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Landslide dams, especially stable landslide dams, have been recognised as important contributors to regional geomorphological evolution. The eastern edge of the Tibetan Plateau provides good conditions for the formation of stable landslide dams. To identify stable landslide dams on the eastern margin of the Tibetan Plateau, the Google Earth Engine (GEE) was first used to map water surfaces in the study area. Then, stable landslide dams were identified using high-precision remote sensing images provided by Google Earth. A field investigation and a sampling of typical stable landslide dams were also adopted to characterise the landslide dams. The results show that 101 stable landslide dams are present in the study area, covering an area of 27.75 × 104 km2. There are four types of stable landslide dams, as follows: (1) landslides, (2) rock avalanches, (3) moraines, and (4) debris flows. The morphological parameters of a dam, which include dam height, dam width, dam volume, and catchment area, can be fitted with different relationship curves, with respect to the number of landslide dams. The source areas of landslide dams are generally located in the upper-middle and upper sections of adjacent mountains. The stability of a landslide dam is mainly controlled by the structure of the dam and the relationship between the dam volume and catchment area. Structurally, large rocks with large particle sizes are difficult to activate using river water and the large gaps between the rocks provide sufficient channels for the flow of river water. In regard to the relationship between the dam volume and catchment area, a river with a small catchment area in the study area is commonly blocked by a large dam volume. This study provides a unique opportunity to study the spatial distribution and clarify the factors influencing the stability of stable landslide dams. [ABSTRACT FROM AUTHOR]

The topsoil of a clayey slope is easily washed off by rain due to its loose structure. To protect the slope surface, in recent years, several types of non-traditional soil additives have been used by means of mixing with soil. In this work, a new organic polymer soil stabilizer, named aqua-dispersing-nano-binder (ADNB), was sprayed on the soil surface to stabilize the topsoil of a clayey slope. To understand the interaction between the polymer and soil particles during the infiltration process as well as the stabilization mechanism, infiltration tests, water stability tests and scanning electron microscopy (SEM) analyses were performed with different polymer contents. The infiltration tests showed that the infiltration rate of the polymer stabilizer in the soil was slower than that of water due to its characteristics of easy adhesion to soil particles, poor fluidity and large molecular volume. The maximum effective infiltration depth was achieved in the specimen treated with 2% ADNB, and the minimum was achieved in the specimen treated with 5% ADNB. The water stability of the soil increased with the content of the soil stabilizer in the soil aggregates with diameters of either 5–10 mm or 10–20 mm. The SEM analysis showed that the quantity of polymer decreased with infiltration depth; a polymer membrane was formed on the surface of the topsoil and chains were formed inside. The amelioration of the soil water stability may have been due to the bonding between soil particles and polymers generated after evaporation of water in the emulsion. The polymer stabilizer could be applied to improve the erosion resistance of the slope topsoil and reduce soil loss. [ABSTRACT FROM AUTHOR]