Interaction Between Land Cover/Land Use Dynamics and Climatological Variability in the Western Oklahoma/Kansas/Texas Indicator Region
Western Oklahoma, Kansas, and Texas are a critical area for land use and land cover change monitoring. Because of its sensitivity to variations in climate, this region may be one of the first areas in the United States to show significant and detectable changes as a result of global change, functioning as an "indicator region."
The Oklahoma/Kansas/Texas "Dust Bowl" of the 1930s represents a classic negative interaction between human activity and climatological variation. Human modification of the natural land cover by conversion to agriculture has altered the preexisting balance that existed between natural vegetation and climatological conditions, forcing the landscape past a threshold of tolerable variation and triggering significant changes in land condition.
Land cover and land use types in this region are particularly sensitive to spatial and temporal climatic variability. Considerable emphasis has already been placed on this region as its climate is likely to be affected by global climate changes resulting from anthropogenically-derived changes in atmospheric trace gas concentrations.
The project research objectives are to: (1) quantify the temporal and spatial variability in land cover and land use using time-series remote sensing; (2) examine links between spatial and temporal climatic variability and land use and land cover patterns; and (3) investigate the potential effects of regional climate change on land use and land cover patterns. Previous research has focused on the spatial and temporal variability of precipitation and soil moisture for the region. We are building on this previous work by linking the basic climatic elements of precipitation, soil moisture, and energy available (air temperature or solar radiation) to the vegetation regimes that are affected by changes in and the variability of the climate.
We wish to investigate the inter-and intra-annual variability in vegetation and climate with harmonic analysis, principal component analysis, and fact analysis. Harmonic analysis is useful in that seasonal and intra-seasonal cycles can be highlighted. A strong annual cycle clearly exists in all three variables, but of more importance here are cycles that may exist within this annual cycle. In addition, the lag between vegetation and air temperature or between vegetation and precipitation also is particularly useful in determining the vegetative response to climate forcing.