土地利用、覆盖变化对横排头以上流域径流的影响研究

Research on the Impact of LUCC on Runoff of Basin above Hengpaitou

在实际调查基础上,以1980年、1990年和2000年土地利用资料和流域内1980-2009年水文资料为基本支撑,利用遥感和地理信息系统技术,分析淠河流域横排头以上地区土地利用变化对径流变化的影响。结果显示,在研究区域内,草地面积持续稳定增加,耕地、水域、城镇用地和未使用地面积持续减少,林地面积先由大量增加到基本维持稳定。20世纪80年代以来,土地利用变化在不同阶段都使得年平均径流量增加。在年内分配上,汛期内总径流和地面径流减少,枯水期内总径流增加,地面径流略有减少;基流在所有月份均增加,而在汛期内增加更为明显。

On the basis of actual survey and sustained by the land use data in 1980 ,1990 and 2000 and the hydrologic data from 1980 to 2009 within the basin ,this paper analyzes the runoff variation in response to the change of land use above Hengpaitou ,Bihe Ba-sin .With the support of remote sensing and geo-information system ,we have made a series of conclusions .First ,the grassland area continues rising while the proportion of cultivated land ,water area ,urban land and untapped land decreases all the time ,and the woodland area experienced massive increase until leveled off at last .Second ,the annual runoff volume was raised at any period along with the change of land use from 1980s .Third ,in yearly distribution ,the volume of total runoff and the surface runoff is raised in flood season .In the drought period ,however ,the total runoff increases and the surface runoff decreases slightly .The base flow vol-ume augments in all 12 months and this trend is especially obvious in flood seasons .