The Interrelationship between Groundwater Potential and Urban Spatial Growth in the Upper Bagmati Watershed of Kathmandu Valley, Nepal

By : Shobha Shrestha , Prem Sagar Chapagain , Kedar Dahal

Page No: 155-172

Abstract
Groundwater extraction for household and industrial use is proliferating with rapid urbanisation in the upper Bagmati watershed area of Kathmandu Valley. As such, urban water management in Kathmandu Valley raises questions and challenges to fulfill future demand, in achieving sustainable development goals and points toward the need for an examination of the interrelationship between urban growth and water recharge potential. This paper examines the interplay between spatial dynamics of urban growth and the water recharge potential using spatial analysis tools like GIS and remoting sensing. Groundwater recharge potential mapping was done using a weighted overlay analysis method using nine controlling factors and urban built-up modeling was carried out for the year 2031 using the Cellular Automata, CA-Markov model. A reconnaissance survey, field observation, KII, and informal discussions were also carried out for field verification and other information collection. The study found that around thirteen percent of the valley floor area has high groundwater recharge potential and is largely confined to the northwestern, western, and southwestern parts of the Valley. The spatial pattern of built up growth exhibits radial around the road network and expansion is in northern and western parts between 2011 and 2016 whereas it is linear in southern and eastern parts and most dominant along the major road network. between 2016 and 2021, the growth is extensive towards the southern-western, southern, and eastern parts of the Valley. Built up growth between 2011 and 2016 depicts an interesting trend of urban expansion toward relatively high groundwater recharge potential and a safe groundwater extraction zone. Conversely, built-up growth between 2016 and 2021 is dominant growth in the southern and southeastern parts which are moderate to low recharge potential and critical zone for groundwater extraction. Though groundwater extraction and use guidelines are in place, monitoring and implementation of regulation are hindered by intensifying built up growth, particularly towards low recharge potential and critical extraction zones confronting protective resource management and sustainability of existing resources and their potential.

Authors :
Shobha Shrestha ,Prem Sagar Chapagain And Kedar Dahal   
Central Department of Geography, Tribhuvan University, Kathmandu, Nepal.
 

DOI: https://doi.org/10.32381/ATNAGI.2024.44.01.10