Lili YU & Fengyue SUN
General Institute of Water Resources and Hydropower Planning and Design (GIWP),
Ministry of Water Resources, China
Framework of the “Dual Control Management
Groundwater overexploitation is one of the problems of water resources sustainable management in China and in many regions worldwide. Under the Most Stringent Water Resources Management System, the “cap” of total water use for each province and each
city has been determined in China, and in which, some provinces have also developed the “cap” of groundwater use for sub-regions. However, since the limited measuring system for groundwater pump, it is hard to only rely on the groundwater pump amount to manage
groundwater use. Focusing on difficulty of groundwater management, China has been trying to carry out “dual control” management of groundwater throughout the country - it means to control both groundwater overexploitation and groundwater table.
The management and control of groundwater table is a complicated problem, the standard groundwater table is set based on the average water table in each region. On one side, the groundwater table should not be too high in order to prevent secondary soil
salinization, infiltration of surface pollutants, and ensure the safety of buildings. On the other hand, the groundwater table should not be too low either therefore ensuring the groundwater supply to the watercourse, maintaining the spring discharge, conserving the
vegetation growth in arid areas and preventing a series of environmental and geological problems including land subsidence, seawater intrusion and surface crack.
Affected by human activities such as groundwater overexploitation, the groundwater t a b l e i n m a n y r e g i o n s o f C h i n a i s f a r f r o m r e a c h i n g t h e r a t i o n a l groundwater table. Therefore, the formulation of groundwater table control quota at different stages is requested. The determination of quota should firstly depend on the current state of groundwater exploitation and utilization, existing issues, objectives and tasks of groundwater governance. Also, the influence on seasonal variations in precipitation has to be taken into consideration when deciding the control quota for a specific year in the future, because it has direct impact on changes in groundwater table, however, it is difficult to be predicted precisely. Therefore, for a specific year, there is no need to specify control quota, giving a particular range by assuming long-term high precipitation and high precipitation can work.