Conjunctive Operation of Sand Dam and Groundwater Well for Reliable Water Supply during Drought Conditions

Abstract

Some mountainous regions without water service facilities are among the areas most vulnerable to drought. In these locations, it is particularly essential to establish practical alternatives to cope with the increase in the intensity and duration of droughts caused by climate change. This study proposes a methodology for the conjunctive use of a sand dam and groundwater well under various drought conditions. The method has been applied to a small mountainous area in South Korea. Owing to the scarcity of observational data, it is crucial to properly estimate the hydrological components necessary for judging the feasibility and reliability of conjunctive operations. The step-by-step procedures for performing the tasks are presented in this study. For the inflow of the sand dam, which is a portion of the basin runoff, two different approaches were employed and compared: the Kajiyama formula and a simple two-parameter monthly water balance model (TPM). Water budget analysis allowed for the determination of whether the current and increased water demand could be met under various drought conditions. Preliminary analysis revealed that a sand dam alone could not reliably meet the demand for 10-year or more severe drought conditions. Various water allocation scenarios between surface water (i.e., sand dam) and groundwater were tested. Conjunctive use of a sand dam and groundwater well turned out to increase the reliability of the water supply. As water demand increases and droughts become more severe, the role of groundwater increases. With appropriate resource allocation, 100% water supply reliability could be achieved, even for one year-lasting 50-year drought. We demonstrated how a system could be flexibly operated to meet the target demands monthly, given the system reliability level.

Study on coordinated allocation of conventional and unconventional water resources in typical regions of North China

“…The treatment cost of unconventional water resources is also much smaller than the corresponding water transfer cost. Therefore, the principle of controlling groundwater exploitation and expanding the scale of unconventional water resource utilization is adhered to, and the water supply order of each water source is defined as follows: reclaimed water, mine drainage water, surface water, and groundwater (Kim et al, 2022;Mu and Wang, 2020).…”

Drought and Groundwater Development

“…In terms of water welfare, fundamental policies for drought relief and securing water resources should be pursued for these upstream areas that are marginalized [11]. Some of the technologies covered in this Special Issue are applicable to such water-welfare blind spots [12].…”