Computing Simulation and Spatial difference Analysis of Resources and Environment Ecological footprint out of Control

: As a quantitative evaluation method, the ecological footprint theory analysis method (EFA) is a frontier subject in the field of sustainable development. The production activities of human beings will inevitably produce certain consumption, including the occupation of natural resources, consumption of W and the production of waste, which will have a certain impact on the ecological environment, just as one foot on the ground will leave footprints. On the other hand, the ecological environment itself will also provide a certain bearing capacity, supply human material consumption. The ecological footprint theory is to quantitatively convert the material consumption produced by human activities into the biological productive land area, and compare it with the supply area in the study area. Since Rees put forward the theory of ecological footprint, the development of ecological footprint model has gone from one-dimensional model to two-dimensional model, and from two-dimensional model to three-dimensional model. This paper reviews the evolution of ecological footprint model from four aspects: scientific problem, model connotation, interpretation ability and application direction, in order to cause new thinking on ecological footprint model.


Foreword
The sustainable development of the region must take the sustainable development of the ecological environment as the premise and guarantee. The ecological environment is not only the carrying space of the social and economic activities in the region, but also provides the natural material foundation and the space for the waste disposal for the regional development. Therefore, as a decisive factor in regional development, the sustainable development of the region requires comprehensive consideration of the regeneration and substitution capacity of regional resources, the recycling and purification capacity of life support systems and the protection of biodiversity, The ecological footprint model, which has been developing rapidly in recent years, can not only meet the above requirements, but also can be calculated intuitively and has regional comparability [1]. Therefore, the relevant international machines have been quickly obtained. The recognition of government departments and research institutions has become an important method in international sustainable development measurement.

Ecological footprint
Ecological footprint (EF (Ecological Footprint),) [1]also refers to the total area of land and water that can continuously provide certain people with all the resources they consume and absorb all the wastes they produce. EF's calculations are based on the following two facts: humans are able to estimate most of the resources they consume, energy and the amount of waste they produce; These resources and wastes can be converted into ecologically productive areas for the production and consumption of these resources and wastes. The main considerations are as follows : fossil energy land, cultivated land, woodland, pasture land, construction land and water area are weighted to sum up the six kinds of biological production areas with different ecological productivity.
accounting formula: , is the type of consumption commodity and input; is the total ecological footprint; is the population number; is the per capita ecological footprint [2]; it is the average balance factor; it is the per capita consumption of class I commodity; it is the world average living ability of class I consumer goods.

2.1The basic thought and hypothetical premise of ecological footprint research
Ecological footprint refers to the biological productive land area (hereafter referred to as land area) needed to maintain resource consumption and absorb waste under given population and economic conditions. The basic idea is to convert the "interest" (ecological footprint) of the natural assets needed by human consumption and the "interest" (ecological carrying capacity) generated by the natural assets into the land area which can be compared with each other. The comparison between the two is used to judge the overutilization of natural assets by human beings [4]. To this end, there are six assumptions: (1) the annual consumption of available resources and the amount of waste generated; (2) the consumption and waste of most of the resources The material flow can be converted into land area; (3) various different types of land area can be given a certain weight and converted into a standardized global hectare unit (with the world average productive capacity); (4) all types of land use are exclusive, so the total demand can be obtained by adding up the area of resource utilization and waste absorption; (5) the total interest occupied by human activities can be compared directly with the interest provided by itself; (6) aggregate demand may exceed total supply [1][2][3].

