北江流域土地利用/覆盖变化对水文过程影响研究

Effect of LUCC on hydrological response in Beijiang basin

随着社会经济的快速发展,土地利用也发生了剧烈转变。通过采集北江流域2000年和2015年的土地利用/覆盖数据(L1和L2),基于2000年的土地利用情况,假设农业用地被建设用地取代(S1)和农业用地被森林取代(S2)两种极端土地利用情景;并构建分布式水文模型,研究了不同土地利用/覆盖对水文过程的影响。结果表明:农业用地和森林转换为建设用地,导致了径流、产水量和地表径流的增加,以及侧流量、地下水含量和蒸发量的减少;S1是L2情景的极端假设,因此各水文成分相对于L2情景变化更为明显,而S2情景相对于S1情景下的水文过程变化效果相反。不同土地利用情景下的水文响应表明,城市化以及退耕还林导致的土地利用变化都会对水文过程造成巨大影响。

With the rapid development of social economy,land use is undergoing strong transformation.In this paper,we collected LUCC data of Beijiang River basin in 2000 and 2015(L1 and L2),and hypothesized two extreme land use scenarios based on land use in 2000:S1(agricultural land replaced by construction land),S2(agricultural land replaced by forest).Also,distributed hydrological models were constructed to study the impact of different land use scenarios on hydrological processes.The results showed that:under L1 and L2 scenario,farmland and forest were converted to construction land,which resulted in increase of streamflow,water yield and surface runoff,but decrease of lateral flow,groundwater and evaportation.S1 scenario is an extreme hypothesis of L2 scenario,in which changes of hydrological process were more significant under S1 scenario.However,the changes of hydrological process under S2 scenario had the opposite effect compared with S1 scenario.Therefore,hydrological response under different LUCC showed that land use/coverage change due to urbanization and returning farmland to forests would have a huge influence on the hydrological process.