科尔沁沙地固定沙丘土壤水体积分数变化

利用2006-2009年5-9月科尔沁沙地固定沙丘0~150 cm土壤水体积分数监测数据及降水资料,采用偏度、峰度检验法检验了固定沙丘不同月及不同土层土壤水体积分数的正态性,并得到了其正态分布相关参数的估计值及其置信区间;同时,对不同土层、不同月及不同年间的土壤水体积分数变化和差异进行了分析。结果表明:(1)固定沙丘同一月的土壤水体积分数以显著性水平α=0.1通过正态分布的假设检验;固定沙丘土壤水体积分数的平均值范围1.82%~4.95%,主要集中在2%~4%;(2)受降水影响,固定沙丘7月土壤水体积分数较高,且与其他月的差异显著;7月土壤水体积分数均值和方差的点估计及置信水平为0.95的置信区间、统计特征均与其他月的有较大差异;(3)固定沙丘0~10 cm土壤水体积分数较低,且与其他土层有显著差异;而10~30 cm土壤水体积分数较高;(4)2008年土壤水体积分数较低,而2009年土壤水体积分数较高;除2007年与2008年土壤水体积分数没有显著差异外,其余年份间的土壤水体积分数均有显著差异。

Variation of Soil Moisture at Fixed Sand Dune in the Horqin Sandy Land

Based on observed data of soil moisture content (SW) at fixed sand dune (FD) in 0-150 cm and precipitation of May to September from 2006 to 2009, the normality of SW at FD in different month and different soil layer were tested by the skewness, kurtosis test method, and obtained the estimates of the relevant parameters and its confidence interval obeying normal distribution for SW; Moreover, we analyzed the change and difference of SW with different soil layer, different month and year. The results showed that: (1) SW of FD at the same month passed the hypothesis testing of normal distribution at the significance level of α=0.1; The averaged value of SW at FD ranged from 1.82% to 4.95%, and most concentrated in 2%-4%; (2) Influenced by precipitation, SW of FD was higher in July, and significant difference with other month; The estimates and confidence interval with confidence level of 0.95 for the mean and variance of SW at FD in July are quite different from other month; (3) SW of FD was lower at 0-10 cm and significant different from other soil layer; and SW was higher at 10-30 cm; (4). SW was lower in 2008, and higher in 2009; There was no significant difference for SW between 2007 and 2008, in addition to this, SW had significant difference in the other years.