2000 Zambezi Delta Land Cover

What this data is A vector layer derived from a 30 m resolution land cover classification for the Zambezi Delta, mapped from Landsat ETM+ imagery. It represents vegetation and land cover types at the landscape scale, consistent with the ecological “pedo-ecological” framework established in a 1960 land cover classification map. Why we made it (purpose) Provide an end-of-century reference point for detecting land cover changes relative to the 1960 aerial photo classification. Support long-term analysis of ecological change, including mangrove extent, floodplain grasslands, palm savanna dynamics, and forest change. Inform conservation management of the Marromeu Complex and wider delta by quantifying shifts in habitats. Establish a repeatable, satellite-based baseline for future monitoring using medium-resolution sensors. How it was produced (lineage & processing) Source imagery Landsat 7 ETM+, 31 Aug 1999 (path 166, row 73), full-delta coverage. Landsat 5 TM, 13 Jul 1996, used to fill areas with cloud cover. Pre-processing Both images geo-referenced to a 1960's airphoto mosaic. False-colour composites generated from six ETM+ bands (blue, green, red, and three IR bands). Classification approach Supervised on-screen digitizing (ArcView GIS 3.x) at pixel level (30 × 30 m). Unsupervised classification (30 spectral ranges) was conducted in parallel to identify distinct signatures (e.g., mangroves, saline flats, papyrus swamp, palm savanna, acacia woodland). Results integrated: unsupervised clusters used as overlays to refine supervised mapping. Field support Extensive ground truthing from 1995–1999 aerial and ground surveys, with GPS-referenced transects documenting land cover and land use. Usage & limitations Appropriate for landscape-scale analysis (>1:100,000). Not suitable for fine-scale site-level mapping. Some seasonal/phenological effects possible; classification reflects August 1999 conditions. Cloud-masked areas were filled with 1996 TM data, which may slightly underrepresent late-1990s land use in small pockets. Citation Beilfuss, R.D. 2001. Hydrological disturbance, ecological dynamics, and restoration potential: the story of an African floodplain. Ph.D. dissertation. University of Wisconsin-Madison. Also published in: Beilfuss, R., Dutton, P., & Moore, D. (2000). Land Cover and Land Use Change in the Zambezi Delta. In Biodiversity of Zambezi Basin Wetlands, Vol. III: Land Use Change and Human Impacts. IUCN. Beilfuss, R.D., D. Moore, P. Dutton, and C. Bento. 2001. Patterns of vegetation change in the Zambezi Delta, Mozambique. Working paper #3 of the Program for the Sustainable Management of Cahora Bassa Dam and the Lower Zambezi Valley. International Crane Foundation, USA.数据集概述 本数据集为基于陆地卫星增强型专题制图仪（Landsat ETM+）影像绘制的赞比西河三角洲30米分辨率土地覆盖分类衍生矢量图层，表征景观尺度下的植被与土地覆盖类型，契合1960年土地覆盖分类图所确立的‘土壤生态学（pedo-ecological）’生态框架。 ## 研制目的 1. 提供1960年航空照片分类结果的世纪末参考基准，用于检测土地覆盖变化； 2. 支持红树林分布、泛滥平原草原、棕榈稀树草原动态及森林变化等生态变化的长期分析； 3. 通过量化生境变迁，为马鲁穆乌综合体及更大范围三角洲的保护管理提供决策依据； 4. 建立可重复的中分辨率卫星基线，用于未来的生态监测工作。 ## 生产流程与处理谱系 ### 原始影像数据源 - 1999年8月31日获取的陆地卫星7号增强型专题制图仪（Landsat 7 ETM+）影像（轨道号166，行号73），覆盖整个三角洲区域； - 采用1996年7月13日获取的陆地卫星5号专题制图仪（Landsat 5 TM）影像填补云覆盖区域。 ### 预处理流程 两幅影像均配准至1960年代航空影像镶嵌图；基于ETM+的蓝、绿、红及3个红外波段共6个波段生成假彩色合成影像。 ### 分类方法 采用基于像素级（30×30米）的监督式屏幕数字化分类（ArcView GIS 3.x）；同步开展30个光谱范围的非监督分类，以识别不同地物的光谱特征（如红树林、盐滩、纸莎草沼泽、棕榈稀树草原、金合欢林地）；将非监督分类得到的聚类结果作为叠加图层，用于优化监督分类的制图结果。 ### 野外支撑工作 1995至1999年开展了大量航空与地面调查，通过GPS参考样带记录土地覆盖与土地利用情况。 ## 使用范围与局限性 本数据集适用于景观尺度分析（比例尺不小于1:100000），不适用于精细化的场地级制图；可能存在一定季节/物候效应，分类结果反映1999年8月的地表状况；云覆盖区域通过1996年TM影像填补，可能小幅低估小范围区域内20世纪90年代末的土地利用情况。 ## 引用规范 1. Beilfuss, R.D. 2001. 水文扰动、生态动态与恢复潜力：非洲泛滥平原的故事. 博士学位论文. 威斯康星大学麦迪逊分校. 2. 另收录于：Beilfuss, R., Dutton, P., & Moore, D. (2000). 赞比西河三角洲土地覆盖与土地利用变化. 载于《赞比西流域湿地生物多样性 第三卷：土地利用变化与人类影响》. 国际自然保护联盟（IUCN）. 3. Beilfuss, R.D., D. Moore, P. Dutton, and C. Bento. 2001. 莫桑比克赞比西河三角洲植被变化模式. 《卡奥拉巴萨大坝与下赞比西河谷可持续管理计划》工作论文第3号. 国际鹤类基金会, 美国.