Using metadata to improve irrigation district geographic information system spatial reliability (California)

This thesis discusses the need to develop metadata for irrigation district Geographic Information Systems (GIS) programs in the absence of accurate information. The methodology for this research is based on the development of a GIS program for the Fresno Irrigation District for a period of two years, and evaluating the development of similar GIS programs for the Turlock Irrigation District and the Modesto Irrigation District. The compilation of field research examines and identifies the primary GIS themes used by irrigation districts. The importance versus the estimated accuracy of primary GIS themes are ranked as an argument for metadata. Results indicate that as theme accuracy increases the relative importance of the theme decreases. Current GIS metadata and metadata standardization efforts are discussed. Conclusions suggest that GPS (Global Positioning Systems) must generate horizontal control, source information must have estimated accuracies, and irrigation districts must generate metadata to convey data integrity.