Improving the methodology for assessing the level of environmental safety of urban areas as the basis of their life cycle

. The article presents a graphical description of the relative environmental, economic and social indicators in the form of planar diagrams reflecting the state of the industrial and economic functional zones under study. Previously, we have described modern changes in the infrastructure of the urbanized areas, and also justified the necessity of supplementing economic and social indicators with environmental ones. On the basis of the conducted analysis, we have compared each of the indicators of the state of the environment of the urbanized areas with allowable values. In turn, the obtained values of relative indicators are graphically presented in the form of planar diagrams that reflect the most significant characteristics (environmental, economic and social) of the objects under study, on the scales of which the values are equal to 1 characterize the negative value of the corresponding characteristic, and the values are close to the reference point - the most favourable. In further research we plan to continue improving the methodology for assessing the level of environmental safety of the urbanized areas with the aim of its practical testing and implementation. The scientific novelty of the study consists in combining the obtained values of environmental, economic and social characteristics into a comprehensive (integral) assessment of the urbanized territories environmental safety level that would serve as the basis for subsequent selection of environmentally effective and cost-efficient organizational,


Introduction
Successive infrastructural changes of urbanized territories have led to the fact that by the end of the XX century most of major industrial enterprises located in the central areas of large cities began to move beyond their boundaries. Thus, from the late 50s -early 60s, new industrial zones were created outside the urban areas and in their former place three types of modern infrastructure began to form [1][2]. Those types are residential areas (varied-height multifamily residential complexes with a landscaped courtyard area and ancillary facilities), socio-cultural (shopping and entertainment centers or complexes, cultural and exhibition centers, art spaces, etc.) or economic ones (newly built business centers, former industrial workshops transformed into offices, apartments or shopping areas). Such changes have led to the need for a deeper analysis of existing methods of assessing the level of urban areas environmental safety, taking into account changes in urban infrastructure to propose the guidelines to improve those methods.
The subject of the research of the features of modern infrastructure facilities environmental impact in urbanized areas is the production facilities of certain hazard classes, as well as shopping and entertainment centers or complexes located in the former "internal" areas of large cities [3] on the sites previously organized as the location and operation of enterprises. The scientific novelty of the study consists in combining the obtained values of environmental, economic and social characteristics into a comprehensive (integral) assessment of the urbanized territories environmental safety level that would serve as the basis for subsequent selection of environmentally efficient and cost-effective organizational, technical and special environmental engineering measures.

Materials and Methods
The analysis of known methodological approaches to assessing the state of the urban environment lets us draw the following conclusion. It is necessary to take into account social, environmental and economic conditions, as well as a number of restrictions when assessing the level of environmental safety of modern infrastructure facilities in urbanized areas. This approach has not received a sufficiently complete development in modern studies yet. We have previously studied the features of the negative impact on the environment of modern infrastructure facilities in large cities and analyzed the existing methods for assessing the level of environmental safety of urbanized areas [1][2][3]. We found that in the studies of many authors [4][5][6] much attention is given to the tasks related to the development of a comprehensive assessment of urbanized territories state. We also took into consideration the results of studies, in which obtaining of such an assessment is based on the recognition of the importance of not only social and economic components, but, above all, the environmental one. Based on the done research, we consider it is necessary to describe the second stage of improving the methodology for assessing the level of environmental safety of urbanized areas. Its essence lies in the graphical reflection of the features of the negative impact on the environment of modern urban infrastructure for various purposes.
We base the improvement of methods for assessing the environmental security level on the principles of comprehensive consideration of social, economic and environmental components. Previously, we mathematically described three criteria that reflect the environmental, economic and social characteristics of an urbanized area. At the first stage we brought each of them to the corresponding indicators by converting them into dimensionless ones with an interval from 0 (the best condition) to 1 (the worst condition).
At the second stage we compare each of the indicators of the environment of industrial and economic functional zones of urbanized areas with allowable values for environmental, economic and social characteristics. At the same time we consider it is expedient to use a graphical description of relative indicators in the form of planar diagrams of the most significant characteristics (environmental, economic and social) of the studied objects of the corresponding functional zones. The graphical display of research results through diagrams, graphs, etc. is an integral part of modern scientific research in technical and environmental and economic areas [7,8]. We also plan to describe and apply the principles of constructing normative spatial diagrams to compare the actual indicators of industrial and economic functional zones, including when considering two conditional areas of shopping and entertainment centres that have similar parameters of architectural and spatial organization, economic efficiency and turnover, but differing in location in the general infrastructure of an urbanized area.
For comparison each of the indicators of the environment of urbanized areas with allowable values, we have used an approach to determine the environmental and economic efficiency (EEE) of various products and production processes, based on the scientific works of Peter Saling, Andreas Kicherer, Brigitte Dittrich-Kramer, David R. Shonnard, Isabell Schmidt, Manfred Meurer and others [9,10,11], according to which the term "ecoefficiency" was introduced by the scientist Stephan Schmidheiny and his colleagues [12] and subsequently approved by the Business Council for Sustainable Development (WBCSD) in his 1992 publication [12]. It was originally based on the concept of creating more goods and services while using fewer resources and creating less waste and pollution. At the same time Peter Saling, Andreas Kicherer and others understand by the ecological optimization of systems as a whole by "eco-efficiency", taking into account economic factors, namely the ratio of the economic growth to the results of a negative impact on the environment.
In our research according to analogy with products or production processes, the functional zones of an urbanized area have been used for considering as part of a methodological approach to determine environmental and economic efficiency [13,14]. At the same time from an environmental point of view, economic zones deserve a special attention, including both newly built business centres and the conversion of existing workshops into office space, apartments, partly retail space or full-fledged shopping and entertainment centres or complexes. This approach is based on the assessment of the environment, possible impacts on human health and objects of the urbanized area and urban economy [15], as well as the economic performance of the relevant functional areas throughout their entire life cycle. At the same time, we have used a graphical description of relative indicators in the form of planar diagrams of the most significant characteristics (environmental, economic and social) of the studied objects of the corresponding functional zones (Figures 2 and 3), on the scales of which the values are equal to 1 characterize the negative value of the corresponding characteristic, and the values are close to the origin -the most favourable (see Table 1).

