Indian Ocean (2004) Tsunami and following tragic consequences demonstrated lack of relevant experience and preparedness among involved coastal nations. After the event, scientific and forecasting circles of affected countries have started a capacity building to tackle similar problems in the future. Different approaches have been used for tsunami propagation, such as Boussinesq and Nonlinear Shallow Water Equations (NSWE). These approximations were obtained assuming different relevant importance of nonlinear, dispersion and spatial gradient variation phenomena and terms. The paper describes further development of original TUNAMI-N2 model to take into account additional phenomena: astronomic tide, sea bottom friction, dispersion, Coriolis force, and spherical curvature. The code is modified to be suitable for operational forecasting, and the resulting version (TUNAMI-N2-NUS) is verified using test cases, results of other models, and real case scenarios. Using the 2004 Tsunami event as one of the scenarios, the paper examines sensitivity of numerical solutions to variation of different phenomena and parameters, and the results are analyzed and ranked accordingly.

A multiphase oil spill model has been developed to simulate consequences of accidental oil spills in the marine environment. Six state variables are computed simultaneously: an oil slick thickness on the water surface; concentration of dissolved, emulsified and paniculate oil phases in the water column; and concentration of dissolved and paniculate oil phases in the bottom sediments. A consistent Eulerian approach is applied across the model, the oil slick thickness is computed using the layer-averaged Navier-Stokes equations, and for transport of the oil phases in the water column the advection-diffusion equation is employed. The kinetic terms are developed to control the oil mass exchange between the variables. The governing equations are verified using test cases, data and other models. The model is useful for short and long-term predictions of the spilled oil dynamics and fate, including application of the oil combating elements, such as chemical dispersants and booms.