Urban Sustainability Assessing Indicator System Established Under Carrying Mechanism

With the rapid economic development and urban sprawl as well as the population increase, plowland and other renewable resources decreased sharply and entironment was polluted. Urban ecosystem is under great pressure and facing huge challenge. The paper explored carrying mechanism in urban ecosystem and established an urban indicator system, which functioned as an urban macro-management system and helped realize a sound development of urban ecosystem with society, economy and environment.The paper first introduced some researches concerned urban ecosystem structure, function and carrying capacity as well as sustainable development. Making use of barrel model, the paper divided urban ecosystem carrying mechanism into resources carrying mechanism and environment restricting mechanism and explained them separately with principles of resources limiting elements and the shortest clapboard effect. Based on some study about the relationship between ecosystem carrying capacity and sustainable development, a formula using carrying mechanism to judge urban ecosystem sustainability was brought forward.Take economy more developed and more opened city Wujiang in the Yantze River delta and economy less developed and less opened inland city Yichun as examples, the paper compared and analyzed their urban ecosystem carrying mechanisms and proved the urban ecosystem carrying mechanism model set up in the paper can be widely used in different cities.Urban ecosystem carrying mechanisms in Wujiang and Yichun from 2000 to 2004 were assessed through establishing urban carrying mechanism indicator system. Both cities" CCI (comprehensive carrying index) was decreasing. The CCI of Yichun was far above Wujiang's and kept over 1, which means Yichun has been kept in sustainable status during 5 years. The CCI of Wujiang went down less than 1 in 2002 and has been in unsustainable status ever since.After analyzing influencing key factors, measures to relax their urban ecosystem carrying mechanisms were proposed from three aspects- resources carrying...