From water cycle observation to sustainable management: A case study of the Hefeng Basin, Southern Jiangxi

This paper is the result of hydrogeological survey engineering.

Objective The spatial and temporal distribution of water resources is uneven in the Yangtze River Basin, resulting in lots of problems including floods and droughts disasters, and degradation of natural wetlands, which restrict reginal land space optimization and sustainable development.

Methods In this paper, based on the water balance theory, a water cycle monitoring network was constructed through a typical case study with clear hydrogeological boundaries. This water cycle monitoring network consisted of regional atmospheric precipitation, river runoff, cross-sectional flow, groundwater replenishment and drainage, and multilevel groundwater monitoring wells, thereby the integrated evaluation of surface water- groundwater was carried out based on the observation data.

Results The Hefeng Basin, a typical oval-shaped basin inclined to the northwest, is a karst basin enclosed by clastic rock, limestone and magmatic rock. Groundwater flow direction is in a centripetal-shaped from the margin of the basin to the central low-lying area, and flows out of the basin along the Hefeng River to the northwest. The evaluation of surface water-groundwater resources and water balance analysis was conducted based on observation data from water cycle monitoring network at the year of 2020. The results show that the shallow groundwater resources was 2277.86×10⁴ m³/a, and the degree of development and utilization at local was about 17.97%; comparing to the surface-water resources 8611.45×10⁴ m³, and the degree of development and utilization about 15.18%. Combined with the analysis of water utilization structure in the basin in the past 20 years, the proportion of water used for agricultural planting exceeded 70%, and the proportion of domestic water used by residents increased to 11.50%.

Conclusions The Hefeng Basin as a typical catchment in south China, is generally abundant in water resources, ensure sustainable development with the total regional water resources significantly exceeding the annual water consumption. In terms of water usage, it is recommended to measures to reduce total agricultural water consumption. Regarding the water supply, initiatives such as establishing emergency groundwater supply sources should be adopted to enhance the capacity for water resources allocation, thereby improving regional water supply security. It can be learned that, the water cycle monitoring network and water balance analysis are vital to local water resource management, which provide scientific guidelines for green and sustainable development especially in water-constrained cities. Furthermore, cope with emergency flood and drought disasters due to the uneven distribution of water resources, it is advisable to improve the capacity of water supply and optimize the water utilization structure in the region.