Analysis of Evolving Flood Patterns and Associated Damages Across Pakistan

Abstract

This paper presents a comprehensive analytical review of the evolving spatio-temporal patterns of floods and associated damages across Pakistan. Understanding these evolving patterns is essential for improving flood risk management and minimizing avoidable flood-induced damage. Numerous studies have investigated different aspects of flood occurrence, flood management practices, and their socio-economic impacts. However, most have focused on individual flood events or specific flood types. Consequently, a holistic assessment of the spatio-temporal evolution of flood patterns and the associated damages under the influences of climate change and anthropogenic activities is still required. To address this research gap, an extensive literature review was conducted and historical flood data was compiled to investigate the long-term evolution of different flood types across Pakistan. Heat maps of annual peak discharges recorded at major dams, barrages, and hydraulic control points were developed to analyze the temporal and spatial evolution of flood patterns. The analysis revealed that 13 distinct flood types have been reported in Pakistan over the past 75 years, encompassing classifications based on physical origin, geographical setting, flood onset characteristics, and special triggering mechanisms. Among these, riverine, cryospheric, and rural floods have been the most persistent flood types, whereas urban flooding, Glacial Lake Outburst Floods (GLOFs), and pluvial flooding have become frequent in recent decades. The historical analysis further indicates that severe flood events with exceptionally high peak discharges were more common during the period 1970–2000, whereas recent decades have experienced a higher frequency of flood events with comparatively lower peak magnitudes. The simultaneous occurrence of multiple flood types has resulted in compound flooding in 2010, 2020, and 2022 causing exceptionally severe impacts across Pakistan. In particular, the 2022 flood affected more than 33 million people, resulted in the loss of approximately 1.16 million livestock, and damaged approximately 2.29 million houses, that makes it one of the most devastating flood disasters in Pakistan's recorded history.