Sewerage network resilience evaluation model and evaluation method

Abstract

The present invention relates to a sewer network resilience evaluation model and evaluation method, and more specifically, to a model for specifying a region for evaluation and comparing and evaluating the resilience of a sewer network for each of a plurality of regions, comprising: an indicator information collection unit that sets an indicator for evaluation and collects information on said indicator for each of said region; an indicator importance analysis unit that analyzes the importance of said indicator; and a resilience ranking derivation unit that evaluates the resilience of a plurality of said regions and derives a ranking.

Description

Technology Field

[0001] The present invention relates to a model and method for evaluating the resilience of a sewer network. More specifically, it relates to a model and method for evaluating the resilience of a sewer network in response to ground subsidence and urban flooding. Background Technology

[0002] The inevitable aging of social infrastructure has posed numerous threats to cities, and among these, ground subsidence caused by infrastructure is receiving global attention. Sewer pipes, a critical part of urban infrastructure, are a core element of urban sanitation systems. Because sewer pipes are generally larger and buried deeper than other public pipelines, ground subsidence accidents resulting from damaged pipes are often more severe. Even in Seoul, the capital and largest city of Korea, ground collapse-related accidents have occurred frequently, with a relatively large proportion attributed to damage to sewer pipes. Sewer pipes are facilities that are difficult to detect immediately once damaged. Since abnormal conditions can only be identified after a direct accident, such as a road collapse, it is crucial to manage them proactively to prevent damage in order to prevent large-scale disasters. As the focus of core infrastructure design shifts from a "design approach emphasizing rigidity" to a "design approach emphasizing resilience," the importance of preparation, response, and recovery from urban destructive events is being highlighted (Mottahedi et al., 2021).

[0003] Due to climate change, heavy rainfall, storms, and other large-scale damages are occurring in many countries. Seoul is a city where political, economic, and other urban functions are concentrated. It is densely packed with complex networks of buildings and underground infrastructure. If flooding occurs in such a city, it will cause significant damage, incurring enormous costs and requiring long recovery times. Analysis indicates that the causes of flooding include not only torrential rains exceeding the design capacity of drainage facilities, but also surface runoff flowing into low-lying areas, insufficient flow in sewer pipes, reduced transport due to sediment runoff and backflow, failure to consider the impact of climate change in road design, vulnerable aspects of land use (e.g., underground arcades and housing), inadequate warning / alarm systems, inefficient traffic control, poor management of vulnerable areas and facilities, and inadequate recovery systems and disaster follow-up measures. Therefore, major cities around the world are striving to introduce new disaster prevention systems to address climate change.

[0004] This study aims to identify indicators for evaluating the resilience of sewer networks considering the risks of ground subsidence and urban flooding, prior to quantitatively analyzing the resilience of sewer networks in response to ground subsidence and urban flooding. It is expected that this will further enhance the level of sewerage services. Prior art literature

[0005] Republic of Korea Registered Patent 10-1803781 Republic of Korea Published Patent 10-2016-0126763 Republic of Korea Registered Patent 10-1516599 Republic of Korea Registered Patent 10-1557865 The problem to be solved

[0006] Accordingly, the present invention has been devised to solve the aforementioned conventional problems. According to an embodiment of the present invention, the purpose is to provide a sewer network resilience evaluation model and evaluation method that can further improve the level of sewerage services by identifying indicators for evaluating the resilience of a sewer network considering the risk of ground subsidence and urban flooding prior to quantitatively analyzing the resilience of a sewer network responding to ground subsidence and urban flooding.

[0007] According to an embodiment of the present invention, the purpose is to provide a model and method that can identify 14 sub-indicators related to four evaluation indicators regarding sewer network resilience and use them to evaluate resilience through a three-stage hierarchical structure.

