1.0.1 This standard is formulated in order to unify water and soil loss investigations and develop water and soil conservation work.
1.0.2 This standard is applicable to classification and graduation of soil erosion all over the country.
1.0.3 Main normative references of this standard:
"Terminology of Soil and Water Conservation"(GB/T 20465-2006).
1.0.4 The classification and graduation of soil erosion shall not only execute this standard but also those in the current relevant current nations.
2 Terminology
2.0.1 The relevant soil erosion terminology defined in GB/T 20465-2006 are applicable to this standard.
2.0.2 The potential hazard degree of soil erosion
It refers to the hazard degree of soil erosion occurring after unbalance of the ecological system. It is used to evaluate and predict the degree where the erosion is caused in no obvious erosion area and the erosion is aggravated in the erosion area and express the erosion age limit (erosion resistance age limit) borne by this soil horizon at the current erosion rate in the erosion area.
3 Soil Erosion Type Division
3.1 Grade 1 Type Area
3.1.1 Three Grade 1 soil erosion type areas, namely hydraulic power, wind power and freezing and thawing all over the country.
3.1.2 Gravity erosion and mixing erosion shall not be divided into type areas independently.
3.2 Grade II Type Area
3.2.1 Water erosion type area should be divided into five Grade II type areas, namely loess plateau of Northwest China, black soil area in Northeast China, rock-soil mountainous area in North China, red soil hilly area in South China and rock-soil mountainous area in Southwest China.
3.2.2 Wind erosion type area should be divided into two Grade II type areas, namely the sandstorm area in "Three North" gobi desert and sand and the sandstorm area in coastal plain.
3.2.3 Freeze-thawing erosion type area should be divided into two Grade II type areas, namely freezing and thawing soil erosion area in North China and Qinghai-Tibet Plateau glacier frozen soil erosion area.
3.2.4 Each large river basin and each province (autonomous region, municipality directly under the central government) may be subdivided into Grade 3 type areas and subareas on the basis of Grade II zonal partition nationally.
3.3 Scope and Feature
3.3.1 The scopes and features of all-level soil erosion types all over the country are detailed in Table 3.3.1.
