Content: Computer programs are fundamental tools in all activities that require quantitative answers, in particular for environmental systems. Their use presupposes the knowledge of all the characteristics of the system of interest and of the phenomenologies to be studied (Mathematics, Physics, Chemistry, Mechanics). However, the implemented models are only an interpretation of reality. Therefore, for their correct use, it is necessary to know the characteristics of the main mathematical models, their numerical realization and the conditions so that they can provide useful information. The course describes the fundamental bases on which the main computational models used were developed to study environmental phenomenologies, such as seismics, geophysics, transport and diffusion of substances, river dynamics, filtration, debris-flow, consolidation , thermofluidynamics (CFD), the interaction of the built environment with environmental systems. Therefore the following are studied: Basic mathematical and physical tools of Computational Modeling - Differential Equations; General form of the balance equation of scalar, vector and tensor quantities and equations derived from it by means of experimental laws - Navier Stokes CFD equations - Notes on analytical solution methods of the main ordinary and partial differential equations relating to Environmental Computational Modeling - General problem of Sturm_Liouville and series development of orthogonal Fourier functions - General principles of analysis and numerical calculation - Methods of numerical solution of partial differential equations in time and space (FEM, FDM) - Solution of linear and nonlinear systems (general concepts and definitions) - Examples of modeling and numerical computation