Evaluation of the variable infiltration capacity (VIC) model for hydrological simulation using remote sensing observations in the western Black Sea basin

Abstract

This research presents an in-depth analysis and evaluation of the Variable Infiltration Capacity (VIC) model's performance in simulating hydrological processes and assessing the potential impacts of climate change on water resources management in the Batı Karadeniz basin. By calculating water supply and demand, the study area, characterized by diverse climatic, physiographic, and land use conditions, offers a unique opportunity to explore the VIC model's applicability for water resource management across a wide range of hydrological settings. A popular hydrological model that replicates the water and energy balances of the land surface is the VIC model. It is particularly helpful for anticipating the effects of climate change on water resources and recreating the hydrological cycle in vast river basins. Key processes including precipitation, evapotranspiration, infiltration, surface runoff, and subsurface flow are all represented in the model. It also takes into account aspects of the land's surface such topography, soil type, vegetation cover, and land usage. The VIC model has been used in a number of studies, including those that monitor and predict droughts, forecast floods, and manage water resources. The Kizilirmak, Yesilirmak, and Coruh rivers are only a few of the significant rivers that flow through Turkey's northern Karadeniz Basin. The area has a humid climate with a lot of precipitation, but it also frequently experiences floods and droughts. The Karadeniz Basin is essential to the support of numerous economic activities, including agriculture, industry, and energy generation, because of its abundant water supplies. A thorough comprehension of the hydrological processes taking place in the Karadeniz Basin, including interactions between surface and groundwater, water quality, and water usage patterns, is necessary for effective management of the basin's waterresources. The effects of climate change on the area's water supplies must also be taken into account, and suitable adaption measures must be found. The VIC model was used in this study to evaluate the management of water resources in Turkey's Karadeniz Basin. A trusted hydrological model that mimics the water and energy balances of the land surface is called the VIC model. Key hydrological variables such as precipitation, evapotranspiration, runoff, and baseflow were simulated using the model. To find patterns and trends in water availability across the basin, these variables were studied. Important water resources management factors, such as water supply, water demand, and water deficit, were calculated using the VIC model's findings. The water demand was calculated by analyzing the water needs of various industries, including agriculture, industry, and home usage, while the water supply was predicted based on the simulated precipitation and runoff values. The region's overall water scarcity status was determined by calculating the water deficit as the difference between water supply and demand. The study identified monthly and seasonal fluctuations in precipitation by analyzing the Batı Karadeniz Basin's rainfall patterns from 2016 to 2021. The findings indicated that August 2020 had the lowest monthly precipitation and May 2018 had the highest. The study also discovered a seasonal pattern, with spring and early summer seeing higher precipitation and late summer seeing reduced precipitation. Precipitation patterns during the winter months were unpredictable. The study emphasizes how these precipitation patterns affect how water resources are managed in the basin since their unpredictability can have an impact on how much water is available for both environmental and human demands. The study underscores how crucial it is to take climate uncertainties into account for long-term planning and managing the region's water resources. The Batı Karadeniz Basin's evapotranspiration patterns were examined from 2016 to 2021, and the study identified distinct seasonal changes. The highest monthly evapotranspiration value was recorded in July 2020, while the lowest was recorded in December 2018. Evapotranspiration was higher in warmer months and lower in colder months. Interannual variability was also evident in the data, which may have been brought on by changes in vegetation cover, temperature, and solar radiation. In order to manage the region's water resources and handle issues with water shortages, it is essential to understand the patterns of evapotranspiration. The Batı Karadeniz Basin's runoff and baseflow patterns were examined from 2016 to 2021, and it was discovered that variables including precipitation, temperature, and land use can have an impact on seasonal and interannual variability. Due to heavy rain and snowmelt in the spring, runoff values peaked, with summer months having the lowest levels. Baseflow displayed a more complicated pattern, with maxima occurring in the winter and spring months and highlighting the effect of elements like groundwater recharge and soil moisture. The hydrological processes in the basin were influenced by variables like temperature and precipitation, which resulted in large year-to-year changes in both runoff and baseflow levels. For the region's water resources to be managed effectively, it is essential to comprehend the trends and variations in runoff and baseflow. The Batı Karadeniz Basin's water supply and demand were calculated for this study between 2016 and 2021 using the VIC model. The study discovered discernible seasonal fluctuations in water supply and demand, with greater levels in the spring and early summer and lower levels in the late summer and fall. The study also calculated the monthly water deficit, which varied significantly throughout the course of the study period, with water surpluses in some months and shortages in others. In order to address changes in the water deficit and offer a stable supply of water to fulfill demand, the study underlines the significance of good water resource management. The Shuffled Complex Evolution (SCE-UA) technique is used for calibration, which helps to align model predictions with actual data. The calibration error statistics are computed using the root mean square error (RMSE), bias, and Nash-Sutcliffe efficiency (NSE). For the AKSU station and the Afatlar station, the VIC model's calibration in this investigation took place across 5,000 and 10,000 iterations, respectively. With minor seasonal changes in performance, the calibration enhanced the model's ability to simulate the hydrological dynamics of the Batı Karadeniz Basin. Snowmelt processes, precipitation patterns, and other hydrological processes all have an impact on the model's performance. The VIC model's discharge forecasts for the Batı Karadeniz Basin require further study and model improvement.