تحليلي بر جمعيت‌پذيري و توسعۀ شهري با تأكيد بر پايداري منابع آب (مطالعۀ موردي: شهر يزد)

Stability of Water Resources Based On Optimal Loading of Population and Urban Development (Case Study: Yazd, Iran)

در پژوهش پيش رو، در مرحلة اول به ارزيابي پايداري منابع آب شهر يزد براساس مدل‌هاي توسعة شهري پايدار پرداخته شد و سپس جمعيت بهينة يزد براساس تأمين آب مورد نياز در سال 1395 تعيين شد. بر‌اساس ماهيت هدف‌گذاري، از روش تحقيق تركيبي (اطلاعات كيفي پشتوانه‌اي براي اطلاعات كمي) استفاده شد. در اين پژوهش، با استفاده از مطالعات كتابخانه‌اي، فرم‌هاي پايدار شهري بررسي و در ادامه، مدل‌هاي پايداري منابع آب شناسايي شد. وضعيت منابع آبي استان، دشت يزد-اردكان و شهر يزد با استفاده از اسناد مرتبط تعيين و سپس با استفاده از تحليل‌هاي كمي، جمعيت بهينة شهر بر‌اساس دو گزينة توليد و مصرف آب محاسبه شد. نتايج پژوهش، نشان مي‌دهد دشت يزد-اردكان فقط 2 درصد از منابع آب زيرزميني استان را دارد؛ در‌حالي‌كه 82/58 درصد جمعيت شهري استان، در شهر يزد ساكن‌اند و 80 درصد آب مورد نياز از منابع سطحي تأمين مي‌شود كه متعلق به آب انتقالي از زاينده‌رود در فاصلة 330 كيلومتري است؛ بنابراين براي تعيين اندازة بهينة جمعيت و پايداري شهر بر‌اساس مدل‌هاي ويليامز و هال، شهر يزد در ارتباط با منابع آبي، شهر پايداري نيست و براساس عدم وابستگي به خارج از حوزة نفوذ، ادامة حيات در آن ممكن نيست و حتي با وابستگي به خارج از حوزة نفوذ (آب انتقالي از زاينده‌رود) 59000 نفر جمعيت مازاد دارد. از اين رو، بايد در جهت كنترل جمعيت از يك سو و مصرف بهينة آب از سوي ديگر، تدابير لازم انديشيده شود.

Introduction 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. Methodology 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 wateConclusion 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.r 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.