{"title":"遥感揭示了武装冲突如何使埃塞俄比亚提格雷的木本植被覆盖和生态系统恢复工作倒退","authors":"Emnet Negash , Emiru Birhane , Aster Gebrekirstos , Mewcha Amha Gebremedhin , Sofie Annys , Meley Mekonen Rannestad , Daniel Hagos Berhe , Amare Sisay , Tewodros Alemayehu , Tsegai Berhane , Belay Manjur Gebru , Negasi Solomon , Jan Nyssen","doi":"10.1016/j.srs.2023.100108","DOIUrl":null,"url":null,"abstract":"<div><p>In recent years, armed conflicts are globally on the rise, causing drastic human and environmental harm. The Tigray war in Ethiopia is one of the recent violent conflicts that has abruptly reversed decades of ecosystem restoration efforts. This paper analyzes changes in woody vegetation cover during the period of armed conflict (2020–2022) using remote sensing techniques, supplemented by field testimony and secondary data. Extent of woody vegetation cover was analyzed using Normalized Difference Vegetation Index (NDVI) thresholding method from Sentinel 2 images in Google Earth Engine, and scale of de-electrification was qualitatively analyzed from Black Marble HD nighttime lights dataset, acquired from NASA's Black Marble team. The magnitude, direction as well as the mechanisms of change in woody vegetation cover varied across the region and over time. Tigray's woody vegetation cover fluctuated within 20% of the landmass. Mainly scattered to mountainous areas, the dry Afromontane forest cover declined from about 17% in 2020 to 15% in 2021, and 12% in 2022. About 17% of the overall decline was observed between 500 m and 2000 m elevation, where there is higher anthropogenic pressure. Land restoration practices meant to avert land degradation and desertification were interrupted and the area turned warfare ground. In many areas, forests were burned, the trees cut and the area became barren. The suspension of public services such as electricity for household or industrial use created heavy reliance on firewood and charcoal, further threatening to compound weather and climate. The magnitude of disturbance in a region that is already at a very high risk of desertification requires urgent national and international attention. Continued ecosystem disturbance could eventually make the domain part of a wider desert connecting the Sahel to the Afar Triangle, a scenario which may render the area uninhabitable.</p></div>","PeriodicalId":101147,"journal":{"name":"Science of Remote Sensing","volume":"8 ","pages":"Article 100108"},"PeriodicalIF":5.7000,"publicationDate":"2023-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666017223000330/pdfft?md5=b658e500bf436724e013108160162f3f&pid=1-s2.0-S2666017223000330-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Remote sensing reveals how armed conflict regressed woody vegetation cover and ecosystem restoration efforts in Tigray (Ethiopia)\",\"authors\":\"Emnet Negash , Emiru Birhane , Aster Gebrekirstos , Mewcha Amha Gebremedhin , Sofie Annys , Meley Mekonen Rannestad , Daniel Hagos Berhe , Amare Sisay , Tewodros Alemayehu , Tsegai Berhane , Belay Manjur Gebru , Negasi Solomon , Jan Nyssen\",\"doi\":\"10.1016/j.srs.2023.100108\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>In recent years, armed conflicts are globally on the rise, causing drastic human and environmental harm. The Tigray war in Ethiopia is one of the recent violent conflicts that has abruptly reversed decades of ecosystem restoration efforts. This paper analyzes changes in woody vegetation cover during the period of armed conflict (2020–2022) using remote sensing techniques, supplemented by field testimony and secondary data. Extent of woody vegetation cover was analyzed using Normalized Difference Vegetation Index (NDVI) thresholding method from Sentinel 2 images in Google Earth Engine, and scale of de-electrification was qualitatively analyzed from Black Marble HD nighttime lights dataset, acquired from NASA's Black Marble team. The magnitude, direction as well as the mechanisms of change in woody vegetation cover varied across the region and over time. Tigray's woody vegetation cover fluctuated within 20% of the landmass. Mainly scattered to mountainous areas, the dry Afromontane forest cover declined from about 17% in 2020 to 15% in 2021, and 12% in 2022. About 17% of the overall