东江流域水土流失区水土资源评价──以上杨试验区为例

Soil and Water Resources Appraisement in the Soil and Water Loss Area in Dongjiang Watershed──Taking Shangyang Experimental Area as an Example

东江流域水土流失区水土资源评价是在“广东省东江流域防治水土流失措施与规划调查研究的基础上选择典型──惠阳县上杨地区进行的重点深入研究之一。本区水土资源丰富，但成立大亚湾经济开发特区后，工业用水和居民用水激增，水资源不足，需要从西枝江取水补充。土地资源评价，首先应用土地发生学理论将本区划分出10种土地类型，制定出5个土地资源评价因子和指标，并参照国内外土地资源评价分级标准采用八级制进行评价，本区无一等地，二等地最多，占总土地面积33．5％，四级地最少，占总土地面积的1．3％。

The research of the soil and water loss and soil resources appraisement are carried out in the Shangyang district, Huiyang county, based on the investigation and studies on the measures and programmes of preventing soil and water loss in Dongjiang watershed, Guangdong province.The water resources is very deficient because of the increasing water used by industry and people after the establishment of Dayawan economic exploitation region, then the partly supplied water come from Xizhi River. The course of soil resources appraisement is divided into as follows: the soil types in this region are divided into 10 types based on the theory of soil genesis; the 5 factors and indexes of soil resources appraisement are put forward; the 8-grade system appraisement is adopted refering to the soil resources appraisement at home and abroad. Without 1-grade land in this area,the 2-grade land area is 33. 5% of the total land, the 4-grade land is only 1. 3% of the total land.