Integrated surface and groundwater resources management in a coastal aquifer (Cap BonPeninsula-NE of Tunisia)

Ichrak Khammessi,Hamadi Habaieb,Amira Merzougui,Jalel Aouissi,Adel Zghibi,Serge Brouyère,Ali Mirchi,Mohamed Haythem Msaddek,Anis Chkirbene

doi:10.5194/egusphere-egu22-11545

Abstract

&lt;p&gt;Coastal aquifers are usually the main source of water supply for irrigation, drinking&lt;br&gt;and industrial purposes in coastal regions. They are often subject to overexploitation and&lt;br&gt;consequent quantitative and qualitative degradation. The groundwater flow system of the Chiba&lt;br&gt;watershed in the CapBon peninsula (NE of Tunisia) is a typical case of an overexploited aquifer,&lt;br&gt;where a piezometric depression exceeding -10 m (a.m.s.l) appeared has developed over the two&lt;br&gt;last decades. Among the numerous remediation tentatives, the SMART-WATER project aimed&lt;br&gt;to propose a remediation plan based on a smart monitoring and water-energy nexus solution&lt;br&gt;through the installation of smart energy and water meters (SEWM). This technology aims to&lt;br&gt;optimize groundwater pumping at a set of selected representative farming systems in the&lt;br&gt;watershed. In this context, a first coupled surface water-groundwater flow model has been&lt;br&gt;developed and applied, coupled with energy nexus for the irrigated Chiba plain. The model is&lt;br&gt;implemented using a dynamic coupling between MODFLOW WEAP and LEAP in order to&lt;br&gt;assess the SEWM system efficiency in reducing aquifer exploitation and electrical energy&lt;br&gt;consumption at farm level. Multi-objective calibration of the model using river discharge and&lt;br&gt;GW level data has yielded accurate simulation of historical conditions, and resulted in better-&lt;br&gt;constrained parameters compared to using either data source alone. Model simulations show that&lt;br&gt;crop water demand cannot be met during droughts due to limited GW pumping capacity, and that&lt;br&gt;increased GW pumping has a relatively strong impact on GW levels due to the small specific&lt;br&gt;yield of the aquifer. Groundwater and energy models have also revealed that, under different&lt;br&gt;management and climatic scenarios, electric energy consumption and groundwater table decline&lt;br&gt;are intricately connected. Despite the short monitoring period and the intermittence of the&lt;br&gt;received data, SEWMs have shown a promising role in monitoring groundwater pumping and&lt;br&gt;engaging farmers in energy saving and aquifer sustainability.&lt;/p&gt;

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