Geomorphic and Hydrological Impacts of River Sand Mining on Recent Floods and Groundwater Decline in Pakistan

Abstract

This research critically examines the geomorphic and hydrological impacts of riverbed sand mining on flood intensity and groundwater reduction in Pakistan, integrating local data with global perspectives. A thorough review of literature, field reports, and GIS-based analyses, along with case studies from international rivers such as the Mekong, Mississippi, Ebro, Yamuna, Meghna, and Athi, was conducted to assess how sediment extraction alters river morphology and hydrological functions. The findings indicate that excessive sand mining deepens river channels, accelerates bank erosion, disrupts sediment transport, and reduces floodplain storage, leading to geomorphic instability. In Pakistan, rivers within the Indus Basin, including the Ravi, Chenab, Jhelum, Swat, Indus, and Malir, show similar patterns, with deep pits, channel shifts, and loss of agricultural land weakening natural flood defenses. These changes exacerbated the 2022 and recent 2025 floods, resulting in more extensive water overflow, prolonged flooding, and increased damage. Hydrologically, the lowering of riverbeds and disrupted sediment dynamics have weakened groundwater–river connectivity, accelerating groundwater depletion in Punjab, Sindh, and Khyber Pakhtunkhwa. At the same time, climate-related stressors such as extreme rainfall, glacial melt, and rising temperatures further intensify flood risks and water shortages. Despite legal requirements for Environmental Impact Assessments, there is weak enforcement, inadequate monitoring, and widespread informal extraction allowing unsustainable practices to persist. Comparisons with international sediment management frameworks highlight the effectiveness of monitoring, sediment budgeting, and community involvement in mitigating negative impacts. This study underscores the urgent need for integrated, climate-resilient river management, evidence-based policies, and enhanced monitoring strategies to protect Pakistan’s river systems, reduce flood vulnerability, and safeguard vital groundwater resources