Calculation of Regional Water Resources Based on Different Hypothesis of Evapotranspiration

In order to study the impact of proportional evapotranspiration and complementary evapotranspiration 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 evapotranspiration.Then the monthly water balance model coupled with the proportional evapotranspiration and complementary evapotranspiration 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 average difference attains 26.3%;the calculation result based on proportional evapotranspiration is possibly large.