Department of Geography and Environmental Studies, Addis Ababa University, Addis Ababa, Ethiopia.
Environ Monit Assess. 2022 Sep 27;194(11):833. doi: 10.1007/s10661-022-10498-7.
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, whereas forestland and grassland shrunk at a rate of 1.2% year and 2.4% year, 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. 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.
量化土地利用/土地覆盖（LULC）变化及其对农牧生计系统的影响非常重要，因为在我们的研究区域，土地利用/土地覆盖变化对环境资源和人类生计的影响尚未完全了解。本文分析了埃塞俄比亚中央裂谷中部奥罗米亚州 Middle Awash 流域土地利用/土地覆盖变化的趋势及其对自然资源和人类生计的影响。为此，使用了 Landsat 专题制图仪（1987 年）、增强型专题制图仪（2002 年）和运行陆地成像仪和热红外传感器（2016 年）的图像，并利用遥感和地理信息系统（GIS）软件和技术进行了分析，同时还进行了定性数据分析。结果表明，耕地以每年 2.6%的速度扩张，而林地和草地则以每年 1.2%和 2.4%的速度萎缩。入侵的普罗斯皮拉·朱利弗拉（Prosopis juliflora）的面积从 1987 年的 3.7%扩大到 2016 年的 37.9%，年增长率为 1.2%。小规模和大规模商业灌溉农业的引入以及村庄化计划的实施，重点是将牧民转变为定居生活方式。因此，灌溉农业、村庄化、一系列干旱等气候变化、水坝的建设以及普罗斯皮拉·朱利弗拉（Prosopis juliflora）的迅速扩张是该研究区域土地利用/土地覆盖变化的主要驱动因素。尽管我们发现了一些积极的发展，例如基础设施和社会服务的改善（例如学校和家庭供水）、收入多样化以及普罗斯皮拉·朱利弗拉（Prosopis juliflora）带来的生态效益（例如盐碱地处理、碳封存和土壤侵蚀控制），但土地利用/土地覆盖变化也给该研究区域带来了一系列负面影响。土地利用/土地覆盖变化降低了牧场资源的质量，因为具有生态和经济价值的本地树木和草种的数量明显减少。因此，该研究区域的土地利用动态变化使传统的畜牧业生计系统变得更加脆弱。此外，村庄化计划的实施对社区产生了社会经济影响，并对生态系统造成了挑战，例如将生产性牧场转变为灌溉作物农场。因此，我们的研究结果表明，迫切需要进行相关政策干预，以支持畜牧业生计和景观，并修改村庄化以及灌溉农业计划的实施，更好地管理和控制研究区域普罗斯皮拉·朱利弗拉（Prosopis juliflora）的扩张。
