Fluviokarst Landscape Whole-System Sensitivity to Land Use Influences, Kentucky River, KentuckyEPA Grant Number: FP916327
Title: Fluviokarst Landscape Whole-System Sensitivity to Land Use Influences, Kentucky River, Kentucky
Investigators: Martin, Linda L.
Institution: University of Kentucky
EPA Project Officer: Lee, Sonja
Project Period: January 1, 2004 through December 31, 2006
Project Amount: $102,490
RFA: STAR Graduate Fellowships (2004) RFA Text | Recipients Lists
Research Category: Fellowship - Geography , Academic Fellowships , Ecological Indicators/Assessment/Restoration
The objective of this research project is to examine the changes in hillslope hydrology related to both short- and long-term vegetative cover effects that appear to be responsible for erosion in a historically forested humid temperate fluviokarst landscape bordering the Kentucky River. In the Bowman’s Bend region of Garrard County, KY, the entrenched Kentucky River downcuts some 100 meters into the developed karst of the Bluegrass limestones. The escarpment of the river bend is edged by deciduous forest, but the historically forested inner area was cleared for crop and pasture in the early 1800s. Within the 1.5 kilometer area included in this study, a pattern of increasing erosion has become apparent, and shallow surface incisions and gully heads have formed in association with geomorphically sensitive locales along the grassland/forest boundary. Hillslope hydraulic characteristics related to post-settlement land uses may be causing the increase in the rate of erosion, conduit exhumation, and karst to fluvial transitioning currently seen along the forest edge. Recent conversion of fescue upland fields to tufted native grass species has created a loss of solid sod matting that likely induces increased runoff. Runoff increase possibly overlies a much more slowly-evolving tendency for soil moisture to perch at the soil/bedrock interface, which is caused by loss of tree roots and their ability to penetrate bedrock layers and wick flow into epikarstal storage. Whereas some erosion features appear to be evolving solely due to one or the other of these two factors, the spatially nonuniform mix of both influences likely creates the current erosion pattern.
This project will investigate the causative factors behind erosion development by examining historical emergence of the pattern as well as current soil conditions and hydrologic pathways. Examination of geologic structure, hillslope gradient, topographic convergence, and land use history will be combined with laboratory soil texture tests, field infiltration tests, automated TDR hillslope water content tracking, and soil dye tracing to explore the biogeomorphic effects of grassland and forest communities on soil profile characteristics, infiltration rates, and bedrock water penetration. The goal of the project is to create a whole-system picture of spatial and temporal land use effects on hillslope hydrology. Results from this study should provide not only data on the evolution of hillslope hydrology after deforestation, but information on the use of various cover types for management purposes in sensitive karst terrains as well.