基于下垫面遥感资料的海河流域水文类型分区划分

以海河流域为研究对象,根据1956—2005年的年降雨量和水面蒸发资料、DEM、土地利用、土壤和植被覆盖遥感图,提取了反映下垫面条件和气候特征的物理因子,并以此作为分区指标,以子流域为划分单元,依据下垫面条件和气候因子的相似性和差异性,采用地理信息系统和多元统计分析的方法,将海河流域内1 399个子流域划分7类水文类型分区(HTR),并分析了各水文类型分区的空间分布特征及产汇流机制。其中HTR1、HTR2和HTR4位于平原地区,土地利用类型以耕地为主,其他水文类型分区位于山区和丘陵区。HTR1耕地面积比例最大;HTR2土壤透水性最差,易产生超渗地表径流;HTR3土壤透水性最好,易产生地下径流和壤中流;HTR4年蒸发量较大,年降雨量较小,气候最干旱;HTR5和HTR6土地利用类型分别以草地和林地为主;HTR7年降雨量较大,年蒸发量较小,气候最湿润。分区成果明确地反映了流域的下垫面情况及气候条件,分区结果与流域的地形地貌非常吻合,也反映了流域水文特征的分布规律。通过分析水文类型分区内典型流域的下垫面和气候情况以及水文特征,阐述了分区结果的准确性及合理性,为海河流域水文特征的研究及水资源评价提供了依据。

Hydrologic Type Regions Delineation of Haihe River Basin Based on Remote Sensing Data of Underlying Surface Cover

Taking the Haihe River Basin as the study area, based on the annual rainfall and water surface evaporation data of 1956-2005, digital elevation model and the remote sensing data of land use, soil and vegetation cover, the physical factors which reflect underlying surface conditions and climate characteristics were extracted in geographic information system(GIS), and then the underlying surface conditions and climate characteristics were taken as the regionalization indexes. Using GIS and multivariate statistical analyses, 1399 sub-basins of the Haihe River Basin were assigned to 7 hydrologic type regions(HTR) according to their similarities and differences of underlying surface conditions and climate factors. We also analyzed the spatial distribution and hydrological characteristics of each region. HTR1, HTR2 and HTR4 are located in plain area where the main land use type is cultivated land, and other HTRs are located in mountainous and hilly regions. The area proportion of agricultural land in HTR1 is the largest; the soil permeability of HTR2 is the worst and surface runoff over infiltration is easily generated; the soil permeability of HTR3 is the best, and subsurface runoff and interflow are more expected to happen; HTR4 has lager annual evaporation, smaller annual rainfall, and the driest climate; the main land use type of HTR5 and HTR6 is grassland and forestland respectively; HTR7 has smaller annual evaporation, larger annual rainfall, and the wettest climate. The result of hydrologic type regions delineation is very anastomotic with the landforms of watershed, explicitly reflects the underlying surface and climate factors, and reflects the distribution regularities of basin’s hydrologic characteristics. Then the result was verified to be accurate and rational by analyzing the underlying surface and climate factors of typical watersheds in hydrologic type regions, and it could provide fundamental basis for water resources assessment and study of hydrologic characteristics in the Haihe River Basin.