1

Landscape Hydrology and Hydraulics

2

1.Hydrological Analysis

2.Hydraulic Design of

Structures

Scope of Drainage Design and Construction

3

HYDROLOGY – Factors affecting runoff

1. Catchment Area

2. Rainfall

3. Topography

4. Vegetation and Soil

5. Catchment Shape

6. Avaialable storage – lake/swamp

7. Degree of urbanisation

4

Hydrology – Catchment area

5

Hydrology – topography

6

Hydrology – rainfall

7

Major Waterway

Pond

Hydrology - storage

8

Existing Landuse–vegetation/development/urbaniz

9

HYDROLOGY – Rational Method

or

Q = CIA/360

A = area in hectare (ha)

10

Rainfall intensity , I

Intensity

Intensity

13

Runoff Coefficient C

Time of Concentration , Tc or Rainfall Duration

15

Time of Concentration , Urbanizing area

1

10

100

1000

1 10 100 1000 10000

Inte

nsiti (m

m/h

r)

Duration (min)

ARI 2

ARI 5

ARI 10

ARI 20

ARI 50

ARI 100

17

Hydraulic – Manning Eq

Hydraulic – Manning coeff