5.30 THE RISK OF FARMING IN DIFFERENT AREAS

 

Data ID

 

Description:

Risk of farming in different areas based on a synthesis of rainfall and vegetation production

 

Chapter:

5 Land and History

 

 

File name:

The risk of farming in different areas

 

File type:

Arcview shapefile

 

Geographical area:

Namibia

 

Keywords:

risk

 

 

farming

 

Notes on data, analysis and

A perspective on risk of farming in Namibia based on a synthesis of information on average rainfall (Figure 3.18),

 

compilation:

variation in rainfall (Figure 3.21), average plant production (Figure 4.6) and variation in plant production (Figure 4.7).

 

 

It therefore takes account of both actual levels of rainfall and plant production and the degree of variability in an area.

 

 

 

 

 

Average rainfall:

 

 

values for grid cells were converted to a percentage using the cell with the highest value as the denominator. These

 

 

values were then inverted using the formula (100-cell value) so that areas with high rainfall have a low value and areas

 

 

with low rainfall have a high value.

 

 

 

 

 

Average plant production:

 

 

values for grid cells were converted to a percentage using the cell with the highest value as the denominator. These

 

 

values were then inverted using the formula (100-cell value) so that areas with high production have a low value and

 

 

areas with low production have a high value.

 

 

 

 

 

Variation in rainfall and variation in plant production:

 

 

In both cases, values for grid cells were converted to a percentage using the cell with the highest value as the

 

 

denominator. Cells with high values reflect areas with high variation

 

 

 

 

 

The resulting 4 grid files (each with values on a scale from 0-100) were summed to produce one grid file with values

 

 

ranging from 0 - 400 (maximum). This provides a relative measure of risk as those areas having high values are in

 

 

general, areas with low rainfall, low plant production and high variability in rainfall and plant production.

 

 

 

 

 

The scale 0- 400 was summarised into 7 class intervals which allowed a relative ranking to be made of high to low risk

 

 

areas and a smoothed shapefile was created from the grid file.

 

Data quality and organisation

 

Positional Accuracy:

Very generalised

 

Vector/Raster:

Vector

 

Spatial reference

 

Projection:

Geographic

 

Fields

 

Field name

Field description

 

RISKY

Scale of 1 to 7 indicating high (1) to low (7) risk

 

Source/Distribution

 

Data Source:

Atlas of Namibia

 

Distribution notes:

Unrestricted

 

5.30 THE RISK OF FARMING IN DIFFERENT AREAS - PREDICTED RAINFALL

 

CHANGES

 

Data ID

 

Description:

Predicted rainfall over Namibia and southern Africa

 

Chapter:

5 Land and History

 

 

Geographical area:

southern Africa

 

Keywords:

climate

 

 

predicted

 

 

rainfall

 

 

change

 

Notes on data, analysis and

Created by digitising from an image published in: Hadley Centre. 2001. Hadley Centre regional climate modelling

 

compilation:

system. Met Office, London. For data contact the Hadley centre (see source).

 

Source/Distribution

 

Data Source:

Hadley Centre

 

Contact:

Hadley Centre

 

Online/Offline Address:

London Road

 

 

Bracknell

 

 

Berkshire

 

 

RG12 2SY

 

 

UK

 

 

 

 

 

www.metoffice.com

 

Distribution notes:

Unrestricted