[0008] According to an embodiment of the present invention, the resilience of a sewer network against ground subsidence and urban flooding can be quantified as performance based on resilience indicators. By rationally identifying detailed sub-indicator elements corresponding to resistance, reliability, redundancy, and response and recovery, starting from the four basic attributes of resilience, the resilience of the sewer network can be better characterized. Furthermore, through research on the resilience of drainage areas in Seoul to respond to ground subsidence and urban flooding, the academic community can pay more attention to the application of the concept of resilience to sewer networks and explore feasible ideas. The purpose of this invention is to provide a sewer network resilience evaluation model and evaluation method that can offer a new perspective to the planning, design, and construction departments of sewer networks in the future.

[0009] Meanwhile, the technical problems to be solved by the present invention are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0010] The first objective of the present invention can be achieved by a sewer network resilience evaluation model characterized by comprising: a model for specifying a region for evaluation and comparing and evaluating the resilience of a sewer network for each of a plurality of regions, wherein the model comprises: an indicator information collection unit that sets an indicator for evaluation and collects information on said indicator for each of said region; an indicator importance analysis unit that analyzes the importance of said indicator for each of said indicator; and a resilience ranking derivation unit that evaluates the resilience of the plurality of said regions and derives a ranking.

[0011] And the above indicators may be characterized as resistance, reliability, redundancy, and response and recovery.

[0012] In addition, each of the above indicators may have sub-indicators, and the resistance may be at least one of the pipe extension ratio, the ratio of sections where image data cannot be investigated, and traffic complexity; the reliability may be at least one of the pipe improvement ratio with insufficient flow capacity, the pipe extension ratio per capita, pump discharge volume, the number of priority pump stations in the river management department, and the area of ​​the retention basin; the redundancy may be at least one of the sewage flow capacity margin ratio and the presence or absence of sewage storage facilities; and the response and recovery may be at least one of the recovery allowable time, accessibility, departmental cooperation plan, training exercises according to the recovery plan, resource securing plan and mobilization capability, expenditure of major accident avoidance costs, recovery cost securing rate, and technical availability.

[0013] In addition, the above indicator importance analysis unit may be characterized by analyzing the importance of each indicator using the AHP technique.

[0014] In addition, if n experts assign the importance of pairwise compared indicators as Q1, Q2, Q3, Q4, ..., Qn, the geometric mean becomes the overall importance of the pairwise compared indicators, and when the hierarchical analysis procedure is completed, the importance and weight for each indicator can be derived.

[0015] In addition, the resilience ranking derivation unit may be characterized by being derived by performing the PROMETHEE technique based on the importance and weights derived from the indicator importance analysis unit.

[0016] In addition, the above-mentioned PROMETHEE technique can be characterized by selecting a specific preference function for each indicator and defining parameter values ​​to calculate the preference associated with the best alternative in the pairwise comparison process.

[0017] And, after determining the evaluation matrix and preference function, it can be characterized by deriving a ranking for each region from the positive flow, negative flow, and net flow values ​​obtained from the evaluation.

[0018] The second objective of the present invention can be achieved by a method for evaluating the resilience of a sewer network for each of a plurality of regions, comprising: a step of specifying a region for evaluation; a step of setting an indicator for evaluation and collecting information on said indicator for each of said region; a step of an indicator importance analysis unit analyzing the importance of said indicator; and a step of a resilience ranking derivation unit evaluating the resilience of the plurality of said regions and deriving a ranking; wherein said indicators are resistance, reliability, redundancy, and response and recovery.

[0019] Furthermore, the step of analyzing the importance above may be characterized by analyzing the importance of each indicator using the AHP technique, and when n experts designate the importance of the pairwise compared indicators as Q1, Q2, Q3, Q4, ..., Qn, the geometric mean becomes the overall importance of the pairwise compared indicators, and when the hierarchical analysis procedure is completed, the importance and weight for each indicator are derived.

[0020] In addition, the above AHP technique may be characterized by including the steps of establishing a hierarchical structure, establishing a pairwise comparison matrix using a relative measurement scale, determining a relative rank matrix for each criterion of the hierarchy to calculate the importance of the pairwise comparisons, and calculating a consistency index and a consistency ratio.

