Evaluation of the prediction capability of AHP and F-AHP methods in flood susceptibility mapping of Ernakulam district (India)

Reshma T Vilasan,Vijay S Kapse

doi:10.1007/s11069-022-05248-4

Reshma T Vilasan, Vijay S Kapse

Open Access

https://doi.org/10.1007/s11069-022-05248-4

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Abstract

Floods are one of the frequent natural hazards occurring in Kerala because of the remarkably high annual rate of rainfall. The objective of this study is to prepare the flood susceptibility maps of Ernakulam district by integrating remote sensing data, GIS, analytical hierarchy process (AHP), and fuzzy-analytical hierarchy process methods. Ernakulam is one of Kerala's most flood-prone districts. The development of this map can help to raise awareness about the risks of flooding. Factors such as slope angle, soil types (texture), land use/land cover, stream density, water ratio index, normalized difference built-up index, topographic wetness index, stream power index, aspect, and sediment transport index have been selected. The area of the final maps is grouped into five flood susceptible zones, ranging from very low to very high. The major reasons for flood occurrence in Ernakulam district are the combined effect of multiple factors such as excess silting, reduction of stream width due to anthropogenic activities, and changes in land cover and land-use pattern, lower slope, higher soil moisture content, lower stream capacity, and poor infiltration capacity of soils. The prepared map was validated using the receiver operating characteristic (ROC) curve method. The area under the ROC curve (AUC) values of 0.75 and 0.81 estimated by the ROC curve method for the AHP and F-AHP methods are considered acceptable and excellent, which confirms the prediction capability of the prepared maps. The very high susceptible zone constitutes around 19% of the district. This map is useful for land-use planners and policymakers to adopt strategies that will reduce the impact of flood hazards and damage in the future.

Highlights

Flooding is one of the natural hazards that often cause significant damage to property and loss of life (Merkuryeva et al 2015)
The flood susceptibility maps were prepared using the weights derived by the analytical hierarchy process (AHP) and F-AHP methods
Floods are one of the most common natural hazards occurring in the Ernakulam district and result in serious damage to agriculture, infrastructure, and human and animal habitats

Summary

Introduction

Flooding is one of the natural hazards that often cause significant damage to property and loss of life (Merkuryeva et al 2015). This condition can arise from diverse hydrological processes, such as high tide levels, precipitation, high groundwater levels, and high river flows (Acreman and Holden 2013). Fluvial floods can occur due to the clogging of river channels because of sedimentation (Martín‐Vide et al 2014), snowmelt, or, in rare cases, dam collapse (Acreman and Holden 2013). Floods can cause infrastructure losses (transportation networks, communication networks, etc.), residential losses, public facilities losses, and agricultural losses (damages to land, productivity, crop loss), and impact on water quality, accessibility, and availability (Petersen 2001; Smiley and Hambati 2019). Electrical injuries, and hypothermia are the direct health consequences, while indirect health effects include displacement of populations, intermittent disruption of public health services, lower income, and insufficient temporary living conditions (Allaire 2018)

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