calculation method of ecological footprint
The ecological footprint calculation process is shown in figure 1.  It can be seen from figure 1 that the calculation method of ecological footprint can be divided into two parts: (1) converting human consumption and waste emissions into corresponding land area; (2) comparing ecological footprint and ecological carrying capacity with common standards. The first part is mainly through the establishment of the consumption-land conversion matrix [6]. It is relatively simple to convert the consumption of biological resources into the corresponding land area, only the embedding of the corresponding land area should be considered, that is, how much land area is needed for a given consumption quantity to produce and supply. The second part is the use of multiplicative equilibrium factor and yield factor. The ecological footprint and ecological carrying capacity are converted into comparable global hectares. In addition, 12% of biodiversity conservation area should be deducted in the calculation of ecological carrying capacity. At the same time, at the national or regional level, due to the impact of trade, the ecological footprint can cross regional boundaries, so the amount of consumption needs to be adjusted to calculate the net consumption [4] 2.3The key points in the calculation of ecological footprint Conversion of energy consumption to land area: Land disposal of fossil energy: usually, the exploitation and utilization of fossil energy means the depletion of stocks and the generation of waste gas. Therefore, in view of the development and utilization of fossil energy, the fossil energy land can be treated from the point of view of flow evaluation and the land area needed to provide the energy consuming substitute and absorb the waste gas. For example, the emission of PCDD (PCB), has no obvious absorption capacity because of nature, although it has obvious influence on natural regeneration ability and is not taken into account in the calculation. Because the natural system has the obvious absorption ability to CO2, and the data is more abundant, This mainly deals with the waste gas of CO2 [10]. At present, it is mainly used to estimate the land area needed to absorb the new CO2 to calculate the demand for fossil energy land. The absorptive capacity of forests is calculated by calculating the average absorptive capacity of 26 different biota. The detailed calculation process is shown in tables 1 and 2 [5]   explain the dynamic changes of the eco-economic and social system [6]. The two-dimensional and three-dimensional models belong to the closed model, and their calculation results can not accurately reflect the real state of the regional ecology. Finally, the direction of further optimization of ecological footprint model is discussed.

calculation method of ecological footprint model
The formula for calculating the ecological footprint of the project is as follows: Among them, is the population of the project, is the ecological footprint per capita, is the equilibrium factor( j=1,2......6) to indicate the land type, and is the per capita bioproductive land area of the class I consumption project.
is per capita consumption for Category projects, and says average global production capacity for Category projects [7].
With the construction of the project going on, there will be some waste. Every 1m 2 construction project in our country will produce about 60kg waste. However, due to the lack of strict supervision and management of the treatment of Lakzaka in our country, Construction waste is usually disposed of by direct stacking or landfill. The construction waste of each 1000kg will occupy the land of 0.067m 2 , so the calculation formula of the ecological footprint of construction waste is as follows: The calculation formula of ecological carrying capacity of the project is as follows:

S EF
Among them, is the per capita ecological carrying capacity, is the equilibrium factor, is the yield factor, and is the per capita biological productive land area.
According to the proposal of the (WCED) of the World Commission on Environment and Development, 12% of the area of bio-productive land should be set aside for biodiversity conservation, and the actual ecological capacity of the project should be multiplied by a coefficient of 0.88. Namely: Calculation of ecological surplus: The concept of surplus (ecological deficit) is defined as follows: If > 0, there is ecological surplus, and the ecological carrying capacity of the project is higher than that of the sustainable improvement of the project. If < 0, there will be ecological deficit, the ecological carrying capacity of the project is not as good as the ecological footprint, the sustainability of the project is poor, and the project is in a critical state between sustainability and unsustainability, such as =0. [8] 3.2 One-dimensional ecological footprint model

Scientific issues
At present, mankind is facing the problem of how to coordinate the relationship between economic development and ecological protection. "all human activities on Earth are carried out in the biosphere and have an impact on the biosphere", This is consistent with the evolution of the ecological footprint model of natural resource accounting and its comment law 1 proposed by Hardin. It can also be explained by the second law of thermodynamics [8]. The economic system is only a sub-system under the ecosystem. In order to maintain the orderly state of the economic system, it is necessary to continuously absorb low-entropy substances and release high-entropy substances from the ecosystem.
To maintain economic growth Increased ecosystem disorder (or entropy value) at the cost of [9]. If the economic system demands more from the ecosystem than it can regenerate, the entropy of the ecosystem will increase, and the ecosystem will change to a disordered state (such as climate change).
As a subsystem of the biosphere, the human economic society in a certain region may have broken through the upper limit of the natural resources that the region can provide, and the ecological environment of the region and the whole world is facing severe challenges. How to trace the source of natural resource consumption and its decomposition and assimilation after use, and put forward a kind of self-directed ecological protection. However, the accounting method of resource consumption, which reveals the occupation of human activities to the ecology, has become a hot issue in academic circles, various organizations and government departments. As a biophysical tool for natural resource consumption accounting, the ecological footprint model provides a unique way to solve this scientific problem.

