贵州典型喀斯特灌丛草坡类型区土壤水分及其影响因子研究

SOIL MOISTURE AND ITS CONTRIBUTING FACTORS AT THE SHRUB-GRASS ZONE IN KARST REGIONS

对贵州龙里灌丛草坡类型区2005—2006年度土壤水分及局地小气候进行了连续的定位观测,并通过相关分析等手段对土壤水分影响因子进行了分析.得出以下结论:1)大致呈现出三起两落的趋势,12—2月和9—11月为土壤水分缓慢积累期,2—4月和8—9月为土壤水分强烈消耗期,4—8月随着雨季的来临,降水量大,使得土壤水分迅速增加,为雨季土壤水分补充期;2)通过对土壤水分体积分数及其环境因子的相关分析得到,雨季,土壤水分体积分数主要受降水量的影响,而在非雨季,温度是主要的控制因子,偏相关系数达0.851(P<0.01),其次为相对湿度,偏相关系数为0.733(P<0.01),而与太阳辐射和地表温度的偏相关系数分别为0.525、0.241(P>0.05);3)通过对下垫面状况各异、气象条件基本一致的各实验点土壤水分规律的研究,发现土壤水分分布特征与地表植被覆盖状况有着重要的关系.

Based on observation at locations of shrub-grass zone in Karst region from Sept 2005 to A 2006, correlation analysis, with an emphasis on meteorological factors and soil water content, was employed analyze relationships among these different factors. Data show that： 1） Seasonal farmland soil moisture affect by rainfall, evaportranspiration and the status of shrub-grass zone used presented 8 peaks and two valleys; ug to ed 2） rainy seasons, the main factors were temperature〉relative humidity〉solar radiation 〉 surface temperature, and partial coefficients were 0.851（P〈0. 01）,0. 733（P〈0. 01） ,0.525 （P〉0.05）,0.241 （P〉0.05） respectively; 3） Analyzing relationships of soil moisture at different sites, state of the underlaying surface strongly affects soil moisture.