Work

Relative Contribution of the Topographic Influence on the Triangle Approach for Evapotranspiration Estimation over Mountainous Areas

Year: 2014

Type: article

Abstract: Evapotranspiration (ET) is an important component of the water budget. Estimation ET through remote sensing over a mountainous terrain is typically obstructed by topographic effects. In this paper, topographic corrections were applied to ET estimates using the surface-air temperature difference-Normalized Difference Vegetation Index (( Ts-Ta )-NDVI) triangle method with MODIS data for the Taihu Basin in China. The effect of topography on ET was evaluated over an area with a complex terrain. After applying the topographic correction, the results indicate that the ET decreased with elevation and slope. The slope had a stronger impact on ET than the elevation, which caused the corrected ET to decrease by 90% from 6.8 mm day−1to 0.6 mm day−1for slopes over 50°. On average, the corrected ET decreased by 10.4% and 32.1% for north- and south-facing slopes, respectively. The ET corrected using the triangle method strongly depended on the evaporative fraction correction, which can mainly be attributed to the surface temperature correction. We conclude that a topographic correction is necessary when the triangle method is applied to areas with a complex terrain.

Source: Advances in Meteorology

DOI: 10.1155/2014/584040

Authors: Xiaosong Zhao, Yuanbo Liu

Institutions: Chinese Academy of Sciences, Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment

Language: English

Topic: Hydrology and Drought Analysis

Subfield: Global and Planetary Change

Field: Environmental Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,630

Funders: National Natural Science Foundation of China, Chinese Academy of Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences