Implications of land use/land cover dynamics and Prosopis invasion on ecosystem service values in Afar Region, Ethiopia.

Land use/land cover (LULC) dynamics and the resulting changes in ecosystems, as well as the services they provide, are a consequence of human activities and environmental drivers, such as invasive alien plant species. This study assessed the changes in LULC and ecosystem service values (ESVs) in the Afar National Regional State, Ethiopia, which experiences a rapid invasion by the alien tree Prosopis juliflora (Swartz DC). Landsat satellite data of 1986, 2000 and 2017 were used in Random Forest algorithm to assess LULC changes in the last 31 years, to calculate net changes for different LULC types and the associated changes in ESVs. Kappa accuracies of 88% and higher were obtained for the three LULC classifications. Post-classification change analyses for the period between 1986 and 2017 revealed a positive net change for Prosopis invaded areas, cropland, salt flats, settlements and waterbodies. The rate of Prosopis invasion was estimated at 31,127 ha per year. Negative net changes were found for grassland, bareland, bush-shrub-woodland, and natural forests. According to the local community representatives, the four most important drivers of LULC dynamics were climate change, frequent droughts, invasive species and weak traditional law. Based on two different ESVs estimations, the ecosystem changes caused by LULC changes resulted in an average loss of ESVs in the study area of about US$ 602 million (range US$ 112 to 1091 million) over the last 31 years. With an increase in area by 965,000 ha, Prosopis-invaded land was the highest net change during the study period, followed by grassland (-599,000 ha), bareland (-329,000 ha) and bush-shrub-woodland (-327,000 ha). Our study provides evidence that LULC changes in the Afar Region have led to a significant loss in ESVs, with serious consequences for the livelihoods of the rural people.

Shiferaw H ，Bewket W ，Alamirew T ，Zeleke G ，Teketay D ，Bekele K ，Schaffner U ，Eckert S ... -  《-》

Dynamics of land use/land cover: implications on environmental resources and human livelihoods in the Middle Awash Valley of Ethiopia.

Quantifying the recent LULC changes and associated impacts on pastoral and agro-pastoral livelihood systems is important since the effects of LULC changes on environmental resources and human livelihood are not fully understood in our study area. This paper analysed the trend of land use/land cover (LULC) dynamics and its implications on natural resources and human livelihood in the Middle Awash Valley, Central Ethiopian Rift Valley. For the purpose, Landsat imageries of thematic mapper (1987), enhanced thematic mapper (2002) and operational land imager and thermal infrared sensor (2016) were employed and analysed using Remote Sensing and Geographic Information System (GIS) software and techniques, and qualitative data analysis had been performed as well. The results showed that cultivated land expanded at a rate of 2.6% year-1, whereas forestland and grassland shrunk at a rate of 1.2% year-1 and 2.4% year-1, respectively. The invasive Prosopis juliflora has been expanded from 3.7% in 1987 to 37.9% in 2016 at a rate of 1.2% year-1. The introduction of both small- and large-scale commercial irrigation farming and the implementation of villagization programme focused on transforming pastoralists into sedentary lifestyles. Consequently, irrigation farming, launching of villagization, climate variability as in series of droughts, construction of water dam and the rapid expansion of Prosopis juliflora were the major drivers of LULC changes in the study area. Although we found some positive developments such as improvement on infrastructural and social services (e.g. school and domestic water supply), income diversification and ecological benefits from Prosopis juliflora (e.g. saline soil treatment, carbon sequestration and soil erosion control), there were a range of negative impacts resulting from LULC changes in the study area. LULC changes reduced quality of rangeland resources as the ecologically and economically valuable indigenous tree and grass varieties were significantly degraded. As a result, the traditional pastoral livelihood system has been much vulnerable with the LULC dynamism of the study area. Furthermore, the implementation of the villagization programme has brought socioeconomic impacts on the community and challenges on the ecology, e.g. changing productive rangeland to irrigation crop farms. Our research results, thus, suggest the urgent need for relevant policy interventions in support of the pastoral livelihoods and landscapes with the modification in the implementation of villagization as well as irrigation farming programmes and its better management and controlling Prosopis juliflora expansion in the study area.

Abebe MT ，Degefu MA ，Assen M ，Legass A ... -  《-》

Impact of land use/land cover dynamics on ecosystem service value-a case from Lake Malombe, Southern Malawi.

Lake Malombe ecosystem provides a vast range of services that are vital for the sustenance of the riparian communities. Understanding land use and land cover (LULC) dynamics, as well as the associated impacts on the multiple ecosystem service value (ESV), is extremely important in decision-making processes and effective implementation of an ecosystem-based management approach. This study analyzed the LULC dynamics from 1989 to 2019. The primary objective of the study was to assess its impact on ecosystem services (ES). The ESV was determined using LULC analysis and established global ESV coefficient. The LULC analysis showed a reduction in forest cover by 84.73% during the study period. Built-up, cultivated land, bare land, shrubs, and grassland increased considerably. Rapid population growth, climate change, government policy conflicts, and poverty were identified as the most important drivers of LULC dynamics. Based on ESVs estimations, the ES changes instigated by LULC dynamics in the study area result in an average loss of US$45.58 million during the study period. Within the same period, the lake fishery also recorded a net loss of US$8.63 million. The highest net loss of US$79.832 million was recorded from 1999 to 2019 due to increased loss of forest, a decrease in water bodies and marsh areas. The sensitivity analysis (CS) indicated that our estimates were relatively robust. This study findings provide a piece of empirical evidence that LULC dynamics in the Lake Malombe catchment have led to a significant loss of ESVs, with serious implications for the livelihoods of the local population.

Makwinja R ，Kaunda E ，Mengistou S ，Alamirew T ... -  《-》

Analyses of LULC dynamics in a socio-ecological system of the Bale Mountains Eco Region of Southeast Ethiopia.

Analysis of land use and land cover (LULC) change and its drivers and impacts in the biodiversity hotspot of Bale Mountain's socio-ecological system is crucial for formulating plausible policies and strategies that can enhance sustainable development. The study aimed to analyze spatio-temporal LULC changes and their trends, extents, drives, and impacts over the last 48 years in the Bale Mountain social-ecological system. Landsat imagery data from the years 1973, 1986, 1996, 2014, and 2021 together with qualitative data were used. LULC classification scheme employed a supervised classification method with the application of the maximum likelihood algorithm technique. In the period between 1973 and 2021, agriculture, bare land, and settlement showed areal increment by 153.13%, 295.57%, and 49.03% with the corresponding increased annual rate of 1.93%, 2.86%, and 0.83%, respectively. On the contrary, forest, wood land, bushland, grass land, and water body decreased by 29.97%, 1.36%, 28.16%, 8.63%, and 84.36% during the study period, respectively. During the period, major LULC change dynamics were also observed; the majority of woodland was converted to agriculture (757.8 km2) and grassland (531.3 km2); and forests were converted to other LULC classes, namely woodland (766.5 km2), agriculture (706.1 km2), grassland (34.6 km2), bushland (31.9 km2), settlement (20.5 km2), and bare land (14.3 km2). LULC changes were caused by the expansion of agriculture, settlement, overgrazing, infrastructure development, and fire that were driven by population growth and climate change, and supplemented by inadequate policy and institutional factors. Social and environmental importance and values of land uses and land covers in the study area necessitate further assessment of potential natural resources' user groups and valuation of ecosystem services in the study area. Hence, we suggest the identification of potential natural resource-based user groups, and assessment of the influence of LULC changes on ecosystem services in Bale Mountains Eco Region (BMER) for the sustainable use and managements of land resources.

Ayana B ，Senbeta F ，Seyoum A 《-》

Land use and land cover dynamics and ecosystem services values in Kewet district in the central dry lowlands of Ethiopia.

A better comprehensive and quantitative analysis of the tempo-spatial dynamics of land use and cover (LULC) in the dry lowlands areas of Ethiopia is crucial for restoring degraded landscapes. This study aimed at analyzing the trends of LULC changes and determine their ecosystem service values in Kewet district central dry lowlands of Ethiopia using multi-temporal satellite imagery for three periods: 1995, 2008, and 2017. Supervised classification, using the maximum likelihood classifier, was applied to quantify LULC changes. Ecosystem Service values were estimated using the modified ecosystem service value coefficients. LULC analysis showed that cultivated land was the most predominant which covered over 41% of the study area in all three periods. Forests showed a net increase of 18.2%. Shrubland occupied the second largest portion in all LULC analysis next to cultivated land, and it showed a net decrease of 29.2%. Open grassland showed a periodic increase. Over the past 20 years, built-up area and bared land grew continuously by 1.80 and 1.01 km2 yr-1, respectively. However, some degraded land was converted into woody vegetation land through area exclosure, which improved the vegetation coverage of the study area. Ecosystem Service values ranged from US$ 2.37 million for shrubland in 1995 to US$ 22.49 million for forest land in 2008. The total ESVs of the district also continuously decreased over the past two decades. Generally, the LULC in the Kewet district has been dynamic in that some of the LULC classes were expanding, while the others were shrinking through time.

Tesfay F ，Kibret K ，Gebrekirstos A ，Hadgu KM ... -  《-》