摘要
Since the 1960s, dramatic changes have taken place in land-use patterns characterized by the persistent expansion of cultivated land and a continuous decrease in natural woodland and grassland in the arid inland river basins of China. It is very important to assess the effects of such land-use changes on the hydrological processes so vital for water resource management and sustainable development on the catchment scale. The Maying River catchment, a typical arid inland watershed located in the middle of the Hexi Corridor in northwest China, was the site chosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow, maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selected as the variables in the hydrological processes. Statistical-trend analysis and curvilinear regression were utilized to detect the trends in hydrological variables while eliminating the climatic influence. The relationship between cultivated land-use and hydrological variables was analyzed based on four periods of land-use variation data collected since 1965. A runoff model was established composed of two factors, i.e., cultivated land use and precipitation. The impact of land use changes, especially in the large ar- eas of upstream woodland and grassland turned into cultivated lands since 1967, has resulted in a mean annual runoff decrease of 28.12%, a base flow decline of 35.32%, a drop in the maximum peak discharge of 35.77%, and mean discharge decreases in spring and autumn of 36.05% and 24.87% respectively, of which the contribution of cultivated land expansion to the influence of annual runoff amounts to 77%-80%, with the contribution to the influence of spring discharge being 73%-81%, and that to the influence of base flow reaching 62%-65%. Thus, a rational regulation policy of land use patterns is vitally important to the sustainable use of water resources and the proper development of the entire catchment.
Since the 1960s, dramatic changes have taken place in land-use patternscharacterized by the persistent expansion of cultivated land and a continuous decrease in naturalwoodland and grassland in the arid inland river basins of China. It is very important to assess theeffects of such land-use changes on the hydrological processes so vital for water resourcemanagement and sustainable development on the catchment scale. The Maying River catchment, a typicalarid inland watershed located in the middle of the Hexi Corridor in northwest China, was the sitechosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow,maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selectedas the variables in the hydrological processes. Statistical-trend analysis and curvilinearregression were utilized to detect the trends in hydrological variables while eliminating theclimatic influence. The relationship between cultivated land-use and hydrological variables wasanalyzed based on four periods of land-use variation data collected since 1965. A runoff model wasestablished composed of two factors, i.e., cultivated land use and precipitation. The impact of landuse changes, especially in the large areas of upstream woodland and grassland turned intocultivated lands since 1967, has resulted in a mean annual runoff decrease of 28.12%, a base flowdecline of 35.32%, a drop in the maximum peak discharge of 35.77%, and mean discharge decreases inspring and autumn of 36.05% and 24.87% respectively, of which the contribution of cultivated landexpansion to the influence of annual runoff amounts to 77%—80%, with the contribution to theinfluence of spring discharge being 73%—81%, and that to the influence of base flow reaching62%—65%. Thus, a rational regulation policy of land use patterns is vitally important to thesustainable use of water resources and the proper development of the entire catchment.
作者
WANG Genxu1,3, ZHANG Yu2, LIU Guimin2 & CHEN Lin3 1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
2. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
3. Resource and Environment School, Lanzhou University, Lanzhou 730000, China
基金
This work was supported by the National Natural Science Foundation of China(Grant No.40171002)
the'Hundred People'Project of the Chinese Academy of Sciences under the leadership of Prof.Wang Genxu
the State Key Project(973)(Grant No.2003CB415201).
