Application of Geographical Information System (GIS) and Remote Sensing
(RS) Technologies to Clarify the Occurrence of Rift Valley Fever (RVF) In
White Nile State, Sudan

Adam I. Ahmed1, Manal A. Khairy2, Mohammed S., Dafalla3 and Atif E. Abdelgadir4*
Page No. 58-73

An attempt was made in this study in order to apply Geographical Information System (GIS) and
Remote Sensing (RS) for disease mapping of Rift Valley Fever (RVF) in the White Nile State, Sudan.
Rift Valley Fever (RVF) is an acute vector-borne zoonotic disease caused by an Arbovirus.
Geographical Information System (GIS) is a computer based programme used to store and display
digital data on a map representing earth surface. While, Remote Sensing (RS) is a method for
acquisition of information about an object without physical contact.The results revealed that there
was a relationship between occurrence of RVF and heavy total rainfall which was 382mm in 1973
and 782 mm in 2007 at Kosti station. The maximum temperature in the dry hot season was 43.1,
40.8 and 40.3 ºC in 1973 and 41.9, 42.6 and 38.0 ºC in 2007 for April, May and June respectively.
In both two years the disease was reported there and the rainfall was more than the normal
average. It is well known that the high temperature in summer followed by heavy rainfall might be
responsible for occurrence of Rift Valley fever (RVF). The soil type is a clay soil in Kosti and Guda,
however, in Tendalti is a sandy one. An assumption was made that the clay soil has a great impact
on vector replication habitat. The elevation level above sea surface was 415, 378 and 372 meters
for Tendelti, Guda and Kosti, respectively. As seen from the results, Kosti is the most depressed
point in the study area, which made it the most prone for accumulation of rain water. The results
confirmed the fact that Normalised difference Vegetation Index in Sudan increase when total
rainfall increase. In conclusion, there was a relationship between the occurrence of Rift Valley
Fever and heavy total rainfall, maximum temperature in summer seasons, soil type, elevation level
and animal species. Furthermore, the epidemiological importance of the locality can be determined
by landscape of the area and its natural foci disease as well as the extent and nature of contact of
man and his environment. Based on that, more investigations regarding the relationship between the
disease and the climatic indicators are required in order to enable the veterinary authorities to use
the Early Warning System, regulate and restrict animal's movements, and explore the influence of
herd immunity on the epidemiology of Rift valley Fever.
Keywords: Geographical Information System (GIS), Remote Sensing (RS), Rift Valley Fever
(RVF), White Nile State, Sudan