Non-point source pollution (NPS) of water resources has become a major problem in recent years due to more human interactions and disturbances to natural landscapes. The problem can have more impacts in sub-humid subt...Non-point source pollution (NPS) of water resources has become a major problem in recent years due to more human interactions and disturbances to natural landscapes. The problem can have more impacts in sub-humid subtropical regions where high intensity monsoon rains have greater effects on hydrologic proc-esses and thus the assessment of those effects is necessitated for strategic water resources and environmental management. Since spatial and temporal changes of NPS pollutants are difficult to assess on a watershed scale, the assessment can be done effectively using a suitable water quantity-quality model coupled with GIS and remote sensing that incorporates spatial variations. The objective of this study was to assess the N and P loads from a small mixed type watershed comprising different land use land covers with the aid of Soil and Water Assessment Tool (SWAT)-a hydrologic-water quality model. The model was calibrated for runoff and sediment transport and then simulation of associated N and P loads as NPS pollution was done and compared with measured values at the outlet of the watershed which is part of the DVC Command, Hazaribagh, India. The calibrated SWAT model was used to estimate the water soluble NO3-N, NH4-N, P, organic N and or-ganic P loads being transported as pollutants by runoff and percolated water. The estimates of these pollut-ants provided information on the extent of NPS pollution of water downstream. The results of the study re-veal that the NPS pollutant load in runoff varies with seasonal rainfall patterns and ranges from 2.57 to 4.52 kg/ha in case of NO3-N which accounts for a maximum load of 7661.40 kg of NO3-N in surface runoff from the watershed under study. The total loss of N from the watershed accounts for as high as 8.84 kg/ha, whereas the P load is 0.02 kg/ha. These losses can be as high as 14984.14 kg of total N and 50.85 kg of total P when estimated as NPS pollutants from the watershed. The study is therefore important to get an estimate of the extent of these pollutants and develop measures for mitigating the losses as nutrient as well as pollu-tion of water resources.展开更多
Shaanxi is a leading province in animal husbandry(AH)in China.However,the lack of provincial information on the characteristics and utilization potential of livestock manure(LM)hinders crucial management decisions.The...Shaanxi is a leading province in animal husbandry(AH)in China.However,the lack of provincial information on the characteristics and utilization potential of livestock manure(LM)hinders crucial management decisions.Therefore,we investigated the spatiotemporal distribution,availability and biogas potential of LM in Shaanxi,and examine the carbon emission reduction potential of AH.There has been a 1.26-fold increase in LM quantities in Shaanxi over the past 35 years,reaching 4635.6×10^(4)t by 2021.LM was mainly concentrated in northern Shaanxi and the eastern part of Hanzhong.Cattle and pig manure were the primary sources of LM,with the average LM land-load of 14.57 t·ha^(−1)in 2021.While the overall AH in Shaanxi has not exceeded the environmental capacity,the actual scales of AH in Ankang and Hanzhong have already surpassed the respective environmental capacities,posing a higher risk of N and P pollutions.In 2021,the estimated biogas energy potential of LM was 1.2×10^(11)MJ.From 2012 to 2021,the average carbon emission reduction potential in Shaanxi was 22%,with an average potential scale of 10%.The results of this research provide valuable data and policy recommendations for promoting the intensive use of LM and reducing carbon emissions in Shaanxi.展开更多
Intensive farming is a primary cause of increased sediment and associated nitrogen(N)and phosphorus(P)loads in surface water systems.Determining their contributing sources,pathways and loads present major challenges i...Intensive farming is a primary cause of increased sediment and associated nitrogen(N)and phosphorus(P)loads in surface water systems.Determining their contributing sources,pathways and loads present major challenges in the high-intensity agricultural catchments.Herein,we quantify the sediment sources and magnitude of sediment total N and total P from different sources using a novel application of compound-specific stable isotope(CSSI)and fallout radionuclides(FRNs)of^(137)cs and^(210)pbex in an intensive agricultural catchment in North China.Sediment sources from surface and sub-surface soils were estimated from FRNs fingerprint and accounted for 62±7%and 38±7%respectively,while surface soil from land uses that originated from hillslope were identified by CssI fingerprint.Using a novel application of FRNs and CSSI sediment fingerprinting techniques,the dominant sediment source was derived from maize farmland(44±0.1%),followed by channel bank(38±7%).The sedimentation rate(13.55±0.30 t ha^(-1)yr^(-1))was quantifed by the^(137)cs cores(0-60 cm)at the outlet of this catchment.The total N and total P in sediment were both mostly derived from maize farmland and least from channel banks.The channel banks are significant sediment sources but contribute little to the input of sediment N and P for eutrophication.It implies that chemically-applied farmlands are the main hotspots for catchment erosion control and pollution prevention.The novel application of FRNs and CSSI techniques cost-effectively quantified sediment N and P loads from different sources with a single visit to the catchment,enabling rapid assessment for optimizing soil conservation strategies and land management practices.展开更多
