植被恢复影响下河川基流的广义水资源效应变化研究——以黄河上游北川河流域为例

Variation in generalized water resources effect of river base stream under the influence of vegetation recovery——Case of Beichuan river basin in upstream of Yellow River

针对当前水资源评价中基流量不能反映水循环过程中全部有效水量的问题,从广义水资源的角度出发,引入经济学的乘数效应理论,探索创建了基于水循环过程的水资源效应评价模型,结合黄河上游北川河流域1970~2020年的降水、径流数据,评价了植被恢复前后典型时期内河川基流量及其在水循环过程上的广义水资源效应变化。结果表明:大规模植被恢复引起北川河流域水循环条件发生改变,基流产流能力增强,平均基流系数由1970~1980年的0.128增加至2010~2020年的0.147,更多降水参与长周期的降水-土壤水-地下水-基流的水循环过程;单位基流量(10mm)在整个循环路径上的广义水资源效应由57.80mm增加至83.91mm,增加比例为45.17%,水循环变化引起降水-基流循环路径上的广义水资源效应显著提高。

In response to the problems in current water resource evaluation, that the base stream cannot reflect all effective water in the process of water circulation, and from the perspective of generalized water resources, a water resource effect evaluation model based on water circulation evolution was created by learning the multiplier effect theory in economics. Based on the precipitation and runoff data of the Beichuan river basin in upper reaches of Yellow River, the change of base stream and its general water resource effect in the process of water circulation in two typical periods before and after vegetation recovery were evaluated. The results show that the water circulation conditions in Beichuan river basin have changed owing to the large-scale vegetation recovery. The average base stream coefficient during 1970-1980 was 0.128, and it is increased to 0.147 during 2010-2020, which shows the enhanced base stream output capacity. It means that more precipitation involved in the long-term water circulation process: precipitation-soil water-groundwater-base stream. The generalized water resources effect on the whole water circulation process of the unit base stream(10 mm) increasesd from 57.80 mm to 83.91 mm, and the increase amplitude was 45.17%,which indicates a significant improvement in the generalized water resources effect in the whole water circulation process caused by the change of water circulation.