Classification of Climates of Sudan Using Aridity Indices

This study aims at determining a suitable climate classification system for Sudan through comparison of different aridity indices computed using long term (1971-2000) climatic data for 19 weather stations. Sudan has a total area of 2,505,800 sq km and lies approx. between latitudes 4O to 22O N and longitudes 21O and 39O E. Six aridity indices were used to assess the aridity in Sudan: (1) Emberger Aridity Index (2) De Martonne Aridity Index, (3) Thornthwaite Aridity Index, (4) UNEP Aridity Index (5) UNESCO Aridity Index and a newly devised Aridity Index (Eddebba Aridity Index). The results showed that Eddebba and Emberger aridity indices are more appropriate for classification of Sudan climates compared to other methods and that Sudan climate can be classified into hyper-arid, arid, semi-arid, sub-humid and humid zones.