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United States Department of Agriculture

Agricultural Research Service

Title: Challenges in Conducting Hydrologic and Water Quality Research in Drastically Disturbed Watersheds

Author
item Bonta, James

Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 28, 2005
Publication Date: May 2, 2005
Citation: Bonta, J.V. 2005. Challenges in conducting hydrologic and water quality research in drastically disturbed watersheds. Journal of Soil and Water Conservation. 60(3):121-133.

Interpretive Summary: Conducting watershed-scale studies in drastically disturbed areas is expensive, long-term, high-risk, and difficult research. A nine-year investigation was conducted on the impacts of drastic land disturbances in small watersheds due to coal mining and reclamation activities on surface and subsurface hydrology and water quality. The current increased interest in coal mining may require additional watershed-scale studies on the short and long term effects of drastic land disturbances on watershed hydrology, water chemistry, and sedimentation. The challenges and experiences of conducting the 9-yr study are identified so that other investigators may efficiently plan and conduct similar watershed-scale research in mines. Three small watersheds in Ohio (12 to 20 ha) were monitored before mining, during mining and reclamation, and after reclamation for hydrology and water quality, resulting in many publications. Hydrological instrumentation must be dependable and operational to collect data from the short duration disturbances because these periods are not repeatable, and watersheds require many years to approach a new equilibrium. The experimental design of the project, actual conditions during the project, and challenges in conducting the research are discussed. Watersheds used for an unchanging control must be free from previous disturbances. It was not feasible to quantitatively characterize the watersheds during the rapid and transitory periods of disturbance. Undisturbed and reclaimed watersheds can be visually undisturbed, but hydrologically disturbed. Surface and ground water hydrology and water chemistry processes may not reach a dynamic equilibrium until many years have passed. Association of data with periods of disturbance is not precise, depends on available data, and requires scientific judgment. The "drop-box weir" works well for sediment-laden flows with large rocks expected from drastically disturbed areas. Many recommendations are presented for future watershed-scale research on drastic land disturbances. This paper addresses challenges in researching the impacts of mining and reclamation activities but is applicable to studying other land disturbances such as urbanization.

Technical Abstract: A nine-year investigation was conducted on the impacts of drastic land disturbances in small watersheds due to coal mining and reclamation activities on surface and subsurface hydrology and water quality. Three small watersheds in Ohio (12 to 20 ha) were monitored before mining, during mining and reclamation, and after reclamation for hydrology and water quality, resulting in many publications. The current increased interest in coal mining may require additional watershed-scale studies on the short and long term effects of drastic land disturbances on watershed hydrology, water chemistry, and sedimentation. Conducting watershed-scale studies in drastically disturbed areas is expensive, long-term, high-risk, and difficult research. The challenges and experiences of conducting the 9-yr study are identified so that other investigators may efficiently plan and conduct similar watershed-scale research in mines. The experimental design of the project, actual conditions during the project, and challenges in conducting the research are discussed. Hydrological instrumentation must be dependable and operational to collect data from the short duration disturbances because these periods are not repeatable, and watersheds require many years to approach a new equilibrium. Control watersheds must be free from previous disturbances. It was not feasible to quantitatively characterize the watersheds during the rapid and transitory periods of disturbance. Undisturbed and reclaimed watersheds can be visually undisturbed, but hydrologically disturbed. Surface and ground water hydrology and water chemistry processes may not reach a dynamic equilibrium until many years have passed. Association of data with periods of disturbance is not precise, depends on available data, and requires scientific judgment. The "drop-box weir" works well for sediment-laden flows with large rocks expected from drastically disturbed areas. Many recommendations are presented for future watershed-scale research on drastic land disturbances. This paper addresses challenges in researching the impacts of mining and reclamation activities but is applicable to studying other land disturbances such as urbanization.

Last Modified: 10/1/2014
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