This textbook is concerned with the highly topical area of reaction-diffusion equations. This popular textbook provides a compendium of useful techniques for the analysis of such equations and shows how they find application in a variety of settings, notably in pattern formation and nonplanarwave-like structures. New to the second edition, is a chapter on geochemical systems with applications to environmental modelling problems. This is an ideal introduction to the subject for graduate students as well as those mathematicians and scientists whose work touches on these topics.