Lu Wang1 ,*, Wolfgang Kinzelbach 1 , Huaixian Yao 2 , Jakob Steiner 3 and Haijing Wang 4
1 Institute of Environmental Engineering, ETH Zurich, Switzerland ;
2 Guantao Department of Water Resources, Guantao , Hebei, China
3 Utrecht University, Utrecht, The Netherlands
4 hydrosolutions Ltd., Zurich , Switzerland
(a) Purpose or objectives and status of study or research hypothesis
This study presents the method of groundwater abstraction monitoring using electric energy as proxy, which is applicable to areas of intensive pumping by numerous small-scale wells.
(b) Key issue(s) or problem(s) addressed
The feasibility and challenges of applying this method in a typical county in the North China Plain was discussed. The accuracy of the conversion from electricity consumption to water volume pumped was investigated. Trade-offs between data accuracy and efforts in data collection was analyzed.
(c) Methodology or approach used
Intensive field experiments at individual wells were carried out to provide a basis for the conversion from electric energy consumption to groundwater abstraction and to explore the feasibility of indirect abstraction monitoring methods in the study area.
(d) Results and conclusions derived from the project
Field experiments in Guantao revealed the large variability of the electricity-to-water conversion factors between individual wells. The error of electricity-to-water conversion for an individual well based on field test is within 20%. The same accuracy is achieved on spatially aggregated levels such as townships or the whole county with conversion factors averaged over a relatively small number of wells. Trade-offs between data accuracy and efforts in data collection can be made by selecting the number of pumping tests. Energy based groundwater abstraction monitoring substantially reduces the investment and efforts required in system maintenance and data collection. Meanwhile, it provides satisfactory data accuracy for use in groundwater modelling and planning.
(e) Implications of the project relevant to selected conference theme, theory and/or practice
Any direct monitoring or control action on the small-scale wells involves millions of individual users, which greatly complicates an effective abstraction management. Achieving a sustainable and effective indirect abstraction monitoring has fundamental implications for the praxis of groundwater management, not only for the whole of the North China Plain but also for comparable regions in the developing world.