Results
The spatial diagram of the factor-by-factor assessment of the environment of the industrial zone of an urbanized area, shown in Figure 1, clearly shows that a typical industrial zone, as a rule, has the highest value of an economic indicator, but lower social and environmental indicators. This is due to the significant economic effect of enterprises for the region with a controversial impact on the socio-demographic sphere and a negative impact on the environmental components of the surrounding areas. At the same time, it is important to note that only the general position of the social, environmental and economic indicators of the researched area below the limits of allowable values (below 0,37 on the normative spatial diagram) is strategically effective. In other cases, we can talk about the uneven functional development of the area, which for the industrial zone of the urbanized area in Figure 1, is its high efficiency from an economic point of view with unfavourable environmental and social indicators, which in the long term is an example of irrational use of the area.
In turn, the spatial diagram of the factor-by-factor assessment of the environment of the economic zone of the urbanized area in Figure 2 illustrates the typical values of the environmental, economic and social indicators of shopping and entertainment complexes and centers as the most significant infrastructure objects of this zone. Thus, it can be seen that the environmental indicator is below the limit of allowable values with sufficiently high social and economic indicators. It makes a shopping mall or a shopping centre similar to industrial facilities in terms of the complex negative impact on the environmental components of the surrounding areas. Moreover, in some cases, we can talk about close indicators of the magnitude of the negative impact on the environment from shopping and entertainment centers concerning industrial enterprises located within the territorial boundaries of urbanized areas.

Discussion
In our opinion, the research results described above provide sufficient grounds to confirm the stated goal, namely, to revise the existing methods for assessing the environmental safety level of urbanized areas and propose new scientific principles for methodology improvement, which would take into account the negative impact of modern urban infrastructure on the environment. Moreover, the basics of the proposed approach of combining three criteria that reflect the environmental, economic and social characteristics of an urbanized area are supplemented with illustrations in Figures 1-2 and their detailed descriptions.
These results represent the continuation of the previously described first stage of our research. At the first stage we transferred each of the three criteria into the corresponding indicators in such a way that each of them was converted into a dimensionless one with an interval from 0 (the best condition) to 1 (the worst condition). Each of the indicators of the environment of urbanized areas with allowable values was compared at the second stage. The corresponding functional zones of an urbanized area were considered as an object of the research. At the same time, we used a graphical description of relative indicators in the form of planar diagrams of the most significant characteristics (environmental, economic and social) of the studied objects, where one can see the limits of allowable and actual values of the corresponding functional zone, as well as the actual values limits of industrial and economic zones.
The obtained results are important to carry out the third stage of the research, on which we plan to present visually a comprehensive assessment of the environmental safety of urbanized areas in the form of a spatial diagram. In its three-dimensional space the values are plotted in the form of points characterizing the complex state of the environment of the considered sections of the urbanized area (of an industrial zone and an economic zone) in terms of environmental, economic and social indicators.
In our opinion, the three-stage improvement of the methodology for assessing the environmental safety level of urban areas is a necessary process for the subsequent selection of environmentally effective and cost-efficient organizational, technical and special environmental engineering measures. This, in turn, can be the basis for subsequent improvement of the environmental quality of the various areas of modern urban infrastructure.

Conclusions
The result of our research, namely the second stage of improving the methodology for assessing the environmental safety level of urbanized areas contain a graphical description of the relative environmental, economic and social indicators. We present it in the form of planar diagrams of the corresponding characteristics of the studied objects of industrial and economic functional zones. We thereby show the application of assessment criteria in an improved methodology for assessing the environmental security level of urbanized areas.
Thus, along with the environmental characteristics of the state of the urban environment, it will be possible to take into account and visually display the economic and social indicators of the development of the studied areas, or their individual sections, both at the moment and in the future when developing design solutions for new urban infrastructure facilities for various purposes, including shopping and entertainment centres or complexes with the surrounding territory. At further stages of the research, we plan to continue improving the methodology for assessing the level of environmental safety of urbanized areas in order to ensure the possibility of its practical testing and implementation.