Geology topics

Research about Hamilton County, Ohio

Source-linked reports with geographic coverage including Hamilton County, Ohio.

2 recordsLinked to original sources

USGS2025

Evaluating large wood additions as a scalable method of urban stream restoration

Urbanization is associated with increased erosion and habitat homogenization in stream ecosystems. This habitat degradation often has biological consequences, such as decreased species richness. Conventional stream restoration practices are costly, and projects are limited to small areas with easy access. A scalable, low-cost method of stream restoration is needed to address the widespread degradation occurring in urban streams. Large wood (LW) is an important element in stream ecosystems that is typically abundant in forested watersheds but scarce in urban streams. LW can reduce water velocities, generate pool habitat, decrease erosion, and provide cover for aquatic organisms. In this study, we performed experimental LW installations to assess the capacity of LW restoration to improve habitat and reduce sediment transport in an urban headwater stream in Cincinnati, Ohio. We tracked the geomorphic effects of these installations using a before-after-control-impact study design in four 60-m reaches, two treatment and two control, over a 1.5-year period to investigate the following questions: (1) Will unanchored LW additions remain stable in a flashy urban stream? (2) Will LW additions increase the availability of pool habitat? (3) Will wood additions increase bed stability and modify sediment size distributions? We found that LW installations rapidly increased pool habitat availability (size) around stable jams, but a majority of the LW jams were frequently mobilized and reconfigured by high-flow events. LW additions had no significant impact on the probability of stream bed mobilization, likely due to the instability of LW; however, the distance particles traveled once mobilized significantly decreased. While LW additions can increase the availability of pool habitat in urban headwater streams, further investigation is needed to understand the stability of such structures and the environmental context where these additions will be most beneficial.

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USGS1996

Overview of landslide problems, research, and mitigation, Cincinnati, Ohio, area

Landslides cause much damage to property throughout the metropolitan area of Cincinnati, Ohio. Most landslides occur in unconsolidated deposits, including colluvium, till, glacial lake clays, and man-made fill derived from colluvium and glacial deposits. Landslides in thin colluvium are widespread on steeper slopes that wall the valleys of the Ohio River and its tributaries. Abundant landslides also form in thick colluvium on flatter slopes, especially where the colluvium has been disturbed by earthwork. Unusual block glides and block-extrusion glides form where till rests on lake clay. Through the years, knowledge of the distribution and causes of landslides has increased as a result of many investigations. This knowledge became part of the basis for landslide mitigation programs adopted by the City of Cincinnati and Hamilton County, Ohio. In 1974 the Cincinnati City Council passed an excavation and fill ordinance to help reduce landslide damage in areas of new construction. In 1989 following much additional study, Cincinnati created a geotechnical office within its Department of Public Works. The office, which is staffed by a geotechnical engineer, an engineering geologist, and two technicians, carries out a mitigation program. Since 1989, members of the geotechnical staff have worked in several ways to reduce landslide damage in the city; their work includes engineering-geologic mapping of selected parts of the city, inspection of retaining walls that impact public right-of-way, review of proposed construction in hillside areas, inspecting and arranging for repair of landslide areas that affect city property, and compiling geologic and geotechnical data on landslide areas within the city. In 1990, Hamilton County also adopted an excavation and fill ordinance to help reduce the damage due to landslides in areas of new construction.

Ohio↗