SCS Soil Survey

This soils feature class is a cleaned and edited version of WA Department of Natural Resources and Soil Conservation Service soils coverage for Washington State received in December of 2000. Soil polygons were merged to eliminate township lines from original coverage after its convertion to a feature class. Slivers, overlaps, and other topological discrepancies were cleaned, and DNR soil map unit names and identifier symbol ('IDENTIFIER') were added to the attribute table. Polygons were subsequently dissolved by 'Identifier', and associated info lookup tables (SOILS_CLASS, SOILS_COMPLX, SOILS_COMB, SOILS_MAIN, SOILS_PFLG) then joined to the polygon attribute table. _____________________________________________________________________________ Information for the soils data layer was derived from the Private Forest Land Grading system (PFLG) and subsequent soil surveys. PFLG was a five year mapping program completed in 1980 for the purpose of forest land taxation. It was funded by the Washington State Department of Revenue in cooperation with the Department of Natural Resources Soil Conservation Service (USCS), USDA Forest Service and Washington State University. State and private lands which had the potential of supporting commercial forest stands were surveyed. Some Indian tribal and federal lands were surveyed. Because this was a cooperative soils survey project, agricultural and non-commercial forest lands were also included within some survey areas. After the DNR originally developed its GIS, digitized soils delineations and a few soil attributes were transferred to the system. Remaining PFLG soils attributes were added at a later time and are available through associated lookup tables. SCS soils data on agricultural lands also have subsequently been added to this data layer. Approximately 1100 townships wholly or partially contain digitized soils data (2101 townships would provide complete coverage of the state of Washington). - "Detailed Layer Description", Washington State Department of Natural Resources Geographic Information System, 1998. - _____________________________________________________________________________本土壤要素类为2000年12月获取的华盛顿州自然资源部（WA Department of Natural Resources）与土壤保护局（Soil Conservation Service）针对华盛顿州的土壤覆盖数据的清理编辑版本。将原始覆盖数据转换为要素类后，土壤多边形已被合并以移除其中的乡界。同时完成了狭长碎多边形、重叠区域及其他拓扑异常的清理工作，并向属性表中添加了DNR土壤图单元名称与标识符符号（'IDENTIFIER'）。随后依据“Identifier”字段对多边形进行溶解操作，并将关联的信息查找表（SOILS_CLASS、SOILS_COMPLX、SOILS_COMB、SOILS_MAIN、SOILS_PFLG）连接至多边形属性表。 _____________________________________________________________________________ 本土壤数据层的信息源自私有林地分级系统（Private Forest Land Grading system, PFLG）及后续土壤调查。PFLG是一项为期五年的制图项目，于1980年完成，旨在服务于林地税收征管。该项目由华盛顿州税务局联合自然资源部土壤保护局（USCS）、美国农业部森林局与华盛顿州立大学共同资助。调查覆盖了具备商用林分生长潜力的州属与私有林地，部分印第安部落土地及联邦土地亦被纳入调查范围。由于本项目为合作性土壤调查，部分调查区域同时涵盖了农业用地与非商用林地。在DNR最初开发其地理信息系统（GIS）后，数字化土壤图斑与少量土壤属性被转入该系统。剩余的PFLG土壤属性于后续补充，并可通过关联的查找表获取。农业用地的SCS土壤数据后续亦被纳入本数据层。目前约1100个乡完整或部分覆盖了数字化土壤数据（华盛顿州全域覆盖需2101个乡）。 —— "Detailed Layer Description", 华盛顿州自然资源部地理信息系统, 1998年。 _____________________________________________________________________________