基于前期降水量和蒸发量的土壤湿度预测研究

为了更好地了解和探讨土壤湿度预测方法，根据衡阳2009-2010年土壤湿度资料和相关气象资料，建立了基于前期降水量和蒸发量的土壤湿度预测模型，并进行试报和验证。结果表明：基于1 mm降水与蒸发的差建立的土壤湿度线性回归模型和基于1 mm降水量和1 mm降水与蒸发的差建立的土壤湿度逐步回归模型试报了2009年8-12月0~10 cm、10~20 cm、20~30 cm土层的土壤湿度，线性回归模型预报的平均相对误差分别为10.06%、5.56%、7.14%，逐步回归模型预报的平均相对误差分别为10.05%、5.59%、6.85%。2种模型预测的土壤湿度状况基本能反映旱情发展的动态趋势。模型可为准确预测土壤湿度的变化，为开展气象为农服务和防灾减灾提供参考。

Study on Soil Moisture Forecast Based on Previous Precipitation and Evaporation

In order to provide better understanding and studying on soil moisture forecast methods,according to the soil moisture and meteorological data of 2009-2010 in Hengyang City,soil moisture forecast models were built and validated based on previous precipitation and evaporation.Research showed that soil moisture forecast line regression model was built based on the difference between precipitation by 1mm and evaporation and stepwise regression model was built based on precipitation by 1 mm,the difference between precipitation by 1 mm and evaporation,the soil moisture in 8-12 months of 2009 was predicted.The average forecast error for soil layer 0-10 cm,10-20 cm and 20-30 cm was 10.06%,5.56% and 7.14%,respectively by line regression model.The average forecast error for soil layer 0-10 cm,10-20 cm and 20-30 cm was 10.05%,5.59% and 6.85%,respectively by stepwise regression model.The results for the soil moisture forecasted by 2 models revealed the developing tendency of the drought in Hengyang City.The models could predicted the change of soil moisture accurately,that provided references for carrying out meteorological services for farmers and disaster prevention and mitigation.