With the continuous development of city, traffic inconvenience, urban economy, the ecological environment problem increasingly prominent, such as urban development and large quickly, not only may cause no reasonable relationship to the input and output, and can cause irreversible ecological problems, and further affect the social and economic security. And "smart growth" gives people a kind of brand-new concept of urban planning, thus determine whether a city smart growth stage is particularly important. This article through the analysis of the Alashan and two cities in Canberra, concluded that Alashan's current plan is not successful, and Alashan's current growth plan does not comply with the principle of smart growth. However, Canberra's current plan is relatively successful, and Canberra's current growth plan complies with the principle of smart growth. And according to two different cities, based on three E target of the city and the ten principles, this eassy gives two cities growth plans.

With the acceleration of urbanization, the city is also facing the challenges of environmental pollution, traffic congestion, energy shortage, housing shortage, unemployment, disease and so on. In this background, "sustainable city" and "smart growth" become a feasible way to solve urban problems, we develop and optimize the metrics to judge the success rate of urban smart growth and smart growth plan from the economic prosperity, social justice and sustainable environment three aspects, to solve a series of problems brought by the blind expansion of city planning. A comprehensive metric evaluation model can be established through Analytic hierarchy process (AHP), given three E metrics---economically prosperous, socially equitable, and environmentally sustainable and each corresponding influencing factors, we give each metric an evaluation interval as a measure of the standard through literature research and analysis, and a detailed simulation method is formed. 92

Electric heating is helpful in resolving air pollution, and also utilizes renewable energy power. However, the environmental benefits of electric heating are restrained by regional resources endowment and regional electrical energy structure. In the context of the active promotion of electric heating in Beijing-Tianjin-Hebei, the paper studied the development potential and limits of wind power electric heating under the constraints of environmental effects to provide reference for the orderly development of electric heating. A model to predict the capacity of the installed wind power improved by the fruit fly optimized ELM (Extreme Learning Machine) algorithm and an electric heating environment effect calculation model are constructed. The optimal value and critical value of the newly added heating area in Beijing-Tianjin-Hebei are obtained through calculation under four scenarios of wind abandonment rate. As the wind abandonment rate increases from 4-10% (with interval of 2%), the optimal value of the newly added electric heating area in Beijing-Tianjin-Hebei will be 19. 15, 29.47, 36.26, and 47.90 million m 2 by the year 2030. Additionally, as the utilization rate of thermal power exceeds 41.16%, electric heating will produce more carbon emissions compared to coal-fired heating. Therefore, if we want to develop electric heating on a large scale, we need to control the proportion of thermal power in the power supply structure and increase the proportion of new energy. This study can be used as theoretical reference to the development programme of electric energy substitution in the future.