土地利用变化对海河流域典型区域的径流影响

为研究海河流域径流对土地利用变化的响应,以阜平流域、匡门口流域和界河铺流域为研究区,利用1970—2011年的水文气象资料,分析了不同土地利用的时空转移特征,然后结合SWAT(Soil and Water Assessment Tool)模型,设置4种土地利用情景,评价了土地利用变化对径流的影响。结果表明:模型能够较好地模拟全年及汛期月流量过程;多年径流量呈下降趋势,20世纪80年代到90年代中期呈波动性变化;不同的土地利用类型在时空上的转化呈现可逆性,主要是林地增加,草地减少,耕地略有增加;林地的增加和草地的减少会降低汛期径流量以及最大月径流量;汛期径流系数随着林地面积的增加而减小。合理地规划土地利用格局,对控制流域水文事件具有重要意义。

Effects of land use change on runoff in the typical areas in Haihe River basin

In order to research the reaction of the runoff of Haihe River basin towards the change of land use, Fuping basin, Kuangmenkou basin and Jiehepu basin were regarded as the research areas and the data of hydro meteorology from 1970 to 2011 were combined to analyze the space-time transfer characteristics of different land use. Moreover, four scenarios of land use were set in combination of SWAT (Soil and Water Assessment Tool) model and influence on runoff by the change of land use types was evaluated. Result showed that this model could better simulate monthly flow process of the whole year as well as in flood seasons. The runoff had experienced a gradual decrease for many years and it fluctuated from 1980s to the middle of 1990s. The transformation in time and space among different types of land use presented the reversibility and major changes included an increase in forest, a decrease in grassland and a little increase in agricultural land. The increase of forest and the decrease of grassland would cause a decrease of runoff in flood season and the maximum monthly peak discharge. The coefficient in flood season decreased with the increase of forest area. Therefore, it was very important to properly plan land use pattern so as to control watershed hydrological events.