In-situ pumping tests and numerical simulations of seepage wells in the Yellow River valley, China

Abstract

Seepage wells that can convert surface water into groundwater are often constructed near river valleys to obtain more water and lead to smaller drawdown compared with traditional wells. Seepage wells have been widely used, whilst the groundwater and river-level variations caused by seepage wells are still unclear, and numerical models are rarely verified due to the lack of in-situ observational data, which may lead to results that are quite different from the actual conditions. To address those limitations, a large-scale pumping test was carried out near the Yellow River valley in China and a coupled seepage–pipe flow model was established using the exchange yield between the aquifer and pipe as the coupling key in this research. The coupled model was evaluated with in-situ measurement. The field observation showed that both the river and groundwater had a positive response to the pumping of the seepage wells. The simulation results indicated that our model can well estimate the pumping rate and drawdown with root-mean-square deviations of 158.235 m3/d and 0.766 m, respectively. Further, it is also found that the groundwater showed the obvious characteristics of three-dimensional flow under the influence of seepage wells and the maximum drawdown should be less than 15 m to ensure exploitation efficiency. These findings provide important information that can guide the design and construction of seepage wells to improve the rational exploitation of groundwater. HIGHLIGHTS A large-scale pumping test of seepage wells was designed, which revealed the relationship among aquifers, river, and seepage wells.; A coupled seepage–pipe flow model of seepage wells was established and verified using field observational data and simulated the groundwater drawdown field.; The applicable conditions of the model under different drawdowns were discussed and the maximum pumping drawdown was determined.;

Keywords

• coupled seepage-pipe flow model
• groundwater
• pumping test
• seepage wells
• water level