Department of Urban and Infrastructure Engineering, NED University of Engineering & Technology, Karachi, Sindh, Pakistan.
Department of Civil Engineering, NED University of Engineering & Technology, Karachi, Sindh, Pakistan.
Environ Monit Assess. 2023 Feb 9;195(3):381. doi: 10.1007/s10661-023-10971-x.
Karachi is the largest industrial metropolitan of Pakistan facing an acute water shortage which is leading to an overdraft of groundwater resources in the city. Groundwater is an important freshwater resource for the city as millions of people depend for sustenance. However, over-exploitation of groundwater has led to decreased groundwater levels within the city leading to environmental issues of depleting aquifers, deteriorating groundwater quality, land subsidence, and harm to groundwater-dependent ecosystems. The objective of the study was to assess the potential groundwater accumulation zones by integrating hydrogeological aspects of the city through nine thematic layers using the Geographic Information System (GIS) based multi-criteria decision analysis (MCDA) technique. The potential groundwater accumulation map reveals that 20% of the area has a low potential, 70% has moderate potential, and around 10% of the area in the city is composed of a high potential accumulation zone. The upstream regions of the city have the highest recharge potential because of sandy soil and barren land use, which promote high infiltration rates. The urbanized downstream areas have the lowest recharge potential due to impervious fabric. The findings reveal that the MCDA technique can be used with confidence in data-scarce regions for groundwater resource assessment and management. The recharge potential map can help better manage groundwater resources in the city by helping explore groundwater extraction opportunities and could hint at areas suitable for artificial recharge wells/ponds.
卡拉奇是巴基斯坦最大的工业大都市，面临着严重的水资源短缺问题，这导致了该市地下水资源的过度开采。地下水是该市重要的淡水资源，因为数百万人的生计都依赖于此。然而，地下水的过度开采导致城市地下水位下降，从而导致含水层枯竭、地下水水质恶化、地面沉降和依赖地下水的生态系统受到损害等环境问题。本研究的目的是通过利用地理信息系统（GIS）为基础的多准则决策分析（MCDA）技术，整合城市的水文地质方面，评估潜在的地下水积聚区。潜在的地下水积聚图显示，该市 20%的地区具有低潜力，70%的地区具有中等潜力，约 10%的地区具有高潜力积聚区。由于沙土和荒地的利用，城市上游地区具有最高的补给潜力，这促进了高渗透率。由于不渗透的织物，城市下游的城市化地区具有最低的补给潜力。研究结果表明，MCDA 技术可以在数据匮乏的地区用于地下水资源评估和管理，这是可靠的。补给潜力图可以帮助更好地管理城市的地下水资源，通过帮助探索地下水开采机会，并暗示适合人工补给井/池塘的区域。
