## 2 Materials and Methods
### Dataset  
ERA-Interim [41] and CMFD [42, 43, 44] were used as driving data for the Noah-MP land surface model, respectively. ERA-Interim data were downloaded from the European Centre for Medium-Range Forecasts ([[https://apps.ecmwf.int/](https://apps.ecmwf.int/)]([https://apps.ecmwf.int/](https://apps.ecmwf.int/)) (accessed on 4 May 2020)). Air temperature, dew point temperature, and wind speed are real-time data with a time resolution of 6 h. Radiation and precipitation are forecast data, and 3 h time resolution can be obtained through processing. There are 11 kinds of spatial resolution available; the highest resolution is 0.125 \(\times\) 0.125\({}^{\circ}\), the lowest resolution is 3 \(\times\) 3\({}^{\circ}\), and the data resolution selected in this study is 0.125 \(\times\) 0.125\({}^{\circ}\). The CMFD data has a temporal resolution of 3 h and a spatial resolution of 0.1 \(\times\) 0.1\({}^{\circ}\). The data can be downloaded from the National Tibetan Plateau Third Pole Environment Data Center ([[http://data.tpdc.ac.cn/](http://data.tpdc.ac.cn/)]([http://data.tpdc.ac.cn/](http://data.tpdc.ac.cn/)) (accessed on 26 April 2020)), and the detailed description of the data can also be obtained from the website. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Observations** & **Instruments** & **Accuracy** \\ \hline Air temperature & 1000 \(\Omega\) PRT, IEC 751 1/3 Class B & \(\pm\)0.4 \({}^{\circ}\)C \\ Wind speed & [PERSON]. [PERSON] 05103 & \(\pm\)0.3 m/s \\ Wind direction & [PERSON]. [PERSON] 05103 & \(\pm\)3 \\ Relative humidity & HUMICAP 180R & \(\pm\)2\% \\ Precipitation & Geonet T-200B & \(\pm\)0.1 mm \\ Radiation & Kipp and Zone CNR4 & \(\pm\)1\% \\ Snow depth & Campbell SR50A & \(\pm\)1 cm \\ Snow water equivalent & Snow pillow & \(\pm\)1 mm \\ Snow temperature & Campbell SI-111 (USA) & \(\pm\)0.5 \({}^{\circ}\)C \\ Soil temperature & Hydra & \(\pm\)0.1 \({}^{\circ}\)C \\ Soil moisture & Campbell CS616/CS625 (USA) & \(\pm\)0.1\% \\ Soil heat flux & Thermopile & \(\pm\)5\% \\ Data logger & Campbell CR1000 (USA) & - \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Specifications of the observations and the instruments at Kuwei site. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Physical Process** & **Short Name** & **Parameterization Schemes** \\ \hline Vegetation model & DEVG & 1. prescribed (table LAI, shdfac = FVEG); 2. dynamic; 3. \\  & table LAI, calculate FVEG 4. table LAI, shdfac = maximum \\ Canopy stomatal resistance & CRS & 1. Ball-Berry; 2. [PERSON] \\ Soil moisture factor for stomatal resistance & BTR & 1. Noah; 2. CLM; 3. SSiB \\ Runoff and groundwater & RUN & 1. SIMGM; 2. SIMTOP; 3. Schaake96; 4. BATS \\ Surface layer drag coefficient & SFC & 1. M-O; 2. Chen97 \\ Supercooled liquid water & FRZ & 1. NY06; 2. Koren99 \\ Frozen soil permeability & INF & 1. NY06; 2. [PERSON] \\ Radiation transfer & RAD & 1. gap = F (3D, cos2); 2. gap = 0; 3. gap = 1-veg \\ Snow surface albedo & ALB & 1. BATS; 2. CLASS \\ Rainfall and snowfall & SNF & 1. Jordan91; 2. BATS; 3. [PERSON] \\ Lower boundary of soil temperature & TBOT & 1. zero-flux; 2. [PERSON] \\ Snow/soil temperature time scheme & STC & 1. semi-implicit; 2. fully implicit \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Alternative parameterization schemes for 12 physical processes in Noah-MP model. In addition to meteorological data, land use data is also needed for Noah-MP model operation. In this study, we selected the global land use data developed by Tsinghua University ([[http://data.ess.tsinghua.edu.cn/](http://data.ess.tsinghua.edu.cn/)]([http://data.ess.tsinghua.edu.cn/](http://data.ess.tsinghua.edu.cn/)) (accessed on 10 May 2020)), and the spatial resolution of the data was 30 m [45]. By resampling, we obtained land use data with the same resolution as ERA-Interim and CMFD data. A gridded dataset of snow depth at Chinese meteorological stations (GDSD) was used to evaluate the simulation accuracy of the Noah-MP model at watershed scale.