Data of biocrusts model tests

To explore the control effect and mechanism of biological soil crusts (BSCs) on the shallow surface layer of loess under short-duration intense rainfall conditions, bare soil (BS) and BSC-covered soil from the semi-arid region of the Loess Plateau were selected as the research objects.

Indoor scaled slope model tests were conducted to simulate the alternating environment of short-duration intense rainfall and drought. The variation characteristics of soil volumetric water content, matric suction, and cone penetration resistance during the dry-wet cycle were analyzed, and the underlying mechanism was revealed by combining the microstructure of BSCs. The results showed that, relying on the layered structure of "surface fiber network + deep EPS-soil particle porous structure", BSCs could reconstruct the water distribution in the shallow loess layer and improve the water retention capacity of the soil, with the area within 30 cm depth being the core zone for water retention.