Namik Kemal University Turkey
The water is basic source for all living in the world and it covers two third of the earth, it is the lifeblood of plants and its permanent of temporary shortage can cause serious damage to plants yield and quality. However, despite the importance of water for the continuation of life, 97.5 % of existing water is in ocean and high seas water that cannot be used. The remaining just 2.5 % is fresh water and can be used by living things; however, the vast majority, like 90% of this fresh water is in the poles and underground water and it doesn’t have usable form (William, 2007). Available water resources in the world not showing continuity in time and space, the increasing effect of global warming and the three main water users (agriculture, industry and domestic sectors) creating a growing demand and pressure for water supply increases the importance of water.
Irrigation has an important place in terms of water usage, its environmental impact and reuse of urban waste water. Irrigation; firstly begin with people becoming sedentary and agricultural practices, it has been made to improve the quality and quantity of crop production. Especially since the 1950s, people living in the cities started to be the owner of a garden, studies conducted in the urban landscape water is needed in these areas with different types of grass and ornamental crops, in order to ensure the sustainability of irrigation, which resulted in entering of irrigation into urban life. Today, irrigation emerges as an indispensable element in Landscape architecture.
2. Irrigation water quality and reuse of waste water for irrigation
2.1 Irrigation water quality
Irrigation water quality is important for two reasons for irrigation engineers. The first , depending on the quality, irrigation method and irrigation system components are determined, the needed additional equipment lead to an increase in total cost of the system. The second, water quality affects adversely plant growth and soil fertility after the system operates. Irrigation water characteristics are examined in three groups; physical, chemical and biological (Wilko & Short, 2007).