Assessing Sustainable Groundwater Management Strategies for Climate Change Adaptation: Comparison of Cyclic and Non-Cyclic Conjunctive Use Approaches

Climate change and its effect on droughts has led to overuse of groundwater resources and endangered the sustainability of these resources. Climate change studies shows that the recent attempts are not solely concentrated on “impact assessment” and “adaptation” is winning more focus in the studies. Accordingly, presenting appropriate strategies is of importance for increasing of surface and groundwater conjunctive use system adaptability with adverse effects of this phenomenon. In the present study, the adaptability of cyclic and non-cyclic conjunctive use systems with the aim of increasing groundwater sustainability while reducing costs and water shortage have been compared by considering climate change scenarios. In this regard, in order to simulate climate change in the Basin of Abhar River, precipitation and temperature variables are extracted from the results of three global atmospheric circulation models under RCP2.6 and RCP8.5 greenhouse gas emission scenarios in the period 2021-2031. Data spatial downscaling was performed using the M5 decision tree algorithm. In the next step, the Wavelet-M5 hybrid model was used to predict runoff values for rainfall-runoff modeling. The Kharrufa method has also been used to calculate evaporation in future seasons. In the next step, these values were provided as input to the cyclic and non-cyclic multi-objective optimization models. Results showed that, CSS operation strategy improves the conjunctive use system adaptability, compared to the optimal operation strategy which employs the NCSS approach, so that in the cyclic approach, the sustainability of the groundwater resources is guaranteed by about 18% more than of the same in the non-cyclic approach.