating microbial mats were similar,indicating that the short-chain n-alkanoic acids in the IIL3 sediment profile predominantly originated from phototrophic organisms.Theδ13C values for the short-chain n-alkanoic acids varied widely through the sediment profile,and 13C-enrichment of n-alkanoic acids was most likely related to high productivity due to carbon-limited conditions caused by enhanced photosynthetic efficiency.Theδ13C values for the n-alkanoic acids changed over the past 3200 years in similar ways to organic proxies for aquatic productivity(n-alkanoic acid and sterol sedimentary fluxes).C16 n-alkanoic acid was enriched in 13C in periods of high aquatic productivity~750–1650 and 3000–3200 a BP but depleted in 13C in periods of relatively low productivity~150–600 and 2500–3000 a BP.The results indicated that carbon isotope ratios of lipids from phototrophic organisms could be used as new proxies to reconstruct paleo-productivity in Antarctic lakes and ponds and therefore improve our understanding of past climate changes. 展开更多
关键词 East Antarctica lipid biomarkers carbon isotopic ratios pond primary productivity climate change
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Impacts of Climate Change on Economic Performance of Tilapia Pond Operations in Minalin, Pampanga: A Case of Intensive Large-Scale Pond Culture
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作者 Edilyn V. Lansangan Jairus Jesse M. Tubal 《Open Journal of Ecology》 2023年第7期516-523,共8页
Pampanga is the top tilapia-producing province in Philippines. One of its municipalities, Minalin, is considered as one of its major centers of production. This study aims to determine the impacts of climate change ha... Pampanga is the top tilapia-producing province in Philippines. One of its municipalities, Minalin, is considered as one of its major centers of production. This study aims to determine the impacts of climate change hazards on the economic performance of tilapia-intensive pond culture in Minalin, Pampanga considering the threats to the industry, livelihoods, and food security. Results revealed that the economic performance of tilapia pond operations using semi-intensive large-scale culture was affected by climate change, as reflected in the reduction of yield among tilapia pond operators. This makes intensive tilapia pond farming in Minalin still a viable venture but will now require more than a year to pay for investment (variable and fixed) costs if under climate change risks. The study recommends strengthening capacity building related to climate-smart tilapia farming technologies for pond operators and to implement appropriate technologies to address climate change risks. 展开更多
关键词 Climate Change Economic Performance Intensive Pond Culture TILAPIA Tilapia Pond Culture
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Hydrodynamic Characterization of the Water Table of the Upper Dallol Maouri Basin (Niger)
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作者 Habi Hamani Abdoul-Hayou Adamou Mahaman Moustapha +1 位作者 Sandao Issoufou Alassane Hado Halidou 《Open Journal of Modern Hydrology》 CAS 2023年第2期77-93,共17页
The Dallol Maouri is a valley of an ancient tributary of the Niger River. The groundwater in this area of the upper Dallol Maouri is little known because of the weakness of the data. The purpose of this study is to ma... The Dallol Maouri is a valley of an ancient tributary of the Niger River. The groundwater in this area of the upper Dallol Maouri is little known because of the weakness of the data. The purpose of this study is to make a hydrodynamic characterization of the water table of the upper dallol Maouri by piezometric approach. A piezometric monitoring network made up of 65 points (54 wells and 11 piezometers) was set up. Six (6) piezometric measurement campaigns were carried out from June 2018 to June 2021. The piezometric survey is carried out once every six months: in January and June corresponding respectively to the high and low water period. The results show that the water table is multi-layered in places with a combination of alluvial and Continental Terminal 3 (CT3) aquifers, or perched aquifers and inferoflux aquifers around permanent ponds. The flow direction of the Continental Terminal 3 (CT3) aquifer is mainly North-East/South-West. The piezometric levels are around 219 m (in the South-West part) and 281 m (in the North-East part). The hydraulic gradient varies from 0.018‰ to 1.83‰. The recharge zones are located in the outcrop zone of the aquifer and in the valleys. A lack of recharge is observed on the plateaus despite the presence of numerous permanent ponds. The recharge coefficient in 2020 is estimated at 25% of the total rainfall recorded. 展开更多
关键词 AQUIFER Piezometry POND RECHARGE ISOTOPIC
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Ecological Remediation Technologies of Freshwater Aquiculture Ponds Environment 被引量:4
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作者 宋超 陈家长 +3 位作者 裘丽萍 孟顺龙 范立民 胡庚东 《Agricultural Science & Technology》 CAS 2013年第1期94-97,196,共5页
