Abdalla Fadl Elmula, Isam Eldin
WOODY VEGETATION DAMAGE ASSESSMENT 1253
USING LANDSAT IMAGERY AND GIS
Dr. Gar Alnabi Ibrahim Mohammed*, Isam Eldin Abdalla Fadl Elmula**
*Dept. of Surveying Engineering,
University of Khartoum, Sudan.
P. O. Box 321
**Forests National Corporation (FNC), Sudan.
Mohiedeen@mailcity.com
Inter-technical Commission Session Themes IC-7
KEY WORDS: Remote Sensing, Interpretation, Land use/land cover, Drought, GIS
ABSTRACT:
* This paper presents the application of landsat imagery for mapping and assessing the forests damage. To fulfil the goals
of this study landsat thematic mapper (TM) hard copy images were used. Moreover the paper presents the advantages of
the false color images, to differentiate between the vigorous vegetation and the dead forests. In addition to that the study
has carried out a comparison operation for the land cover change in the study area in three periods, namely (1958,1972,
and 1985). For this task extra data were used; those are multispectral scanner hard copy images acquired in 1972, and
land cover maps produced from aerial photographs acquired in 1958. This assessment and comparison was done with
the aid and use of the GIS applications (Arc/ Info, software).
The comparison of the land cover over the three periods (1958, 1972, and 1985) showed a clear change (increase)in the
forest damage.
1. INTRODUCTION:
The drought of 84-1985 in the Sudan has put clear signatures on the vegetation cover. Kurdofan and Darfor states, were
the most affected areas by the drought. That is most of the vegetation cover was damaged and the (natives) have faced a
great famine. This drought has led to a desertification phenomenon caused by the human being and the animals. The
farmers posed by the decline of the soil productivity began to increase the area of their farms horizontally. Doing this
they continued cutting the wooded areas, because the soil under the wooded area is of good fertility. Also an over
grazing process was produced by the large amounts of animals which have suddenly lost the usual range and pasture.
The inventory and assessment of the amounts of damage for this large area, needs the use of remotely sensed data.
The purpose of this paper is to try to develop a methodology based on the interpretation of landsat imagery (hard copy)
as a mean of vegetation damage assessment, supported by field check data. Also to make use of the inventory of the
wood areas, which were destructed and changed to cultivation areas, and comparing these areas with damaged areas in
other data sets taken in different dates.
The study area chosen is Abu Zabad area. This area is included in the worksheet of Abu Zabad enclosed between
latitudes 13° 00’ - 14° 00’ North and longitudes 28° 30’ - 30° 00’ East. Four training areas were chosen for the
evaluation of the land cover change, which is caused by the effects of the desertification. These training areas are Sa'ata
Ezzarqa, Hillat Said, Abu Ku', and Addibeibat area. All these training sites were interpreted for the damaged vegetation.
This vegetation is damaged by the drought in some areas, and by cutting the wood trees for cultivation in others.
Moreover animal over grazing also take place in some areas.
To fulfill these goals land use/land cover maps were produced for the study area (represented by the above mentioned
training sites). These maps included the following land cover types:
1. Cultivated areas (and these includes the damaged areas, the cultivated, and over grazing areas).
2. Vegetation areas (areas not utilized).
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 13