High‐resolution modeling became popular in recent years due to the availability of multisource observations, advances in understanding fine‐scale processes, and improvements in computing facilities. However, modeling of hydrological changes over mountainous regions is still a great challenge due to the sensitivity of highland water cycle to global warming, tightly coupled hydrothermal processes, and limited observations. Here we show a successful high‐resolution (3 km) land surface modeling over the Sanjiangyuan region located in the eastern Tibetan plateau, which is the headwater of three major Asian rivers. By developing a new version of a Conjunctive Surface‐Subsurface Process model named as CSSPv2, we increased Nash‐Sutcliffe efficiency by 62–130% for streamflow simulations due to the introduction of a storage‐based runoff generation scheme, reduced errors by up to 31% for soil moisture modeling after considering the effect of soil organic matter on porosity and hydraulic conductivity. Compared with ERA‐Interim and Global Land Data Assimilation System version 1.0 reanalysis products, CSSPv2 reduced errors by up to 30%, 69%, 92%, and 40% for soil moisture, soil temperature, evapotranspiration, and terrestrial water storage change, respectively, as evaluated against in situ and satellite observations. Moreover, CSSPv2 well captured the elevation‐dependent ground temperature warming trends and the decreased frozen dates during 1979–2014, and significant increasing trends (p < 0.05) in evapotranspiration and terrestrial water storage during 1982–2011 and 2003–2014 respectively, while ERA‐Interim and Global Land Data Assimilation System version 1.0 showed no trends or even negative trends. This study implies the necessity of developing high‐resolution land surface models in realistically representing hydrological changes over highland areas that are sentinels to climate change.

中文翻译：

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青藏高原东部三江源地区水文变化的高分辨率地表模拟：1.模型开发与评价

由于多源观测的可用性，对精细过程的理解的进步以及计算设备的改进，高分辨率建模近年来变得流行。但是，由于高原水循环对全球变暖的敏感性，热液过程紧密耦合以及观测结果有限，对山区的水文变化进行建模仍然是一个巨大的挑战。在这里，我们展示了位于青藏高原东部三江源地区成功的高分辨率（3 km）地表建模，该地区是亚洲三大河流的上游。通过开发名为CSSPv2的新版本的联合地表-地下过程模型，由于引入了基于存储的径流生成方案，我们将Nash-Sutcliffe效率提高了62-130％，用于水流模拟。在考虑了土壤有机质对孔隙度和水力传导率的影响之后，将土壤湿度模型的误差降低了31％。与ERA-Interim和全球土地数据同化系统1.0版重新分析产品相比，CSSPv2分别将土壤湿度，土壤温度，蒸散量和地面储水量变化的误差分别降低了30％，69％，92％和40％。 ，针对现场和卫星观测进行评估。此外，CSSPv2很好地捕捉了1979-2014年间海拔高度依赖的地暖趋势和冻结日期的减少，以及显着增加的趋势（与ERA-Interim和全球土地数据同化系统1.0版重新分析产品相比，CSSPv2分别将土壤湿度，土壤温度，蒸散量和地面储水量变化的误差分别降低了30％，69％，92％和40％。 ，针对现场和卫星观测进行评估。此外，CSSPv2很好地反映了1979-2014年间海拔高度依赖的地暖趋势和冻结日期的减少，以及显着增加的趋势（与ERA-Interim和全球土地数据同化系统1.0版重新分析产品相比，CSSPv2分别将土壤湿度，土壤温度，蒸散量和地面储水量变化的误差分别降低了30％，69％，92％和40％。 ，针对现场和卫星观测进行评估。此外，CSSPv2很好地反映了1979-2014年间海拔高度依赖的地暖趋势和冻结日期的减少，以及显着增加的趋势（p  <0.05）分别在1982-2011年和2003-2014年期间的蒸散量和地面水储量中，而ERA-Interim和全球土地数据同化系统1.0版则没有任何趋势，甚至没有负趋势。这项研究表明，有必要开发高分辨率的地表模型，以现实地表示高地地区的水文变化，这些变化是气候变化的前兆。