Impacts of landuse/land cover change on flow and sediment yield in monsoon dominated watershed
Abstract
Land use/land cover (LULC) changes significantly affect catchment hydrology and sediment yields. The current study intends to analyze the hydrological responses of LULC changes in a monsoon dominated watershed of the Periyar River basin (PRB), Kerala, India. The Soil and Water Assessment Tool (SWAT) model is used to assess impacts on surface runoff and sediment yield. The model runs are performed by varying LULC inputs between 1988 to 2100 to evaluate the effects of LULC change. The historical LULC maps were prepared from maximum likelihood classification technique and the future LULC maps using Markov chain- cellular automata algorithm. The major LULC changes were identified as an increase of urban area by 4.13% of the catchment area and a decrease of plantation coverage by 3% between 1988 and 2016. The increase in urban area is anticipated to expand by up to 15.65%, while the decline in plantation is projected to increase by up to 6.44%. At the catchment scale, the differences in the long-term mean annual values for the surface runoff and sediment yield showed an increasing trend with varying LULC till 2100. The results of the monthly time scale analysis show that the monsoon months, when there is a greater amount of precipitation, have the greatest impact on water discharge and sediment loads to the PRB. The current study highlighted the impacts that the LULC changes in PRB had on hydro-sedimentological variables. Furthermore, it is understood that it can have a significant influence in affecting the hydrological cycle, and as a result, these changes can have an impact on a wide range of human activities in the region, including agribusiness, cattle, food security, energy production, and public water supply. Overall, the findings indicated that LULC change should be considered when managing water and environmental resources and should be used as a key planning tool while looking forward to manage the watershed.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFMGC34B..02S