[0021] The step of evaluating the resilience and deriving a ranking may be characterized by including: a step of deriving a ranking by performing the PROMETHEE technique based on the importance and weight derived from the indicator importance analysis unit, selecting a specific preference function for each indicator, defining parameter values, and calculating the preference associated with the best alternative in the pairwise comparison process; and a step of deriving a ranking for each region from the positive flow, negative flow, and net flow values ​​obtained from the evaluation after determining the evaluation matrix and preference function.

[0022] In addition, the above-mentioned PROMETHEE technique may be characterized by including the steps of defining judgment items and alternative functions, selecting a preference function corresponding to an indicator, calculating the total preference index, calculating the preferred outflow and preferred inflow, and calculating the net flow.

[0023] The third objective of the present invention can be achieved as a comparative evaluation program for the resilience of a sewer network for each of a plurality of regions, which is read and executed by a computer, comprising: a function for specifying the regions for evaluation; a function for setting indicators for evaluation and collecting information on said indicators for each of said regions; a function for analyzing the importance of said indicators; and a resilience ranking unit for evaluating the resilience of the plurality of said regions and deriving a ranking; wherein said indicators are resistance, reliability, redundancy, and response and recovery. Effects of the invention

[0024] According to the sewer network recovery resilience evaluation model and evaluation method according to an embodiment of the present invention, prior to quantitatively analyzing the recovery resilience of a sewer network responding to ground subsidence and urban flooding, an indicator for evaluating the sewer network recovery resilience considering the risk of ground subsidence and urban flooding is identified, thereby having the effect of further improving the level of sewerage service.

[0025] According to the sewer network resilience evaluation model and evaluation method according to an embodiment of the present invention, 14 sub-indicators related to four evaluation indicators regarding sewer network resilience are identified, and resilience can be evaluated through a three-stage hierarchical structure using these indicators.

[0026] According to the sewer network resilience evaluation model and evaluation method of the embodiment of the present invention, the resilience of a sewer network against ground subsidence and urban flooding can be quantified as performance based on resilience indicators. Furthermore, by rationally identifying detailed sub-indicator elements corresponding to resistance, reliability, redundancy, and response and recovery, starting from the four basic attributes of resilience, the resilience of the sewer network can be better characterized. Additionally, through research on the resilience of drainage areas in Seoul to respond to ground subsidence and urban flooding, the academic community can pay greater attention to the application of the concept of resilience to sewer networks and explore feasible ideas. This has the advantage of providing a new perspective to the planning, design, and construction departments of sewer networks in the future.

[0027] Meanwhile, the effects obtainable from the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present invention belongs from the description below. Brief explanation of the drawing

[0028] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a block diagram showing the concept of a sewer network recovery resilience evaluation model according to an embodiment of the present invention. FIG. 2 is a table showing indicators and sub-indicators according to an embodiment of the present invention, FIG. 3 is a map showing a region (block) to be evaluated according to an embodiment of the present invention, FIG. 4 is an information table for four sub-blocks selected according to an embodiment of the present invention, FIG. 5 shows the weights of the indicators and sub-indicators derived according to an embodiment of the present invention, and an importance table, FIG. 6 is a 10-point scale table for some subdivision elements of an evaluation subject according to an embodiment of the present invention, FIG. 7 shows four alternative sample items of an evaluation method using the PROMETHEE technique according to an embodiment of the present invention, FIGS. 8a and 8b are definitions of evaluation criteria according to embodiments of the present invention, FIG. 9 illustrates the preference index and flow results for PROMETHEE II according to an embodiment of the present invention. Specific details for implementing the invention

[0029] The above objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments associated with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to ensure that the spirit of the invention is sufficiently conveyed to a person skilled in the art.

[0030] In this specification, when a component is described as being on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them. Also, in the drawings, the thicknesses of the components are exaggerated for the effective description of the technical content.

