An Integrated Geotechnical Framework for Flood-Induced Ground Failure and Infrastructure Resilience in Charsadda, Khyber Pakhtunkhwa, Pakistan

Abstract

Introduction: Flood assessment in Pakistan is commonly organized around inundation depth, exposed population, and direct asset loss. These measures are necessary, but they do not explain why bridge approaches settle, riverbanks retreat, earthen bunds pipe, culvert embankments breach, or saturated foundations lose capacity. The limitation is important in Charsadda District, Khyber Pakhtunkhwa, where the Kabul-Swat River system, low-relief alluvial terrain, irrigation infrastructure, and dispersed road networks create coupled hydraulic and ground-failure pathways.

Objective: This study develops an integrated, field-calibratable framework that connects flood loading, geotechnical failure mechanisms, infrastructure consequences, and intervention priorities for Charsadda.

Methodology: A systematic, PRISMA-informed evidence review was completed to 28 August 2025. Forty-four peer-reviewed studies, engineering standards, government reports, and authoritative data products were retained using transparent relevance and quality criteria. Evidence was appraised for source authority, methodological transparency, mechanism specificity, spatial transferability, and validation or uncertainty, then synthesized into a multiscale decision-support architecture.

Results: Five recurrent mechanism groups were identified: local and contraction scour, bank and surface erosion, seepage, uplift and internal erosion, saturation- and drawdown-induced instability, and settlement or bearing-capacity degradation. Existing Charsadda studies provide useful flood-hazard and social-vulnerability mapping but seldom connect hydraulic forcing with soil stratigraphy, erodibility, transient pore-water pressure, foundation geometry, or observed asset distress. IGFRF-Charsadda addresses this gap through district screening, corridor diagnosis, asset-level investigation, coupled hydraulic-geotechnical analysis, intervention selection, and performance monitoring. It also introduces a transparent risk priority index combining geotechnical hazard, asset-condition deficiency, exposure-consequence, and recovery difficulty.

Conclusion: The proposed framework provides a practical route from flood maps to defensible engineering decisions while maintaining a clear boundary between screening, detailed assessment, and design. Its provisional weights and action bands require local calibration, consistency testing, and sensitivity analysis before operational adoption.