USA SSURGO - Soil Hydric Class

Hydric soils are soils that form under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions in the upper part of the soil. Hydric soils are poorly or very poorly drained and under natural conditions, these soils are either saturated or inundated long enough during the growing season to support the growth and reproduction of wetland vegetation. Hydric soils are part of the legal definition for wetlands in the United States and are used to identify wetland areas that require a permit issued by the Army Corps of Engineers under Section 404 of the Clean Water Act prior to any ground disturbing activities. For more information on hydric soils see the Natural Resources Conservation Service’s publication Field Indicators of Hydric Soils in the United States. Dataset Summary Phenomenon Mapped: Hydric soils Geographic Extent: Contiguous United States, Alaska, Hawaii, Puerto Rico, Guam, US Virgin Islands, Northern Mariana Islands, Republic of Palau, Republic of the Marshall Islands, Federated States of Micronesia, and American Samoa. Projection: Web Mercator Auxiliary Sphere Data Coordinate System: WKID 5070 USA Contiguous Albers Equal Area Conic USGS version (contiguous US, Puerto Rico, US Virgin Islands), WKID 3338 WGS 1984 Albers (Alaska), WKID 4326 WGS 1984 Decimal Degrees (Guam, Republic of the Marshall Islands, Northern Mariana Islands, Republic of Palau, Federated States of Micronesia, American Samoa, and Hawaii). Units: Percent Cell Size: 30 meters Source Type: Discrete Pixel Type: Unsigned integer Source: Natural Resources Conservation Service Update Frequency: Annual Publication Date: December 2025 Data from the gNATSGO database was used to create the layer. This layer is derived from the 30m rasters produced by the Natural Resources Conservation Service (NRCS). The value for hydric class is derived from the gSSURGO map unit aggregated attribute table field Hydric Classification - Presence (hydclprs). What can you do with this layer? This layer is suitable for both visualization and analysis acrossthe ArcGIS system. This layer can be combined with your data and other layers from the ArcGIS Living Atlas of the World in ArcGIS Online and ArcGIS Pro to create powerful web maps that can be used alone or in a story map or other application. Because this layer is part of the ArcGIS Living Atlas of the World it is easy to add to your map: In ArcGIS Online, you can add this layer to a map by selecting Add then Browse Living Atlas Layers. A window will open. Type "hydric" in the search box and browse to the layer. Select the layer then click Add to Map. In ArcGIS Pro, open a map and select Add Data from the Map Tab. Select Data at the top of the drop down menu. The Add Data dialog box will open on the left side of the box, expand Portal if necessary, then select Living Atlas. Type "hydric" in the search box, browse to the layer then click OK. In ArcGIS Pro you can use the built-in raster functions or create your own to create custom extracts of the data. Imagery layers provide fast, powerful inputs to geoprocessing tools, models, or Python scripts in Pro. Online you can filter the layer to show subsets of the data using the filter button and the layer's built-in raster functions. The ArcGIS Living Atlas of the World provides an easy way to explore many otherbeautiful and authoritative maps on hundreds of topics like this one. Read more in our blogs: Analyzing Soil Capability for Agriculture in the Living Atlas of the World Working with Soil Data from the Living Atlas in ArcGIS Pro Questions? Please leave a comment below if you have a question about this layer, and we will get back to you as soon as possible.水文土壤（Hydric soils）指在生长季长期处于饱和、淹没或积水状态，致使土壤上层形成厌氧环境的土壤。水文土壤排水不良或极差，在自然条件下，这类土壤在生长季长期处于饱和或淹没状态，足以支撑湿地植被的生长与繁衍。 水文土壤是美国湿地法定定义的组成部分，用于识别需依据《清洁水法》（Clean Water Act）第404条，由美国陆军工程兵团（Army Corps of Engineers）发放许可后方可开展地面扰动活动的湿地区域。如需了解更多水文土壤相关信息，请参阅美国自然资源保护服务局（Natural Resources Conservation Service，NRCS）的出版物《美国水文土壤野外指示标志》。 数据集摘要 制图现象：水文土壤 地理覆盖范围：美国本土、阿拉斯加、夏威夷、波多黎各、关岛、美属维尔京群岛、北马里亚纳群岛、帕劳共和国、马绍尔群岛共和国、密克罗尼西亚联邦和美属萨摩亚。 投影：Web Mercator Auxiliary Sphere 数据坐标系：WKID 5070 美国本土阿尔伯斯等面积圆锥投影（美国本土、波多黎各、美属维尔京群岛）；WKID 3338 WGS 1984 阿尔伯斯投影（阿拉斯加）；WKID 4326 WGS 1984 十进制度（关岛、马绍尔群岛共和国、北马里亚纳群岛、帕劳共和国、密克罗尼西亚联邦、美属萨摩亚及夏威夷）。 单位：百分比 像元大小：30米 源数据类型：离散型 像元类型：无符号整数 数据源：美国自然资源保护服务局 更新频率：年度更新 发布日期：2025年12月 本图层基于gNATSGO数据库制作而成，源自NRCS生成的30米栅格数据。水文等级数值源自聚合后的gSSURGO制图单元属性表字段"Hydric Classification - Presence (hydclprs)"。 可使用本图层进行何种操作？ 本图层适用于ArcGIS系统内的可视化与分析工作。可在ArcGIS Online及ArcGIS Pro中，将本图层与您自有数据及ArcGIS世界生活地图集（ArcGIS Living Atlas of the World）的其他图层相结合，制作可独立使用的优质Web地图，或应用于故事地图及其他程序中。由于本图层属于ArcGIS世界生活地图集的一部分，因此可轻松添加至您的地图中： 在ArcGIS Online中，可通过依次选择「添加」→「浏览生活地图集图层」将本图层添加至地图。届时将弹出窗口，在搜索框中输入"hydric"，浏览至目标图层后选中并点击「添加至地图」即可。 在ArcGIS Pro中，打开地图并选择「地图」选项卡中的「添加数据」。在下拉菜单顶部选择「数据」，左侧将弹出「添加数据」对话框，如有需要请展开「门户」选项，随后选择「生活地图集」。在搜索框中输入"hydric"，浏览至目标图层后点击「确定」。 在ArcGIS Pro中，可使用内置栅格工具或自定义工具对数据进行定制化提取。影像图层可为Pro中的地理处理工具、模型或Python脚本提供高效优质的输入源。在线环境中，可通过筛选按钮及图层内置的栅格功能过滤图层，以显示数据子集。 ArcGIS世界生活地图集提供了便捷途径，可探索数百个主题下的众多优质权威地图，本图层即为其中一例。更多详情可参阅我们的博客文章： 1. 《分析世界生活地图集中的农业土壤生产力》 2. 《在ArcGIS Pro中使用生活地图集的土壤数据》 如有疑问？请在下方留言，我们将尽快回复您。