Spatial and Temporal Distribution of Soil Moisture and Its Influence Factor Analysis in Sichuan Basin

This paper analyzed the seasonal spatial and temporal distribution characteristics of soil moisture and the effect of meteorological factors on it based on 10 cm meadow soil relative humidity,temperature precipitation and sunshine from agro-meteorological stations during the period 1996 ~ 2012 of the Basin region by statistical methods. The spatial distribution of shallow soil moisture was higher in south Sichuan Basin than that in north,and was higher in summer and autumn than that in spring and winter,especially highest in autumn. The temporal distribution of soil moisture was a weak decreasing trend in spring and summer,and an opposite in autumn and winter. There was a 4 ~ 6 year quasi-periodic in each season by Wavelet analysis. Soil moisture was reduced in south and northeast Sichuan Basin in seasons by climate tendency rate,which in other areas showed an increase trend. In Mianyang,soil moisture was significantly changed by climate change,and was 1. 4%/a in summer and autumn.Precipitation was greatest impact on shallow soil moisture in northwest Sichuan Basin where was more dry. However,in humid areas such as south Sichuan Basin and northeast Sichuan Basin,sunshine was the most factor impact on shallow soil moisture.