Model test of the influence of cyclic water level fluctuations on a landslide

Many landslides in reservoir areas continuously deform under cyclic water level fluctuations due to reservoir operations. In this paper,a landslide model, developed for a typical colluvial landslide in the Three Gorges Reservoir area, is used to study the effect of cyclic water level fluctuations on the landslide. Five cyclic water level fluctuations were implemented in the test, and the fluctuation rate in the last two fluctuations doubled over the first three fluctuations. The pore water pressure and lateral landslide profiles were obtained during the test. A measurement of the landslide soil loss was proposed to quantitatively evaluate the influence of water level fluctuations. The test results show that the first water level rising is most negative to the landslide among the five cycles. The fourth drawdown with a higher drawdown rate caused further large landslide deformation. An increase of the water level drawdown rate is much more unfavorable to the landslide than an increase of the water level rising rate. In addition, the landslide was found to have an adaptive ability to resist subsequent water level fluctuations after undergoing large deformation during a water level fluctuation. The landslide deformation and observations in the field were found to support the test results well.

The Strategies for Market Risk Management in International Shipping

International shipping market is a risky market associated with a variety of risks which shipping companies have to cope with. International shipping has been seriously hit by the financial crisis in 2008. Since then, this industry has experienced market downturn for a long period which was considered to be the longest period of depression in the history. This paper mainly focuses on the key market risks in international shipping including cyclical fluctuation risk, cost risk, freight rate volatility risk, and competition risk. It analyses the source of these market risks, and identifies some strategies to cope with these market risks. In the meantime, Maersk and China Ocean Shipping Group （COSCO）, the world leading international shipping companies, are taken as two cases. Their strategies in market risk management are analyzed, which enable the reader to learn from their success and failure. Based on the international experience in market risk management in shipping industry as well as the real practice of Maersk and COSCO, this paper provides useful guidance for shipping companies to reduce market risks, overcome market downturn, and improve competitiveness.