The Upper Indus Basin(UIB)is a crucial freshwater source for millions of people in South Asia,although its water resources are increasingly threatened by climate change,population increase,and land-use changes.Effecti...The Upper Indus Basin(UIB)is a crucial freshwater source for millions of people in South Asia,although its water resources are increasingly threatened by climate change,population increase,and land-use changes.Effective monitoring and management of these resources are essential for long-term sustainability.This study employs the Modified Normalized Difference Water Index(MNDWI)and remote sensing techniques to assess spatiotemporal variations in water resources and land cover from 2005 to 2020.Using a region-specific empirical formula,rainfall intensity in the UIB was estimated while statistical approaches using logarithmic trends and polynomial equations quantified rainfall probability and return periods to forecast extreme events.The results illustrate(i)a significant reduction in permanent water bodies and glaciers together with an increase in barren land and vegetation cover,consequently highlighting the influence of climate variability and anthropogenic activities specifically,permanent water bodies/Glaciers decreased from 22,216.2 km^(2) in 2005 to 18,816.4 km^(2) in 2020,marking a decline of 3,399.8 km^(2)(2%),(ii)fallow land increased from 69,684.8 km^(2) in 2005 to 83,568.2 km^(2) in 2020,while,(iii)vegetation land expanded from 35,346.2 km^(2) in 2005 to 36,257.9 km^(2) in 2020,reflecting a 16%rise,(iv)the rainfall probability analysis revealed annual precipitation fluctuations,with the maximum recorded as 830.45 mm in 2000 and the lowest at 399.34 mm in 2013,representing a reduction in annual rainfall.This study highlights the importance of geospatial approaches in hydrological management,contributing to the development of sustainable strategies for the UIB.展开更多
The Jhelum River Basin in Pakistan has experienced recurrent and severe flooding over the past several decades,leading to substantial economic losses,infrastructure damage,and socio-environmental disruptions.This stud...The Jhelum River Basin in Pakistan has experienced recurrent and severe flooding over the past several decades,leading to substantial economic losses,infrastructure damage,and socio-environmental disruptions.This study uses multi-temporal satellite remote sensing data with historical hydrological records to map the spatial and temporal dynamics of major flood events occurring between 1988 and 2019.By utilizing satellite imagery from Landsat 5,Landsat 8,and Sentinel-2,key flood events were analyzed through the application of water indices such as the Normalized DifferenceWater Index(NDWI)and theModified NDWI(MNDWI)to delineate flood extents.Historical discharge data from key hydrological control points,including Mangla Dam and Rasul Barrage,were incorporated to validate and interpret flood intensity and inundation patterns.Flood footprints were extracted and mapped using preand post-flood images in Google Earth Engine,while land use and land cover(LULC)analysis revealed a consistent increase in built-up areas and a corresponding decline in vegetative cover in flood-prone tehsils from 1988 to 2023.Findings indicated that the flood years 1992 and 1997were themost catastrophic,with over 180 km2 of land submerged.A substantial proportion of inundated zones consisted of agricultural land and low-lying urban settlements,underscoring the vulnerability of these areas.This study proved the effectiveness of integrating satellite imagery and historical hydrological data for spatio-temporal flood monitoring and provides essential insights for future flood risk assessment and the development of site-specific mitigation strategies in vulnerable areas of the Jhelum River Basin.展开更多
文摘The Upper Indus Basin(UIB)is a crucial freshwater source for millions of people in South Asia,although its water resources are increasingly threatened by climate change,population increase,and land-use changes.Effective monitoring and management of these resources are essential for long-term sustainability.This study employs the Modified Normalized Difference Water Index(MNDWI)and remote sensing techniques to assess spatiotemporal variations in water resources and land cover from 2005 to 2020.Using a region-specific empirical formula,rainfall intensity in the UIB was estimated while statistical approaches using logarithmic trends and polynomial equations quantified rainfall probability and return periods to forecast extreme events.The results illustrate(i)a significant reduction in permanent water bodies and glaciers together with an increase in barren land and vegetation cover,consequently highlighting the influence of climate variability and anthropogenic activities specifically,permanent water bodies/Glaciers decreased from 22,216.2 km^(2) in 2005 to 18,816.4 km^(2) in 2020,marking a decline of 3,399.8 km^(2)(2%),(ii)fallow land increased from 69,684.8 km^(2) in 2005 to 83,568.2 km^(2) in 2020,while,(iii)vegetation land expanded from 35,346.2 km^(2) in 2005 to 36,257.9 km^(2) in 2020,reflecting a 16%rise,(iv)the rainfall probability analysis revealed annual precipitation fluctuations,with the maximum recorded as 830.45 mm in 2000 and the lowest at 399.34 mm in 2013,representing a reduction in annual rainfall.This study highlights the importance of geospatial approaches in hydrological management,contributing to the development of sustainable strategies for the UIB.
文摘The Jhelum River Basin in Pakistan has experienced recurrent and severe flooding over the past several decades,leading to substantial economic losses,infrastructure damage,and socio-environmental disruptions.This study uses multi-temporal satellite remote sensing data with historical hydrological records to map the spatial and temporal dynamics of major flood events occurring between 1988 and 2019.By utilizing satellite imagery from Landsat 5,Landsat 8,and Sentinel-2,key flood events were analyzed through the application of water indices such as the Normalized DifferenceWater Index(NDWI)and theModified NDWI(MNDWI)to delineate flood extents.Historical discharge data from key hydrological control points,including Mangla Dam and Rasul Barrage,were incorporated to validate and interpret flood intensity and inundation patterns.Flood footprints were extracted and mapped using preand post-flood images in Google Earth Engine,while land use and land cover(LULC)analysis revealed a consistent increase in built-up areas and a corresponding decline in vegetative cover in flood-prone tehsils from 1988 to 2023.Findings indicated that the flood years 1992 and 1997were themost catastrophic,with over 180 km2 of land submerged.A substantial proportion of inundated zones consisted of agricultural land and low-lying urban settlements,underscoring the vulnerability of these areas.This study proved the effectiveness of integrating satellite imagery and historical hydrological data for spatio-temporal flood monitoring and provides essential insights for future flood risk assessment and the development of site-specific mitigation strategies in vulnerable areas of the Jhelum River Basin.
