Abstract: The concept of soil effective precipitation and soil quasi-evapotranspiration was introduced in this paper.The 9 grades of precipitation were determined according to water efficiency.Models of effective precipitation,ten-day period water change storing soil and soil water evapotranspiration were established.According to the models and index of soil moisture,soil moisture change in real-time was estimated.Further using every day precipitation of automatic weather station,the profit and loss of soil water and the changes of droughts and floods were observed in movement.The results provided a new ideas and methods for using the data of automatic weather station,observing soil moisture and droughts forecast.

Key words: Automatic weather station, Effective precipitation, Soil standard evapotranspiration, Soil moisture content monitoring