Key issues in groundwater utilization and challenges for groundwater management in China's coastal regions

Código

I-EBHE0220

Autores

Dong Mei Han, Xianfang Song

Tema

WG 1.01: REHYDRATE - REtrieve historical HYDRologic dATa & Estimates

Resumo

Coastal regions of China account for less than 15% of the nation?s land area but nearly 50% of the total population, making them one of the world's most densely populated regions. Escalating demand for freshwater resources, compounded by the effects of climate change, renders these regions highly vulnerable to human activities and climate change. The significant alteration of natural hydrological conditions and increasing pressure on existing water resources and ecosystems have become the key issues of groundwater utilization in China's coastal zones. Over the past 50 years, the combined impacts of climate change (e.g., droughts) and human activities (e.g., agricultural irrigation and fertilization, land use changes, land reclamation, land-based aquaculture) have resulted in concentrated and continued decline of groundwater levels in the coastal areas of North China, and led to environmental problems such as land subsidence, seawater intrusion, and water quality deterioration, etc. Groundwater supply has declined significantly in recent years under unprecedented control measures, particularly benefiting from the South-to-North Water Diversion (SNWD) project. However, great challenge remains in coastal groundwater management in China, with large groundwater depression cones and unreplenished aquifers resulting from long-term over-exploitation. The future development of seawater intrusion and land subsidence remain uncertain, and potential negative impacts of groundwater level recovery have arisen in some local regions. Optimizing sustainable management strategies to promote gradual and controlled groundwater level recovery represent profound challenges in groundwater management.