The Prediction Model Of Soil Moisture Affected By Meteorologic Elements During Spring Sowing

Water has always been the main factor restricting agricultural production in Northeast China.In this paper,we constructed a soil moisture prediction model for the surface layer(0-10cm)in Northeast China according to control experiments of temperature and precipitation.Combined with other meteorological factors such as wind speed and saturation deficiency to analyze the processes of surface soil moisture exchanges by these factors.We selected Shenyang as the representative area,using 2016-2017(April-May)meteorological and soil data to evaluate the forecasting ability and applicability of the model.The results show that:(1)The surface soil moisture content decreased rapidly at first and then became slowly after each precipitation,and finally maintained at a relatively stable value.When the precipitation was small,the daily changes were small,but the time for the surface soil moisture to reach relative stability was short.When the temperature rose,the daily changes increases,and the time for the surface soil moisture to reach relative stability became shorter.(2)In addition to the temperature and precipitation,the wind speed and saturation deficiency had a linear correlation with surface soil water content.We constructed a surface soil moisture content prediction model during the spring sowing period in Northeast China according to four meteorological factors and combined with soil characteristics.(3)The prediction ability of the surface soil moisture content prediction model was verified by using the soil data of the spring sowing period of 2016-2017 in Shenyang area,and the precipitation part of the model was modified according to the predicted value will be overestimated on individual days.The correlation coefficient between the actual value and the predicted value of surface soil moisture predicted using the modified model predicted by the modified model was 0.781 meanwhile the root mean square error was 0.027cm3/cm3.It is indicated that the prediction model can predict the surface soil moisture content well.(4)The surface soil moisture content had certain sensitivity to precipitation,temperature and wind speed.The effects of precipitation on surface soil moisture content was positive;temperature and wind speed had negative effects.In summary,the surface soil water content prediction model has good predictive effects on the surface soil moisture content in the spring sowing period.It can be used as a model for predicting surface soil moisture content in Northeast China.