我国不同自然带的化学剥蚀过程

CHEMICAL DENUDATIONAL PROCESSES IN DIFFERENT NATURAL ZONES OF THE MONSOON-INFLUENCED EASTERN CHINA

化学剥蚀过程具有明显的地带性.化学剥蚀模数在华南、华中热带、亚热带湿润地区最高,暖温带半湿润区次之,华北暖温带半干旱区最小,东北寒温带半湿润区又有所回升.气温、降水、流域干湿程度、植被状况是决定化学剥蚀强度的主要因子.

Based on the data of dissolved matter measurement collected from more than 70 gaging stations in the rivers of the monsoon-influenced eastern China.this paper deals with the chemical denudational processes, including the effect of zonal factors such as temperature, precipitation, vegetation and the drainage basin dryness upon the chemical denudational rate,and the zonal differentiation in the chemical denudation in the mon-soon-influenced eastern China. As a result, a curve has been established, which shows the latitudinal variation of the chemical denudational rate in this region.It is suggested that, at the macro-scale , temperature, precipitation, drainage basin dryness and vegetation are the main factors controlling the chemical denudational inten-sity. With the increase of temperature, precipitation, forest cover and a decrease of drainage basin dryness,the chemical denudational rate increases. On the other hand,at amoderate and a small space scale,the rock types determine the differences in the chemi-cal denudational rate under the same climatic conditions.An obvious zonality in the chemical denudational processes in the monsoom-influ-enced eastern China has been indicated by this study. The chemical denudational rate is the highest in the tropical and subtropical humid areas in the southern and central China,and it becomes lower in the warm temperate sub-humid areas. In the north China warm temperate semi-arid areas, it declines to the lowest value, when going further northeastward, it increases again in the northeast China cool temperate sub-humid ar-eas. The foregoing zonal variation can be explained by the different combinations of tem-perature,precipitation,drainage basin dryness and vegetation in different natural zones.