潘家口水库流域土地利用变化的水文响应分析

Analysis of hydrological response to change of land use in Panjiakou reservoir watershed

以潘家口水库流域为研究区域,采用SWAT分布式水文模型定量评估土地利用变化对流域径流过程的影响。相对于1980年土地利用情景,2006年土地利用变化主要表现为耕地减少,林地和草地面积增大,而水域和城镇用地变化相对较小。利用3个水文站1986年1月至1999年12月的月径流实测数据进行模型的校准和验证。在不同土地利用情景下,对流域的天然径流过程进行模拟分析,模拟结果显示,与1980年土地利用情景相比,2006年土地利用情景下的多年平均径流减少11%;对于不同典型水文年份而言,土地利用变化对枯水年的影响最大,对丰水年和平水年的影响相当;土地利用变化对年径流的影响主要表现为汛期径流减少。潘家口水库流域水资源涵养能力有所增加。模拟研究土地利用变化对潘家口水库流域径流的影响对合理规划土地利用和流域水资源的综合管理具有现实意义。

Taking Panjiakou Reservoir watershed as study area ,the paper applied distributed mechanism hydrological model SWAT( soil and water assessment tool) to quantitatively evaluate the effects of land use change on runoff process in the watershed.The changes land use in 2006 mainly showed the reduction of agricultural land the increase of forest and pasture area compared with that in 1980 ,and there were lit-tle changes in water area and urban land.It used observed monthly flow data from Jan.1986 to Dec1999 at three hydrologic stations to calibrate and validate the model.It simulated the natural runoff processes in different land use scenarios.The results showed that compared with land use scenarios of 1980,the aver-age runoff of many years in 1986 decreased by eleven percent.For different typical hydrological years, the influence of land use change on runoff is the greatest in dry years and is general in wet years and mean years;the influence of land use change on runoff mainly indicated the decrease of runoff in flood season. The result shows that water conservation capacity of Panjiakou Reservoir watershed is increasing in resent years.The study on impacts of land use change on runoff in Panjiakou reservoir watershed has practical significance for the plan of reasonable land use and comprehensive management of local water resources.