چكيده لاتين
Groundwater, due to lower contamination and easier access compared to surface water sources, holds very high value. About 33% of the world population uses groundwater for daily drinking water. Global climate changes, population growth, improper management, and changes and improvements in human lifestyle and hygiene have contributed to the depletion of groundwater reserves. The reduction in groundwater levels can lead to serious environmental and ecological problems. Therefore, identifying groundwater storage locations and optimizing its allocation is critically important. This study aimed to analyze and estimate groundwater level changes in the Samirim region of Isfahan Province, leveraging the integration of ground-based observational data and satellite data. The datasets used included comprehensive information on precipitation, evapotranspiration, surface runoff, groundwater level, and storage changes, collected from reputable sources.
In the first step, a correlation analysis among variables was conducted to identify the influential factors. To enhance prediction accuracy, satellite GRACE data were downscaled using two machine learning models, namely Convolutional Neural Networks (CNN) and Support Vector Machines (SVM). The evaluation results indicated that the CNN model, with a coefficient of determination (R² = 0.71), performed substantially better than the SVM model (R² = 0.60). Moreover, to estimate missing GRACE data, three models—CNN, ANN (Artificial Neural Network), and SVM—were employed. In this section as well, CNN demonstrated superior performance (R² = 0.70) due to its ability to account for neighborhood patterns in the data (matrix inputs).
One of the key applications of GRACE data is the water balance calculation in hydro basins. In this study, downscaled GRACE data were used to estimate groundwater level changes. Finally, using the Q-Q plot, the estimated groundwater level change values derived from satellite data were compared and validated against the ground-based observational data. The results of this study demonstrate the high potential of machine learning models, especially CNN, to improve the accuracy of hydrological analyses and the management of groundwater resources.