Analyzing the Ghizer River Flood Using Hydrological Approach ((HEC-RAS) in Gilgit-Baltistan Region, Pakistan

Abstract

Flood disasters occur when extreme flooding poses a significant threat to human life, infrastructure, and the environment. These disasters result from excessive rainfall, rapid snowmelt, glacier outbursts, or other hydrological events that cause rivers to overflow their banks, inundating surrounding areas. Flooding leads to loss of life, economic hardship, displacement of communities, and environmental degradation. Ghizer region is our focus study area, which is one of the mountainous regions of Gilgit-Baltistan, Pakistan that experiences several disasters, including geological, meteorological, hydrological, and manmade disasters. Among them, floods are the common natural disaster that damages the infrastructure every year. This research study examines the Ghizer River, using the Hydrologic Engineering Center River Analysis System (HEC-RAS) and the Automated Water Extraction Index (AWEI) as analysis models. The HEC-RAS steady flow modeling utilizes to predict river flow behavior in return periods, providing water surface profiles and floodplain inundation maps. The AWEI technique of remote sensing is used to assess the changing morphological pattern of Ghizer River over time. This study focuses on the communities that exhibit heightened vulnerability to flood occurrences in the vicinity of the Ghizer River and to investigate the river's morphological patterns. These advance approaches help for understanding of flood risk zones, early warning system, and disaster awareness. The study covers the period from 1990 to 2023 to analyze historical flood trends and river morphology changes over time.