decline was observed between 500 m and 2000 m elevation, where there is higher anthropogenic pressure. Land restoration practices meant to avert land degradation and desertification were interrupted and the area turned warfare ground. In many areas, forests were burned, the trees cut and the area became barren. The suspension of public services such as electricity for household or industrial use created heavy reliance on firewood and charcoal, further threatening to compound weather and climate. The magnitude of disturbance in a region that is already at a very high risk of desertification requires urgent national and international attention. Continued ecosystem disturbance could eventually make the domain part of a wider desert connecting the Sahel to the Afar Triangle, a scenario which may render the area uninhabitable.</p></div>\",\"PeriodicalId\":101147,\"journal\":{\"name\":\"Science of Remote Sensing\",\"volume\":\"8 \",\"pages\":\"Article 100108\"},\"PeriodicalIF\":5.7000,\"publicationDate\":\"2023-11-11\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S2666017223000330/pdfft?md5=b658e500bf436724e013108160162f3f&pid=1-s2.0-S2666017223000330-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Science of Remote Sensing\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2666017223000330\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENVIRONMENTAL SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Science of Remote Sensing","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2666017223000330","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
摘要
近年来,全球武装冲突呈上升趋势,对人类和环境造成严重危害。埃塞俄比亚的提格雷战争是最近的暴力冲突之一,它突然扭转了几十年来的生态系统恢复努力。本文利用遥感技术,结合实地证词和二手数据,分析了武装冲突期间(2020-2022年)木本植被覆盖的变化。采用归一化植被指数(NDVI)阈值法对Google Earth Engine Sentinel 2图像中的木本植被覆盖范围进行分析,并对NASA Black Marble团队获取的Black Marble高清夜间灯光数据集进行定性分析。木本植被覆盖变化的幅度、方向和机制在不同区域和不同时期都存在差异。提格雷的木本植被覆盖在陆地面积的20%上下波动。非洲干旱森林主要分布在山区,从2020年的17%左右下降到2021年的15%,到2022年下降到12%。在海拔500米至2000米之间观测到的总降幅约为17%,该区域的人为压力较高。旨在避免土地退化和荒漠化的土地恢复措施被中断,该地区变成了战场。在许多地区,森林被烧毁,树木被砍伐,这片地区变得贫瘠。家庭或工业用电等公共服务的中断造成了对木柴和木炭的严重依赖,进一步威胁到天气和气候的恶化。在一个已经处于非常高的沙漠化风险的区域发生如此严重的动乱,需要国家和国际社会的紧急关注。持续的生态系统干扰可能最终使该地区成为连接萨赫勒和阿法尔三角的更广阔沙漠的一部分,这种情况可能使该地区无法居住。
Remote sensing reveals how armed conflict regressed woody vegetation cover and ecosystem restoration efforts in Tigray (Ethiopia)
In recent years, armed conflicts are globally on the rise, causing drastic human and environmental harm. The Tigray war in Ethiopia is one of the recent violent conflicts that has abruptly reversed decades of ecosystem restoration efforts. This paper analyzes changes in woody vegetation cover during the period of armed conflict (2020–2022) using remote sensing techniques, supplemented by field testimony and secondary data. Extent of woody vegetation cover was analyzed using Normalized Difference Vegetation Index (NDVI) thresholding method from Sentinel 2 images in Google Earth Engine, and scale of de-electrification was qualitatively analyzed from Black Marble HD nighttime lights dataset, acquired from NASA's Black Marble team. The magnitude, direction as well as the mechanisms of change in woody vegetation cover varied across the region and over time. Tigray's woody vegetation cover fluctuated within 20% of the landmass. Mainly scattered to mountainous areas, the dry Afromontane forest cover declined from about 17% in 2020 to 15% in 2021, and 12% in 2022. About 17% of the overall decline was observed between 500 m and 2000 m elevation, where there is higher anthropogenic pressure. Land restoration practices meant to avert land degradation and desertification were interrupted and the area turned warfare ground. In many areas, forests were burned, the trees cut and the area became barren. The suspension of public services such as electricity for household or industrial use created heavy reliance on firewood and charcoal, further threatening to compound weather and climate. The magnitude of disturbance in a region that is already at a very high risk of desertification requires urgent national and international attention. Continued ecosystem disturbance could eventually make the domain part of a wider desert connecting the Sahel to the Afar Triangle, a scenario which may render the area uninhabitable.