The environmental issues confronted by traditional freshwater aquaculture are increasingly sedous, promoting development of ecological remediation technolo- gies. The in-situ remediation represented by fish-vegetable ... The environmental issues confronted by traditional freshwater aquaculture are increasingly sedous, promoting development of ecological remediation technolo- gies. The in-situ remediation represented by fish-vegetable mutualism mode (FVMM) and ex-situ remediation represented by recirculating aquaculture system (RAS) are highlights of related researches. In the paper, the advantages and disadvantages of FVMM and RAS were analyzed and area allocation was discussed in terms of eu- trophication and pond nitrogen cycle. The results showed that the FVMM could re- duce pollutant-discharge coefficient of fish ponds, but the ecological balance would still be hard to be achieved nationwide. In contrast, although the extra cost and land resources would produce inevitably, the application is of great significance in small regions, especially for eutrophication areas thanks for zero-discharge. 展开更多
关键词 POND ENVIRONMENT Remediationon
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Prediction Model of Dissolved Oxygen Fuzzy System in Aquaculture Pond Based on Neural Network 被引量:4
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作者 王瑞梅 傅泽田 何有缘 《Agricultural Science & Technology》 CAS 2010年第8期14-18,共5页
A dissolved oxygen fuzzy system predicting model based on neural network was put forward in this study. 106 groups of data were used to confirm the fitness of the predicting model. The first 80 groups of data were act... A dissolved oxygen fuzzy system predicting model based on neural network was put forward in this study. 106 groups of data were used to confirm the fitness of the predicting model. The first 80 groups of data were acted as training input and the other 26 groups of data were acted as the confirmed data in the system. The result showed that the testing data was approximately the same as the predicted data. So it gave a new way to solve the problem that the status of the water quality couldn't be predicted in time and it's hard to watching and measuring the factors dynamic. 展开更多
关键词 Aquaculture pond Dissolved oxygen Fuzzy system Neural network
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Metabolic Characteristics and Functional Diversity of Carbon Source in Microflora of Ponds with Recirculating Aquaculture System 被引量:2
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作者 李谷 宋景华 +3 位作者 李晓莉 张世羊 陶玲 张春雪 《Agricultural Science & Technology》 CAS 2014年第2期278-282,299,共6页
With Biolog Eco microplate, metabolic characteristics and functional diver-sity of carbon source in microflora of ponds were researched based on recitculating ponds and control ponds in order to explore effects of eco... With Biolog Eco microplate, metabolic characteristics and functional diver-sity of carbon source in microflora of ponds were researched based on recitculating ponds and control ponds in order to explore effects of eco-adjustments on microflo-ra in ponds. The results indicate that total number of bacterium, microbial metabolism activity, and diversity index in P7, P8, P1 and P2 kept higher, fol owed by P3, P4, P5 and P6. The utilization rate of microbes on sugars achieved the highest (31.0%-48.7%), fol owed by carboxylic acid (13.4%-18.0%), amino acid (10.1%-20.5%), polymers (9.4%-17.0%), biopolymer (5.7%-9.7%) and phenol (4.95%-7.50%). Principal component analysis divided microflora in different ponds, suggesting that microbial community has varied carbon source characteristics and nitrogen-containing compound and biopolymer metabolisms are most affected. 展开更多
关键词 Aquaculture pond MICROBE -Metabolic characteristics of carbon source Functional diversity
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The Relationship between the Area of Aquaculture Pond and Purification Pond in Water Circulation Aquaculture System 被引量:1
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作者 宋超 陈家长 +3 位作者 戈贤平 孟顺龙 范立民 胡庚东 《Agricultural Science & Technology》 CAS 2013年第4期684-688,共5页
The establishment of water circulation aquaculture system realized the hi- erarchical use of nitrogen, phosphorus and other eutrophic substances in aquaculture wastewater and the recirculation use of water resource. H... The establishment of water circulation aquaculture system realized the hi- erarchical use of nitrogen, phosphorus and other eutrophic substances in aquaculture wastewater and the recirculation use of water resource. However, no research has been reported on the detailed calculation of the relationship between the area of aquaculture pond and purification pond. In this study, referring to the absorption ability of aquatic plants to pollutants in aquaculture wastewater and pollutant generation and discharge coefficient in aquaculture pond, based on the general rules of water quality management in freshwater aquaculture system, a calculation mode was es- tablished to investigate the relationship between the area of aquaculture pond and purification pond in freshwater recirculation aquaculture system, which was feasible to explain related cases and would provide theoretical basis to reduce the economic costs in the construction of water circulation aquaculture system and realize the bal- ance between the ecological benefits and the economic benefits. 展开更多
关键词 Freshwater fish pond Recirculation aquaculture system Area of aquaculture pond Area of purification pond Calculation mode
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