祁连山土地利用情景下生态系统水源供给特征

Characteristics of ecosystem water supply in the Qilian Mountains under land use scenarios

基于InVEST模型的水源供给模块,对祁连山区天涝池流域的水源供给能力进行估算,研究不同土地利用情景下水源供给的变化情况.结果表明:InVEST模型水源供给模块在本研究区具有较好的适用性,模拟相对误差为7.52%;在自然发展优先、经济发展优先和环境保护优先情景下,模型模拟水源供给量分别为2.51×10~6、3.16×10~6、2.18×10~6m^3;与当前情景相比,经济发展优先情景下,流域水源供给量增加,增幅约为25.78%,环境保护优先情景下,水源供给量减少,降幅约为13.37%;大力开展植树造林活动会使流域内水源供给能力减少,只关注水源供给前提下,当前关于祁连山区以增加森林面积为主的生态恢复策略值得重新思考.

A water yield module was used in In VEST model to estimate water yields in Tianlaochi Catchment in the Qilian Mountains under different vegetation distribution scenarios. The results showed that the module was applicable in assessing the water yields in the study area and the relative error was 7.52%, compared with the true value. The water yields of the catchment were 2.51 ×10^6, 3.16×10^6 and 2.18 × 10^6 m^3 under the natural development priority scenario, economic development priority scenario and ecological protection priority scenario, respectively. Compared with the current conditions the water yields under the economic development priority scenario increased by about 25.78%, whereas those under the ecological protection priority scenario decreased by about 13.37%. With the water yields in consideration,potential risks of water yield reduction makes an ecological restoration strategy with a massive afforestation program a necessity.