Water Related Land Use Statewide (2023) (Features)

For a file geodatabase (.gdb) Click Here (includes files used to create data). For the final report, full documentation, and metadata Click Here. Feature Classes are loaded onto tablet PCs and Field crews are sent to label the crop or land cover type and irrigation method for a subset of select fields or polygons. Each tablet PC is attached to a GPS unit for real-time tracking to continuously update the field crew’s location during the field labeling process. Digitizing is done as Geodatabase feature classes using ArcPro 3.2.1 with Sentinel imagery as a background with other layers added for reference. Updates to existing field boundaries of individual agricultural fields, urban areas and more are precisely digitized. Changes in irrigation type and land use are noted during this process. Cropland Data Layer (CDL) rasters from the United States Department of Agriculture (USDA) National Agricultural Statistics Service (NASS) are downloaded for the appropriate year. https://nassgeodata.gmu.edu/CropScape/ Zonal Statistics geoprocessing tools are used to attribute the polygons with updated crop types from the CDL. The data is then run through several stages of comparison to historical inventories and quality checking in order to determine and produce the final attributes. Attributes Landuse– A general land cover classification differentiating how the land is used Agriculture: Land managed for crop or livestock purposes Other: A broad classification of wildland Riparian/Wetland: Wildland influenced by a high water table, often close to surface water Urban: Developed areas, includes urban greenspace such as parks. Water: Surface water such as wet flats, streams, and lakes. CropGroup– Groupings of broader crop categories to allow easy access to or query of all orchard or grain types etc. Description– Attribute that describes/indicates the various crop types and land use types determined by the GIS process. IRR_Method– Crop Irrigation Method carried over from statewide field surveys ending in 2015 and updated based on imagery and yearly field checks. Drip: Water is applied through lines that slowly release water onto the surface or subsurface of the crop Dry Crop: No irrigation method is applied to this agricultural land, the crop is irrigated via natural processes. Flood: Water is diverted from ditches or pipes upland from the crop in sufficient quantities to flood the irrigated plot None: Associated with non-agricultural land Sprinkler: Water is applied above the crop via sprinklers that generally move across the field. Sub-irrigated: This land does not have irrigation water applied, but due to a high water table receives more water, and is generally closely associated with a riparian area Acres– Calculated acreage of the polygon. State– State where the polygons are found. County– County where the polygons are found. Basin– The hydrologic basin where the polygons are found, closely related to HUC 6. These basin boundaries were created by DWRe to include portions of other basins that have inter-basin