[0031] The embodiments described herein will be explained with reference to cross-sectional and / or plan views, which are exemplary illustrations of the invention. In the drawings, the thicknesses of films and regions are exaggerated for effective explanation of the technical content. Accordingly, the shapes of the exemplary drawings may be modified by manufacturing techniques and / or tolerances, etc. Accordingly, the embodiments of the invention are not limited to the specific shapes depicted but include variations in shape produced according to the manufacturing process. For example, a region depicted as a right angle may be rounded or have a certain curvature. Accordingly, the regions illustrated in the drawings have properties, and the shapes of the regions illustrated in the drawings are intended to illustrate specific shapes of the regions of the device and are not intended to limit the scope of the invention. Although terms such as first, second, etc., have been used to describe various components in the various embodiments of this specification, these components should not be limited by such terms. These terms are used merely to distinguish one component from another. The embodiments described and illustrated herein also include their complementary embodiments.

[0032] The terms used herein are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, 'comprises' and / or 'comprising' do not exclude the presence or addition of one or more other components to the mentioned components.

[0033] In describing the specific embodiments below, various specific details have been included to explain the invention more specifically and to aid understanding. However, a reader with sufficient knowledge in the art to understand the invention will recognize that it can be used without these various specific details. In some cases, it is noted in advance that commonly known aspects that are not significantly related to the invention have been omitted to prevent unnecessary confusion in describing the invention.

[0035] Hereinafter, a sewer network recovery resilience evaluation model and evaluation method according to an embodiment of the present invention will be described.

[0036] First, FIG. 1 illustrates a block diagram showing the concept of a sewer network recovery resilience evaluation model according to an embodiment of the present invention.

[0037] The sewer network recovery resilience evaluation model according to an embodiment of the present invention is a model for specifying a region for evaluation and comparing and evaluating the recovery resilience of a sewer network for each of a plurality of regions.

[0038] This evaluation model may be composed of an indicator specific section, an indicator importance analysis section, a ranking derivation section, etc.

[0039] Overall, the indicator information specification section sets and specifies indicators for evaluation and collects them for each of the aforementioned regions.

[0040] Furthermore, the Indicator Importance Analysis Unit analyzes the importance of each indicator. This unit analyzes the importance of each indicator using the AHP technique. If n experts assign the importance of pairwise compared indicators as Q1, Q2, Q3, Q4, ..., Qn, the geometric mean becomes the overall importance of the pairwise compared indicators, and once the hierarchical analysis procedure is completed, the importance and weight for each indicator are derived.

[0041] Furthermore, the resilience ranking unit evaluates the resilience of multiple of the aforementioned regions and derives a ranking. The resilience ranking unit according to this embodiment of the present invention is derived by performing the PROMETHEE technique based on the importance and weights derived from the indicator importance analysis unit.

[0042] Through the PROMETHEE technique, a specific preference function is selected for each indicator and parameter values ​​are defined to calculate the preference associated with the best alternative in the pairwise comparison process. Additionally, after determining the evaluation matrix and preference function, rankings for each region are derived from the positive, negative, and net flow values ​​obtained from the evaluation.

[0044] Below, each module of the sewer network recovery resilience evaluation model and method according to the embodiment of the present invention will be described in more detail.

[0045] The indicator information specification section sets and specifies indicators for evaluation. The evaluation indicators according to this embodiment of the present invention are resistance, reliability, redundancy, and response and recovery.

[0046] FIG. 2 illustrates a table showing indicators and sub-indicators according to an embodiment of the present invention.

[0047] As shown in Figure 2, each indicator has a sub-indicator, and resistance is the pipe length ratio, the ratio of sections where image data cannot be surveyed, and traffic complexity.

[0048] And reliability is the improvement rate of pipes with insufficient flow capacity, the ratio of improved pipe length per capita, pump discharge volume, the number of priority pump stations of the River Management Division, and the area of ​​retention basins.

[0049] In addition, redundancy refers to the margin of wastewater flow capacity and the presence or absence of wastewater storage facilities.

