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European Journal of Applied Sciences – Vol. 11, No. 3
Publication Date: June 25, 2023
DOI:10.14738/aivp.113.14769.
Mamba, M. P., Mkhonta, S. V., Vilane, B. R. T., Mkhwanazi, M. M., & Hlanze, D. K. (2023). An Assessment of Land Use and Land
Cover Change for Lubovane Reservoir Sub-Catchment in Eswatini. European Journal of Applied Sciences, Vol - 11(3). 233-242.
Services for Science and Education – United Kingdom
An Assessment of Land Use and Land Cover Change for Lubovane
Reservoir Sub-Catchment in Eswatini
Mamba, M. P.
Department of Agricultural and Biosystems Engineering,
Faculty of Agriculture, University of Eswatini, Luyengo
Campus P. O. Luyengo M205, Kingdom of Eswatini
Mkhonta, S. V.
Ifa Lethu Technologies CC, P. O. Box 360, Badplaas, 1190
Vilane, B. R. T.1
Department of Agricultural and Biosystems Engineering
Faculty of Agriculture, University of Eswatini, Luyengo
Campus, P. O. Luyengo M205, Kingdom of Eswatini
Mkhwanazi, M. M.
Department of Agricultural and Biosystems Engineering,
Faculty of Agriculture, University of Eswatini, Luyengo
Campus P. O. Luyengo M205, Kingdom of Eswatini
Hlanze, D. K.
Centre for Financial Inclusion, Plot 2176 First Floor Lilunga House,
Somhlolo Road P. O. Box 6805, Mbabane, Kingdom of Eswatini
ABSTRACT
The increasing population in rural areas, increased livestock densities and
extensive deforestation have been reported as the main drivers of land degradation
in Eswatini. Land degradation, along with biodiversity loss and climate change
presents serious challenges to the environment, economy and the country’s
development agenda. This study was conducted to assess the land use land cover
(LULC) changes within the Lubovane reservoir catchment. Landsat 4-5 TM images
were used for mapping LULC changes for 1995, 2000, 2005, 2009 and a Landsat 8
image was used for mapping 2015 LULC. A supervised LULC classification was
conducted using 6 classes (water, settlements, irrigation, cultivation, shrubs and
forests, as well as bare land) in ArcGIS version 10.3.1. The classification was
validated using a confusion matrix and the results reflected that water, irrigation,
cultivation, forests and shrubs were well classified. The LULC assessment results
indicated that there was low coverage of water bodies observed from 1996 – 2005,
while a 3% increase was observed in 2009. Water coverage decreased to 1.9% in
2015 due to the El-Niño induced drought that hit Southern Africa, resulting in low
inflow to the dam. A reduction of shrubs and forest cover was experienced in 2000
1 Corresponding author.
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European Journal of Applied Sciences (EJAS) Vol. 11, Issue 3, June-2023
due to conversion of forested areas into settlements for resettled households.
However, a slight increment of shrubs and forest was observed from 2009 to 2015.
A reduction in the concentration of forests cover around the reservoir, an increase
of settlements and bare land were also observed.
Keywords: Land use, land cover, catchment, reservoir, vegetation
INTRODUCTION
Land use land cover (LULC) influences global environmental changes. Therefore, it is crucial to
undertake LULC assessment in order to understand trends of on-going changes ([17] et al.
2021). Land use is defined as the purpose for which land is utilized, whereas land cover refers
to the physical features of the land surface [16]. Changes in LULC may contribute to significant
effects on various environmental, ecological and hydrological systems [13]. The changes of
LULC are caused by multiple interacting factors which could be anthropogenic or natural
processes occurring at different spatiotemporal scales, globally these has been characterized
by gains in agricultural land and reduction of forests [8]. The drivers of LULC changes comprise
a combination of demographics, politics, socioeconomic systems, institutions, as well as nature,
technology and culture. Therefore, due to the diversity of the drivers, LULC change does not
comply to a strict model and is non-deterministic [14]. These challenges have direct impacts to
the livelihoods of the community and subsequently the population both in urban and rural
areas.
The increasing human population densities in rural areas, increased livestock population on
poorly managed rangelands and extensive deforestation have been reported as the main
drivers for land degradation in the Kingdom of Eswatini [6]. Additionally, agricultural
expansion and settlements have led to intensification of land use and adoption of unsustainable
practices, which include loss of natural resources, changes in natural habitats and ecosystems,
biodiversity loss, decrease in water quality and quantity, as well as reduction in productivity of
arable and rangelands in Eswatini [7]. Land degradation, along with biodiversity loss and
climate change presents serious challenges to the environment, economy and the country’s
development agenda [4]. As, such in order to achieve sustainable development, the country has
to respond to these challenges.
In response to these challenges, the government of Eswatini implemented the Lower Usuthu
Smallholder Irrigation Project - Global Environment Facility (LUSIP-GEF)-Sustainable Land
Management (LUSLM) project. Through this project the government intended to reduce land
degradation, biodiversity loss and mitigate climate change in the Lower Usuthu River Basin
area through the application of sustainable land management practices [6]. The LUSLM project
was implemented within the Lubovane reservoir catchment, which also contributed towards
improved management of the watershed draining into the reservoir. This study was
undertaken to assess the LULC changes within the Lubovane reservoir catchment.
The application of remote sensing (RS) and geographic information systems (GIS) theories has
been widely recognized as accurate and highly efficient tools for mapping, characterizing and
monitoring changes in LULC [18]; [12]. RS data also provides valuable information regarding
the processes, location, rate, trend, nature, pattern and magnitude of LULC changes while GIS
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Mamba, M. P., Mkhonta, S. V., Vilane, B. R. T., Mkhwanazi, M. M., & Hlanze, D. K. (2023). An Assessment of Land Use and Land Cover Change for
Lubovane Reservoir Sub-Catchment in Eswatini. European Journal of Applied Sciences, Vol - 11(3). 233-242.
URL: http://dx.doi.org/10.14738/aivp.113.14769.
enables mapping and analysing the patterns captured in the remotely sensed data thus
enhancing the interpretation and understanding of LULC dynamics [11].
Description of the Study Area
The Lubovane reservoir, is located between latitude 26°46'57.60"S and 26°43'46.28"S and
longitudes 31°38'42.52"E and 31°42'54.45"E (Figure 1). The reservoir occupies a total surface
area of 13.9 km2 at the downstream end of the Mhlathuzane River catchment. The Lubovane
reservoir catchment sits in the Lower Usuthu sub-basin and the Usuthu Basin within Eswatini
covering about 12 700 km2 [10]. The LUSIP began in the late 90s, hence the study covered the
period prior to construction (1995, 2000) and the period after construction (2005, 2009 and
2015) of the reservoir. These years were chosen so that mapping could cover the time period
before the introduction of the project up to 2015, when the project was almost fully
implemented and activities in the project area were highly intensified.
Figure 1. Location of the Lubovane reservoir and its catchment area
The catchment area of the Lubovane reservoir is 524 km2 with a Mean Annual Runoff (MAR) of
70 x 106 m3 as well as a slightly high coefficient of variation (98%) [2]. The average temperature
range for Lubovane Reservoir catchment is 190 C to 300C, with maximum temperatures
reaching 400C, usually around December and January (Figure 2). The annual rainfall in the basin
ranges from 600 to 1000 mm, with the lower parts of the basin receiving the least rains [9].