landscape effects watershed anache
TRANSCRIPT
Jamil Alexandre Ayach AnacheabIsabel Kaufmann de Almeidac
Cláudia Gonçalves Vianna BacchicTeodorico Alves Sobrinhoc
a. University of São Paulo – EESC‐USPb. Purdue University – NSERL‐ARS‐USDAc. Federal University of Mato Grosso do Sul – FAENG‐UFMS
1
Can the physical features of a watershed be affected by geological, geomorphological and
pedological aspects?
2
Presentation Outline
Objective
The study area
How we did it?
What we found?
Conclusions
Questions
3
Objective
We evaluated the correlation between physical features and geological, geomorphological and pedological aspects in a watershed.
4
The study area
Guariroba stream subwatershed, a 5th order watershedlocated in an Environmental Protection Area.
~50% of Campo Grande water supply
5
The study area
36100 m² of area
Mean outflow ~ 6 m³/s
1 of 8 the watersheds included in a nationalEcosystem Services Payment Program• Water Producer Program – National Water Agency: www.produtordeagua.ana.gov.br
6
The study area
7
How we did it?
1st step: Watershedphysical
characterization
2nd step: Spatial data survey (thematic
maps)
3rd step: Correlation between spatial data
and physical features
8
How we did it?
Hydrological Response Units (HRUs)
Stream order (U)
Streams total length (Lt)
Axial length (L)
Overland flow length (l)
Drainage density (Dd)
Elongation coefficient (Kc)
Form factor (F)
Circulatory ratio (Rc)
1st step: Watershed physicalcharacterization
9
How we did it?
2nd step: Spatial data survey (thematic maps)
GeologyGeomorphologyPedology
10
How we did it?
3rd step: Correlation between spatial data and physical features
• Data has normal distribution• Pearson’s correlation matrix• Strong correla ons (│ρ│ ≥ 0.70) within a confidence interval of 95% were considered
• Data was compared by HRU
11
What we found?
12
What we found?
13
What we found?
PhysicalCharacteristics
• Dendritic drainage• Poorly developed• 7 HRUs• Min. 3rd order streams
14
What we found?
Physical characteristics Spatial data distribution
15
What we found?
• The physical features of the subwatershedshow that 1st and 2nd order watercourses predominate in the watershed
• Only 6 correlations were found: between pedology (entisols occurrence and physical features – area, perimeter, elevation, drainage density, and overland flow length)
16
What we found?
Physical characteristic Landscape feature
↑ HRU Area and Perimeter ↓ Sandy soils with organic layer
↑ Elevation ↑ Sandy soils without organic layer
↑ Drainage Density ↑ Sandy soils with organic layer
↓ Drainage Density ↑ Sandy soils without organic layer
↓ Overland flow coefficient ↑ Sandy soils with organic laye
17
Conclusions
The physical features of the watershed andlandscape (geology and geomorphology) did notexhibit linear dependence.A strong linear correlation was found betweenwatershed pedology and a number of physicalfeatures (area, perimeter, elevation, drainagedensity and overland flow length).
18
