Моделирование стока горных рек Илейского Алатау с применением модели HBV-light

Abstract

The research aimed to evaluate the possibility of applying the HBV model for assessing the flow of the Ile Alatau Mountain Range rivers. The main part of the corresponding water resources forms on the northern slopes of the Ile Alatau making them a significant water balance and water supply factor for the major cities of Almaty, Kaskelen, Talgar, and Yesik. The article includes a brief description of the HBV model, as well as hydrometeorologicaland topographical inputs, and continues with the description of the flow simulation outputs for the rivers with the catchment area varying between 71-601 km2. For the periods of 2000-2016, the model parameters were calibrated using the GAP optimization algorithm. The model’s performance was evaluated based on several criteria: Nash-Sutcliffe Efficiency (NSE), Percent bias (PBIAS), and Root Mean Standard Deviation Ratio (RSR). The selection of optimal parameters allowed obtaining the following model efficiency values: 0.80-0.93 (as per NSE), -0.78 to -15.33% (as per PBIAS), and 0.27–0.80 (as per RSR). The calculated model efficiencies point to the sufficient correlation between the dynamics of the observed and simulated runoffs during the calibration period. The study likewise included the assessment of the HBV model applicability as a forecasting technique based on the ratio. The outcomes of that exercise confirmed the facility of using the model for predicting the runoff of the Kaskelen, Talgar, Ulken Almaty, and Kishi Almaty Rivers. Due to the fact that the observation data were available only for 2020, the HBV model parameters of all the studied rivers, except the Talgar River, underwent validation for the periods of 2017-2020. The calibrated and validated parameters of the obtained Ile Alatau Mountain River Model can be recommended for runoff modeling based on the HBV-light model as well as for runoff forecasting, namely for short- and medium-term water flow forecasts, with the exception of the Turgen, Prokhodnaya and Uzyn Kargaly River Basins.