论文部分内容阅读
基于DEM数据和土壤分类、土壤属性、土地利用分类、植被属性和观测气象数据,利用分布式水文模型SWAT(Soiland Water Assessment Tool),对陕西区域进行了土壤湿度模拟和检验.模拟土壤湿度与实际观测土壤湿度的对比分析表明:SWAT较好的模拟了区域土壤湿度的变化特点及其长期趋势,且对多气候类型及复杂地形区域的土壤含水量时空变化有较强的模拟能力;表层土壤湿度在植被状况好的陕南地区和地形性降水明显的秦岭山地等区域量值较大,而深层土壤湿度较大值出现在河流及平原地区;1951～2004年土壤湿度变化总体上不同深度的土壤湿度均呈下降趋势,深层下降趋势较表层表现更明显,秦岭以北地区比以南地区表现更明显;土壤干化趋势的强度深层大于表层,秦岭以北地区大于以南地区,土壤干化(土壤湿度减小的趋势)的范围深层亦大于表层,且多分布于秦岭以北地区.与NCEP和ERA40再分析土壤湿度数据对比分析表明,SWAT模拟的土壤湿度日变化、月和年平均值的变化趋势均优于NCEP和ERA40的土壤湿度变化趋势.
Based on the DEM data and soil classification, soil attributes, land use classification, vegetation attributes and observational meteorological data, soil moisture was simulated and tested in Shaanxi Province using the distributed hydrological model SWAT (Soiland Water Assessment Tool) The comparative analysis of observed soil moisture shows that SWAT simulates the characteristics of soil moisture change and its long-term trend, and has strong simulation ability for the temporal and spatial variations of soil moisture in multi-climate types and complex terrain areas. The surface soil moisture In the areas of southern Shaanxi with good vegetation status and Qinling Mountains with obvious topographic precipitation, larger values of soil moisture in deep areas appeared in rivers and plains. In the period from 1951 to 2004, soil moisture varied widely in different depths The trend of deep descent was more obvious than that of the surface layer, and the area north of the Qinling Mountains was more obvious than that of the south area. The intensity of soil desiccation trend was deeper than the surface layer. The area north of the Qinling Mountains was larger than the south area and the soil was dry The trend of decreasing soil moisture is deeper than the surface layer and distributed in the area north of the Qinling Mountains. The comparative analysis of NCEP and ERA40 reanalysis soil moisture data shows that the diurnal variation of soil moisture, the monthly and annual average values of SWAT simulation are better than the changes of soil moisture of NCEP and ERA40.