Objective Innovation of compact and low-carbon urban planning theory and method under the climate resilience oriented has become a strategic direction to meet the needs of future spatial management development. The compact and low-carbon urban spatial morphology planning guided by the climate resilience concept has broader research connotation, which not only contains a single theoretical unit, but could be regarded as a comprehensive system including quantitative evaluation and practical guidance, emphasized the coordination organization and comprehensive regulation among complex urban systems, with a view to enhancing the structural adaptability of urban synthesis.

Methods This study took the climate resilience planning as the objective, reviewed the foundational research and development trends of climate resilience cities, compact cities, low-carbon cities, and their intersection, followed the workflow of evolution description - mechanism analysis - simulation optimization, we constructed a theoretical framework and technical pathway for optimizing multi-scale climate resilience urban spatial comprehensive evaluation system, as well as proposed compatible optimization for different scales.

Results As a new concept, the connotation and application of climate resilience have been widely discussed in the planning research field in recent years. Review the existing research, the application of interdisciplinary research, comprehensive quantitative assessment and technical innovation to promote the development of spatial practice of climate resilience theory has become the main research direction in the planning field to cope with the climate dilemma. The multi-scale and systematic evaluation index system of compact cities, the quantification of the development efficiency of compact cities, and the integration of low-carbon development will remain the focus of future research. Based on the panel data of cities or urban agglomerations to calculate the level of urban low-carbon development, construction, economy or efficiency, used emerging measurement methods or models to carry out research of spatial form and adaptive strategies have become essential contents for realizing low-carbon cities. Therefore, the cross-direction development with economics, ecology and other disciplines, covering multiple urban construction elements, and the construction of operable evaluation technology under multi-scale planning still need to be further expanded and improved. The theoretical framework of climate resilience urban spatial comprehensive evaluation could be summarized as three progressive steps included feature description, mechanism analysis and simulation optimization. The evaluation indicator system integrated the typical indicators of climate resilience cities, low-carbon cities and compact cities and the indicators with high overlap, and was divided into five categories included spatial structure, functional layout, social economy, balanced carbon emission and carbon sink, and ecological environment. In terms of work flow, firstly, according to the indicator evaluation table, comprehensive evaluation was carried out based on quantity and spatial pattern, as well as temporal trend. Secondly, through the coupling and coordination analysis of various indicators, the internal collaborative development trend was reflected, and the external driving factors affecting the overall evaluation and coupling and coordination degree were explored to fully reflect the internal and external interaction, and focused on the influence relationship of different scales. Finally, the results were compared with the predictions of natural development and climate resilience development scenarios, and multi-level optimization strategies were proposed.

Conclusion As for specific optimization strategies, the spatial planning from the region to the block scale was interrelated and cooperative. At the regional scale, the spatial optimization strategy was the regulation of the total scale and the construction of security pattern. Based on the status resource endowment and with the total scale control of urban construction and carbon emissions as the preset goals, the ecological security network barrier was constructed by important blue and green nature resources, and the basic stability ability to cope with climate change was comprehensively improved by the scale constraint of construction expansion and total carbon emissions and the soft constraint of natural ecology. At the urban scale, the optimization strategy was climate risk prevention and resource flow assurance. By responding and connecting macro-management at the regional level, urban scale was more complex in governance, and could be delimited from the boundary demarcation, land use, functional layout, infrastructure facility coverage and other planning construction aspects to support climate resilience. Considered urban as the central agglomeration areas of economic development and population, corresponding various planning and construction contents with emergency measures to cope with extreme climate can ensure the timely deployment and flexible supply of facilities and services, and ensure that cities can better prevent and cope with climate risks. At the district scale, the optimization strategy was to innovate pilot construction and transformant district specific spatial. As the urban spatial construction unit, district scale spatial form optimization was more feasible to response timely and accuracy of climate change through pilot construction and spatial order organization, and carry out relevant planning work from the aspects of technological innovation, digital management, space utilization and public participation. By building a theoretical framework, refining work processes, integrating multi-scale evaluation indicators and technical methods, and bridging cross-scale optimization content, we expanded the research perspectives and application scenarios of climate resilience spatial governance from the support of compact and low-carbon development, which provided scientific and technical basis for achieving urban sustainable development.