Evaluating Urban Growth Hazard Risk and Resilience in Major Urban Centers in Himalayas Using Geoinformatics

Abstract

The rapid urban growth (135.02%) and population influx (333.45% growth) in the newlineHimalayan region over the last few decades (1991-2018) led to severe impacts on the newlinefragile mountainous ecosystem through the loss of ecological (blue-green) newlineinfrastructures. The rising frequency of natural hazards with accelerated anthropogenic newlinealteration in the fragile mountainous ecosystem needs serious attention. Therefore, the newlinepresent thesis analyses the spatial dimensions of urban ecological services (UESs) newlinetransformation and population density in major Himalayan urban agglomerations newline(UAs) in recent decades (1991-2018). The multi-temporal satellite-based study newlineexhibited a remarkable increase (193 km 2 ; 15%) in the built infrastructures while a newlinesignificant decline (-24%) in the ecological infrastructures in the Himalayan UAs newlineindicating the continuous rising anthropogenic influence on the Himalayan ecosystems newlinein the last three decades (1991-2018). The large-scale UESs alteration is evident within newlinelarger cities in Western and Central Himalayas (Kathmandu, Srinagar and Dehradun) newlinein contrast to low transformation in Eastern Himalayas cities (Gangtok, Thimphu and newlineItanagar) barring Shimla UA. The investigation highlighted the rapid population influx newlinein combination with the unregulated urban growth imposed a higher risk of natural newlinehazards in Eastern and Central Himalayan UAs. Being one of the largest growing UAs newlinein the Himalayas, the spatial patterns of rapid urban growth in the Kathmandu Urban newlineAgglomeration (KUA) was assessed by coupling multi-temporal satellite observations newlineand statistical approaches. A significant urban growth (123.97%) with haphazard urban newlineexpansion (by 51.82 km 2 ) was observed in Kathmandu UA over the last three decades newline(1989-2018) led to the comparable compactness index (0.50 to 0.75) to cities in the newlineplain regions indicating the compact and circular urban growth. newline