Maryland Archived Submerged Aquatic Vegetation - SAV 2018

The 2018 Chesapeake Bay SAV Coverage was mapped from digital multispectral imagery with a 25cm GSD to assess water quality in the Bay. Each area of SAV was interpreted from the rectified imagry and classified into one of four density classes by the percentage of cover. The SAV beds were entered into an SDE GIS fetaure class using the quality control procedures documented below. The dataset contains all SAV areas that were identified from the areas flown. Some areas that are presumed to contain no SAV were not flown. Some small beds, particularly along narrow tributaries may not have been distinguishable on the aerial photography. This is a MD iMAP hosted service. Find more information on https://imap.maryland.gov. Feature Link Service: https://mdgeodata.md.gov/archive/rest/services/Biota/MD_ArchivedSubmergedAquaticVegetation/FeatureServer/332018年切萨皮克湾沉水水生植物（Submerged Aquatic Vegetation, SAV）覆盖范围数据集，采用25厘米地面采样距离（Ground Sample Distance, GSD）的数字多光谱影像进行制图，旨在评估该海湾的水质状况。所有沉水水生植物区域均通过校正后的影像解译获取，并依据植被覆盖百分比划分为四个密度等级之一。沉水水生植物床通过下述文档记录的质量控制流程，被录入至空间数据引擎（Spatial Database Engine, SDE）地理信息系统（Geographic Information System, GIS）要素类中。本数据集涵盖了所有在航拍作业区域内识别出的沉水水生植物分布区域。部分被认定无沉水水生植物生长的区域未纳入航拍范围。部分小型沉水水生植物床，尤其是沿狭窄支流分布的此类床体，可能无法在航空摄影影像中被识别。本数据集为马里兰州iMAP（MD iMAP）托管服务。更多信息可访问：https://imap.maryland.gov。要素链接服务地址：https://mdgeodata.md.gov/archive/rest/services/Biota/MD_ArchivedSubmergedAquaticVegetation/FeatureServer/33