The study looked at different layers of underground water to understand their abundance and quality. By testing water levels and chemical isotopes in Hengshui, the researchers found that agriculture affects groundwater the most. They also discovered that water pressure decreases from deep to shallow layers, while water recharge increases. The study suggests using salty water for irrigation, exploiting rich aquifers for industry and agriculture, and using deep water for drinking. By following these recommendations, sustainable groundwater use can be achieved.