Estuarine Vegetation, BotanyBay, 1998. VIS_ID 4133

Coverage showing the distribution of seagrass, mangrove and saltmarsh Botany Bay derived from recent aerial photographs.\r\n\r\nAerial photographs from 1995 at 1:16 000 scale were used to map mangrove, saltmarsh and seagrass in Botany Bay. Vegetation boundaries were digitised from images created by scanning and rubbersheeting the photographs with ground control points and were checked by field surveys undertaken in June and July 1998. The area of each vegetation type was calculated in IDRISI GIS software and recently transferred to ERDAS IMAGINE format.\r\n\r\nAMG coordinates obtained from a +/-1m DGPS and 1:10 000 orthophotomaps were used to resample classified images to a 2m grid with RMS errors of between 2.55 and 5.37 for individual images.\r\n\r\nVegetation boundaries were identified on aerial photographs and the boundaries were confirmed in the field and the species identification checked. Families or in some case species of vegetation were mapped in the following categories: Zostera capricorni, Sparse Zostera, Posidonia australis, Mixed Posidonia (indicating presence of P. australis and Z. capricorni and/or Halophila spp.), Mixed Halophila (indicating presence of Halophila spp and Z. capricorni and/or P. australis which occurs on the southern shore only.) saltmarsh (all species combined), mangroves (all species combined) and Kelp (all species combined). Kelp was mapped incidentally and does not represent the full extent of this group of aquatic plants within Botany Bay.\r\n\r\nAll cells within the Grid are coded for the given attributes.\r\n\r\nClassification to species level is complete for seagrass only. Kelp was mapped incidentally and does not represent the full extent of this group of aquatic plants within Botany Bay.\r\n\r\nSimilar data was collected and mapped in 1985 in nondigital format and published in West, R.J., Thorogood, C.A. Walford, T.R. and Williams, R.J. (1985) An estuarine inventory for New South Wales, Australia. N.S.W. Department of Agriculture, Fisheries Bulletin No. 2, 140 pp.\r\nVIS_ID 4133

本数据集呈现了博塔尼湾（Botany Bay）内海草、红树林与盐沼的空间分布，数据源自近期航空航拍照片解译成果。

本次研究采用1995年拍摄、比例尺为1:16000的航空航拍照片，对博塔尼湾内的红树林、盐沼与海草开展制图工作。植被边界通过扫描航空照片后，结合地面控制点进行橡皮映射（rubbersheeting）生成校正影像，再从中数字化提取，并于1998年6月至7月通过野外实地调查完成核验。各类植被类型的面积通过IDRISI地理信息系统（GIS）软件计算得出，近期已转换为ERDAS IMAGINE格式文件。

采用精度为±1米的差分全球定位系统（DGPS, Differential Global Positioning System）获取的澳大利亚地图格网（AMG, Australian Map Grid）坐标，以及1:10000比例尺的正射影像图，将分类后的影像重采样为2米分辨率的栅格网格，单幅影像的均方根误差（RMS, Root Mean Square Error）介于2.55至5.37之间。

植被边界首先在航空航拍照片上解译识别，随后通过野外实地调查确认边界并核验物种鉴定结果。本次制图将植被按科或部分物种划分为以下类别：卡普里大叶藻（Zostera capricorni）、稀疏大叶藻（Sparse Zostera）、澳洲波喜荡草（Posidonia australis）、混合波喜荡草（Mixed Posidonia，指同时存在澳洲波喜荡草与卡普里大叶藻和/或喜盐草属（Halophila spp.）物种的群落）、混合喜盐草（Mixed Halophila，指仅分布于博塔尼湾南岸的喜盐草属（Halophila spp.）物种与卡普里大叶藻和/或澳洲波喜荡草共存的群落）、盐沼（所有盐沼物种合并统计）、红树林（所有红树林物种合并统计）以及大型褐藻（Kelp，所有该类群物种合并统计）。需注意，大型褐藻仅为附带制图对象，并未涵盖博塔尼湾内该类群水生植物的完整分布范围。

网格内的所有栅格单元均已按照预设属性完成编码。

仅海草类群完成了物种级别的分类制图。大型褐藻的制图仍为附带开展，未覆盖博塔尼湾内该类群水生植物的完整分布范围。

1985年曾以非数字化格式采集并绘制过同类数据集，相关成果发表于West R.J.、Thorogood C.A.、Walford T.R.及Williams R.J.（1985）所著的《澳大利亚新南威尔士州河口清查名录》，刊载于新南威尔士州农业与渔业部《渔业通报第2号》，全文共140页。

数据集VIS_ID：4133