العواصف الرملية و الغبارية و أثرها في ترب الحقول الزراعية : في واحة الاحساء بالمملكة العربية السعودية

الملخص EN

The northern part of the eultivated land in Al-Hassa Oasis is threatened by dust and sand drift.

The results of this study indieate that : (1) The average annual drift ٠٢ dust and sand days is 105.5, and the average annual blowing days of dust and sand is 25.8.

The percentage of the wind speed frequency of less than 11 knots, and greater than ل ل knots is 71%, and 29% respectively.

(2) Results of the eorrelation coefficient equation indicate that the relationship between the value of monthly wind speed and air pressure, relative humidity, and temperature is very weak.

Also the relationship between the monthly drifting dust and sand days, and the monthly value of air pressure, relative humidity, and temperature is weak, but the relationship between the monthly value of drifting dust and sand days, and wind speed is verry high.

The relationship between the monthly blowing dust and sand days, and the monthly value of wind speed is high, but the relationship between the monthly blowing dust and sand days, and the monthly value of air pressure, relative humidity, and temperature is weak.

Results of multiple regression equation indicate that about 31% of the variation in the monthly wind speed can be explained by the variation of the monthly air pressure, relative humidity, and temperature (R2= ,31).

And about 40% in the variation of the monthly value of drifting dust and sand days ean be explained by the variation of the monthly air pressure, relative humidity, temperature, and wind speed (R2= ,40).

Also About 28% of the variaition in the monthly blowing dust and sand days can be explained by the variation of the average monthly air pressure, relative humidity, temperature, and