The slope map, on a scale of 1:25 000, of the relief of the cultivated land, which covers light darkly-brown soil of the Zhambyl administrative district, located on the north slope of the Ile Alatau, was constructed on the basis of GIS technology, and the erosive action of runoff flow was researched. It is defined flow amount, flow coefficient, amount of the area with soil erosion and intensity of erosion, which appeared in connection with the degree of declivity of slopes with exposure to the south and north of researched subjects of melt-water and atmospheric water, which are integrated parts of them, and each of them was given differentiated descriptive evaluation. As a result it was proved that the resistance to water erosion of the soil with exposure to the north is much better than the resistance of the soil with the south exposure. Another defined principle is that the influence of rain to the soil erosion is much higher than the influence of melt-water. While comparing grain fields with fields left fallow, it was defined that perennial plants can resist to the soil erosion much better.