Wetlands of the Lowland Amazon Basin: Extent, Vegetative Cover, and Dual-season Inundated Area as Mapped with JERS-1 Synthetic Aperture Radar
Wetlands of the Lowland Amazon Basin: Extent, Vegetative Cover, and Dual-season Inundated Area as Mapped with JERS-1 Synthetic Aperture Radar
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DOI：
10.1007/s13157-015-0666-y
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发表时间：
2015-08-01
期刊：
影响因子：
2
通讯作者：
Novo, Evlyn M. L. M.
中科院分区：
文献类型：
--
作者：
Hess, Laura L.;Melack, John M.;Novo, Evlyn M. L. M.
使用日本地球资源卫星 (JERS-1) 在 1995 年至 1996 年枯水期和丰水期获取的马赛克图像，首次以中等高 (100 m) 的分辨率绘制了整个低地亚马逊盆地的湿地范围、植被覆盖和淹没状态。通过马赛克的分割和所得多边形的聚类来创建湿地掩模；然后应用一套规则，利用双季节反向散射值将湿地地区分为五个土地覆盖类别和两个洪水类别。地图上的湿地面积为8.4 x 10(5) km(2)，相当于流域总面积(5.83 x 10(6) km(2))的14%和低地盆地(5.06 x 10(6) km(2))的17%。丰水期，开阔水面占湿地面积的9%，木本植被占77%，水生植物占14%。使用高分辨率数字摄像评估的生产者的湿地范围准确度优于 85%。绘制的洪水范围代表了南纬 6A 度以北纬度地区的平均高洪水和低洪水情况；流域南部地区的洪水状况捕捉得不太好。来自低分辨率光学传感器的全球数据集捕获的湿地面积不到 25%。
Wetland extent, vegetation cover, and inundation state were mapped for the first time at moderately high (100 m) resolution for the entire lowland Amazon basin, using mosaics of Japanese Earth Resources Satellite (JERS-1) imagery acquired during low- and high-water seasons in 1995-1996. A wetlands mask was created by segmentation of the mosaics and clustering of the resulting polygons; a rules set was then applied to classify wetland areas into five land cover classes and two flooding classes using dual-season backscattering values. The mapped wetland area of 8.4 x 10(5) km(2) is equivalent to 14 % of the total basin area (5.83 x 10(6) km(2)) and 17 % of the lowland basin (5.06 x 10(6) km(2)). During high-water season, open water surfaces accounted for 9 % of the wetland area, woody vegetation 77 %, and aquatic macrophytes 14 %. Producer's accuracy as assessed using high-resolution digital videography was better than 85 % for wetland extent. The mapped flooding extent is representative of average high- and low-flood conditions for latitudes north of 6A degrees S; flooding conditions were less well captured for the southern part of the basin. Global data sets derived from lower-resolution optical sensors capture less than 25 % of the wetland area mapped here.