Complexity and organization in hydrology: A personal view

The hydrologic cycle is an exquisitely coordinated and balanced interaction between the atmosphere, the ocean, and the land that controls, among other things, the planet's temperature by moving large quantities of matter and energy. The system is incredibly complex with a myriad of positive and negative feedbacks acting at a variety of scales. Much of what we experience in our natural and altered environments results from these complex interactions. Surprisingly (or maybe not) this complexity many times results in beautifully organized expressions of the hydrologic state that are commonly amenable to fairly simple explanations. This paper illustrates hydrologic complexity and organization in the context of the author's and collaborator's work during the past decades, a lot published in Water Resources Research. Topics include the impact of soil moisture on the atmosphere and vice versa, the impact of deforestation on the Amazon cloud climate and precipitation, the estimation of surface energy and mass fluxes, the self‐organization of landscapes and river basins over very long time periods, and the roles of vegetation on landscape evolution. Key Points: Examples of complexity and organization of hydrologic processes Work by the author and colleagues over the last 25 years Covers advances in the study of land‐atmosphere interactions and geomorphology