Hydrological cycle is the cyclic movement of water from the sea to the atmosphere by evaporation, precipitate to the Earth, then collects in streamflows and groundwater movement and run back to the sea.
A convenient starting point to describe the cycle is in the ocean. Water in the ocean evaporates by the heat energy of solar radiation. The water vapors is then form the clouds as they move upward. By wind effect, clouds may move to land areas, then condense and precipitate onto the land as rain or snow. Falling rain may take part in evaporation and the other part may be intercepted by vegetation. Water will be evaporated back to atmosphere or move down to the ground surface. For water reaches the ground, some of it infiltrates into the soil and moves down or percolates into the saturated ground zone beneath the water-table. Transpiration takes place when vegetation sends a portion of water from underground surface to the atmosphere. The remaining water is then collected by streams and runs as surface runoff to rivers and finally back to the sea.
Processes in hydrological cycle can be summarized as follows:
1. Precipitation
2. Evaporation and transpiration
3. Infiltration and percolation
4. Ground water flow
5. Surface runoff
Hydrology in Engineering
Hydrology finds its greatest application in the design and operation of water-resources engineering projects.
In a general sense, Engineering hydrology deals with:
1. Water supply to a city
sources available
estimate of capability of supplying water
rain, dry period of designated city
Water supply structures
2. Reservoir storage scheme
3. Capacity of dam spillway
4. abstraction of groundwater flow from wells
Final Year Project - Web-based interactive computer-aided learning package on engineering hydrology
