Land Use and Land Cover Changes and Their Effects on the Landscape of Abaya-Chamo Basin, Southern Ethiopia

Abstract

This study uses a combination of remote sensing data, field interviews and observations, and landscape indices to examine the dynamics of land use and land cover (LULC), identify their driving forces, and analyze their effects on the landscape of Abaya-Chamo Basin (ACB) between 1985, 1995, and 2010. The results reveal that the landscape of ACB has changed considerably during the past 25 years between 1985 and 2010. The main changes observed imply a rapid reduction in shrubland (28.82%) and natural grassland (33.13%), and an increase in arable land (59.15%). The basin has become more fragmented and formed less connected patches in 2010 compared to 1985. Rapid population growth, internal migration, policy shifts, and regime change were identified as the key driving forces of LULC changes in ACB. The LULC changes and related trend of increasing landscape fragmentation in the basin increased soil erosion, the volume of surface runoff, and sediment transport in the landscape and, consequently, affected the levels and water quality of the lakes found in the rift floor. Furthermore, the destruction and fragmentation of shrubland and natural grassland led to the decline of wild plants and animals previously prominent in the basin. Therefore, protective measures that take into consideration the economic, social, and ecological dynamics of the basin are urgently needed to save the aquatic and terrestrial ecosystems of the basin from further damage.

Assessing Changes in Ecosystem Service Values over 1985–2050 in Response to Land Use and Land Cover Dynamics in Abaya-Chamo Basin, Southern Ethiopia

“…The observed (1985 and 2010) LULC dataset used in this study were obtained from Woldeyohannes et al [30], whereas the simulated LULC dataset was created using statistical inference method and Cellular Automata (CA) allocation approaches. As it is briefly indicated in Woldeyohannes et al [30], the observed dataset was generated from Landsat imageries by employing a pixel-based supervised image classification method. Post-classification refinement was applied to enhance the classification accuracy of the final LULC maps.…”

“…In the past few decades, rapid population growth and rising demand for food in Ethiopia have led to a considerable expansion of cropland at the expense of forest, shrubland/woodlands and grasslands in various part of the country [25][26][27][28][29][30][31]. More than 23 million ha of forest and shrubland/woodlands were cleared since the second half of the twentieth century to make way for agricultural production in the country [32].…”

“…More than 23 million ha of forest and shrubland/woodlands were cleared since the second half of the twentieth century to make way for agricultural production in the country [32]. More recent case studies from different parts of Ethiopia have indicated that the conversion of natural ecosystems to settlement and cultivated land is continuing at an increasing trend [28][29][30]33,34]. This trend is expected to continue in the future as rapid population growth and declining average farm size per capita in the country further drive the expansion of cultivated land into areas covered by forest, shrubland, grassland, and wetland [35].…”

“…However, the situation has changed, and arable land solely dominated the landscape and became a major LULC type of the basin in 2010. These changes have affected the basin's ecosystem functions and flow of services, both of which affect the livelihood of the people living in the basin [30]. Despite being regionally significant, research in the ACB so far has been focused mainly on the area of biodiversity, LULC change, and water management.…”

Land-Cover Change Analysis and Simulation in Conakry (Guinea), Using Hybrid Cellular-Automata and Markov Model

“…Urbanization is generally influenced by national laws, plans, policies and poor governance in many developing countries [9,10]. Population growth increases the demand for natural resources, including land for construction, thus, human disturbances such as pollution, fire, grazing, cutting, and cultivation can also lead to spatial shift in land-use systems [11]. Because of various anthropogenic and natural factors, developing countries experience relatively more rapid urban growth and land-cover changes compared to developed countries [12].…”