Catchment Characteristics Flashcards
Catchment
Area from which excess of water flows towards the river
Zones. We can subdivide catchment area of a river into 3 zones
Upper course: various sub-catchments-> main region where sediments and surface water are formed: production area
Middle course: distinguished main channel, few branches: transportation
Lower course: The delta where the river divides into multiple branches as a result of the flat landscape. Low flow velocity causes sediments to settle: deposition zone.
Surface water divide
Found by following river channels upstream until their sources-> drawing the divide between channel leading to the outlet and channels leading to another river
Topographical water divide
When surface water divide follows highest points in landscape
Groundwater divide
The boundary between groundwater basins; defined by a line connecting the high points on the water table or other potentiometric surface.
Groundwater flows away from a groundwater divide
Basin
Una cuenca es un territorio cuyas aguas fluyen todas hacia un mismo río, lago o mar, y a esta clase de cuencas se les llama “cuencas hidrográficas
Polder
consisten en aislar por medio de diques (dikes) un espacio cubierto por el mar, permanentemente o durante la marea alta.
Topography.
What does it determine?
Determines which areas within a catchment are wet&flood vulnerable
- High slope: reduced wetness->water flows away quiclky from that point
- Ratio between Local draining area and slope: topographic wetness index
When topographic wetness index is high ponds form and channels begin.
Land cover
Most land surface covered by vegetation.
Impacts hydrology processes
Easier for soil to absorb water (leaves stems and roots)
Buildings and pavements>less absorption
Info about landcover helps predict what hydrological processes occur and how discharge responds to rainfall
Geology
Properties of soil or rock determine how much water stored and how fast it will flow underground
2 MAJOR PROPERTIES
Determined by the size shape and origin of soil particles.
Porosity: How much water can be stored on ground
Conductivity :How easy it is for water to flow between soil particles. Determines how fast water is transported
Often related.
Aquifer layer of permeable soil.
Can store and transport water well.
Layer of permeable soil.
Can store and transport water well.
Bedrock
Under layers of soil.
Topographic wetness index
Ratio between Local draining area and slope:
