Submitted to: GIScience and Remote Sensing
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/2008
Publication Date: 1/1/2009
Citation: Giraldo, M.A., Madden, M., Bosch, D.D. 2009. Landuse/Land Cover and Soil Type Covariation in a Heterogeneous Landscape for Soil Moisture Studies Using Point Data. GIScience and Remote Sensing 46, No. 1, p. 77-100. DOI: 10.2747/1548-1603.46.1.77. Interpretive Summary: Significant advances have been made in the last decades in sensor technology and data transfer. These advances have made it possible to collect a larger number of measurements of physical processes on the landscape. However, these measurements represent the conditions at a single point in space. Little is known about how these point measurements relate to larger areas across the landscape. This research examines the relationships between point measurements of soil moisture and soil moisture conditions across larger portions of the landscape. The results showed a highly heterogeneous landscape with greater landscape fragmentation caused by land use and land cover than by soil types. For the conditions examined, point observations of soil moisture are well suited for site specific hydrologic studies and to validate high spatial resolution remote sensors. However, extrapolating the point data out to larger scales based upon geophysical landscape characteristics may be difficult due to the large variability in the region.
Technical Abstract: This research investigates the spatial co-variation of soil and Landuse/land cover (LULC) at the Little River watershed to assess landscape heterogeneity and the spatial extent to which point data from the USDA hydrological network near Tifton, Georgia can be used for regional representations of environmental variables and to validate remote sensing data. Analysis were performed at the landscape scale and within square areas equivalent to four pixel units of environmental satellites commonly reported in soil moisture studies. The results showed a highly heterogeneous landscape with greater landscape fragmentation caused by LULC than by soil types and even greater when the two variables were considered together; we found a 23:1 ratio of soil types to LULC and few combinations of soil type/LULC dominating the landscape. We conclude that the stations are better suited for site specific hydrologic studies and to validate high spatial resolution remote sensors.