Maryland Archived Submerged Aquatic Vegetation - SAV 2016

The 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 imagery and classified into one of four density classes by the percentage of cover. The SAV beds were entered into an SDE GIS feature 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 Service Link: https://mdgeodata.md.gov/archive/rest/services/Biota/MD_ArchivedSubmergedAquaticVegetation/FeatureServer/31切萨皮克湾沉水水生植被（Submerged Aquatic Vegetation, SAV）覆盖范围采用地面采样距离（Ground Sample Distance, GSD）为25厘米的数字多光谱影像进行制图，以评估该海湾的水质状况。所有沉水水生植被区域均通过几何校正后的影像解译得到，并依据覆盖百分比划分为四个密度等级之一。沉水水生植被床按照下文所述的质量控制流程，被导入至空间数据库引擎（Spatial Database Engine, SDE）地理信息系统（GIS）要素类中。本数据集涵盖了所有航空测绘区域内识别出的沉水水生植被区域。部分被认定无沉水水生植被的区域未开展航空测绘作业。部分小型沉水水生植被床，尤其是沿狭窄支流分布的植被床，可能无法在航空影像中被识别。本服务由马里兰州iMAP（MD iMAP）托管。更多信息可访问：https://imap.maryland.gov。要素服务链接：https://mdgeodata.md.gov/archive/rest/services/Biota/MD_ArchivedSubmergedAquaticVegetation/FeatureServer/31