Research on the Evolutionary Law of Runoff in the Nenjiang River Basin in Recent 45 Years

摘要

This paper analyzes the evolutionary features of annual runoff in the Nenjiang River Basin in Northeast China during the 45 years from 1956 to 2000 using the random hydrologic method. The results indicate that the hydrologic cycle of runoff in the basin is 32 years. On the whole, there exists no significant runoff tendency in the 45 years. Furthermore, the paper also studies the level of human water consumption in the basin, and the results show the general extent of impact of mankind water consumption on the water cycle in the basin is 5%, but it varies greatly in different subbasins. For example, the impact factor in the Taoer River subbasin is up to 16%, showing a higher human water consumption level. In terms of annual runoff analysis, the impact factor during the 1970s in the whole basin is higher than that in any other decade, reflecting a higher extent of impact of human water consumption on the water cycle in the basin during a low flow period.