基于恒定蒸发比的区域蒸散量计算研究

Calculation of regional evapotranspiration based on constant evaporative ratio

蒸散量是水资源评价中的一项重要内容。多年来,区域蒸散量计算一直是水文地质研究领域的热点研究问题。随着卫星遥感技术的不断发展,区域蒸散量计算研究得到了长足的发展。根据前人的研究,日净辐射通量与蒸散量之间的比值恒定。将该研究成果应用于我国西北黑河流域。通过计算蒸发比,进而得到日内的蒸散量。同时,利用传统蒸散量计算公式——penman-monteith公式和张掖地区高台气象的监测数据,进行了蒸散量计算。对比分析了基于恒定蒸发比和基于penman-monteith公式的蒸散量计算结果,并通过插值技术计算年度区域蒸散量。根据实际应用研究,该方法可为区域蒸散量计算提供方法借鉴。

Evapotranspiration is one of the most important factors in water resources assessment. Over the past years,calculation of regional evapotranspiration has been focused on the hydrogeological research domain.With the development of remote sensing technology,obvious advances in the research on calculation of regional evapotranspiration has been obtained. According to the previous researches,the ratio between the daily net radiation flux and evapotranspiration is constant in a day. In this paper,the research results are applied in the Heihe River Basin in Gansu Province. The daily evapotranspiration is obtained by using the constant evaporation ratio. At the same time,the traditional method of evapotranspiration-penman-monteith equation is applied by using the meteorological data from the Gaotai weather station in the Zhangye region of Gansu. The calculated evapotranspiration results in two different ways are compared. Finally,an interpolated method is used to get the daily evapotranspiration map in the year 2011. The results show that the way of evapotranspiration calculation illustrated in this paper is very valid and can provide a reference for evapotranspiration calculation in other regions.