## 6 Conclusions  
For this study, we conducted a sensitivity analysis. The \(z_{\text{0m}}\), as well as forest height, turned out to be one of the most important factors for parameterizing the SEBS, whose 50% deviations could generate errors of more than 40% for the SEBS derived sensible heat fluxes. As the forest structural dynamic information (height, FBH, crown width, and LAI) largely affect the temporal changes in \(z_{\text{0m}}\), it is necessary to apply the multi-disciplinary techniques to develop the effective parameterization of \(z_{\text{0m}}\). Here, we propose a time-series parameterization scheme (for the years 2000 to 2012) for two critical parameters (\(d\) and \(z_{\text{0m}}\)) using MOS theory, which is the basic mechanism for the SEBS. We calibrated two parameters (the forest height and FAI) of the SD00 model against forest measurements using regression models. The two regression equations were linked to interannual forest AGB dynamics derived from 2009 forest AGB basis maps and interannual forest AGB increments obtained from the synergistic simulations of two ecological models. By combining GLASS LAI products, forest height, and FAI dynamics, \(d\) and \(z_{\text{0m}}\) were derived using the SD00 model. Afterward, \(d\) and were further employed in order to derive \(z_{\text{0h}}\) using the \(kB^{-1}\) model. These three parameters were used to parameterize the SEBS from 2000 to 2012. With the incorporation of original MODIS products (NDVI and LST), GLASS LAI, Albedo products, and downscaled WRF estimates, the parameterized SEBS was used to simulate eight-day forest ET over the QMs. As compared to MODIS MOD16 ET products (eight-day average) at the site (the nearest pixel), the SEBS estimates (eight-day average) were much better and agreed well with EC measurements, with the exception of the growing seasons for which the SEBS underestimated forest ET during 2010 and overestimated ET during 2011. The dynamic parameterization scheme employed in this study is more realistic than that obtained by assuming \"static\" conditions based on constant values for \(d\), \(z_{\text{0m}}\), and \(z_{\text{0h}}\). The spatial distribution of forest ET estimates provides valuable information for the sustainable management of forest and water resources, which are extremely important to the QMs and the entire HRB river basin. Runoff generated from mountainous regions is recognized as the main water source for the HRB. The local forests are important for flood control, runoff regulation, and soil erosion control, and, thus, contribute to hydrological service at the basin scale. The interannual forest ETs, as estimated here, showed a downward trend that was largely caused by a local climate trend of warm dryness to warm wetness [100]. Moreover, the current forest belt may shift upward in response to warm wetness, and the grassland (or shrubland) above an elevation of 3300 m may convert to a forest on shady slopes [86]. Rigorous local forest protection measures, including the expansion of grazing prohibition areas and the conversion of grasslands to secondary _Picca crassifolia_ forests, that have been implemented within the Qilian Mountains since the 1980s could have caused decreased runoff but may also have expanded the water retention capacity of this mountain ecosystem. This work was supported by the National Basic Research Program of China (973 Program) under grant 2013 CB733404; Fundamental Research Funds for the Central Non-profit Research Institution of IFRIT, CAF under grant IFRIT201302; and the National Natural Science Foundation under grant 41101379. Portions of the ground measurements used for this work were obtained from Heihe Watershed Allied Telemetry Experimental Research (HiWATER). We also thank the joint team for providing measurement support. [PERSON] is the principal author of this manuscript. He wrote the majority of the manuscript and contributed to all phases of the investigation.