Department of Geography and Environmental Studies, Madda Walabu University, Robe, Ethiopia.
Department of Geography and Environmental Studies, Woldia University, Woldia, Ethiopia.
Environ Monit Assess. 2021 Jun 28;193(7):453. doi: 10.1007/s10661-021-09222-8.
Rangeland in Bale lowlands has been seriously degraded due to human-induced problems and natural factors. The study was conducted to analyze LULC change and its deriving factors and evaluate the impacts of rangeland dynamics on livestock mobility in Bale lowlands from 1990-2020. Landsat Thematic Mapper (TM) 1990, Enhanced Thematic Mapper Plus (ETM +) 2000, and Operational Land Imager (OLI) 2014 and 2020 were chosen to derive LULC classes using maximum likelihood image classifier. Besides, a household survey was used to understand the major causes of LULC change, as well as the impacts of rangeland dynamics on livestock mobility. The accuracy reports of classified LULC classes of the study were 88.2% (1990), 89.19% (2000), 93.8% (2014), and 95.2% (2020). The result of the study revealed that there was extreme bush encroachment (545.54%), expansion of settlement (19,166%), and farmland (171.27%) while forest cover has slightly decreased (-8.76%) from 1990 to 2020. On the other hand, shrubland (-72.74%) and grassland (-59.2%) have extremely declined. During the study period, rangeland of Bale lowlands was degraded with annual rate of -0.8%. The study also revealed that expansion of farmland, settlement, communal land, and bush encroachment was the main driving factors for LULC change in Bale lowlands. Bale pastoralists are vulnerable to the death of their livestock, and they need to travel long distances because of rapid rangeland degradation. Therefore, suitable land-use and management policies for pastoral communities should be formulated and implemented so as to permanently mitigate the problem.
由于人为问题和自然因素，贝尔低地的牧场已经严重退化。本研究旨在分析 1990-2020 年间贝尔低地土地利用/土地覆盖变化及其驱动因素，并评估牧场动态对牲畜流动性的影响。选择 Landsat 专题制图仪（TM）1990 年、增强型专题制图仪 Plus（ETM+）2000 年和操作陆地成像仪（OLI）2014 年和 2020 年，使用最大似然图像分类器得出土地利用/土地覆盖类别。此外，还进行了一项家庭调查，以了解土地利用/土地覆盖变化的主要原因，以及牧场动态对牲畜流动性的影响。研究中分类土地利用/土地覆盖类别的准确率报告为 88.2%（1990 年）、89.19%（2000 年）、93.8%（2014 年）和 95.2%（2020 年）。研究结果表明，从 1990 年到 2020 年，灌木林大量蔓延（545.54%）、定居点扩张（19166%）和农田（171.27%），而森林覆盖面积略有减少（-8.76%）。另一方面，灌木林地（-72.74%）和草地（-59.2%）急剧减少。在研究期间，贝尔低地的牧场以每年-0.8%的速度退化。研究还表明，农田、定居点、公共土地和灌木林的扩张是贝尔低地土地利用/土地覆盖变化的主要驱动因素。贝尔牧民容易遭受牲畜死亡的影响，由于牧场迅速退化，他们需要长途旅行。因此，应该制定和实施适合牧民社区的土地利用和管理政策，以永久缓解这一问题。