connotation and characteristics of models
Rees defines ecological footprint as the ecological productive land area needed to support the natural resource consumption of a certain population and assimilate the waste produced in a given area.
He likened the ecological footprint to "a city, factory, and farmland loaded with human creation." The footprints left by the giant feet on the earth " [30]." From this definition, ecological footprint is only a quantitative concept, not limited to specific space. Therefore, this paper calls it a one-dimensional ecological footprint model (hereinafter called one-dimensional model). Rees). The one-dimensional model classifies the biological products and ecological services consumed by human beings into 23 categories, respectively. According to the six types of eco-productive land, the human consumption of natural resources is converted into the corresponding eco-productive land area by land productivity data, and the equilibrium factor is proposed to balance the productivity difference among different types. The regional area data can be added and summarized after the correction of the equilibrium factor, and the ecological footprint of regional human activities can be obtained. One-dimensional model is based on its calculation. The result is the value of land area and does not consider the concept of space. Therefore, the one-dimensional model can be applied to the measurement of ecological footprint on any scale. At present, some people try to measure the ecological footprint on various scales, which are summed up by scholars as global [10][11][12], and national macro scale. Provincial and urban meso scale [12], institutional group activity and individual [10] microscale. At the same time, the calculation of ecological footprint at different scales requires different calculation methods (for example, Table 3) due to the difference of data acquisition methods and regional characteristics.

Scientific issues
The one-dimensional model proposed by Rees constructs an eco-system-based natural resource consumption accounting method. The calculation results represent the ecological occupation of human activities in the form of eco-productive land area. However, the one-dimensional model is only the accounting of resource consumption, how to define and calculate the supply capacity of regional natural resources, and compare the consumption of natural resources with the supply of natural resources. To evaluate whether the natural resource consumption of the region is within its ecological carrying capacity, to establish a set of evaluation system for sustainable development, to judge whether the economic, social and ecological environment are developing harmoniously, which has become the academic circle's view of one-dimensional model to two-dimensional [11].

the connotation and characteristics of the model
Wackernagel improved the one-dimensional model, introduced the concept of ecological carrying capacity to characterize the supply capacity of regional natural resources, and formed a two-dimensional ecological footprint model [12] (hereinafter referred to as two-dimensional model).  is the area of ecologically productive land that can be provided by region; is ecological deficit.
In a three-dimensional model, there are the following relationships: for footprint breadth, for footprint depth.
In the three-dimensional model, when the ecological footprint is smaller than the ecological carrying capacity, the footprint breadth is used to characterize the extent of human activity occupying the natural resource flow, and the footprint breadth is equal to the ecological footprint (for example, the formula (2);). When the ecological footprint is larger than the ecological carrying capacity, A footprint depth index will be introduced to characterize the extent to which human activities occupy natural resource stocks (e.g. formula (3). Footprint depth is equal to the ratio of ecological footprint to ecological carrying capacity (e.g. formula (4),). The ratio can represent the number of years required to meet regional development needs, reproduce the consumption of human resources in 1a, or, in theory, how many times as much ecological production as is required Land area can meet the demand of natural resources consumption. It can be concluded that footprint depth is an indicator of regional ecological pressure on a time scale [14][15][16]. According to 175 related research papers which have been retrieved at present, the research on ecological footprint in China is mainly focused on three aspects (Fig. 4), that is, model review, scale footprint research and specific industry / sector footprint analysis.

