基于Sufer7.0的黄河流域不同旱作类型区土壤水分动态变化的比较

土壤水分是土地持续利用、水资源规划与管理及节水农业技术研究的基础,土壤水分的动态变化已经成为前沿研究领域的热点之一。论文以黄河流域43个国家级农气站点资料为数据基础,以Sufer7.0为技术手段,就不同旱作类型区土壤水分季节和垂直变化动态进行了比较分析。研究结果表明:①由半干旱偏旱区→半干旱区→半湿润偏旱区→半湿润区土壤水分含量的季节变化呈逐渐增加趋势,而且半干旱偏旱区和半干旱区,因大量失墒的时间长、耗水强度大而引起的干旱比半湿润偏旱区和半湿润区更为强烈;②不同旱作类型区土壤水分垂直变化的趋势均表现为上层变化幅度较下层大。且由干旱区→半干旱偏旱区→半干旱区→半湿润偏旱区→半湿润区,表层0～5cm→下层50～100cm的变化幅度逐渐减小。同时,可将土壤含水量从上到下的变化趋势分为增长型、降低型和波动型三种情况;③黄河流域土壤水分活跃变化层大致为0～30cm,缓慢变化层为30～100cm,相对稳定层为>100cm土层。活跃变化层由干旱区向半湿润区依次加厚,从0～5cm到0～30cm。

Comparison of Soil Moisture Dynamics Based on Sufer7.0 between Different Dry Farming Areas in the Yellow River Basin

Soil moisture is an important basis for sustainable use of land,planning and manage-ment of water resources and water-saving technique in agriculture,so soil moisture has become one of the focuses in the study of Global Climate Change.According to the soil moisture data at 43 national level agrometeorological stations and based on Sufer7.0 technology,the seasonal and vertical variations of soil water contents between different dry farming areas during the last 20 years are compared in this report.The results indicate that (1)Soil moisture increases gradually from dry semi-arid area to semi-arid area,dry semi-humid area and semi-humid area,and the dru-ness is more serious in dry semi-arid area and semi-arid area than that in dry semi-humid area and semi-humid area because of the long period of soil moisture loss and large quantity of water consumption.(2)In views of vertical changes of soil moisture,it is showed that the variation range of upper layers is greater than that of lower in the different dry farming areas in the Yellow River Basin.Moreover,the variation range from 0-5cm to 50-100cm reduces gradually from arid area,dry semi-arid area,semi-arid area,dry semi-humid area to semi-humid area.Moreover,the variation tendency of soil moisture from top to bottom can be divided into three types i.e.,increasing type,reducing type and fluctuating type.(3)The vertical changing range of soil moisture in the Yellow River Basin can be roughly divided into three layers;the active changing layer lying between 0-30cm,the slow changing layer between 30-100cm,and the relatively stable layer under surface soil of 100cm.Moreover,the thickness of active changing layer increased gradually from arid area to semi-humid area and changed from 0-5cm to 0-30cm.