[0050] And response and recovery are recovery allowance time, accessibility, departmental cooperation plan, training exercises based on the recovery plan, resource securing plan and mobilization capability, expenditure of major accident avoidance costs, recovery cost securing rate, and technology availability.

[0051] FIG. 3 shows a map representing a region (block) to be evaluated according to an embodiment of the present invention. In an embodiment of the present invention, four sub-blocks are selected to evaluate resilience. The locations are shown in FIG. 3, and related information is shown in FIG. 4.

[0053] Below, we will explain the method for analyzing the importance of each indicator using the AHP technique.

[0054] The basic steps of the AHP approach will be explained below.

[0055] Step 1: Establish a hierarchical structure. The structure starts at the top (goal) and middle layer (criteria and sub-criteria), placing alternatives at the lower layer.

[0056] Step 2: Set up a pairwise comparison matrix (n-x-n) using Saaty's 1-9 relative measurement scale. The pairwise comparison matrix is ​​determined by whether one criterion dominates another.

[0057] (1)

[0058] Here is the compared alternative It is an expression of the decision maker's preference strength for all comparisons i, j=1, 2, ···, n. The decision makers facilitated two rounds of comparisons of alternative criteria or factors until the score was considered stable. Stability was reached when a certain consensus was reached on the sum of the scores.

[0059] Step 3: Determine the relative rank matrix for each criterion in the hierarchy and calculate the importance of pairwise comparisons.

[0060] Step 4: Calculate the consistency index (CI) and consistency ratio (CR).

[0061] (2)

[0062] Here λ is the maximum eigenvalue calculated by averaging all individual eigenvalues ​​λ, and N is the number of elements (or indicators) subject to priority determination. Then, CR is obtained using the following formula.

[0063] (3)

[0064] Here, RI is the random consistency index. Additionally, the acceptable range for CR must not be exceeded by 0.10. If it exceeds 0.10, it means the results are inconsistent, and the evaluation process must be reviewed or re-performed.

[0066] According to an embodiment of the present invention AHP execution results , 10 experts rated the importance of paired indicators Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, Q 10 If you set it to geometric mean This becomes the overall importance of the pairwise compared indicators. Once the above hierarchical analysis procedure is completed, it provides the importance and weight for each indicator.

[0068] Below, we will explain the determination of resilience priorities for four sub-blocks using the PROMETHEE method.

[0069] The main calculation steps of the PROMETHEE technique are as follows.

[0070] Step 1: Defining and Formulating Judgment Criteria and Alternatives

[0071] A set of alternatives for multi-attribute decision problems Defines. And is a judgment item Alternatives It is said to represent the evaluation value of. Judgment item Alternatives A substitute The degree to which decision makers prefer it more F It is as follows.

[0072] (4)

[0073] Among these, q is called the threshold of indifference and p is called the threshold strict preference. F is a non-decreasing priority function.

[0074] In actual application, for ease of understanding, generally Assuming Set to . That is, d is alternative a i and alternative a j Judgment item f k It is the difference between the attributes. Then, the above equation (4) is transformed as follows.

[0075] (5)

[0076] To adapt shapes to general human habits, they are structured as another function representing the degree of preference.

[0077] (6)

[0079] Step 2: Selection of the preference function corresponding to the indicator

[0080] Brans (1985) proposed six types of preference functions commonly used by decision makers, which are divided into usual criterion, quasi-criterion, criterion with linear preference, level criterion, linear criterion with linear preference and indifference area, and Gaussian criterion.

[0081] (1) Usually criterion

[0082] (7)

[0084] (8)

[0085] Preference function Is When, that is There is no difference only when, and It exhibits a strict priority that is only slightly different.

[0086] (2) U-shaped (quasi-criterion)

[0087] (9)

[0088] (10)

[0089] q is an uncorrelated threshold set by the decision maker based on their experience. Preference function Is There is no difference when, When and indicates strict priority.

[0090] (3) V-type (criterion with linear preference)

[0091] (11)

[0093] (12)

[0094] p is the decision maker's firm preference threshold. Preference function Is When this occurs, the decision maker's preference increases linearly with the deviation d. When and indicates strict priority.

