**2. Spatial carrying capacity and sustainability**

#### **2.1 The analytical framework of spatial carrying capacity**

Carrying capacity originally refers to the mechanical or engineering characteristics of manufactured objects or systems. It appears in the shipping field with steam power as a sign, and is used to evaluate wind and steam power [3]. In the 1870s, when carrying capacity was first applied to biological and natural systems, it was used to measure the maximum amount of animals and food from natural system extremes. The evolution of carrying capacity is the inevitable result of human transformation and development in nature. From the initial biosphere consideration of the maximum of individuals or populations to the planet-scale development, sustainability research on carrying capacity is playing an increasingly important role under the constraints of global environmental change.

China is one of the most populous countries in the world. The degree of governance of climate change and environmental degradation has a profound impact on the process of global sustainable development. Therefore, the establishment of carrying capacity as the core analysis tool selects three levels of cities, basins and regions, and through multi-scale and multi-level element coupling, respectively proposes promotion strategies and spatial layout models, in order to achieve the realization of China's economic society sustainable development goals. Cities are relatively small carrying capacity units, river basins are secondary carrying capacity units. The basic urban units constitute the spatial carrying capacity unit at the basin scale. The basin carrying capacity unit belongs to the regional carrying capacity unit.

#### **2.2 The spatial carrying capacity of cities**

A city is a multi-dimensional carrying space consisting of resources, environment, ecology, population, economy, and society, which are the foundation of sustainability. A city is an important carrying space not only consisting of population, ecosystems, industrial clusters, but also for resource consumption and environmental pollution. The space provided by the urban unit is a construction and industrial development space, such as economic output, city scale, traffic capacity, land resources, etc. The spatial scale and growth boundary are affected by the interaction of resources, environment and technology, human activity and environmental sustainability, which is coordinated to the ultimate goal, so that it can be protected and improved the resources for the survival of humans.

The preconditions oriented in multi-element expansion of urban space are spatial carrying capacity for the development of sustainable. Sustainability of urban units is the foundation of social economic development, which lie both in regional and higher levels of units. They are the fundamental area for various aggregation factors of production, which carry more and more efficient production through the expansion of space scale, population size, industry, transportation and urban infrastructures. Despite that, sustainability is the precondition for expansion of units,

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*Spatial Carrying Capacity and Sustainability: Cities, Basins, Regional Transformation*

setting goals within the boundaries of spatial carrying capacity and taking baseline of resources and environment, in such a way as to facilitate comprehensive benefits.

Basin scale is a spatial unit divided by natural geographical ecosystem. Due to the sharing of water resources in the basin, the upstream and downstream water resources competition is fierce, and the water resources carrying capacity of each city forms a common support and constraint, the total amount is fixed, and the relationship between this and the other changes. It is characterized by linking different administrative units and stakeholders through water resources. The sustainable development of river basin mainly focuses on the rational allocation of water resources and maximizes the economic, social and ecological conditions

*DOI: http://dx.doi.org/10.5772/intechopen.94130*

the overall carrying capacity of the basin.

problems highlight contradictions.

**2.3 The spatial carrying capacity of River Basin**

within the threshold value of water resources carrying capacity.

The basin carrying capacity should be innovated in management mode in upstream and downstream. In the new stage of coordinated development of river basin, it is necessary to take full account of the disharmonious separation of basin units, the limited overall development space of the basin, the enhancement of the correlation between the development activities of different units in the same basin and the constraint of the total amount threshold of the carrying capacity of resources and environment, so it is necessary to carry out fine management of water resources in the basin. The current basin development model still has many problems, such as low efficiency of water resources utilization, fierce competition between upstream and downstream water resources, and low overall water quality. Therefore, it is necessary to coordinate the cooperation among different units in the basin to enhance

**2.4 The comprehensive carrying capacity of regional function division**

The comprehensive carrying capacity of a region is different in space and changes dynamically with time. The comprehensive carrying capacity of the region is the sum of all resources in a specific space (material resources, energy resources, information resources, space resources, human resources, social resources, etc.), which can provide the comprehensive development capacity of the region. On one hand, Because of the difference of economic development level and resource endowment in each region, the comprehensive carrying capacity of each region is different. On the other hand, the spatial carrying capacity of a region changes dynamically with time. In some resource-based urban areas, the development of natural resources will generally promote the development of industry and the growth of population, bringing about the improvement of carrying capacity. However, When the stock of natural resources to reduce or dried up, there will be a leading industry gradually decline, the ecological environment is destroyed, social

To promote the coordinated development of regions, it is necessary to concentrate population and economic activities in regions with high carrying capacity according to the differences of core functions of each region, while reducing the scale of population aggregation and economic activities in ecologically fragile regions. The connotation of regional coordinated development is to comprehensively coordinate the relationship among economy, society, population, resources and environment, and guide the economic layout and population distribution to adapt to the carrying capacity of resources and environment. In order to reduce the imbalance of regional development is to promote regional harmonious

setting goals within the boundaries of spatial carrying capacity and taking baseline of resources and environment, in such a way as to facilitate comprehensive benefits.