flows for management purposes. SubArea– The subarea where the polygons are found, closely related to the HUC 8. Subareas are subdivisions of the larger hydrologic basins created by DWRe. Label_Class– Combination of Label and Class_Name fields created during processing that indicates the specific crop, irrigation, and whether the CDL classified the land as a similar crop or an “Other” crop. LABEL– A shorthand descriptive label for each crop description and irrigation type. Class_Name– The majority pixel value from the USDA CDL Cropscape raster layer within the polygon, may differ from final crop determination (Description). OldLanduse– Similar to Landuse, but splits the agricultural land further depending on irrigation. Pre-2017 datasets defined this as Landuse. LU_Group– These codes represent some in-house groupings that are useful for symbology and other summarizing. SURV_YEAR– Indicates which year/growing season the data represents.文件地理数据库（File Geodatabase, .gdb）相关文件可点击此处下载，其中包含用于构建该数据集的全部素材。最终报告、完整文档及元数据可点击此处获取。 将要素类（Feature Classes）加载至平板电脑（Tablet PC），并安排野外作业人员对选定的部分田块或多边形地块开展作物、土地覆被类型与灌溉方式的标注工作。每台平板电脑均搭载全球定位系统（Global Positioning System, GPS）单元，实现实时追踪，在野外标注流程中持续更新作业人员的位置信息。数字化作业采用ArcPro 3.2.1软件生成地理数据库要素类（Geodatabase feature classes），以哨兵（Sentinel）影像作为底图，并叠加其他参考图层辅助作业。针对单个农田、城区等现有地块的边界开展精准数字化更新，并在作业过程中记录灌溉类型与土地利用的变化情况。 从美国农业部（United States Department of Agriculture, USDA）下属的国家农业统计服务中心（National Agricultural Statistics Service, NASS）下载对应年份的作物数据层（Cropland Data Layer, CDL）栅格数据，下载地址为：https://nassgeodata.gmu.edu/CropScape/。使用分区统计（Zonal Statistics）地理处理工具，为多边形地块赋予CDL中更新后的作物类型属性。随后，该数据集将经过多轮与历史清单的比对及质量检查流程，以确定并生成最终属性字段。 ### 属性字段说明 1. **Landuse（土地利用类型）**：通用土地覆被分类体系，用于区分土地利用方式，具体分类如下： - Agriculture（农用地）：用于作物种植或畜牧生产的土地 - Other（其他野生地）：野生区域的宽泛分类 - Riparian/Wetland（河岸/湿地）：受高地下水位影响、通常邻近地表水的野生区域 - Urban（城区）：已开发建设区域，包含公园等城市绿地 - Water（水体）：地表水，如滩涂、溪流与湖泊 2. **CropGroup（作物组别）**：宽泛的作物类别分组，便于快速查询所有果园、谷物等作物类型 3. **Description（描述信息）**：该属性用于描述或标注通过地理信息系统（Geographic Information System, GIS）流程确定的各类作物类型与土地利用类型 4. **IRR_Method（灌溉方式）**：该字段数据源自截至2015年的全州田间调查结果，并基于影像数据与年度野外核查进行更新，具体类型包括： - Drip（滴灌）：通过输水管道缓慢向作物地表或地下区域供水的灌溉方式 - Dry Crop（旱地作物）：该农用地未施加人工灌溉，作物仅依靠自然过程获取水分 - Flood（漫灌）：从作物上游的沟渠或管道引水，以足够水量淹没灌溉地块的灌溉方式 - None（无灌溉）：对应非农业用地 - Sprinkler（喷灌）：通过喷头向作物上方喷水的灌溉方式，通常可在田间移动作业 - Sub-irrigated（浸润灌溉/地下灌溉）：该地块未施加人工灌溉水，但因高地下水位获得充足水分，通常与河岸区域密切相关 5. **Acres（地块面积）**：多边形地块的英亩（acre）计算面积 6. **State（所属州）**：多边形地块所在的州级行政区域 7. **County（所属县）**：多边形地块所在的县级行政区域 8. **Basin（水文流域）**：多边形地块所在的水文流域，与美国地质调查局水文单元代码6级（Hydrologic Unit Code 6, HUC 6）密切相关。该流域边界由DWRe划定，包含因跨流域流动而纳入管理的其他流域部分区域 9. **SubArea（子流域）**：多边形地块所在的子流域，与美国地质调查局水文单元代码8级（Hydrologic Unit Code 8, HUC 8）密切相关。子流域是由DWRe划定的大型水文流域的细分单元 10. **Label_Class（标注类别）**：处理流程中生成的`Label`与`Class_Name`字段的组合值，用于指示具体作物类型、灌溉方式，以及CDL分类的作物是否与最终确定的作物类型一致或属于"Other"类别 11. **LABEL（简化标签）**：每种作物描述与灌溉类型的简写说明 12. **Class_Name（类别名称）**：多边形内USDA CDL Cropscape栅格图层的多数像素值，可能与最终作物判定结果（Description）存在差异 13. **OldLanduse（旧土地利用类型）**：与Landuse类似，但会根据灌溉方式进一步细分农用地。2017年之前的数据集将该字段直接定义为Landuse 14. **LU_Group（土地利用分组代码）**：这些代码代表部分内部自定义分组，可用于符号化制图及其他汇总分析工作 15. **SURV_YEAR（调查年份）**：指示数据对应的年份或生长季