太湖流域平原区土壤水分动态分析

以太湖流域平原区两种土地利用方式(林地和菜地)为例,在长期定位观测土壤水分数据的基础上,采用时间序列法定量分析了土壤水分与降水之间的相关关系。结果表明:(1)降水量在时间上不相关,而各层土壤水分均为自相关序列;(2)降水与土壤水分之间存在一定的相关性,相关时长受季节、土壤深度、土地利用方式等的影响较为明显(1~8d不等);(3)林地相关时长的季节变化表现为:夏秋季春季冬季。随着土壤深度的增加,菜地土壤含水量与降水相关关系在夏秋季节呈减小趋势,而在冬春季节则相反。整体上林地降水对土壤含水量的有效影响时间长于菜地,且林地降水量与土壤含水量相关关系的规律性优于菜地。

Dynamic Analysis of Soil Water in Plain Area of Taihu Lake Basin

Based on the long time monitoring data, taking the two typical land-use types(vegetable land and forest) in the plain of Taihu Lake basin as an example, the correlation between soil moisture and precipitation was analyzed with the time series method. The results showed that:(1) Precipitation time series was temporally uncorrelated, soil moisture contents in different depths, however, were self-correlation series.(2) There was a relationship existed between soil moisture and precipitation, the related time was in the range of 1~8 days due to the influence of seasons, soil depths and land-use types.(3) The seasonal change of the related time in forest can be described as:summer and autumn >spring >winter. With the increase of soil depth, the relationship between soil moisture and precipitation showed a trend of decrease in summer and autumn. The correlation in winter and spring, however, were the opposite. In conclusion, the effective time of precipitation on soil moisture was longer in forest than in vegetable land, and the regularity of the relationship between soil moisture and precipitation in forest was much better than that in the vegetable land.