嫩江流域土地覆被变化对径流量的影响分析

Effect of Landcover Change in Nei Jiang Watershed on Runoff Volume

以泥鳅河和科洛河流域为例分析了土地利用/土地覆被变化与河流径流量的关系。森林覆被变化导致了流域用水量的减少,而这部分并没有形成地表径流,而是存储在了森林和草地转变成的沼泽湿地中。科洛河流域耕地和林地面积的减少增加了地表径流,而且林地变化的影响大于耕地的变化。流域土地覆被变化与流域河流径流量的关系复杂,并非单一的覆被类型变化起主导作用,而是各种变化耦合作用影响了河流径流,但其中影响最为显著的是沼泽湿地的变化。

Taking the case of Niqiu river and Keluo river, the relation of land use/cover change with river runoff is discussed. When total precipitation increases in Niqiu river watershed, surface runoff decreases. The change of forest cover results in decreasing of evaporative capacity. However, superfluous water has not formed surface runoff but was stored in mire wetland transformed from forest and grass land. The surface runoff was increased in Keluo river watershed because the forest area decreased. Forest change affects surface runoff more than farmland change. The relation of land use /cover change affecting river runoff is complicated, and it is not the result of unique land use/cover change, but the coupling operation of land use/cover change which affects river runoff. In general, the change of marsh is most effective in all the change.