[0095] (4) Level criterion

[0096] (13)

[0097] (14)

[0098] q is the uncorrelated threshold set by the decision maker based on their experience, and p is the decision maker's firm preference threshold. Preference function Is There is no difference when, When and indicates strict priority. When and has a weak preference.

[0099] (5) Linear (criterion with linear preference and indifference area)

[0100] (15)

[0101] (16)

[0102] q is the uncorrelated threshold set by the decision maker based on their experience, and p is the decision maker's firm preference threshold. Preference function Is There is no difference when, When and indicates strict priority. When this occurs, the decision maker's preference increases linearly with the deviation d.

[0103] (6) Gaussian criterion

[0104] (17)

[0105] (18)

[0106] The Gaussian preference function is used when the priority value of a room has a non-linear relationship with the index value.

[0108] Step 3: Calculate overall preference index

[0109] For all judgment items, a i of a j Overall preference index for Defines as follows.

[0110] (19)

[0111] Here is the weight for each judgment item is, and k is the number of judgment items.

[0113] Step 4: Calculate Preference Outflow and Preference Inflow

[0114] Alternative a i leaving flow , that is, alternative a i The degree to which is preferred over other alternatives; generally, a higher value means that the alternative is better than the others. On the other hand, alternative a i inflow (entering flow) , that is, other alternatives are alternative a i The degree of preference; generally, the smaller the value, the better the alternative is compared to other alternatives.

[0115] (20)

[0116] (21)

[0117] In addition, according to the PROMETHEE I technique, three relationships—P (rank preference), I (indifference), and R (incomparability)—can be derived depending on the inflow and outflow situations of each plan, and the specific judgment criteria are as follows.

[0118] (22)

[0119] (23)

[0120] (24)

[0121] The PROMETHEE I method assigns ranks when runoff is assumed to have the same rank as inflow; that is, it estimates this by assigning the highest priority to the largest runoff and the smallest inflow. Since it does not assign ranks when the ranks of runoff and inflow differ, PROMETHEE I can only obtain partial ranks.

[0123] Step 5: Calculate Net Flow

[0124] Barns et al. (1985) used net outranking flow to obtain a perfect ranking among alternatives The concept of [this] was added. A perfect ranking result can be obtained by simultaneously considering the difference between the sum of preferences that are better than other alternatives and the sum of preferences that are worse than other alternatives. Generally, the higher the net flow value, the better, and is defined by the following equation (25).

[0125] (25)

[0128] In an embodiment of the present invention, the weights of the sub-criteria in Fig. 5 and the minimum / maximum preferred directions were created and calculated using PROMETHEE. Evaluations were made for ‘A3 (traffic complexity)’, ‘D1 (allowable recovery time)’, ‘D2 (accessibility)’, ‘D6 (expenditure of major accident avoidance costs)’, and ‘D7 (recovery cost securing rate)’, while ‘D8 (technological availability)’ was difficult to quantify and was evaluated based on brainstorming sessions within the evaluation team and empirical analysis.

[0129] To this end, a 10-point scale ranging from 1 (very low) to 10 (very high) was applied (see Table 4). The evaluation of the four qualitative criteria—'C2 (presence or absence of sewage retention facilities)', 'D3 (departmental cooperation plan)', 'D4 (training exercises based on recovery plans)', and 'D5 (resource acquisition plan and mobilization capability)'—was based on empirical analysis within the evaluator team and social surveys.

[0130] The evaluation of the four quantitative criteria, 'A1 (ratio of good pipeline length),' 'A2 (ratio of sections where CCTV inspection is not possible),' 'B (reliability),' and 'C1 (margin of sewage flow capacity),' can be directly verified in the 2030 Basic Plan for Sewerage System Improvement.

