Based on the principle of soil erosion, using the research methods combining large scale and small scale, the paper studied the general ground substance’s impact on regional soil erosion in Guizhou Province. Results show that ground substances not only affect soil’s mechanical or physical composition in small scale, but also affect erosion landscape and vegetation in large scale . Meanwhile, there are close relationship between ground substance and soil’s errodibility or anti-scouring. The main research results are as follow.1. There are significant differences among soils developed from different ground substances about sand grain ratio, silt ratio, clay ratio and water-stable aggregation. The soil developed from carbonatite group has lower sand grain ratio (17.84%) but higher silt ratio (43.93%) and higher clay ratio (38.24%). The soils developed from purple sand-shale and sand-shale have higher sand grain ratio and lower clay ratio. About water-stable aggregation, the research indicates that carbonatite’s soil has highest percentage on 0.5-2mm level, sand-shale’s soil has highest percentage on 0.25-0.5mm level and that slate group’s soil has highest percentage on the level over 5mm. On the total water-stable aggregation, there is an order as follow: slate group (78.16%) > basalt group (65.19%) > carbonatite group (60.68%) >coal series (58.96%) > sand-shale group (47.52%) > Purple sand-shale group (42.1%).2. Ground substances significantly affect soil’s errodibility value K on slope cultivated lands. In Guizhou Province, the soils developed from general ground substance have strong anti-errodibility，which is between 0.18 and 0.26 and greatly lower than those of northeast area of Yunnan Province. 3. Slope cultivated land soils developed from different ground substances have obviously different anti-scouring ability. The scouring modulus order is as follow: purple sand-shale group (24.75g.(m2.s)-1) > sand-shale group (21.09g.(m2.s)-1) > carbonatite group (14.02g.(m2.s)-1) > basalt group (10.08g.(m2.s)-1) > Slate group (8.78 g.(m2.s)-1) > coal series (4.89g.(m2.s)-1).Soil’s scouring modulus reduces along with increasing of water-stable aggregation content. Meanwhile, there is a close logarithm correlation between water-stable aggregation ratio on 1 to 5mm level and soil’s scouring modulus.4. Ground substance has significant influence on surface erosion landscapeGround substance’s influence on surface erosion landscape is reflected by different water-way’s developing degree on different rock groups. The water-way’s developing process shows a universal law, that is, a random walking principle. The difference of ground substance does not influence a water-way system’s inner laws. Between the different scales, there are certain contrasts or transition relationships for water-way’s levels. Water-way’s length of the first level on water-way system map of 1:200000 scale is amount to the length of the second or third level on 1:50000 scale.Water-way’s length of the first level on water-way system map of 1:50000 scale is amount to the length of the third level on 1:10000 scale. Ground substances affect lower level water-way’s number, total length, average length, frequency and density, which causes the different normal erosion on different ground substance types. The influence order indicated by water-way’s frequency is as follow:Slate group (11.88 /km2) > sand-shale group (8.48/km2) > basalt group(8.00/km2)> coal series(5.98/km2) >carbonatite group (3.66/km2).Meanwhile, there is a close relationship between the area ratio of carbonatite group and water-way system.5. Ground substances affect the vegetation types and indicate a certain character of non-zonation.6. Establishing the regional division system for soil erosion degree and soil erosion potential danger based on ground substance in Guizhou Province.All in all, in Guizhou Province or similar areas, the diversity of ground substance controls regional soil erosion’s spatial distribution laws. Ground substance is an important factor and shouldn’t be ignored during regional soil erosion studying. Research results will provide the scientific foundation for regional soil erosion’s evaluation and prediction.
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