The aim of an ongoing Swiss Development and Cooperation project in China is to develop strategies how to monitor and control over-pumping in arid Heihe river basin and semi-arid North China Plain.
A real-time monitoring and control system has been designed to control groundwater overpumping in two pilot regions. The real-time data collection includes groundwater pumping rates, groundwater level observations, cropping areas from remote sensing and volumes of surface water imported. All data are collected monthly in real-time and fed to a groundwater model to provide decision support for where and how to enforce water right.
The two regions represent different features: the wells in Heihe cover much larger irrigation areas (over 200 mu per well) with an annual water right of 800 m3/mu, while a typical well in in NCP covers only 30-50 mu with an annual water right of 150 m3/mu. The real-time pumping monitoring and control through smart meters works well in Heihe. Water rights are loaded on IC cards through which pumps are operated. The system is installed and maintained through a private-public-partnership model in Luotuocheng irrigation district. It is in the service company's direct interest to maintain the system for water fee collection.
Pumping monitoring in North China Plain showed a challenge due to the huge number of irrigation wells which are not suitable for installing smart meters. Metering pumping of every single well in in Hebei province (3.9 million wells) is not feasible. Yet, electricity consumption of every single well is monitored for electricity fee collection. On this basis, pumping volume can be monitored through electricity consumption metering, provided the conversion ratio is determined by pumping tests.
High capacity wells can be monitored and controlled through smart meters. The large amount of small wells on the other hand can be monitored and controlled through electricity consumption.