Soils, groundwater, and land-use relations for Finney county, Kansas: A GIS and remote sensing approach

Soils and water are two fundamental land resources sustaining our world. In western Kansas, soil erosion and groundwater depletion present major problems for the management of land resources. Limited by available tools and the lack of quality data, many important issues related to these problems have not been adequately addressed. The objectives of this dissertation were to evaluate the effectiveness of the Conservation Reserve Program (CRP) and present its management alternatives, to identify land-use changes, features, and alternatives, and to develop models between groundwater and selected land-use categories in Finney County, Kansas. Land-use/cover was derived from Landsat Thematic Mapper images. Incorporated with other data sources, geographic information systems (GIS) were used as data manipulation and modeling tools.; An efficient procedure was developed to accurately calculate an erosion index (EI). Based on a series of overlay and query, findings emerged. The present CRP did not necessarily include the lands most susceptible to erosion. Aquifer thickness (AT), with co-occurrence of gas or oil fields, played a significant role in determining which land could be used for CRP. All other factors, including EI, major soil properties, physiography, and topography, were not significantly influence on CRP. Thus, evidence is persuasive that the program could be substantially improved. It should be continued in this area, but its eligibility rules need modification. CRP lands ineligible for early release were identified, and an approach to determine acceptability of offers was developed.; Land-use practices were significantly dependent on AT. Soil properties were not seriously considered in determining land-use options. From the view of sustainable cultivation, cropland that should be under more restrictive use for conservation and grassland that could be converted to cropland were identified. Economic benefits occurred if GIS and remote sensing were employed for determining optimal land-use practices.; Several models were developed, including a decay model that fits AT and CRP(%), a non-intercept linear model fitting AT and corn (%), a logistic model simulating AT and alfalfa (%), and a multi-variable model correlating land-use and aquifer decline rates. In addition, a critical value was derived, which could be used for evaluating irrigation wells, and a typical curve was plotted, revealing the relationship between water-use index and aquifer decline.; All cases proved that the integration of remote sensing and GIS can greatly help in the management of soil, groundwater, and land related resources.