Advertisement

Journal of Mountain Science

, Volume 1, Issue 3, pp 264–269 | Cite as

Channel response to gravel mining activities in mountain rivers

  • José Luis López S.Email author
Article

Abstracts

The removal of bed material from active river channels usually affects the bed profile of the streambed, causing progressive degradation upstream and downstream of the extraction site. These effects can extend for kilometers affecting hydraulic structures located in the vicinity of the river reach. In this paper, the geomorphic effects of gravel mining are reviewed and summarized. Some cases in Venezuelan streams are presented to illustrate the problem. To describe the processes of erosion and sedimentation in a gravel extraction pit, a recent developed mathematical model for the simulation of flow and sediment transport in gravel-cobble bed streams is applied to a hypothetical case of gravel mining in a river channel. A simple rectangular dredge pit is imposed as initial condition in the channel bed, and changes in bed elevations and grain size distribution of bed material are calculated by using the numerical model. The process of deposition within the pit, and the downstream and upstream migration of the erosion wave are well simulated by the model and closely resemble the phenomena observed in laboratory experiments. The response of the friction coefficient to the changes in flow and bed elevations shows the importance in modeling adequately flow resistance and sediment transport in gravel-cobble bed streams.

Keywords

Channel response gravel mining Venezuelan cases 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Aguirre Pe, J. and Fuentes, R. 1993. Stability and Weak Motion of Riprap at a Channel Bed. In: C. Thorneet al. (eds.),River, Coastal and Shoreline Protection. Erosion Control using Riprap and Armourstone. John Wiley & Sons Ltd.: 77–92.Google Scholar
  2. Kondolf, G.M., Swanson, M.L. 1993. Channel Adjustments to Reservoir Construction and Gravel Extraction along Stony Creek, California.Environmental Geology 21: 256–269.CrossRefGoogle Scholar
  3. Kondolf, G.M. 1994. Geomorphic and Environmental Effects of Instream Gravel Mining.Landscape and Urban Planing 28: 225–243.CrossRefGoogle Scholar
  4. Kondolf, G.M. 1997. Hungry Water: Effects of Dam and Gravel Mining on River Channels.Environmental Management 21(4):533–551.CrossRefGoogle Scholar
  5. López, J.L. 1994. Problems caused by Gravel Extraction in the Tuy River Basin.Agency of the Tuy River Basin, Ministry of Environment, Internal Report (in Spanish), Caracas, Venezuela.Google Scholar
  6. López, J.L. Falcón M. 1999. Calculation of Bed Changes in Mountain Streams.Journal of Hydraulic Engineering. ASCE, March125 (3):263–270.CrossRefGoogle Scholar
  7. Raynov, S., Pechinov, D., Kopaliany, Z. 1986. River Response to Hydraulic Structures.Technical Documents in Hydrology, Unesco, Paris.Google Scholar

Copyright information

© Institute of Moutain Hazards and Environment, Chinese Academy of Sciences and Science Press 2004

Authors and Affiliations

  1. 1.Institute of Fluid Mechanics, Faculty of EngineeringUniversidad Central de VenezuelaCaracasVenezuela

Personalised recommendations