## 3 Algorithm Improvement and Scheme Evaluation
### Improvement Strategy for the NSGA-III Algorithm
#### 3.1.4 Algorithm Implementation Process:
The distribution ratios of water allocation for various users under different scenarios in the planning year are shown in Figure 6. As depicted, agricultural water use in Jinzhong City is the highest, accounting for 54% to 62%. With the promotion of water-saving technologies and adjustments in planting structures, the demand for agricultural water in 2035 is 5% to 7% lower than in 2030. Industrial water use ranks second, comprising 17% to 18% of the total. This is followed by residential and ecological water use. Notably, the proportion of water use by tertiary industry increases from 2% to 4% or 5% by 2035. Due to population growth and the advancement of urbanization, people's needs have shifted, leading to significant development in the service industry and related sectors, thereby increasing water demand accordingly. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Scheme** & **Administrative Region** & **Domesticity** & **Agriculture** & **Secondary Industry** & **Tertiary Industry** & **Ecology** & **Total** \\ \hline \multirow{8}{*}{Baseline Scenario} & Taigu & 1644 & 7927 & 2177 & 287 & 662 & 12,697 \\  & Yushe & 551 & 2322 & 890 & 503 & 818 & 5084 \\  & Zuoquan & 720 & 944 & 580 & 514 & 955 & 3713 \\  & Qixian & 1244 & 7716 & 925 & 230 & 452 & 10,567 \\  & Pingyao & 2205 & 10,327 & 804 & 192 & 631 & 14,159 \\  & Lingshi & 1242 & 1404 & 2648 & 773 & 602 & 6669 \\  & Jiexiu & 2223 & 4425 & 3425 & 554 & 751 & 11,377 \\ \cline{2-8}  & Total & 9828 & 35,064 & 11,450 & 3054 & 4871 & 64,268 \\ \hline \multirow{8}{*}{Water— Saving Scenario} & Taigu & 1644 & 8203 & 2089 & 287 & 630 & 12,853 \\  & Yushe & 551 & 2832 & 890 & 503 & 818 & 5594 \\  & Zuoquan & 720 & 1141 & 580 & 514 & 955 & 3911 \\  & Qixian & 1244 & 9278 & 925 & 230 & 452 & 12,129 \\  & Pingyao & 2205 & 10,089 & 780 & 199 & 617 & 13,890 \\  & Lingshi & 1242 & 1652 & 2648 & 773 & 602 & 6917 \\  & Jiexiu & 2223 & 4926 & 3403 & 541 & 739 & 11,832 \\ \cline{2-8}  & Total & 9828 & 38,121 & 11,316 & 3048 & 4813 & 67,127 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Water resources allocation results of two schemes in 2035. Figure 6: _Cont._

(2) Analysis of Configuration Objectives. An analysis of the objective values for the optimized water resource allocation scheme in Jinzhong City is presented, with the benefit values of the three objective functions for different allocation schemes shown in Table 11. The results indicate that, in the planning year 2030, as the water frequency increases, the social benefit objective function also increases, with the water shortage rising to 84.47 million m\({}^{3}\), indicating a severe water scarcity situation. With the increase in water frequency, the economic benefit objective decreases from 17.56215 billion CNY to 16.19397 billion CNY, and the total COD emissions in wastewater also decrease from 63,144 tons to 60,303 tons. This phenomenon reveals the characteristics of multi-objective optimization problems, where different objective functions influence each other and often have conflicting relationships; an improvement in one objective's benefit often leads to a decline in others. Comparing the planning years 2035 and 2030, the water shortage decreases and economic benefits increase, but pollutant emissions also rise. This is because the available reclaimed water supply in 2035 further increases compared to 2030, optimizing the water supply structure. With technological upgrades and industrial structure optimization, the demand for water use in the high-benefit tertiary industry increases, generating more economic benefits but also more pollutants. ## 6 Discussion

(1) Jinzhong City is a typical resource-scarce city with diverse industries and developed agriculture. The insufficiency of surface water resources has led to the over-extraction of groundwater, forming a funnel area that severely impacts local ecological health and sustainable development.