Analysis of the uncertainties in urban ecological planning

Uncertainties in urban ecological planning mainly result from the following aspects: uncertainty in the planning process and uncertainty in decision-making and analysis. To decrease the uncertainties in urban ecosystem, the following theories and methodologies may be applied, such as sensitivity analysis, error transmission analysis, cybernetics approach and uncertainty mathematical methodologies, including stochastic approach, fuzzy approach, grey system approach and unascertained mathematical approach. Based on the above analysis, this paper proposed the idea of 'flexible planning', which includes the flexibility of planning objectives and that of planning schemes. Based on optimum seeking methods such as the isolation of dimensions, the elimination of alternatives and the continuous increase of dimensionality, the goal of the planning can both meet the requirements of the development of urban ecological level and take into account the restrictions of various uncertainty factors.