Study on the Assessment Model of Soil Water Resources in Hebei Plain

The soil water resources have special storing space and properties,and it is independent of surface water resources and the groundwater resources. This model focuses upon the following problem:firstly,the whole plain is divided into twelve assessment zones according to the texture of soil and types of plants;secondly,the thickness of assessment layer of Hebei Plain is identified according to the texture of soil and the scales of plant roots;thirdly,in order to calculate the surface flow that does not produce soil water,the hydrological model of runoff yield in excess of infiltration is applied;fourthly,the hydrological model of runoff yield at natural storage is used to calculate the water quantity of infiltration out of the assessment layer,and fifthly,by using day as the time length to determine the different parameters.