宜林荒山春季土壤含水率与气象因子的相关分析

Correlation Between Soil Moisture Content and Climatic Elements of a Calcareous Area in Southeastern Shanxi Province

利用4年观测资料,进行了晋东南石灰岩区宜林荒山春季土壤含水率与气象因子的相关分析.土壤解冻至6月上旬雨季到来之前土壤含水率逐渐降低,为土壤水分的跑墒阶段,这段时间坡向间、土层间的年际变化较大.经对17个气象因子的筛选,以气温、空气绝对湿度、降水量等9个因子与土壤含水率相关最紧密,每个气象因子按前5天、前10天、前20天三个时段,采用逐步回归方法,建立了阳坡、半阳坡、阴坡的5cm和20cm两个层次土壤含水率与气象因子的回归方程,复相关系数均在0.9以上,平均精度94.7％.

Data collected over a four year period demonstrating the correlation between soil moisture content and climatic elements in barren hills (suitable for afforestation) of a calcareous area of southeastern Shanxi was discussed.During the period from soil thaw to the first ten-day period of June (called the evaporation period),the soil moisture content decreased gradually.The yearly differences of soil moisture among different slope directions and soil depthes also were great.Through correlation analysis,nine climatic factors such as temperature,absolute air moisture,precipitation etc,were significantly correlated with the soil moisture content.The effect of climatic (actors on soil moisture is not synchronous,so the climatic factors of three time stages,5,10 and 20 days preceding the soil moisture testing were measured are calculated.By the use of stepwise regression,the regression equations of climatic factors of three time stages plus the soil moisture content at two soil depthes ( 5 cm,20cm) of three slope directions (south-facing,semi-south-facing and north-facing slopes) were respectively established and all of their coefficients of multiple correlation were above 90%,and average precision was 94.7%.