Bei dem Beitrag handelt es sich um die erweiterte Fassung der gleichnamigen Keynote Lecture auf der 4. Bodenmechanik Tagung im Rahmen der Fachsektionstage Geotechnik, die auf Anregung der Fachsektionsleitung auch in der Zeitschrift geotechnik veroffentlicht werden soll. Bei den Phanomenen der inneren Erosion in durchstromtem Boden und in Erdbauwerken geht es um das Losen, den Transport und die Ablagerung bevorzugter Fraktionen mit der Folge einer anderung der Bodeneigenschaften. Die Phanomene der inneren Erosion werden als Kontakterosion, Suffosion, Kolmation und ruckschreitende Erosion charakterisiert. Die Kinematik dieser physikalischen Prozesse ergibt sich mit der Energie einer Sickerstromung aus der Bewegung des Einzelkorns im Porenraum, den moglichen Freiheitsgraden beim Transport. Der Artikel gibt einen uberblick uber die Art und Bedingungen der verschiedenen Phanomene sowie uber deren spezifische Kinematik innerhalb der Bodenstruktur. Die relevanten international verwendeten Nachweismethoden und Kriterien werden aufgefuhrt und in ihrer Aussagekraft bewertet. Die kennzeichnenden Einflussparameter werden aufgezeigt. Fur die einzelnen Phanomene der inneren Erosion werden Strategien zur Bewertung und Beherrschung des Erosionsrisikos diskutiert. Phenomena, kinematics and risk assessment strategies of internal erosionInternal soil erosion due to seeping water in natural sediments as well as in earthworks can lead to a significant change in soil properties and could even destroy the structural integrity. The physical process of erosion always is induced by loosening, migration, and deposition of predominant fine particles within the soil structure. Depending on the kinematics, the phenomena are divided into contact erosion, suffusion, colmation and backward erosion piping. The kinematics is controlled by the energy of a seepage on the one hand, on the other by the degrees of freedom and the boundary conditions of an individual grain movement within the pore space. This article provides an overview of the characteristic, specifics, and conditions of the different phenomena considering their kinematics within the soil structure. Internationally used approaches and methods of assessment are listed, their significance and their limitations will be evaluated. The impact parameters that control the different processes are shown. Strategies for assessing and controlling the risk of structural damage are discussed for the different phenomena of internal soil erosion.

Most land surface models (LSMs) used in climate models do not perform well in modeling the permafrost processes. Due to the complex permafrost distribution characteristics and landscapes of the Qinghai-Tibet Plateau (QTP), the LSMs simulations over QTP are even worse. In this study, we revised the permafrost scheme in the original Common Land Model (CoLM) to improve its capability of simulating permafrost processes. We adopted a new frozen soil parameterization scheme, in which maximum unfrozen water content is defined as a function of soil matric potential. In addition, we extended the model's bottom to a depth below that without annual variations in temperature and replaced the zero-flux lower boundary condition with a constant geothermal heat flux based on literature and temperature gradient measurements in a 34.5-m-deep borehole. What's more, we revised the original snow cover fraction parameterization scheme of CoLM according to the special snow cover distribution characteristics over QTP. We calibrated and validated the modified model against observations from 2005 to 2008. The results indicate that the modified model produced more reasonable simulations of radiation balance components and significantly improved the simulation of soil liquid water content. It also shows an improved capability of reproducing soil temperatures from the top to the bottom of soil layers. The modified CoLM provides a useful tool for understanding and predicting the fate of permafrost in QTP under a warming climate. (C) 2012 Elsevier B.V. All rights reserved.