A non-dimensional relative sensitivity coefficient was employed to predict the responses of reference crop evapotranspiration (ET0) to perturbation of four climate variables in Tao'er River Basin of the northeaste...A non-dimensional relative sensitivity coefficient was employed to predict the responses of reference crop evapotranspiration (ET0) to perturbation of four climate variables in Tao'er River Basin of the northeastern China. Mean monthly ET0 and yearly ET0 from 1961 to 2005 were estimated with the FAO-56 Penman-Monteith Equation. A 45-year historical dataset of average monthly maximum/minimum air temperature, mean air temperature, wind speed, sunshine hours and relative humidity from 15 meteorological stations was used in the analysis. Results show that: 1) Sensitivity coefficients of wind speed, air temperature and sunshine hours were positive except for those of air tem- perature of Arxan Meteorological Station, while those of relative humidity were all negative. Relative humidity was the most sensitive variable in general for the Tao'er River Basin, followed by sunshine hours, wind speed and air tem- perature. 2) Similar to climate variable, monthly sensitivity coefficients exhibit large annual fluctuations. 3) Sensitivity coefficients for four climate variables all showed significant trends in seasonal/yearly series. Also, sensitivity coefficients of air temperature, sunshine hours and wind speed all showed significant trends in spring. 4) Among all sensitiv- ity coefficients, the average yearly sensitivity coefficient of relative humidity was highest throughout the basin and showed largest spatial variability. Longitudinal distribution of sensitivity coefficients for air temperature, relative hu- midity and sunshine hours was also found, which was similar to the distribution of the three climate variables.展开更多
The Taoer River basin is the epitome in the west of Northeast China and it is one of the most fragile and sensitive ecoregions. Thus, protection of water quality of the Taoer River is important. Not only point source ...The Taoer River basin is the epitome in the west of Northeast China and it is one of the most fragile and sensitive ecoregions. Thus, protection of water quality of the Taoer River is important. Not only point source pollution but non-point source (NPS) pollution results in deteriorating water quality. In this study, long-term hydrologic impact assessment model was used to evaluate the impacts of land use change impacts on NPS pollution, and the replacement cost method was used to calculate the economic loss caused by NPS pollution. Through analyzing the NPS pollutant loads of different land categories and the economic loss, the article puts forward that there exists a close relationship between land-use types and NPS pollution, and agricultural pollution is the main component of the NPS pollution in this area. The results of this study can provide decision-making basis for agricultural development and land-use change.展开更多
Baseflow,a component of the total streamflow,plays a key role in maintaining aquatic habitats,particularly during extreme drought events.This study investigated baseflow response to a prolonged and extreme meteorologi...Baseflow,a component of the total streamflow,plays a key role in maintaining aquatic habitats,particularly during extreme drought events.This study investigated baseflow response to a prolonged and extreme meteorological drought event in the Baiyangdian Basin(BYD basin),a temperate water-limited basin in North China.Applying a precipitation series,piecewise regression was used to determine this extreme meteorological drought event,while the Automatic Baseflow Identification Technique(ABIT)was used to estimate a recession parameter(α),which was used to isolate baseflow from total streamflow.Results showed that:1)annual precipitation exhibited significant decreasing trends(P<0.05)with an average change of–1.81 mm/yr^(2).The precipitation deficit revealed that the start and end date of the extreme meteorological drought event was from August 1996 to May 2011,respectively,persisting for a total of 178 months(roughly 15 yr);2)hydrological drought(including streamflow and baseflow)lagged behind meteorological drought while predictably persisting longer than extreme meteorological drought(i.e.,precipitation);and 3)baseflow decreased dramatically under meteorological drought at both seasonal and annual scales,resulting in significantly decreasing trends during drought periods.Findings from this study confirmed that hydrological events caused by extreme meteorological drought can alter the magnitude and duration of baseflow and total streamflow,which will have an inevitable influence on aquatic ecosystems.展开更多
基金Under the auspices of National Natural Science Foundation of China (No. 40571029)
文摘A non-dimensional relative sensitivity coefficient was employed to predict the responses of reference crop evapotranspiration (ET0) to perturbation of four climate variables in Tao'er River Basin of the northeastern China. Mean monthly ET0 and yearly ET0 from 1961 to 2005 were estimated with the FAO-56 Penman-Monteith Equation. A 45-year historical dataset of average monthly maximum/minimum air temperature, mean air temperature, wind speed, sunshine hours and relative humidity from 15 meteorological stations was used in the analysis. Results show that: 1) Sensitivity coefficients of wind speed, air temperature and sunshine hours were positive except for those of air tem- perature of Arxan Meteorological Station, while those of relative humidity were all negative. Relative humidity was the most sensitive variable in general for the Tao'er River Basin, followed by sunshine hours, wind speed and air tem- perature. 2) Similar to climate variable, monthly sensitivity coefficients exhibit large annual fluctuations. 3) Sensitivity coefficients for four climate variables all showed significant trends in seasonal/yearly series. Also, sensitivity coefficients of air temperature, sunshine hours and wind speed all showed significant trends in spring. 4) Among all sensitiv- ity coefficients, the average yearly sensitivity coefficient of relative humidity was highest throughout the basin and showed largest spatial variability. Longitudinal distribution of sensitivity coefficients for air temperature, relative hu- midity and sunshine hours was also found, which was similar to the distribution of the three climate variables.
基金supported by the Key Project of Knowledge Innovation Program of CAS(Grant No.KZCX2-YW-Q06-1)
文摘The Taoer River basin is the epitome in the west of Northeast China and it is one of the most fragile and sensitive ecoregions. Thus, protection of water quality of the Taoer River is important. Not only point source pollution but non-point source (NPS) pollution results in deteriorating water quality. In this study, long-term hydrologic impact assessment model was used to evaluate the impacts of land use change impacts on NPS pollution, and the replacement cost method was used to calculate the economic loss caused by NPS pollution. Through analyzing the NPS pollutant loads of different land categories and the economic loss, the article puts forward that there exists a close relationship between land-use types and NPS pollution, and agricultural pollution is the main component of the NPS pollution in this area. The results of this study can provide decision-making basis for agricultural development and land-use change.
基金Under the auspices of the Major Science and Technology Program for Water Pollution Control and Treatment(No.2018ZX07110001)National Key Basic Research and Development Project(No.2017YFC0404505)National Natural Science Foundation of China(No.42071129,41771042,51579008)。
文摘Baseflow,a component of the total streamflow,plays a key role in maintaining aquatic habitats,particularly during extreme drought events.This study investigated baseflow response to a prolonged and extreme meteorological drought event in the Baiyangdian Basin(BYD basin),a temperate water-limited basin in North China.Applying a precipitation series,piecewise regression was used to determine this extreme meteorological drought event,while the Automatic Baseflow Identification Technique(ABIT)was used to estimate a recession parameter(α),which was used to isolate baseflow from total streamflow.Results showed that:1)annual precipitation exhibited significant decreasing trends(P<0.05)with an average change of–1.81 mm/yr^(2).The precipitation deficit revealed that the start and end date of the extreme meteorological drought event was from August 1996 to May 2011,respectively,persisting for a total of 178 months(roughly 15 yr);2)hydrological drought(including streamflow and baseflow)lagged behind meteorological drought while predictably persisting longer than extreme meteorological drought(i.e.,precipitation);and 3)baseflow decreased dramatically under meteorological drought at both seasonal and annual scales,resulting in significantly decreasing trends during drought periods.Findings from this study confirmed that hydrological events caused by extreme meteorological drought can alter the magnitude and duration of baseflow and total streamflow,which will have an inevitable influence on aquatic ecosystems.
