Hydrology

O. E. SCARPATI

Geography

Eolss Publishers/ UNESCO

Lugar: Oxford; Año: 2007; p. 212 - 247

Hydrology in its broadest sense is the science that relates to water. It is an earth science because it deals with water primarily on earth. Hydrology can be defined as: a) “a science dealing with the occurrence, circulation, distribution and properties of the waters of the earth and in its atmosphere” according Webster Encyclopaedic Unabridged Dictionary (1996). b)“the science that treats of the waters of the Earth, their occurrence, circulation and distribution, their chemical and physical properties, and their reaction with their environment, including their relation to living things. The domain of hydrology embraces the full life history of water on the earth”, and: c) “the science that deals with the processes governing the depletion and replenishment of the water resources of the land areas of the earth. It is concerned with the transportation of water through the air, over the ground surface, and through the strata of the earth. It is the science that treats of the various phases of the hydrologic cycle”. Water is the most abundant substance on Earth and is the principal constituent of all living things. Water in the atmosphere plays a major role in maintaining a habitable environment for human life. The occurrence of surface waters has played a significant role in the rise and decline of the major civilisations in world story. In many societies the importance of water to humankind is reflected in the legal and political structures. At the present time rising populations and improving living standards are placing increasing pressures on available water resources. There is, in general, no shortage of water on the Earth‘s land surface, but the areas of surplus water are often located far from major centres of population. Moreover, in many cases these centres prove to be sources of water pollution. Thus, the availability and quality of water are becoming an ever-increasing constraint on human activities, notwithstanding the great technological advances that have been made in the control of water surfaces.