Vegetation - Suisun Marsh - 2024 [ds3221]

To create the 2024 Suisun Marsh vegetation map, vegetation was interpreted from a mosaic of the true color imagery that was flown in June 2024. Polygons were delineated using heads-up digitizing (i.e., a photo interpreter manually drew polygons around each stand of vegetation) in Esri's ArcGIS Pro 3.4.3, and polygon attributes were recorded within a file geodatabase. All attributes were interpreted using the Suisun Marsh 2024 imagery as the base imagery. The photo interpreters obtained information primarily from the 2021 map and 2024 reconnaissance points as reference data, which were used during mapping to determine vegetative signatures and the appropriate mapping type for each polygon. Several other imagery sources were used as ancillary data, including 2024 NAIP, 2024 NAIP Color Infrared, all imagery available through Google Earth (including street view), and the 2021 NAIP imagery. Minimum mapping unit (MMU): Typically, the minimum mapping size is 0.25 acres. However, the photo interpreters use their best judgment to determine if a stand below 0.25 acre should be separately delineated. For example, a smaller polygon would be appropriate for any new visible occurrence of a non-native species of concern, such as Phragmites australis, Arundo donax, Carpobrotus edulis, Eucalyptus spp., and Lepidium latifolium. Minimum mapping width: There are many long and narrow polygons within the Suisun Marsh study area, most of which are roads, ditches, levees, and sloughs. The minimum mapping width is typically 10 feet; however, if small sections of a stand fell below the minimum width, the polygon was not split. More information can be found in the project report, which is bundled with the vegetation map published for BIOS and available for viewing here: https://filelib.wildlife.ca.gov/Public/BDB/GIS/BIOS/Public_Datasets/3200_3299/ds3221.zip and here: https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=232836.为制作2024年苏森沼泽（Suisun Marsh）植被图，研究团队基于2024年6月航拍获取的真彩色影像镶嵌数据集开展植被解译工作。研究人员采用目视数字化（heads-up digitizing）技术，在Esri公司的ArcGIS Pro 3.4.3软件中，通过人工为每一处植被斑块勾勒多边形边界的方式完成面要素勾绘，并将面要素属性录入至文件地理数据库（file geodatabase）中。 所有属性信息均以2024年苏森沼泽影像作为基准影像进行解译判定。 目视解译人员主要以2021年植被图与2024年野外踏勘点位作为参考数据源，在制图过程中依托二者确定植被光谱特征与各面要素对应的适宜制图分类类型。 本次制图还辅以其他多源影像作为辅助数据源，包括2024年美国国家农业航空影像计划（National Agricultural Imagery Program，NAIP）真彩色影像、2024年NAIP彩色红外影像、谷歌地球（Google Earth）可获取的全部影像（含街景影像）以及2021年NAIP影像。 最小制图单元（Minimum Mapping Unit，MMU）：常规最小制图面积为0.25英亩。但目视解译人员可结合专业判断，决定是否对面积不足0.25英亩的植被斑块单独进行勾绘。 例如，当出现新发现的、需重点关注的外来入侵物种（如芦苇*Phragmites australis*、芦竹*Arundo donax*、长茎番杏*Carpobrotus edulis*、桉属*Eucalyptus* spp.及宽叶独行菜*Lepidium latifolium*）时，即便斑块面积小于阈值，也应单独勾勒多边形边界。 最小制图宽度：苏森沼泽研究区内存在大量狭长面要素，多数为道路、沟渠、堤坝及河汊。常规最小制图宽度为10英尺；但若某植被斑块的局部片段宽度低于阈值，无需对该面要素进行拆分。 更多详细信息可查阅随BIOS项目发布的配套植被图项目报告，相关报告可通过以下链接获取：https://filelib.wildlife.ca.gov/Public/BDB/GIS/BIOS/Public_Datasets/3200_3299/ds3221.zip 及 https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=232836。