Changes in The High-Latitude Headwater Basin of The Nenjiang River Basin, Northeast China, 1970s-2000s

Abstract The Nenjiang River Basin (NRB), an important wetland area in China, has experienced large-scale degradation of the wetland area and the evolution of land-use patterns over the last 50 years due to global warming, changes in precipitation patterns and anthropogenic activities, especially in the headwater basin of the NRB. In order to investigate these changes, temperature, precipitation, runoff, land-use/vegetation and wetland changes from 1970s-2000s were analyzed using the Mann-Kendall non-parametric test and Arcgis10.2 software. Our results show that a temperature increase was recorded in the headwater basin of the NRB, and precipitation showed an overall increasing trend which became more evident in the headwater basin. Runoff presented an increasing trend on the right side of the basin and a decreasing trend on the right side. The occupation of agricultural land on the wetland area and a decrease of forest and grassland areas did not result in a significant reduction in floodplain wetland area. These land-use changes, however, did have an impact on water supply shortages in the agricultural zone to the left side of the NRB.