基于不同蒸散假设的区域水资源量计算

Calculation of Regional Water Resources Based on Different Hypothesis of Evapotranspiration

为研究蒸散互补和蒸散正比两种蒸散发理论对区域水资源评价结果的影响,以南四湖湖东泗河流域为例,验证了泗河流域蒸散互补关系的存在,将蒸发皿蒸发量引入平流—干旱模型,计算了基于蒸散互补假设的流域实际蒸散发,并将月水量平衡模型分别与基于蒸散互补和蒸散正比假设的流域实际蒸散发计算方法相耦合,建立了两种区域水资源量评价模型,对泗河流域水资源量进行了模拟。结果表明,两种评价模型所得结果相差明显,多年平均值差异高达26.3%,基于蒸散正比假设计算得到的区域水资源量可能偏大。

In order to study the impact of proportional evapotranspiration and complementary evapotransplratlon on the regional water resources evaluation, taking Sihe river basin in the east of Nansi lake as the study area, the existence of complementary evapotranspiration was confirmed in this area. And the pan evaporation was introduced to the Advection- Aridity model to calculate the regional actual evapotranspiration based on the hypothesis of complementary evapotranspira- tion. Then the monthly water balance model coupled with the proportional evapotranspiration and complementary evapo- transpiration methods was used to establish two models of regional water resource assessment. Finally, water resources quantity of Sihe basin is simulated. The case study shows that the difference of two models is obvious, and the annual av- erage difference attains 26.3 % ; the calculation result based on proportional evapotranspiration is possibly large.