摘要
在单层土壤水分模型基础上，建立起针对于黔中部典型喀斯特地区的0—15cm、15～40cm两层土壤水分模拟模型。在此基础上，依托遥感和GIS手段，将模型扩展到区域尺度上，模拟出黔中部典型喀斯特地区2005—10～2006—05日尺度上0～15cm、15～40cm土壤水分动态转化规律，并以实测值进行了验证。结果表明：①构建模型在数据获取上比较容易，使其实际的可操作性得到加强；②黔中部典型喀斯特地区不同植被类型下土壤水分变化特征有着重要的差异。从土壤水分变化幅度上看：农用地〉灌丛〉草地；从土壤水分垂直变化规律上看，灌丛和草地的0～15cm层土壤水分含量低于15～40cm层，水分梯度为正，而农用地相反；从土壤保水性上来看，草地〉灌丛〉农用地；③不同植被类型季节变化表现出同样的特征：12—2月日土壤含水量平均值大于其它月份日均值，主要是由于冬季贵州地区降水丰富，再加上气温低，蒸（散）发量小；月相变化，10～2月为土壤水分缓慢积累期，2～4月为土壤水分强烈消耗期，4～5月为雨季土壤水分补充期。
The transport flux of soil moisture between soil and vegetation, soil and native rock determines the vitality of the soil ecosystem in Karst areas. And it is also the key dynamic factor for the soil degradation . So the studies on the modeling of the water transport flux between these interfaces from the facial scale are important to reveal quantitatively the major mechanism of the soil degradation and the eco-environmental deterioration in the Karst area. Many different models about soil moisture have been established for different areas. The paper introduces a two-layer soil moisture model based on the single-layer model and applies the model to the facial scale of the typical scrub-grass zone in Karst area of Guizhou Province. In the facial scale, the paper modulates the two-layer soil moisture conversion of motion and reveals the soil moisture variation quantitatively. The main results are indicated as follows ： 1 ） Different types of vegetation cover have different laws of soil moisture transport, so this study has chosen the shrubland, the grassland and the cropland to compare the laws of soil moisture transport, the initial content right after precipitation is in the order of corn field 〉 shrubland 〉 grassland; but at the following descending rate, grassland 〉 shrubland 〉 corn field ; 2 ） Through the analysis of the laws of soil moisture in the shrubland and the grassland, the descending rate of the soil moisture in the grassland is slower than in the shrubland, and its water retention property is strong; the grassland vegetation is different from other regions, and appears very adaptable. 3 ） The seasonal soil moisture variation of farmland affected by rainfall, evaportranspiration and the status of shrub-grass zone used has presented three peaks and two valleys.
出处
《自然资源学报》
CSCD
北大核心
2009年第4期650-662,共13页
Journal of Natural Resources
基金
国家重点基础研究发展计划项目(2005CB422200)
国家自然科学基金项目(40671123)
“高等学校学科创新引智计划资助”(NO.B06004)
长江学者与创新团队发展计划协助
