Optimization of Groundwater Pumping and River-Aquifer Exchanges for
Management of Water Resources
Abstract
Groundwater pumping influences the rate of River-Aquifer (R-A) exchanges
and alters the water budget of the aquifer. Therefore, fulfilling the
total water demand of the area, with an optimal pumping rate of wells
and optimal R-A exchanges rate, is important for the sustainable
management of water resources and aquatic ecosystems. Meanwhile,
comparison of the output of different simulation-optimization
techniques, which is used for the solution of water resource management
problems, is a very challenging task where different Pareto fronts are
compared to identify the best results. In the present work, mathematical
models were developed to simulate the R-A exchanges for the lower part
of the River Ain, France. The developed models were coupled with
optimization models in MATLAB environment and were executed to solve the
multi-objective optimization problem based on the maximization of
pumping rates of wells and maximization of groundwater input into the
river Ain through R-A exchanges. The Pareto front developed by different
simulation-optimization models was compared and analyzed. The Pareto
fronts were juxtaposed based on the convergence, total diversity, and
uniformity with the help of different performance metrics like
hypervolume, generational distance, inverted generational distance, etc.
The impact of different groundwater models based on domain size and
boundary conditions was also examined. Results show the dominance of
MOPSO over other optimization algorithms and concluded that the
maximization of pumping rates significantly changes after considering
the R-A exchanges-based objective function. It is observed that the
model domain also alters the output of simulation-optimization,
therefore the model domain and corresponding boundary conditions should
be selected carefully for the field application of management models.
ANN models were also developed to deal with the computationally
expensive simulation model by reducing the processing time and were
found efficient. Keywords: Simulation-Optimization, Multi-Objective
optimization, Artificial Neural Network, River-Aquifer exchanges.