文摘Non-point source pollution (NPS) of water resources has become a major problem in recent years due to more human interactions and disturbances to natural landscapes. The problem can have more impacts in sub-humid subtropical regions where high intensity monsoon rains have greater effects on hydrologic proc-esses and thus the assessment of those effects is necessitated for strategic water resources and environmental management. Since spatial and temporal changes of NPS pollutants are difficult to assess on a watershed scale, the assessment can be done effectively using a suitable water quantity-quality model coupled with GIS and remote sensing that incorporates spatial variations. The objective of this study was to assess the N and P loads from a small mixed type watershed comprising different land use land covers with the aid of Soil and Water Assessment Tool (SWAT)-a hydrologic-water quality model. The model was calibrated for runoff and sediment transport and then simulation of associated N and P loads as NPS pollution was done and compared with measured values at the outlet of the watershed which is part of the DVC Command, Hazaribagh, India. The calibrated SWAT model was used to estimate the water soluble NO3-N, NH4-N, P, organic N and or-ganic P loads being transported as pollutants by runoff and percolated water. The estimates of these pollut-ants provided information on the extent of NPS pollution of water downstream. The results of the study re-veal that the NPS pollutant load in runoff varies with seasonal rainfall patterns and ranges from 2.57 to 4.52 kg/ha in case of NO3-N which accounts for a maximum load of 7661.40 kg of NO3-N in surface runoff from the watershed under study. The total loss of N from the watershed accounts for as high as 8.84 kg/ha, whereas the P load is 0.02 kg/ha. These losses can be as high as 14984.14 kg of total N and 50.85 kg of total P when estimated as NPS pollutants from the watershed. The study is therefore important to get an estimate of the extent of these pollutants and develop measures for mitigating the losses as nutrient as well as pollu-tion of water resources.
基金supported by the National Natural Science Foundation of China(32172679 and 31902122).
文摘Shaanxi is a leading province in animal husbandry(AH)in China.However,the lack of provincial information on the characteristics and utilization potential of livestock manure(LM)hinders crucial management decisions.Therefore,we investigated the spatiotemporal distribution,availability and biogas potential of LM in Shaanxi,and examine the carbon emission reduction potential of AH.There has been a 1.26-fold increase in LM quantities in Shaanxi over the past 35 years,reaching 4635.6×10^(4)t by 2021.LM was mainly concentrated in northern Shaanxi and the eastern part of Hanzhong.Cattle and pig manure were the primary sources of LM,with the average LM land-load of 14.57 t·ha^(−1)in 2021.While the overall AH in Shaanxi has not exceeded the environmental capacity,the actual scales of AH in Ankang and Hanzhong have already surpassed the respective environmental capacities,posing a higher risk of N and P pollutions.In 2021,the estimated biogas energy potential of LM was 1.2×10^(11)MJ.From 2012 to 2021,the average carbon emission reduction potential in Shaanxi was 22%,with an average potential scale of 10%.The results of this research provide valuable data and policy recommendations for promoting the intensive use of LM and reducing carbon emissions in Shaanxi.
基金supported by the International Atomic Energy Agency through coordination research projects(CRP)under Research Contract No.23008 and technical cooperation project(TCP)RAS 5084,and the Central Public-interest Scientific Institution Basal Research Fund(No.BSRF202004)Funding for AC to collaborate on this work was provided by the High-end Foreign Experts Recruitment Program from State of Administration of Foreign Experts Affairs of ChinaThis work was partly supported by the Science and Technology Major Project of Guangxi(Guike AA17204078).
文摘Intensive farming is a primary cause of increased sediment and associated nitrogen(N)and phosphorus(P)loads in surface water systems.Determining their contributing sources,pathways and loads present major challenges in the high-intensity agricultural catchments.Herein,we quantify the sediment sources and magnitude of sediment total N and total P from different sources using a novel application of compound-specific stable isotope(CSSI)and fallout radionuclides(FRNs)of^(137)cs and^(210)pbex in an intensive agricultural catchment in North China.Sediment sources from surface and sub-surface soils were estimated from FRNs fingerprint and accounted for 62±7%and 38±7%respectively,while surface soil from land uses that originated from hillslope were identified by CssI fingerprint.Using a novel application of FRNs and CSSI sediment fingerprinting techniques,the dominant sediment source was derived from maize farmland(44±0.1%),followed by channel bank(38±7%).The sedimentation rate(13.55±0.30 t ha^(-1)yr^(-1))was quantifed by the^(137)cs cores(0-60 cm)at the outlet of this catchment.The total N and total P in sediment were both mostly derived from maize farmland and least from channel banks.The channel banks are significant sediment sources but contribute little to the input of sediment N and P for eutrophication.It implies that chemically-applied farmlands are the main hotspots for catchment erosion control and pollution prevention.The novel application of FRNs and CSSI techniques cost-effectively quantified sediment N and P loads from different sources with a single visit to the catchment,enabling rapid assessment for optimizing soil conservation strategies and land management practices.
