The evaluation of artificial recharge performance in a historic flooding in southern Iran

The water crisis is a major challenge for water resources managers in semi-arid regions of Iran. Most of the policies to deal with this crisis have been to contain surface water behind dams. Changing the national approach from dam construction to watershed management is inevitable to conserve groundwater resources in Iran. The effects of flood water spreading (FWS) and artificial recharge of groundwater (ARG) were investigated in a large area in southern Iran during the ۱۵۱ hours of historic flooding in ۲۰۱۷. The study area was two basins in the Gareh Bygone Plain (GBP) including the Bisheh Zard Basin (۱۹۲ km۲) and Tchah Qootch Basin (۱۷۱ km۲). The water budget equation was used to evaluate the inflow and outflow of the flood spreading system.  Six installed piezometers in the GBP measured the water recession level. The inflow and outflow were continuously measured by a water-level recorder and five broad-crested weirs, respectively. The soil water content of ۳۰ m depth was recorded by the Time Domain Reflectometry (TDR) sensors. The total volume of water retained by the system on ۱۷ January ۲۰۱۷ was ۱۹,۱۶۰,۹۵۱ m۳. Net replenishment of the aquifer was ۶,۶۷۷,۳۰۱ m۳. The total recharge of the ARG was ۸,۳۳۲,۹۱۶ m۳ in the study duration. The flood water system retained ۷۰% of the total diverted flow to the system and increased the water level wells in the study area from ۱.۰۳ to ۲.۷۴ m. Therefore, it can be concluded that FWS and ARG restrained the rare flood event in Iran .Consequently; they can be the logical processes to avoid flood damage and conserve groundwater resources.

Keywords:

Artificial recharge , Flood water spreading , Gareh Bygone plain , Groundwater