Factors affecting the movement of water through a Drainage Basin

INPUTS and OUTPUTS as shown by the WATER BEDGET

Physical Factors SOIL

GEOLOGY

VEGETATION

SLOPE and Basin SHAPE

Human Factors AGRICULTURAL LAND USE

URBANISATION WATER RESOURCE LAND-USE MANAGEMENT

INDUSTRIAL LAND USE

A

B

Water Budget

Based on the water budget for Cloverdale, California:

* the climate is probably dry summer subtropical.

* the deficit is most intense in July.

* flooding is most likely a problem in January.

Heavy rain on compacted ground will not infiltrate

Effect on speed of passage of water through drainage basin is ………..

Why?

A or B hydrograph?

Soil Conditions

How much open space is there in rock? In this experiment we check the porosity of gravel, sand and silt, the raw materials that sandstone is made of.

For example If you were able to add 90ml of water to 350ml of gravel, the porosity would be

90 ml----------- = .2571 = 25.71%350 ml

Effect of permeable rock on speed of passage of water is…? A or B hydrograph? Why?

The individual cells in the grass paver minimise grass and root compaction maintaining its infiltration capacity therefore reducing surface overland flow.

Human interference to increase infiltration… how does it work?

A or B hydrograph?

Geology

Which rock will cause the most overland flow and why?

Which rock might slow down the passage of water the most? A or B hydrograph shape?

Geology

Which one might be pervious?

Which one would slow down the passage of water the most? A or B hydrograph shape?

Which one would be most likely to flood?

Geology

What is an aquifer?

What is groundwater recharge?

If basin is all aquifer rocks – A or B hydrograph shape?

Infiltration rates in Navajo sandstone.

What sort of climate?

What sort of hydrograph A or B?

Geology and Vegetation

Vegetation What processes are shown?

How does vegetation affect infiltration?

How does vegetation affect the speed of passage of water through the drainage basin?

How does vegetation affect the hydrograph shape? A or B?

Vegetation and Infiltration

Hickory forest will have hydrograph shape A or B?

A larger size outdoor pig unit needs light and permeable soils. This is important, as even after days of constant rain, the farmer has to drive the vehicles to the paddocks to feed and supply water to the animals. However, the condition of the soil is of no considerable importance to the pigs.

Agriculture

What happens to infiltration rate? A or B hydrograph?

Agriculture – what can we see?

Impact on overland flow? Impact on sediment movement? Hydrograph A or B?

Industry May demand increased water supply

Effect on passage of water?

Hydrograph A or B?

Industry

Can also discharge water

Effect on hydrograph?

A or B?

Effect on water quality?

Effect on sediment?

Urbanisation

State four differences in hydrograph shape.

Give a reason for each difference

Urbanisation

What happens to evapotranspiration, overland flow, infiltration?

Increasing Urbanisation or movement towards the (what?)

What happens to evapotranspiration, overland flow, infiltration?

Effect on speed of passage of water?

Effect on hydrograph shape – A or B?