## 3 Results and Discussion
### Prediction Model
#### 3.2.2 Assessment of Exploitable Groundwater Resources in the Zhem Basin--Second Scenario Prediction  
The predictive groundwater head contours and flow paths for 25 years are presented in Figure 18A, and those for 50 years are presented in Figure 18B. While the groundwater flow hydrodynamic pattern and main flow direction will remain similar, the hydraulic gradients will decrease in the northwestern part of the basin, where most of the groundwater reservoirs exist. Intensive extraction of groundwater will lead to a head decreasing below the earth's surface in areas where artesian conditions for the movement of groundwater develop, the cessation of self-flow from wells, and the formation of unconfined or low-pressure conditions of the groundwater flow. An extensive drawdown will form and increase over time in the Emben groundwater aquifer complex (Emba, Kenkiyak, Kokzhide, Atzhaksy, Alibekmola, and Kozhasay), which will reach 50-55 km in length and 30-35 km in width (Figure 19). The maximum predicted groundwater head drop will occur around two centers: the first is in the Kenkiyak deposit area, with decreases of 45-55 m by 2047 (25 years) and 60-65 m by 2070 (50 years), and the second is in the Kokzhide area, with a predicted drawdown of 40-45 m in 25 years and 50-55 m in 50 years. The ellipsoid shape of the depression is due to the linear arrangement of a large groundwater extraction area stretched along the Emba River valley, as well as the higher filtration properties of the aquifer in this area. Figure 18: Second scenario prediction. Groundwater head contours and flow paths for 25 years (**A**) and 50 years (**B**). The Sargbulak aquifer complex is located in the northeast Zhem Basin, in the upper reaches of the Bolshaya, Malaya Khobda, and Temir rivers. The 25-year prediction (Figure 20A) suggests the formation of seven separate rather large drawdown funnels, namely Alginskoye-Bogdanovskoye, Kundaktykirskoe, Moiseevskoe, Sarybulakskoye  
Figure 19: The second scenario drawdown prediction in the Emben aquifer complex for 25 years (**A**) and 50 years (**B**). Shubarsayskoye-West Kandyagchskoye, Kandagachskoe, Dzhurun PTV, and Zharykskoe. A maximal drawdown exceeding 45 m is predicted in Bogdanovskoye, and a maximum drawdown of 15 to 35 m is predicted in the other locations. At the Dzhurun PTV wellfield, the predicted groundwater heads will drop below the modeled layer, i.e., the aquifer will drain completely. For the 50-year forecast period (Figure 20B), the Moiseevskoye and Sarybulak-Shubarsay-Kandyagachsk West field drawdowns merged into an area of 40 km by 20 km. In the depression center, the drawdown will increase by 15-20 m compared with the 25-year forecast period. Notably, after 25 years, the wellfield of the Keregen-Sagyz aquifer and the Sagyz River has completely drained, and after 50 years, the wellfields of Bogdanovsk, Kandagach, and Zharyk have also increased. Figure 20: The second scenario predicts a drawdown in the Sarybulak aquifer complex area for 25 years (**A**) and 50 years (**B**). The calculated maximal predicted groundwater head drawdowns have been developed since 2022 (Table 6), with both currently utilized and approved groundwater reserves exceeding 20,000 m\({}^{3}\)/day. The calculations compensate for an additional decrease in the water head, enabling the computation of the cell area transition cuts to the actual average water drawdown radius. For most large groundwater aquifers (Table 6), the maximal model-calculated drawdowns did not reach the maximal permissible drawdowns. While model calculations confirm the approved exploitable groundwater volume, there are exceptions for the following segments: Kenkiyak, Kandagach, Zharkamys, and Dzhurun PTV. The exploitable groundwater resources (for water pumping) calculated for these areas were previously overestimated, since their interaction during simultaneous operation was not taken into account. The prediction calculations performed in this study suggest a reduction in the exploitable sustainable reserve.