The results discussed in this book are interesting and useful for a wide range of specialists and scientists working in the field of applied mathematics, and in the modelling and monitoring of pollution of natural waters, ecology, hydrology, power engineering and building of different structures of water objects. Their importance and practical value are submitted in the friendly form for comprehension and are ready for direct application for the solution of practical tasks. Advantages of the elaborated methods and algorithms are shown not only through theoretical judgements and calculations, but also through the demonstration of results of particular calculus and modelling.