Based on monthly runoff and climate datasets spanning 2000–2024,this study employed the Theil–Sen’s slope estimation,Mann–Kendall(M–K)trend test,as well as Pearson correlation and Spearman rank correlation analys...Based on monthly runoff and climate datasets spanning 2000–2024,this study employed the Theil–Sen’s slope estimation,Mann–Kendall(M–K)trend test,as well as Pearson correlation and Spearman rank correlation analyses to systematically examine the spatiotemporal patterns of runoff and its climatic driving mechanisms across Tajikistan,providing a scientific basis for sustainable water resource utilization and management in the study area.Results indicated that during 2000–2024,the annual runoff in Tajikistan exhibited statistically non-significant long-term trend(P=0.76),while displaying pronounced seasonal variability and strong spatial heterogeneity.Spring and summer average runoff primarily exhibited slight declining tendencies,while winter average runoff exhibited pronounced reduction in localized regions,such as the Syr Darya Basin,the Vakhsh River Basin,and the lower reaches of the Zeravshan River Basin.Precipitation emerged as the dominant positive driver of runoff,exhibiting moderate to strong positive correlations across over 78.00%of the country,whereas potential evapotranspiration consistently functioned as a negative driver.Rising temperatures exerted a dual competitive effect on runoff:in high-elevation,glacier-covered regions,rising temperatures temporarily increased runoff by accelerating glacier melt;however,at the national scale,the negative impact of rising temperature on runoff has played a slightly dominant role to a certain extent by enhancing evapotranspiration.Collectively,these results indicated that the present stability of runoff in Tajikistan is strongly dependent on the short-term compensatory effects of glacier melt and the risk of future runoff decline is likely to intensify as glacier reserves continue to diminish.This study provides a critical scientific evidence to inform sustainable water resource management in Tajikistan and underscores the need for glacier conservation and integrated water resource management strategies.展开更多
Sanjiang Plain,located in the northeast of Heilongjiang Province,is one of the important grain producing areas in Heilongjiang Province,which has made great contributions to China's grain industry.However,the rapi...Sanjiang Plain,located in the northeast of Heilongjiang Province,is one of the important grain producing areas in Heilongjiang Province,which has made great contributions to China's grain industry.However,the rapid development of agriculture has increased the demand for water resources,and the water cycle process has been damaged,which has caused a series of problems,and the adverse effects have aroused great concern from all sides.In order to study the evolution law of precipitation and runoff in the lower Songhua River basin of Sanjiang Plain,the monthly precipitation data of Fujin,Jiamusi and Yilan meteorological stations and the measured runoff data of Jiamusi and Changjiangtun hydrological stations of the Songhua River from 1956 to 2011 were used.Mann-Kendall method,Hurst index method,sliding T test and wavelet analysis were used to analyze the trend,mutability and periodicity of precipitation and runoff evolution.The results show that the annual precipitation and runoff of the lower Songhua River basin in Sanjiang Plain showed a downward trend in the past 56 years(1956-2011);the mutation time of precipitation at Fujin Station,Jiamusi Station and Yilan Station was 1987,1959 and 2007,1973,respectively,the mutation time of runoff at Jiamusi Station and Changjiangtun Station appeared in 1967 and 1988;the first main periods of the annual precipitation wavelets are 42 years,54 years and56 years,respectively,and the periods are about 28-31 years,36-39 years and 36-38 years,the annual runoff of Jiamusi Station has the first main period of 57 years and the period is about 37-40 years,and the annual runoff of Changjiangtun Station has the first main period of 35 years and the period is about 20-24 years;the freeze-thaw process has significant influence on runoff in the study area.The results of this study have practical significance for rational planning and utilization of surface water resources and joint operation of surface water and groundwater in Sanjiang Plain.展开更多
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0720203)the National Key Research and Development Program of China(2023YFF0805603).
文摘Based on monthly runoff and climate datasets spanning 2000–2024,this study employed the Theil–Sen’s slope estimation,Mann–Kendall(M–K)trend test,as well as Pearson correlation and Spearman rank correlation analyses to systematically examine the spatiotemporal patterns of runoff and its climatic driving mechanisms across Tajikistan,providing a scientific basis for sustainable water resource utilization and management in the study area.Results indicated that during 2000–2024,the annual runoff in Tajikistan exhibited statistically non-significant long-term trend(P=0.76),while displaying pronounced seasonal variability and strong spatial heterogeneity.Spring and summer average runoff primarily exhibited slight declining tendencies,while winter average runoff exhibited pronounced reduction in localized regions,such as the Syr Darya Basin,the Vakhsh River Basin,and the lower reaches of the Zeravshan River Basin.Precipitation emerged as the dominant positive driver of runoff,exhibiting moderate to strong positive correlations across over 78.00%of the country,whereas potential evapotranspiration consistently functioned as a negative driver.Rising temperatures exerted a dual competitive effect on runoff:in high-elevation,glacier-covered regions,rising temperatures temporarily increased runoff by accelerating glacier melt;however,at the national scale,the negative impact of rising temperature on runoff has played a slightly dominant role to a certain extent by enhancing evapotranspiration.Collectively,these results indicated that the present stability of runoff in Tajikistan is strongly dependent on the short-term compensatory effects of glacier melt and the risk of future runoff decline is likely to intensify as glacier reserves continue to diminish.This study provides a critical scientific evidence to inform sustainable water resource management in Tajikistan and underscores the need for glacier conservation and integrated water resource management strategies.
基金funded by Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences commissioned the project Research and Application of Key Technologies of Water Resources Allocation in Ten Million mu Irrigated Area of Sanjiang Plain,grant number XDA28100105。
文摘Sanjiang Plain,located in the northeast of Heilongjiang Province,is one of the important grain producing areas in Heilongjiang Province,which has made great contributions to China's grain industry.However,the rapid development of agriculture has increased the demand for water resources,and the water cycle process has been damaged,which has caused a series of problems,and the adverse effects have aroused great concern from all sides.In order to study the evolution law of precipitation and runoff in the lower Songhua River basin of Sanjiang Plain,the monthly precipitation data of Fujin,Jiamusi and Yilan meteorological stations and the measured runoff data of Jiamusi and Changjiangtun hydrological stations of the Songhua River from 1956 to 2011 were used.Mann-Kendall method,Hurst index method,sliding T test and wavelet analysis were used to analyze the trend,mutability and periodicity of precipitation and runoff evolution.The results show that the annual precipitation and runoff of the lower Songhua River basin in Sanjiang Plain showed a downward trend in the past 56 years(1956-2011);the mutation time of precipitation at Fujin Station,Jiamusi Station and Yilan Station was 1987,1959 and 2007,1973,respectively,the mutation time of runoff at Jiamusi Station and Changjiangtun Station appeared in 1967 and 1988;the first main periods of the annual precipitation wavelets are 42 years,54 years and56 years,respectively,and the periods are about 28-31 years,36-39 years and 36-38 years,the annual runoff of Jiamusi Station has the first main period of 57 years and the period is about 37-40 years,and the annual runoff of Changjiangtun Station has the first main period of 35 years and the period is about 20-24 years;the freeze-thaw process has significant influence on runoff in the study area.The results of this study have practical significance for rational planning and utilization of surface water resources and joint operation of surface water and groundwater in Sanjiang Plain.
