Spatial Expansion of the Parand City Focusing on the Available Water Resources until 2032: Reciprocal Relation between Urban Water Management and Spatial Planning

Beside natural factors, spatial expansions of new cities is one of the main causes of the water crisis. Parand new city, in that regard, has very high restrictions on the potable water supply. Nonetheless, there is an increasing population growth and construction in this city. In this regard, type of residential development of the city has a significant impact on managing the potable water consumption, sufficient for its sustainable development. The current methods of calculating future potable water for cities are more based on population growth scenarios and focus on analyzing population growth rates regardless of the population's physical development capacity. Using the prediction of physical expansion applying LCM simulation (Land Change Modeler), the present study first simulated the physical development of Parand city up to 2032 based on a typical pattern in urban development centered on villas and estimated the amount of potable water required by Parand city according to this model. Accordingly, the initial scenario, called scattering, predicts water requirements by relying on spatial expansion and considering natural population growth by 2032; The second scenario, which is the most common type of urban decision-making and planning, is the scenario of a long-term trend of population growth up to the horizon of 2032. The results indicated a significant difference between the potable water consumption in Parand city based on the first and second approach as the water needs of about forty-three million cubic meters and about thirty-three million cubic meters in 2032, respectively. The result reveals to the planners a style of urban needs assessment and forecasting, considering the natural population growth and the city's spatial expansion. Thus, to prevent the water crisis and move towards sustainable urban development, the present article strongly recommends spatial planning for cities' development due to limited water resources.