عنوان مقاله [English]
Iran is located in an arid region with negligible precipitation, as average downfall is under the third of that of the world average. Yazd province is placed in dry and desert area and has 100 mm precipitation in year. Yazd as one of industrial city in our country was confronted with population traits and migration. This growth caused the requisition for water consumption increase. Requisition has caused the level of underground waters in mean in 30 years period. Thus, answering to the requests and procurement of water require supplying water connected to nonrenewable resources and out of penetration basin. For inhabitation of regional and national tension crisis in the research program, it is required to have solutions for supplying needed water of the city.
To this end, urban development forms were examined by library studies and then sustainability models concerned with water and sewage network. They identified the status of water resources in Yazd province and Yazd Ardakan plain. This was determined using relevant documents and then quantitative analysis to calculate the optimal population of the city based on two options for production and consumption of water. The type and manner of this research is descriptive and analytic using combinational qualitative and quantitative analysis. Using of library researches, civil resistant form were investigated in continuation. Situation of province's water resources, Ardakan-Yazd plain and Yazd city were determined by relevant documents and then by using of quantitative analysis, city optimal population based on water production and water consumption.
Results and discussion
The present research, first of all, is devoted to the assessment of sustainability of Yazd concerning water resources based on sustainable urban development models and then touches on the optimal population of Yazd according to the options for water supply in 2016 with regard to the water transferred from Zayande rood to Yazd. This is to examine the second phase of water transfer as well as water transfer project from Persian Gulf based on goal setting which applied mixed research method. To determine water deficit rate of the inhabitant population, we calculated difference of water need average from inhabitant population and the resources.
To determine excess population in the water deficit rate for the population (30.3 milion cubuc meter in year), we calculated equivalent to 83 million liter for optimum population.
The results have demonstrated that Yazd –Ardekan plain has just 2 percent of underground water resources. While 82.58 percent of population in the province are inhabited in Yazd city and 80 percent of needed water is provided by surface resources. Water from Zayanderod, this water resources in distance of 330 kilometer of Yazd city based on resistant civil models. Evidently population decentralization as a policy along promotion of people using water include reduction of consumption per capita, management of water system, reduction of casualties, progressive in cease of water rate price and reduction of domesticated consumption. Decrease in drinkable water from consumption can be an effectual step in improvement of water resources situation.