Approaches to assessing the daily average ground surface soil heat flux on a regional scale over the Qinghai-Tibet Plateau

•Two approaches (CM and SM) are proposed to assess G0_daily.•The RMSE value of the CM is less than 19 W/m2 under all weather conditions.•The SM estimates G0_daily using fewer input parameter under clear-sky conditions.•The CM performs better than the SM and SEBS.