Impact of Land Use/Land Cover Change on Hydrological Components in Chongwe River Catchment

Tena Tena,Nguvulu Nguvulu,Mwaanga Mwaanga

doi:10.3390/su11226415

Tena Tena, Nguvulu Nguvulu + Show 1 more

Open Access

https://doi.org/10.3390/su11226415

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Journal: Sustainability	Publication Date: Nov 14, 2019
Citations: 26	License type: CC BY 4.0

Affiliation: Copperbelt University

Abstract

Chongwe River Catchment, a sub-catchment of the Zambezi River Basin, has been experiencing changes in land use/land cover (LULC) and in its hydrology. This study aims to assess the impact of LULC changes on the catchment’s hydrological components such as streamflow, evapotranspiration and water abstractions. LULC change data, detected from the 1984, 1994, 2014 and 2017 USGS Landsat imagery using a maximum likelihood supervised classifier, were integrated into the WEAP Model along with soil, slope and hydro–climate data. The results showed that between 1984 and 2017 built-up area increased by 382.77% at 6.97 km2/year, irrigated agriculture increased by 745.62% at 1.70 km2/year, rainfed farms/ranch/grassland increased by 14.67% at 14.53 km2/year, forest land decreased by 41.11% at 22.33 km2/year and waterbodies decreased by 73.95% at 0.87 km2/year. Streamflow increased at a rate of 0.13 Mm3 per annum in the wet seasons and showed a high variation with flow volume of 79.68 Mm3 in February and 1.01 Mm3 in September. Annual actual evapotranspiration decreased from 840.6 mm to 796.3 mm while annual water abstraction increased from 8.94 mm to 23.2 mm from the year 1984 to 2017. The pattern of LULC change between 1984 and 2017 has negatively impacted the hydrology of the Chongwe River Catchment. From these findings, an integrated catchment management and protection approach is proposed to mitigate the negative impacts of LULC dynamics on hydrological components in the Chongwe River Catchment.

Highlights

IntroductionLand and natural resources are fundamental components of the ecosystem of a catchment that provide socio-economic and ecological functions to people [1]
The findings indicate that the pattern of changes in land use/land cover (LULC) has adverse effects on the streamflow and evapotranspiration and available water resources in terms of abstraction
The study has demonstrated the usefulness of the water evaluation and planning (WEAP) Model to successfully simulate the patterns of streamflow and other hydrological components in response to LULC change at catchment level, indicating that it is a useful tool for water resources management planning and catchment management

Summary

Introduction

Land and natural resources are fundamental components of the ecosystem of a catchment that provide socio-economic and ecological functions to people [1]. There have been changes in land use/land cover (LULC) at local, regional and global levels resulting from natural and anthropogenic activities and leading to changes in hydrological components [2]. Land cover is the biophysical state of the Earth’s surface and its upper subsurface, whereas land use is the utilization, human inputs and management levels on the Earth’s surface. Driven by production and consumption dynamics closely tied to social, political and economic activities, leads to land cover modification. One of the most noticeable effects of the modifications of terrestrial ecosystems by human activity is LULC change and its impact on the environment locally, regionally and globally [4]

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