Land Use Attributes: All land use attributes were coded using the Department's Standard Land Use Legend. The legend explains in detail how each delineated area is attributed in the field, and what the coding system is. The actual land use coding given in the legend is different in arrangement than the codes that result from the digitizing process. The file attributes.pdf is a detailed explanation of the coding system from the legend and the codes that end up in digitized form in the database files associated with the shape files.
Information on the Shape Files: Shape files were created for each quad, and one for the whole survey area. The naming convention used for the quad DWG files is used for the quad shape files (for example, 04SS3828.shp, 04SS3828.shx, and 04SS3828.dbf for quad number 3828, the Newman quad). The name of the shape file for the whole survey area is 04SS.shp (and .dbf and .shx). The name of the shape file for the whole survey area including the spring crops found using satellite imagery is 04SSint.shp (and .dbf and .shx). The following is an explanation of the land use attributes in the DBF files: BL_X: This is the X coordinate of the interior point in the delineated area BL_Y: This is the Y coordinate of the interior point in the delineated area ACRES: Number of acres in the delineated area (may or may not be present) WATERSOURC: The type of water source used for the delineated area MULTIUSE: Type of land uses within the delineated area CLASS1: The class for the first land use SUBCLASS1: The subclass for the first land use SPECOND1: The special condition for the first land use IRR_TYP1A: Irrigated or non-irrigated for the first land use IRR_TYP1B: Irrigation system type for the first land use PCNT1: The percentage of land associated with the first land use CLASS2: The class for the second land use SUBCLASS2: The subclass for the second land use SPECOND2: The special condition for the second land use IRR_TYP2A: Irrigated or non-irrigated for the second land use IRR_TYP2B: Irrigation system type for the second land use PCNT2: The percentage of land associated with the second land use CLASS3: The class for the third land use SUBCLASS3: The subclass for the third land use SPECOND3: The special condition for the third land use IRR_TYP3A: Irrigated or non-irrigated for the third land use IRR_TYP3B: Irrigation system type for the third land use PCNT3: The percentage of land associated with the third land use UCF_ATT: Concatenated attributes from MULTIUSE to PCNT3 Important Points about Using this Data Set: 1. The land use boundaries were drawn on-screen using orthorectified imagery. They were drawn to depict observable areas of the same land use. They were not drawn to represent legal parcel (ownership) boundaries, or meant to be used as parcel boundaries. 2. This survey was created as a "snapshot" in the summer, and further improved by the addition of spring crops found through the use of satellite imagery. There still could be fields where there were crops grown before or after the field survey. The surveyor may not have been able to detect them from the field or the photographs, and the satellite imagery processing may not have identified the spring crop. Thus, although the data is very accurate for the summer, and probably the spring, it may not be an accurate determination of what was grown in the fields for the whole year. 3. If the data is to be brought into a GIS for analysis of cropped (or planted) acreage, two things must be understood: a. The acreage of each field delineated is the gross area of the field. The amount of actual planted and irrigated acreage will always be less than the gross acreage, because of ditches, farm roads, other roads, farmsteads, etc. Thus, a delineated corn field may have a GIS calculated acreage of 40 acres but will have a smaller cropped (or net) acreage, maybe 38 acres. b. Double and multicropping must be taken into account. A delineated field of 40 acres might have been cropped first with grain, then with corn, and coded as such. To estimate actual cropped acres, the two crops are added together (38 acres of grain and 38 acres of corn) which results in a total of 76 acres of net crop (or planted) acres. 4. Water source information was not collected for this survey. 5. Not all land use codes will be represented in each survey.