平原区土壤水资源量计算模型的研究

Study on the model of the plain soil water resources quantity

土壤水资源是独立于地表水资源和地下水资源并具有独特存储空间和性质的水资源,本研究结合河北省土壤水资源评价工作,明确了土壤水资源的概念,提出了计算模型。阐述了评价层概念和河北平原区评价层的确定,针对土壤水资源的概念和动态特性,运用水量平衡原理,在地表产流上基于超渗产流模型计算,在评价层以下损失量(不形成土壤水资源的量)上基于蓄满排泄模型计算,以日为计算时段长度,综合考虑截流、蒸发等损失,周年土壤水资源量为逐日降雨量和与逐日损失量和之差。该模型已用于河北省土壤水资源的评价工作。

The soil water resources have special storing space and properties, and unique surface water resources and the groundwater resources. The concept of the soil water resources is explained, and the model calculating the soil water resources quantity of plain is put forward in light of the dynamic characteristics of the soil water resources and the principle of water balance principle. This model focuses upon the following problems： firstly, the whole plain is divided in nine 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, such as the daily quantities of surface flow, the daily recharge water amounts to underneath the assessment layer, the quantity of lost water on the ground surface by evaporation and transpiration etc. The model has been applied to the work of soil water resources assessment of Hebei Plain to achieve better results.