中国开辟区不利开采地形类型及其分布

The types and distribution of the terrain disadvantageous to mining in the Pioneer Area of China

利用1998年"大洋一号"调查船近海底作业所获的深拖海底电视和照相系统资料,对中国开辟区不利开采地形类型及其分布特征进行了研究,并对海底地形的坡度进行了计算,结果表明:(1)中国开辟区东、西两区海底的东向坡和西向坡是均衡分布的。东、西两区海底地形坡度的分布特征明显不同,东区海底地形坡度以0～15°为主,而西区坡度大于3°的地形则很少。坡度大于5°的地形主要分布于坡脚处,特别是坡度超过15°的地形总是出现在水深变化的转折点处。(2)研究区不利开采地形可分为坡度为5～15°和大于15°两种类型,东区地形坡度大于5°的不利开采地形比西区多14%,东区坡度大于15°的地形为3.6%,比西区(仅为1.4%)多,东、西两区都有少量坡度近90°的地形出现,并且这种地形在东区所占比率比西区大,说明东区断崖、陡坎和断裂沟槽比西区多,地形也更为复杂多变。

In this paper, we deal with the data that is gotten by the deeptow system in the Pioneer Area of China and study the types and distribution of the terrain disadvantageous to mining. According to the results of submarine integrated survey and the slope values calculated from the deeptow system survey, the terrain disadvantageous to mining is divided into two types: 5～15°and >15°. We found that the terrain with a slope larger than 5° mainly distributes on the foots of slopes, especially the terrain with a slope larger than 15° distributes on the turning point of water depth change from flat one to uneven one or contrary to it. Eastward slopes and westward slopes are equably distributed in the east area and west area of the Pioneer Area of China. The features of slope distribution in the east area are obviously different from that in the west area. The slopes in the east area are mainly 0～15°, few slopes in the west area are larger than 3°. The terrain in the east area is more complex than that in the west area. The terrain disadvantageous to mining in the east area are more than that in the west area by 14%. There is terrain with a slope close to 90° in the east area and in the west area, and this kind of terrain in the east area is more than that in the west area. About 36% terrain with a slope larger than 15° exist in the east area, and 14% in the west area. The two statistic results as above show that there are more cliffs, steep ridges and break grooves in the east area than in the west area.