Soil Erosion, Floodplain Sedimentation, and Agricultural Sustainability Over Centennial Time Scales.

University Of Denver, Denver CO

Investigators

Abstract

This project will examine patterns of soil erosion and floodplain sedimentation in agricultural landscapes. Soil erosion is a significant environmental challenge facing 21st century society. While many of the physical mechanisms involved in the erosion process are well-understood, there are gaps in the understanding of erosion rates and downstream sediment transport rates measured over centennial time scales. This project takes advantage of an agricultural setting in which landscape patterns have persisted over ~700 years, providing an opportunity to test prevailing models of erosion and improve the scientific understanding of erosion and downstream sediment transfer. This project will promote the teaching and training of U.S. students, foster international scientific collaboration, support international knowledge and technology transfer, and contribute to related fields of study. Results will benefit undergraduate students through practical, experiential-learning in field courses and undergraduate research opportunities. The interdisciplinary project will promote direct scientific collaboration with leading scientists in a variety of related disciplines (landscape ecology, geochemistry, paleoecology, hydrologic engineering). The research will have broad appeal and application in fields such as landscape conservation and agricultural land management. The project will construct high-resolution records of human induced sedimentation at a range of spatial scales representing watersheds from 1 to 1000 square kilometers. These fluvial archives will include sedimentological, geochemical, and paleoecological data, and will be supplemented by shallow geophysical surveys. The project will also employ spatially-distributed erosion modeling to predict expected patterns of erosion and deposition. This model/data comparison will permit the quantification of the degree to which agricultural slopes are hydrologically and sedimentologically connected to downstream sediment sinks. The project will enable quantification of time-lags involved in agricultural sedimentation over multiple centuries. The principal theoretical contributions of the research will improve the understanding of hydrologic and sedimentologic connectivity, fluvial responses to anthropogenic disturbance, and spatio-temporal distributions of agricultural legacy sediments. Although this research project will focus on erosion and sedimentation in Czech Republic, the results will provide new insights and approaches for understanding and mitigating agriculturally-induced soil erosion in many other countries, including the United States.