Water Related Land Use Statewide (2022) (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 3.1.0 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）相关内容请点击此处（包含用于构建数据集的原始文件）；最终报告、完整文档及元数据请点击此处。 要素类将被加载至平板电脑，野外作业人员将对选定的部分地块或多边形进行作物、土地覆被类型及灌溉方式的标注。每台平板电脑均搭载全球定位系统（Global Positioning System, GPS）单元，可进行实时定位追踪，在野外标注过程中持续更新作业人员的位置信息。 本次数字化工作基于ArcPro 3.1.0平台完成，以哨兵（Sentinel）影像作为底图并叠加其他参考图层，生成地理数据库要素类。研究人员将对单个农田、城市区域等现有地块边界进行精准数字化更新，并在此过程中记录灌溉类型与土地利用的变化情况。 将下载美国农业部（United States Department of Agriculture, USDA）国家农业统计服务中心（National Agricultural Statistics Service, NASS）对应年份的作物数据层（Cropland Data Layer, CDL）栅格数据，相关网址：https://nassgeodata.gmu.edu/CropScape/ 将使用分区统计地理处理工具，为多边形赋予CDL中更新后的作物类型属性。随后，数据集将经过多轮与历史清查数据的对比及质量核查流程，以确定并生成最终属性字段。 ### 属性字段说明 1. 土地利用类型（Landuse）：通用土地覆被分类，用于区分土地使用方式，具体包括： - 农业用地：用于作物种植或畜牧养殖的土地 - 其他：野生用地的宽泛分类 - 河岸/湿地：受高地下水位影响、通常紧邻地表水的野生区域 - 城市用地：已开发区域，包含公园等城市绿地 - 水域：地表水体，如滩涂、溪流与湖泊 2. 作物组（CropGroup）：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. 描述信息（Description）：通过GIS流程确定的各类作物类型与土地利用类型的属性说明 4. 灌溉方式（IRR_Method）：沿用2015年结束的全州野外调查所得的作物灌溉方式，并基于影像数据与年度野外核查进行更新。各灌溉方式具体说明如下： - 滴灌（Drip）：通过管道缓慢向作物地表或地下表层输水 - 旱地作物（Dry Crop）：该农田未施加人工灌溉，作物依靠自然过程获取水分 - 漫灌（Flood）：从作物上游的沟渠或管道引水，以足够水量淹没灌溉地块 - 无灌溉（None）：对应非农业用地 - 喷灌（Sprinkler）：通过移动式喷灌设备向作物上方喷洒水源 - 地下水位补给灌溉（Sub-irrigated）：该地块未人工施加灌溉水，但因高地下水位自然获得充足水分，通常与河岸区域密切相关 5. 地块面积（Acres）：多边形对应的测算面积（英亩） 6. 所属州（State）：多边形所在的州 7. 所属县（County）：多边形所在的县 8. 水文流域（Basin）：多边形所在的水文流域，与HUC 6密切相关。该流域边界由DWRe划定，纳入了存在跨流域水流的其他流域部分区域，以满足管理需求 9. 子流域（SubArea）：多边形所在的子流域，与HUC 8密切相关。子流域是DWRe划定的大型水文流域的次级分区 10. 标注类别（Label_Class）：处理过程中由Label与Class_Name字段组合生成的属性，用于说明具体作物类型、灌溉方式，以及CDL是否将该地块归类为同类作物或“其他”作物 11. 简化标注（LABEL）：各类作物描述与灌溉方式的简写说明标签 12. 类别名称（Class_Name）：多边形内USDA CDL CropScape栅格图层的多数像元值，可能与最终作物判定结果（Description）存在差异 13. 旧土地利用类型（OldLanduse）：与Landuse类似，但会根据灌溉方式进一步细分农业用地。2017年之前的数据集将该字段定义为Landuse 14. 土地利用组代码（LU_Group）：该代码为内部自定义分组，用于符号化展示及其他汇总分析工作 15. 调查年份（SURV_YEAR）：用于说明数据集对应的年份或生长季