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The Physical Impact of Mining Yacuambi River Basin, Southern Ecuador May 2011. Emily Shimada, Environmental Science, University of Idaho Research Team B: Watershed Management in the Andean Paramo
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The Physical Impact of MiningYacuambi River Basin, Southern EcuadorMay 2011 Emily Shimada, Environmental Science, University of Idaho Research Team B: Watershed Management in the Andean Paramo Faculty Advisors: Dr. Alex Fremier, Department of Fish & Wildlife Resources, University of Idaho Carlos Iñiguez A. Instituto de Ecología Universidad Técnica Particular de Loja
Introduction: Sediment in Fluvial Environments Texture Classification Bedload(D>1mm) Suspended load (D<0.05mm) Wash load (D<0.0063mm)
Research Objectives • What is the observed grain size distribution in: • Streams considered “un-impacted” from human land use activities (mining) • Impacted stream • Above & Below sites with changes in land use • What is the predicted grain size distribution based on measurable stream dimensions in: • Streams considered “un-impacted” from human land use activities (mining) • Impacted stream- • Above & Below sites with changes in land use • Is there a relationship between: • Observed & predicted D50 in different streams and stream reaches • Land use gradient & observed grain size distribution • Physical stream properties & ecological functioning of the stream? Study Site
Methods: 1) Field Work • General Stream Measurements • Velocity • Cross-sectional Area • Wetted Perimeter • Turbidity • Slope • Depth • Bankfull width • Site Selection • Impacted & un-impacted • Above & Below areas of distinct land use differences (mining) • Establish sites at the Stream Reach scale • Length = approx. 10X Width • Relatively uniform slope, dimensions, velocity 64mm 1mm Sediment Property Measurements • Pebble Count Median Grain Size (D50) • Wet Sieving Median Grain Size (D50) For sediment diameters 1mm & 2mm
Methods: 2) Analytical Work Initiation of Motion 1) Predicted grain size distribution: • D50 that moves at observed flow • D50that moves at bankfullflow G= gRS bf = gRS • 2) Establish relationship between predicted & observed D50: • Between & within un-impacted stream reaches • Between & within impacted stream reaches (above and below land use site) • 3) Compare grain size distribution between impacted & un-impacted streams • Is there a clear correlation of grain size distribution to land use gradient? • Is there an ecological impact? (shear stress) • Additional Measurements • Discharge Q=VA • Turbidity • Manning’s roughness
Bio-indicator Framework • Physical Impact of current land uses Relevance & Connection • Is there an observed ecological impact? • What is the relationship between land use and ecological impact? • What needs to be done? • Current watershed uses & policies • Cultural & political Perceptions of watershed use & resulting impacts • Is there an interest and/or agenda for watershed protection? • What can be done at the local & international level order to accommodate cultural values and stakeholders’ interests, while promoting sustainable land use practices and policies? • Watershed use & policy jurisdiction • (stakeholders) • Societal/Political affect on watershed use & the ecosystem
Thanks & References • Images: http://www.amazonrainforestnews.com/2011_04_01_archive.html • http://www.nativerevegetation.org/learn/manual/ch_5.aspx • http://www.amazonconservation.org/news/newsletter/0812/index.html • http://www.uwsp.edu/geo/faculty/lemke/geomorphology/lectures/03_stream_sediment.html