拒马河流域年季月径流量对土地利用变化的响应

Response of annual,seasonal and monthly runoff to the land use change in Juma River Basin

为探究年、季、月多时间尺度径流量对土地利用变化的响应,以紫荆关水文站以上的拒马河流域为研究对象,构建拒马河流域WEP-L分布式水文模型,采用情景模拟分析方法设置9类土地利用变化情景定量分析土地利用变化对径流量的影响。结果表明:WEP-L模型在拒马河流域适用性较好;退耕还林将减少年径流量,并随着森林覆盖率的增加,径流量减少更为剧烈,森林覆盖率每提高10%,径流量减少13.10 mm;弃耕撂荒和火灾伐木将使径流量增大;季节径流量对土地利用变化的响应程度呈现夏季>秋季>冬季>春季;月径流量响应结果表现为6-9月变化较大,尤其是7月份最为剧烈,而3和4月较小。研究结果对于流域土地利用合理规划具有重要意义。

In order to explore the response of annual,seasonal and monthly runoff to the land use change,we chose the Juma River Basin as the study area,and established the WEP-L(water and energy transfer processes in large river basin)model of this basin.With this model,nine scenarios of land use changes were set to quantitatively analyze the influences of land use change on the runoff.The results showed that the WEP-L model was applicable to the runoff simulation of the Juma River Basin.Returning farmland to forest would reduce the annual runoff,and with the increase of forest coverage rate,the runoff decrease would be more significant.When the forest coverage rate increased by 10%,the runoff decreased by 13.10%.However,abandoned land and fire logging would increase the runoff.The response of seasonal runoff to the land use change was summer>autumn>winter>spring.The response of monthly runoff was greater from June to September,especially in July,while lower in March and April.The research results can provide a valuable reference for the planning of land use pattern in this basin.