Resources in China.
China has a vast territory and is affected by many climatic types, and there is a serious

Ecological footprint model of water resources
It is divided into three major users: domestic water, production water and ecological and environmental water supply (including only urban environmental water supplied by artificial measures and some rivers and lakes, wetland water). The calculation model is as follows:

Ecological carrying capacity model of water resources
The ecological carrying capacity of water resources refers to the ability of the highest value of water supply to maintain the normal operation of economic system and ecosystem in a certain period of time and in a certain region. It also has natural attributes, social attributes and spatial attributes.
As 60% of the water carrying capacity of a region and a country is used to maintain the ecological environment, the water carrying capacity must be multiplied by a factor of 0. 4; ECw, ecw, γw, ψ, Q, Pw, N are water resource carrying capacity (hm 2 ), per capita water resource carrying capacity (hm 2 / person), global equilibrium factor of water resources, output factor of regional water resource source, total water resource amount (m 3 ). Global average water production capacity (m 3 / hm 2 ), population [9] 4.1.2 correlation coefficient between precipitation and ecological carrying capacity of water resources.
The correlation coefficient is a statistical analysis indicator of the degree of correlation between variables, and its formula is as follows: , , , is the correlation coefficient between the ecological carrying capacity of water resources and precipitation, the ecological carrying capacity of water resources (hm 2 ), the mean value of ecological carrying capacity of water resources (hm 2 ), and the value of precipitation (mm), in Water resources ecological surplus (deficit)= When the results of -are greater than, equal to, less than 00:00, the water resources show ecological surplus, ecological balance and ecological deficit respectively.

Results
The  person, domestic water is maintained at 0. 5%. 081hm 2 / person and 0. 094hm 2 / person, showing a slow upward trend, ecological and environmental water supply only 1. 5%. The range of changes over the years is 0. 1%. 01hm 2 / person to 0. 015hm 2 / person. In general, the ecological footprint of water resources of each production account is increasing (Fig. 7), and the water demand of each account is increasing.
[15] The ecological footprint of ten thousand yuan GDP water resources can reflect the utilization rate of water resources. It can be seen from figure .9 that GDP water resources of ten thousand yuan are the lowest in Beijing and Tianjin, and the water resources have been fully utilized. Xinjiang is the highest, mainly because of the economic structure and other factors, one of the characteristics of water use in Xinjiang is that the proportion of agricultural water use is too high, accounting for 95% of the total water consumption; Tibet took the second place, which was mainly related to industrial structure,  (1) on the time scale, the study on the time series of ecological footprint is increased to reveal the internal interaction mechanism between the characteristics of regional ecological footprint and the evolution of regional development, as well as the corresponding coupling relationship between the change of regional ecological footprint and the regional sustainable development.
(2) on the spatial scale, we should increase the comparative study of the ecological footprint in the east, middle and west regions of China, large, medium, small cities, cities and villages, and analyze the structural hierarchy of the ecological footprint. The differences of validity rate, temporal dynamics, spatial superposition and spatial diffusion reveal the relationship between regional development and interregional, intercontinental and even global, and discuss the spatial segmentation scale and degree of regional ecological footprint spillover and transfer. The "mark value" of ecological footprint under the ecological ethics equity of regional development can better reveal the inner nature of regional development and regional and even global sustainable development. Relationship.  context of consumption culture and regional sustainable development, international trade. The inter-regional migration of ecological footprint caused by domestic trade and the inter-regional diffusion of ecological responsibility, energy, transportation, aquaculture, industry, The research on ecological footprint of specific industries and departments, such as agriculture and tourism, will expand the research field of ecological footprint.
(4) on the one hand, the improvement of ecological footprint calculation method should be strengthened, such as regional hectare, yield factor, equilibrium factor, land type, trade adjustment, energy consumption, waste absorption and so on. On the other hand, the ecological footprint analysis method should be combined with other indicators that can reflect the sustainable development of the region in terms of social economy and economy, and the index system and the analysis frame of the regional sustainable development based on the ecological footprint should be established. Vigorously developing HANPP (human appropriation of net primary pro Duction) analysis, strengthen the ecological footprint based on PIOTs (physical input_ output tables) rather than MIOTs (monetary input_output tables), ecological burden research, promote regional and global sustainable development.