Hydrological cycle and water properties.pptx

Hydology basics related to water chemistry and water quality for students in Civil Engineering, Water Resources Management, Geology, Environmental Research, Interdisciplinary studies including biology and ecology related to aquatic systems.

1. Water : Properties and their importance Most of the unusual properties of water are due to its being made up of polar molecules that form hydrogen bonds between adjacent water molecules and between water molecules and earth materials 1

2. Global Water Cycle: The most important cycle on Earth! Oki and Kanae 2006, Science Figure: Big vertical arrows show total annual precipitation and evapotranspiration over land and ocean (1000 km 3 /year), which include annual precipitation and evapotranspiration in major landscapes (1000 km 3 /year) presented by small vertical arrows; parentheses indicate area (million km 2 ). The direct groundwater discharge, which is estimated to be about 10% of total river discharge globally (6), is included in river discharge. Hydrology is the geoscience that describes and predicts the occurrence and circulation of the earth’s fresh water. The principal focus of hydrology includes: • the distribution and movement of water substance on and under the earth’s land surfaces, including its exchanges with the atmosphere; • its physical and chemical interactions with earth materials; and • the biological processes and human activities that affect its movement, distribution, and quality. 2

3. The hydrologic cycle is a central component of the earth’s climate system at all scales, from local to global. Global Water Cycle Movement of water is due to and causes transfer of mass and energy a series of storages and a set of activities that move water among these storages  complex web of continuous flows The exchange of water among the oceans, land and atmosphere is termed as ‘ turnover’ 3

4. The most important processes of the hydrologic cycle are: Global Water Cycle Evaporation Transpiration Condensation Precipitation Runoff Infiltration Evapotranspiration Fig: The principal storages (boxes) and pathways (arrows) of water in the land phase of the hydrologic cycle. The heavy dashed line represents the boundary of a watershed or other region. 4