Polygons Representing Sensitivity of Ground Water to Contamination in Lawrence County, SD

This data set includes 956 polygons labeled with a sensitivity-unit code that represents the sensitivity of ground water to contamination in Lawrence County, SD. This data set is a result of a larger work (WRIR 00-4103 cited above), which includes a paper plate titled: "Map showing sensitivity of ground-water to contamination in Lawrence County, South Dakota." This data set is part of the digital data that was used to create that map. The sensitivity-unit code is an attribute that consists of a letter followed by three numerical digits, which characterizes sensitivity to contamination. Letter codes that begin with upper case letters (A-Z) and continue with lower case letters (a-s) represent characteristics of the rock and sediments, with 'A' being most sensitive and 's' being least sensitive. The first digit represents recharge rate with 1 being the most sensitive and 4 the least sensitive. Three quantitative categories (1-3) and two qualitative categories (4,5) represent depth to water. Groups 1 through 3 represent areas where data was available to estimate depth-to-water with 1 most sensitive and 3 least sensitive. Qualitative categories 4 and 5 represent areas that only can be compared to each other with 4 being the most sensitive. The third digit represents land-surface slope with 1 being the most sensitive and 5 being the least sensitive. An additional attribute, hydrologic setting, represents areas with common hydrologic characteristics. These 11 hydrologic settings are represented by a letter code symbol. The process step section below describes the attributes in more detail and how the attributes were developed from source data. The source data includes digital maps that characterize the geology, precipitation distribution, and water levels, which have been compiled at 1:100,000 scale and published in 1999 and 2000 as part of the Black Hills Hydrology Study. USGS Digital elevation models were used to describe land-surface altitudes. This data set has been archived at the USGS Water Resources National Spatial Data Information Node.

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  "010:12"
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[
  "geospatial"
]