APPROXIMATE AREAS of LAND SYSTEMS in the WSP-2 AREA

 

 

Land Use Planning Note AAH/12/87

 

 

1 INTRODUCTION

 

No definitive estimates appear to have been made of the various Land Systems within the WSP-2 area; this note presents details of present estimates.

 

2 MATERIALS USED AND METHODOLOGY

 

2.1 Materials Used

 

The recently compiled map, ASD 58, at a scale of 1:1,000,000, which shows the Land Systems, but not all the sub-systems, was the source of the data presented here.

 

2.2 Methodology

 

Not having access to a planimeter the well-proven method of cutting and weighing was used to estimate the various extents of the Land Systems. Each portion of each individual Land System was cut out and placed in an envelope, along with cuttings of the same System. The weight of the contents of each envelope was then weighed and the percentage of the total occupied by each Land System was calculated.

 

Several sample blocks of 100 square kilometres size were drawn on the map and these were also cut out and weighed. Once an average figure for the weight of an area of 100 square kilometres was established the areas of the various Land Systems was calculated.

 

The estimates of the areas so determined are presented in Table 1 below.

 

Table 1 Approximate Extents of Land Systems in WSP-2

 

Land System

Dominant Soil

Textures

Square km

%

Baggara

Nagaa

Sl,SCl,Cl

25,476

18.48

 

 

 

 

 

Bahr

Buta

SiC,C

4,163

3.02

 

 

 

 

 

Basement (North)

Basement

Sl,L,Cl,C

29,047

21.07

Basement (South)

Basement

Sl,L,Cl,C

6,672

4.84

 

 

Sub Total

35,719

25.91

 

 

 

 

 

Laterised Basement

Lateritic

Sl,Scl,Cl

12,614

9.15

 

 

 

 

 

Qoz - Dango

Qoz

S,Ls

14,640

10.62

Qoz - Habaniya

Qoz

S,Ls

6,314

4.58

Qoz - Ma'aliya

Qoz

S,Ls

10,712

7.77

Qoz - Rizeigat

Qoz

S,Ls

12,021

8.72

Qoz - Salsilgo

Qoz

S,Ls

2,978

2.16

 

 

Sub Total

46,665

33.85

 

 

 

 

 

Regeba

Alluvial

SiCl,C

11,428

8.29

 

 

 

 

 

Volcanic

Basaltic

L,Cl,C

1,792

1.30

 

 

Totals

137,857

100

Notes:

         Dominant soils are very approximate, refer to Map ASD 58

         Total area estimated as 137,857 square kilometres. This compares with the approximate figure of 135,000 square kilometres given in the SAR, AACM, Feb 1985.

         Textures

: S - sand

: Ls - loamy sand

: L - loam

: Sl - sandy loam

: SCl - sandy clay loam

: SiCl - silt loam

: Cl - clay loam

: C - clay

 

A.A.Hutcheon

 

9 July 1987