天山北麓中段土壤侵蚀影响因素及特征分析

Analysis of influencing factors and characteristics of soil erosion in the middle region on the north slope of Tianshan Mountain

通过对天山北麓中段土地类型、河流径流和植被覆盖等土壤侵蚀影响因素的空间分布特征分析认为 :1天山北麓中段主要侵蚀类型为风蚀、水蚀、冻融侵蚀及人为加速侵蚀 ;2侵蚀产沙类型以及产沙强度在空间上具有明显的垂直变化规律 :沙漠以风力侵蚀、高山和亚高山以冻融侵蚀为强烈侵蚀类型 ,普遍存在微度水力侵蚀 ,局部表现为中度甚至强度 ;3水蚀类型有冰川融雪径流侵蚀和降雨径流侵蚀两种方式。天山北麓中段河流产沙时间上主要在每年的 5月初至 8月末 ,且冰川雪水径流产沙要比雨水径流产沙量大 ,空间上则主要位于海拔 80 0～ 1 50 0 m的由第三纪、第四纪地层和黄土堆积所组成的中。

Through analyzing the spatial distribution of runoff,land types and vegetation cover in the middle region on the north slope of Tianshan Mountain,the characteristics of soil erosion in Xinjiang have been got as follows.① The major types of erosion are erosion of wind,water,freeze thrawing,and man made accelerated erosion.② The types of erosion and sediment and the intensity of sediment show a distinctively vertical change.In the desert the violent type of erosion is by wind,on the high mountain by freeze thrawing,and the slight water erosion spreads widely,however at some plots soil erosion by water reaches to mid,or even strong degree.③ The two types of water causing soil erosion come from melted glacier and snow and rainfall.The time of generating sediment is mainly from the beginning of May to the end of August,and the sediment from melted glacier and snow is more than that rainfall.The elevation of the main region of sediment generating is from 800 to 1 500 meters,which belongs to the mid low mountain and hilly land deposited by the Tertiary and Quaternary stratum and the loess soil.