ABSTRACT

Urban Evapotranspiration (ET) plays a crucial role in controlling irrigation water demand. The estimation of urban ET is difficult because of high spatial variability of urban surfaces. This paper reviews the two most commonly used approaches pertaining to advancements, limitations, and opportunities in arid regions. The two approaches include the landscape coefficient and surface energy balance approach. The key advancements include the standardization of the basic models and consideration of the spatial variability of the atmospheric advection effects. Two key limitations have been highlighted including oversimplification of microclimate effects in the models and lack of precise estimation of water requirement for mixed landscapes. Furthermore, several opportunities to address the existing limitations are discussed including the coupling numerical models, unmanned aerial vehicles (UAV)-based technologies for ET estimates, detection of mixed landscapes using various vegetation indices, and quantification of the atmospheric effects. This study highlights different dimensions and modeling techniques to estimate urban ET.

摘要

城市蒸发蒸腾量（ET）在控制灌溉水需求中起着至关重要的作用。由于城市表面的高度空间变异性，估计城市ET很困难。本文回顾了与干旱地区的进步，局限和机遇有关的两种最常用的方法。两种方法包括景观系数和表面能平衡方法。关键的进展包括基本模型的标准化以及对流平流效应的空间变异性的考虑。突出了两个关键限制，包括模型中微气候效应的过度简化和混合景观的需水量缺乏精确估算。此外，讨论了解决现有局限性的几种机会，包括耦合数值模型，基于无人飞行器（UAV）的ET估算技术，使用各种植被指数的混合景观检测以及大气效应量化。这项研究强调了估计城市ET的不同维度和建模技术。