The method of dividing assessed units on the danger of soil erosion was inquired and the danger of soil erosion appraised in Sanhe ecological orchard

Fengdu county

Chongqing city by means of analytical hierarchy process and system cluster supported by the software of ARC/INFO 8.02 and SPSS 10.0. The factors affecting the danger of soil erosion were considered in an all round way and the limitation and indistinction was avoided during the process of assessment. Results showed that the danger of soil erosion was mainly subject to the three factors of slope

the thickness of soil and the degree of plant cover and the area of the dangerous type

the more dangerous type and the seriously dangerous type was 57.49% of the area of the entire orchard. Because of the danger of soil erosion

it was not suitable that the excessively economical woods was planted and it was reasonable that the economical woods and the ecological woods were paid equal attention during the process of "planting woods after withdrawing cultivated land" in the ecological orchard.