Drivers of municipal water security and vulnerability in Pakistan: A case study of Mardan, Khyber Pakhtunkhwa

Tehsil Mardan has experienced enormous shifts in land use and cover (LULC), growth in population, climate variance, and a drop in the groundwater table. This study sought to evaluate and quantify the vulnerability status of municipal water security in Tehsil Mardan, by incorporating LULC, population, and climate indicators using remote sensing and statistical techniques. LULC changes were quantified from Landsat imageries using Envi from 1990 to 2021. Field and questionnaire surveys were conducted to estimate groundwater depletion and municipal water demand. The Mann-Kendall trend test was applied to temperature and precipitation data. Analysis of correlation was performed to measure the relationship among all the variables. To get a deeper understanding of the vulnerability of municipal water security caused by physical, climatic, and social factors, the analytical hierarchy process (AHP) was utilized. LULC results showed a fivefold rise in built-up class from 37 km² to 188 km² and a substantial decline in bare land from 437 km² to 252 km² from 1990 to 2021. The average groundwater table depletion was one foot per year and showed a significant positive correlation with the number of tube wells, water supply and demand, and population growth. An increase of 0.008 °C per year in average temperature while a declining trend is observed in mean precipitation during the last 30 years. The results showed that municipal water security vulnerability changed from “invulnerable relatively” to “very vulnerable” stage during the last three decades. The study contributed valuable insights to facilitate policymakers, and urban planners for management of the current and future municipal water works, land use planning, and associated environmental opportunities and threats.