Land surface temperature-fractional vegetation coverage (LST-f_c) trapezoid framework based models have been widely developed, applied, and verified to estimate regional latent heat flux (LE) and its partitioning process. The basis of operating these models lies in the determination of end-members within the LST-f_c trapezoid. However, the knowledge of how the end-members affect the LE and ratio of vegetation latent heat flux (LE_v) to latent heat flux (LE_v/LE) estimation is lacking in the literature. In this study, three widely used end-members determination methods, viz., determination of actual end-members within the scatter plot of LST-f_c (AEM), determination of theoretical end-members through the Zhang's method (Zhang et al., 2005, TEM-Z), and determination of theoretical end-members through Long's method (Long and Singh. 2012b, TEM-L) were inter-compared. The outcome of this study was verified at the 11 Eddy Correlation (EC) observation stations for the 183 test days during 2015 using the Moderate-resolution Imaging Spectroradiometer (MODIS) products, revealing that different end-members combinations greatly alter the LE simulation. However, tuning of end-members do not shift the LE_v/LE estimates, and spatial patterns of the LE and LE_v/LE remained unchanged. Moreover, the performance of TEM-Z is better than the AEM, while the TEM-L provide relatively unstable performance during the 183 test days. Conclusively, this study endorses to adopt the TEM-Z method to determine the end-members. This study provides a clear understanding of the effect of different end-members to LE and LE_v/LE simulation within the LST-f_c trapezoid framework, and gives a clear insight for model selection, operation, and subsequent, guidelines for model improvement.

基于地表温度-植被覆盖度分数 (LST-f _c ) 梯形框架的模型已被广泛开发、应用和验证，以估计区域潜热通量 (LE) 及其划分过程。操作这些模型的基础在于确定 LST-f _c梯形内的端元。然而，文献中缺乏关于端部成员如何影响 LE 和植被潜热通量 (LE _v ) 与潜热通量 (LE _v / LE) 估计比率的知识。在本研究中，三种广泛使用的端元确定方法，即在 LST-f _c散点图中确定实际端元(AEM)、通过 Zhang 的方法确定理论端元（Zhang et al., 2005, TEM-Z）和通过 Long 的方法确定理论端元（Long and Singh. 2012b，TEM-L）是相互之间的-比较的。这项研究的结果在 2015 年 183 个测试日的 11 个涡相关 (EC) 观测站使用中分辨率成像光谱仪 (MODIS) 产品进行了验证，表明不同的端元组合极大地改变了 LE 模拟。然而，末端成员的调整不会改变 LE _v / LE 估计，以及 LE 和 LE _{v 的}空间模式/LE 保持不变。此外，TEM-Z 的性能优于 AEM，而 TEM-L 在 183 天的测试期间提供相对不稳定的性能。最后，本研究支持采用 TEM-Z 方法来确定端元。本研究清楚地了解了不同端元对 LST-f _c梯形框架内的LE 和 LE _v / LE 模拟的影响，并为模型选择、操作和随后的模型改进指南提供了清晰的见解。