Page 5 - Water and DSİ

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INTRODUCTION
Water cycle continues to turn all the time in the world. Water evaporates from the earth's surface,
plants, surface of water bodies, lakes, seas, and oceans. Then, it forms clouds. It precipitates back
to earth as form of rain, snow, sleet, hail, dew. While some of it evaporates, some oozes into
underground, and some flows and empty into lakes, seas, and oceans. Then, it evaporates again
and the cycle keeps going.
Water resources development and management may be described to manage the rings in water
cycle. First ring in water cycle is precipitation. The second is runoff. The third is storage. The
fourth is water conveyance to the areas to be used. And the fifth is water consumption by various
sectors.
General Directorate of State Hydraulic Works (DSİ) is the main responsible agency to develop
and manage the rings of the water cycle in Turkey. Chapter 1 deals with the organizational
structure, duties, budget, and the activities of DSİ.
The first ring of water cycle is precipitation forming major element of water budget. Depending
on the topography and climate, snow form of precipitation stays on the mountains and gives its
water by melting during the spring and summer seasons. Data on land and water resources are
directly connected with the information of total amount of water in a country.
The second ring is runoff, lack of which may result in drought and excess of which give rise to
flood damage. Water is to flow in river bed smoothly without interruption. Floods and droughts
affect directly the environment we live in.
The third ring is the water storage. Water storages have various forms of natural and manmade
structures such as lakes, reservoirs, dams, small dams, and regulators. Water storage facilities are
imperative to meet demand of water for living if water unevenly distributed in time and space.
Therefore, part of the runoff needs to be stored to enable society to use it at times and places
where it is needed. Water is stored in scales ranging from the single household tank to large
reservoirs. The purpose of storage and regulation is to ensure water supply, irrigation for
enhanced agricultural production, and recreation. Many systems for storage have been built to
serve multiple purposes, including community water supply, irrigation, hydroelectricity
generation, flood control, and fisheries. Storage and regulation are to be designed and managed
to provide flood protection and to maintain ecological flows as well.
The fourth ring is the water conveyance distributing water up to the demand areas. They may be
form of open or closed channels. They are to be developed and managed so that water is to be
conveyed without loss. Sometimes conveyance lines lay between dam and treatment plant,
sometimes they give service between regulator and main canals of irrigation network.
The last but not least ring is the water consumption of living being. The needs of human being
are hydroelectricity, agricultural irrigation, and domestic and industrial water supply. Limited
water resources supply may not satisfy with all the demand of different sectors. Hereby, the
management has become more challenging issue than that of before.