基于互补原理确定黄土高原Budyko 方程的流域特性参数

Determining the catchment property parameter of Budyko equation based on the complementary principle in the Loess Plateau

Budyko方程的流域特性参数一般根据植被覆盖度等下垫面特征进行确定,但相关资料不易获取。本文针对黄土高原地区29个小流域,通过分析流域特性参数、植被覆盖度和互补关系中大气湿润指数之间的关系发现,大气湿润指数能够间接反映植被覆盖度的大小,进而能够利用常规气象数据确定流域特性参数,并拟合出了经验公式。相比采用固定流域特性参数,这种方法能够提高Budyko方程对实际蒸散发量的模拟效果。相比于植被覆盖度等下垫面资料,常规气象数据时间序列长、且更易获取,因此本方法具有较好的应用前景。

In the present study,the catchment property parameter of Budyko equation was determined based on the complementary principle by using data from 29 catchments in the Loess Plateau.By analyzing the relationships between the catchment property parameter,vegetation coverage and atmospheric wetness in⁃dex from the complementary principle,it was found that the vegetation coverage can be indirectly represent⁃ed by the atmospheric wetness index.Thus,the catchment property parameter can be determined by the at⁃mospheric wetness index,which is calculated by using the routinely measured meteorological variables.Com⁃pared to the fixed catchment property parameter,the performances on actual evapotranspiration estimation were improved by this approach.Because the meteorological data has longer time series and can be ac⁃quired more easily compared with the land surface data,this approach of determining the catchment proper⁃ty parameter has a good application prospect.