The state of the land surface and the water cycle over the South and East Asia can be determined by space observation. New or significantly improved algorithms have been developed and evaluated against ground measurements. Variables retrieved include land surface properties, i.e. NDVI, LAI, FPAR, albedo, soil moisture, glacier and lake levels. Based on these biophysical parameters derived from microwave and optical remote sensing observations, a hybrid remotely sensed evapotranspiration (ET) estimation model named ETMonitor was developed and applied to estimate the daily actual ET of the Southeast Asia at a spatial resolution of 1 km. The changes in glaciers and lakes on the Tibetan Plateau, and the drainage links between glaciers and lakes are determined in this climate-sensitive region.

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A trapdoor system has frequently been used to study soil arching and its development in recent years. The load transfer in the fill of piled embankments is very similar to a trapdoor system with multiple trapdoors. There are multiple arching models described in different standards and guidelines for piled embankments that can be subdivided into three archingmodel families. To study the soil-arching type and its development, a series of model tests with sand fills were carried out in a two-dimensional (2D) multi-trapdoor test setup. The tests considered four factors—the fill height, trapdoor width, pile width, and grain size of the sand—with four values for each factor. Triangular slip surfaces were found at very small deformations using the particle image velocimetry (PIV) technique. These surfaces evolved in ways that could be related to the three types of stress-distribution ratio curves, with development patterns similar to the arching families of piled embankments: (1) the rigidmodel family, (2) the equal-settlement-plane-model family, and (3) the limit-equilibriummodel family. The limit-equilibrium-model family occurred in tests with narrow trapdoor widths. @en

Experimental data of laboratory testing of sands from plane strain compression tests are much less available than those from triaxial tests. In order to get the strength parameters of the sands used in 2D piled embankment model tests and the micro parameters used in the DEM simulations of these tests, a series of tests are done using plane strain test apparatus. These tests consist of three groups with different grain sizes: two coarse sands and a medium sand. For these tests, the relative density was set to 85%. A relative density of 50% was applied to assess the influence of the density. The sample size is large, 600mm^∗ 600mm^∗ 300mm (length^∗ width^∗height) in order to eliminate the side friction effects of the container. The results prove that relative density has a significant impact on the experimental results for the same type of sand, while the grain size has negligible impact. The high peak friction angles are attributed to the feldspar component, confining condition of plane strain tests, and high relative density. Tests of sands with different grain sizes and relative density also provide detailed data for the DEM numerical simulations. The high friction properties can be calibrated using the non-circular particle clumps.

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