| In China, Henan province is a big agricultural produce province. Drought is one of the main influence factors of agricultural production in Henan. Soil moisture is an important index for the soil hydrological changes, it influence by the comprehensive effects of environmental factors, such as soil physical properties, precipitation, temperature and so on. So it is an important way for control the drought is describe the variation of soil moisture and the effect of meteorological factors on the change of soil moisture.The article studied the comparison of the soil moisture automatic observation station data and manual observation data in Henan Province in2012, studied the horizontal and vertical variation changes of soil moisture in the rainfall and no rainfall conditions, and the correlation analysis of soil moisture in each layer with the precipitation, soil temperature, evaporation and so on many environmental factors in different regions, to establish the relation model with the soil moisture automatic observation data and the corresponding environmental factor data station use of Henan Province in 2012.The main results are as follows:(1) It found that the difference of automatic observation data and artificial data was small. From the soil level, the difference of the observation data and the artificial observation data in different soil layers are different, the difference increases with the increase of soil layer. From the correlation coefficient of different stations sample serial, the low correlation coefficient of the site is concentrated in the west of Henan province.(2) The results show that each layer of soil moisture were the lowest in June in semi humid area, January-March and September, October soil moisture values are higher. The soil moisture of each layer was higher in humid region, and the soil moisture was stable in every month. With the increase of soil level, the soil moisture was increased. The seasonal fluctuation of soil moisture was obvious; the soil moisture was the lowest in summer soil in semi humid region. The change of soil moisture was not obvious in humid region, and was stable in each season.The spatial distribution of soil moisture was obvious, and the whole soil increased with the increase of longitude. The high values of soil moisture are concentrated in the southern part of Henan Province, and the low values are in the northwest of Henan province. From the stratification point of view, the overall soil moisture increases with the increase of soil levels. In the period of no rainfall, the variation of soil moisture of each layered are flat, the soil water deeply is slightly higher than shallow layer; fluctuation is different in different soil layers.(3) The variation regular pattern of soil moisture were analyzed, and the relationship between soil moisture and rainfall infiltration was explored by the soil moisture data of automatic observation stations in 2012 and the rainfall data in the same year of Zhengzhou. The article studied the relationship between precipitation and infiltration, and established the relationship equation between the infiltration of soil moisture and precipitation. The results showed that:there was a significant positive correlation between rain penetration depth and initial soil moisture content, and the rainfall intensity had a significant positive effect on the penetration rate in a certain degree; from the layered soil we could conclude that the impact of rainfall on each soil layer decreased with the increased of soil depth.(4) Establish the relation model between soil moisture and meteorological factors, through the study on the relationship between soil moisture and various meteorological elements. We found that effects of different meteorological factors to soil moisture are differently, the influence of the same meteorological elements on different levels is different. Through the study of influence factors with soil moisture on different regions, soil moisture in semi humid region is mainly affected by evaporation and the maximum temperature, layers of soil moisture decreases with the increase of evaporation and the rise of maximum temperature; the soil moisture in humid area is mainly affected by the temperature and decrease with the increase of temperature. |
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