over the past two centuries, the advancements in technology with computers have led to the development of geomatics and new practices such as participant observation and geostatistics being incorporated into geography's portfolio of tools. in the west during the 20th century, the discipline of geography went through four major phases: environmental determinism, regional geography, the quantitative revolution, and critical geography. the strong interdisciplinary links between geography and the sciences of geology and botany, as well as economics, sociology and demographics have also grown greatly, especially as a result of earth system science that seeks to understand the world in a holistic view.