Stream Flow

Question 1

Application of common methods for base flow seperation

Answer 1

1) Draw a base flow line
2) Time after peak to reach base flow
N=0.8A^(0.2)
3) Draw line to mid point of unit rainfall scale (lag time) 4 x lag time = baseflow

Question 2

Application of common methods to estimate effective rainfall

Answer 2

• contributes to direct runoff (i.e. infiltration losses, interception losses)

1) Assume start of rainfall is losses
- after continuous loss
- poor estimate

2) Proportional loss

3) Index method
- assumes constant rate
- anything below lost
= (catchment rainfall - directrunoff)/ (storm duration)