Through rainfall simulating under laboratory , and making slice of sampling , the project researched in the soil crust development , and studied the dynamic rule of erosion factors which were raining and soil erosion factors during soil crust development . in the same time , the research was to find the critical condition of all factors in the process of soil crusting , and to filter the critical factor that could affect soil surface crust 本文采用人工模拟降雨方法，通过采样制作土壤切片，观察分析表土结皮在不同条件下发育的微形态特征，研究降雨、土壤等侵蚀产沙因子在表土结皮发育过程中的动态响应规律，界定表土结皮发育过程中各因子的临界条件，筛选有关土壤颗粒组成、结构特征等物理化学性质对表土结皮形成影响的关键因子。
( 2 ) runoff - yielding time on grassland with a higher cover ratio primarily depended on initial water content , and their relationship might be described by a power function too . surface crust could easily take place on bare land , so its runoff - yielding time primarily depended on rainfall intensity , and their relationship might be described by a linear function ( 2 )植被覆盖度较高的荒草地，产流时间主要取决于初始含水量，两者的关系可用幂函数描述；裸地因降雨产生地表结皮，产流时间主要取决于降雨强度，两者的关系可用线性描述。
The species were separately caragana korshinskii hydysarum scoparim artemisia ordosica in shrubs layer , eragrostis poaeoides bassia dasyphylla in herbs layer , bryum argenteum barbula ditrichodies in microbiotic crusts layer . and the dominant species of them were artemisia ordosica eragrostis poaeoides bryum argenteum respectively . due to the different time and the topographical varieties in the fixing - sand region , the horizontal structure of artificial vegetation manifested out the mosaic characteristics 灌木片层的主要植物种是柠条( caraganakorshinskii ) 、花棒( hydysarumscoparim ) 、油蒿( artemisiaordosica )等灌木植物，其中优势种为油蒿；草本片层的主要植物种有小画眉草( eragrostispoaeoides ) 、雾冰藜( bassiadasyphylla )等，其中优势种是小画眉草；生物结皮由藻类和苔鲜类构成，其中，银叶真鲜( bryumargenteum夕为固沙植被区鲜类地被层优势成分。
