Textural Analysis of Windblown Sand as an Indicator of Susceptibility of Wind Erosion in Atbara Area, River Nile State, Sudan

Abstract

Textural Analysis of Windblown Sand (TAWS) is essential for understanding the characteristics of wind sediment and behaviors of grain movement particularly in the climatically frame of wind erosion. This paper aimed to generate preliminary quantitative data on TAWS by estimating grain size distribution and some textural parameters e.g. median diameter (M50), mean grain size (Mz), graphic standard deviation (σ1) inclusive graphic skewness (Ski) and transgraphic kutosis (KG) in three selected sites namely, north, south east and south Atbara in river Nile state. Coefficient variations of the (M50) and (Mz) results exhibited a colossal similarity with minor differences between them accounted about 1.12%. In spite of the high variability of (σ1) between three sites (30%) but the data can be characterized as very well sorted (< 35), so the study area can be described as highly susceptible to wind erosion, the susceptibility decreased in the following order: north Atbara > south east Atbara> south Atbara. Regarding to (Ski) results the three sites can be described as positively skewed (north and south east Atbara) and very positively skewed (south Atbara). The (KG) data showed leptokurtic (north and south Atbara) and mesokurtic (south east Atbara). The dominant mean grain sizes for sand samples for north Atbara were fine sand 34% and medium sand 50%. Whereas the samples of south east Atbara distributed fine sand 34%, medium sand 45% and courses and 5%. South Atbara gave 25%, 38% and 12% for fine, medium and courses sand respectively.