Book excerpt: Hydrology for Engineers, Geologists and Environmental Professionals presents the fundamental concepts of physical and contaminant hydrology in watersheds, rivers, lakes, soils, and aquifers in an easy and accessible manner to the environmental professional. Recent research developments in nonlinear hydrologic science and new meshless simulation methods are included in this edition: new solutions of nonlinear infiltration; modeling of regional groundwater flow in heterogeneous media, irregularly-shaped domains, transient problems, multiple pumping wells, and nonlinear flow; contaminant transport simulation under nonlinear decay, nonlinear sorption, and unsaturated-saturated zones contaminant propagation. This edition includes 124 solved examples, 187 proposed problems, 153 illustrations, 71 tables, 46 short computer programs, answers to problems, and extensive bibliography.