The Physical Impact of Mining Yacuambi River Basin, Southern Ecuador May 2011
-
Upload
holmes-vega -
Category
Documents
-
view
34 -
download
0
description
Transcript of The Physical Impact of Mining Yacuambi River Basin, Southern Ecuador May 2011
![Page 1: The Physical Impact of Mining Yacuambi River Basin, Southern Ecuador May 2011](https://reader035.fdocuments.in/reader035/viewer/2022081504/56813137550346895d97aa9a/html5/thumbnails/1.jpg)
The Physical Impact of Mining Yacuambi River Basin, Southern EcuadorMay 2011
Emily Shimada, Environmental Science, University of IdahoResearch Team B: Watershed Management in the Andean ParamoFaculty Advisors: Dr. Alex Fremier, Department of Fish & Wildlife Resources, University of Idaho
Carlos Iñiguez A. Instituto de Ecología Universidad Técnica Particular de Loja
![Page 2: The Physical Impact of Mining Yacuambi River Basin, Southern Ecuador May 2011](https://reader035.fdocuments.in/reader035/viewer/2022081504/56813137550346895d97aa9a/html5/thumbnails/2.jpg)
Introduction: Sediment in Fluvial Environments
Bedload (D>1mm)Suspended load (D<0.05mm)Wash load (D<0.0063mm)
Name Diameter (mm)
BouldersCobblesGravelSandSiltClay
>25664-256
2-640.062-2
.004-.062<0.004
Texture Classification
![Page 3: The Physical Impact of Mining Yacuambi River Basin, Southern Ecuador May 2011](https://reader035.fdocuments.in/reader035/viewer/2022081504/56813137550346895d97aa9a/html5/thumbnails/3.jpg)
Introduction: Cause & Effect of Increased Fluvial Sediment
Source ImpactNatural Anthropogenic Course grain/ Bedload Fine grain/ Suspended load
ClimateVegetationTopographyGeology & soilTectonicsBase levelSurface erodibilityTime/history
MiningAgricultureDeforestationUrbanizationDamsTraffic/Roads/
ConstructionGrazing
Increased water levelFlooding potentialAlterations in channel
dimensionsAlterations in the
stream substratesAlterations in aquatic
organism habitat
Increased flow viscosity & reduced settling velocity ->increase transport grain size & bedload
Reduced depth for sunlight penetration ->hinders photosynthesis
![Page 4: The Physical Impact of Mining Yacuambi River Basin, Southern Ecuador May 2011](https://reader035.fdocuments.in/reader035/viewer/2022081504/56813137550346895d97aa9a/html5/thumbnails/4.jpg)
Background: Tropical Mountain Stream Ecosystems
Source Impact
Natural Anthropogenic MiningCourse sedient build up-> increases channel bed elevation (decreasing flow)Decreased aquatic biological activity
Steep topography Tropical Climate High rainfall Abundant vegetation
Land use managementMining activities
![Page 5: The Physical Impact of Mining Yacuambi River Basin, Southern Ecuador May 2011](https://reader035.fdocuments.in/reader035/viewer/2022081504/56813137550346895d97aa9a/html5/thumbnails/5.jpg)
Research Objectives1. 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
2. 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
3. Is there a relationship between: Observed & predicted D50 in different streams and stream reachesLand use gradient & observed grain size distributionPhysical stream properties & ecological functioning of the stream?
Study Site
![Page 6: The Physical Impact of Mining Yacuambi River Basin, Southern Ecuador May 2011](https://reader035.fdocuments.in/reader035/viewer/2022081504/56813137550346895d97aa9a/html5/thumbnails/6.jpg)
Site SelectionImpacted & un-impactedAbove & Below areas of distinct land use differences (mining) Establish sites at the Stream Reach scale
Length = approx. 10X Width
Relatively uniform slope, dimensions, velocity
Methods: 1) Field Work
Sediment Property MeasurementsPebble Count Median Grain Size (D50)
Wet Sieving Median Grain Size (D50)
For sediment diameters 1mm & 2mm
64mm
1mm
General Stream MeasurementsVelocityCross-sectional Area Wetted PerimeterTurbiditySlopeDepthBankfull width
![Page 7: The Physical Impact of Mining Yacuambi River Basin, Southern Ecuador May 2011](https://reader035.fdocuments.in/reader035/viewer/2022081504/56813137550346895d97aa9a/html5/thumbnails/7.jpg)
Methods: 2) Analytical Work1) Predicted grain size distribution:
D50 that moves at observed flow
D50 that moves at bankfull flowbf = gRS
€
τ cr = ηg(ρ s − ρ)π
6D tanφ
Additional Measurements•Discharge Q=VA•Turbidity•Manning’s roughness
€
n =k(R2/3S1/2)
V
Initiation of Motion
2) Establish relationship between predicted & observed D50:
Between & within un-impacted stream reachesBetween & within impacted stream reaches
(above and below land use site)
3) Compare grain size distribution between impacted & un-impacted streamsIs there a clear correlation of grain size
distribution to land use gradient?Is there an ecological impact?
€
D50 =τ
τ cr (ρ s − ρ)g
G = gRS
(shear stress)
![Page 8: The Physical Impact of Mining Yacuambi River Basin, Southern Ecuador May 2011](https://reader035.fdocuments.in/reader035/viewer/2022081504/56813137550346895d97aa9a/html5/thumbnails/8.jpg)
Relevance & Connection
Physical Impact of current land uses
Bio-indicator Framework
Current watershed uses & policies
Cultural & political Perceptions of watershed use & resulting impacts
Is there an observed ecological impact?
What is the relationship between land use and
ecological impact?What needs to be done?
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
![Page 9: The Physical Impact of Mining Yacuambi River Basin, Southern Ecuador May 2011](https://reader035.fdocuments.in/reader035/viewer/2022081504/56813137550346895d97aa9a/html5/thumbnails/9.jpg)
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