基于前期有效降水推算耕作层土壤湿度的方法

土壤水分是研究水资源循环及干旱监测的重要指标。本文基于土壤水分平衡原理提出，在无灌溉的条件下，当前土壤含水量主要由前期有效降水决定，并利用荆州（1982—2006年）、随州和麻城（1993—2006年）3个站点的土壤湿度实测资料，建立了0-10cm、10—20cm土层的土壤湿度与前期有效降水量线性回归方程。模型检验效果较好，0-10cm土层的准确率在85％左右，10—20cm的准确率高于85％；在2007年湖北部分地区秋冬季干旱监测实际应用中准确率达93％以上。此模型与一般经验模型相比，不依赖于前期土壤湿度资料，适用范围更广、时效性强，更具有推广价值。

Method for Soil Moisture Calculation in Plough Layer Based on Antecedent Effective Rainfall

Soil moisture is one of the most important indexes on water resource circular studies and drought monitoring. Based on the soil water balance principle, the point that the main influential factor of the soil moisture was the antecedent effective rainfall under the situation of no irrigation was brought forward. The soil moisture data of Jingzhou in 1982 -2006, Suizhou and Macheng in 1993 -2006 were used to construct the linear regression equation between the effective rainfall and the soil moisture in the layers ofO - 10cm and 10 -20cm. The model checking results showed that the accuracy ratio of the forecast to the observed soil moisture was about 85% in the layer of 0 - 10cm and over 85% in the layer of 10-20cm, while the accuracy rate of the drought monitoring in and winter of 2007 in part areas of Hubei Province was over 93%. Compared with other empirical models, the model could be used without the antecedent soil moisture data, and it had more scope application and higher time-effect, so it was much easier to generalize.