[0131] Among these, the five items considered for the 'B (Reliability)' rating are the ratio of pipe improvement for insufficient flow capacity (40 points), length of improved pipes per capita (15 points), pump discharge volume (15 points), number of priority pump stations for the River Management Division (15 points), and reservoir area (15 points), totaling 100 points. After each item obtained the maximum and minimum values ​​within the evaluation range, points were distributed proportionally, and the overall results were assigned priority from highest to lowest scores. The calculation formula is explained in detail in the reference notes of Figure 7.

[0133] Next, a specific preference function is selected for each criterion and parameter values ​​are defined to calculate the preference associated with the best alternative in the pairwise comparison process. For quantitative evaluation, the PROMETHEE guidelines recommend applying a linear preference function (V-shaped). V-shaped parameters are set within the range of the evaluation indicator using the difference between the maximum and minimum values ​​of the evaluation indicator.

[0134] For qualitative evaluations, general criteria or level criteria can be selected. Among them, the preference of the traditional level function has only three values: 0, 0.5, and 1. However, some sample data have many qualitative indicator levels, and there is a large difference between the number of indicator levels and the number of index levels. Deviations in the results may occur depending on the preference of the step function. Therefore, in this case, two additional steps are added to the step preference function to form a new preference function called a multi-level preference function, with preferences of 0, 0.25, 0.5, 0.75, and 1. Accordingly, the preference function and threshold values ​​for each evaluation criterion are determined as shown in Table 6.

[0135] After determining the evaluation matrix and preference function, the positive flow (Φ+), negative flow (Φ-), and net flow (Φ) values ​​obtained from the evaluation are shown in Fig. 9.

[0136] The results based on PROMETHEE II (overall ranking) relate only to net flow and there are no situations where comparison is impossible. Looking at the calculation results, the drainage basin sub-blocks selected in Seoul appeared in the order of Block III, Block IV, Block I, and Block II.

[0137] In other words, Block III demonstrates the highest resilience, while Block II demonstrates the worst. Therefore, when the government formulates a sewer network rehabilitation plan in the future, it will be able to prioritize investment in areas with weak resilience.

[0139] In addition, the device and method described above are not limited to the configurations and methods of the embodiments described above; rather, all or part of each embodiment may be selectively combined to allow for various modifications to be made.

Claims

Claim 1 As a model for specifying regions for evaluation and comparing and evaluating the resilience of sewer networks for each of multiple regions, an indicator information collection unit that sets indicators for evaluation and collects information on said indicators for each of said regions; and an indicator importance analysis unit that analyzes the importance of each of said indicators; A sewer network recovery comprising: a resilience ranking derivation unit that evaluates the resilience of multiple of the above-mentioned regions and derives a ranking; wherein the indicator is at least one of resistance, reliability, redundancy, and response and recovery, and each of the indicators has a sub-indicator, wherein the resistance is at least one of the pipe extension ratio, the ratio of sections where image data cannot be surveyed, and traffic complexity; the reliability is at least one of the ratio of pipe improvement for insufficient flow capacity, the ratio of improved pipe extension per capita, pump discharge volume, the number of priority pumping stations of the River Management Division, and the area of ​​retention basins; the redundancy is at least one of the sewer flow capacity margin ratio and the presence or absence of sewer retention facilities; and the response and recovery is at least one of the allowable recovery time, accessibility, departmental cooperation plan, training exercises according to the recovery plan, resource securing plan and mobilization capability, expenditure of major accident avoidance costs, recovery cost securing rate, and technical availability. Resilience evaluation model. Claim 2 delete Claim 3 delete Claim 4 A sewer network resilience evaluation model according to claim 1, characterized in that the indicator importance analysis unit analyzes the importance of each indicator using the AHP technique. Claim 5 A sewer network resilience evaluation model characterized in that, in claim 4, if n experts designate the importance of pairwise compared indicators as Q1, Q2, Q3, Q4,,,,Qn, the geometric mean becomes the overall importance of the pairwise compared indicators, and when the hierarchical analysis procedure is completed, the importance and weight for each indicator are derived. Claim 6 A sewer network resilience evaluation model according to claim 4, characterized in that the resilience ranking derivation unit is derived by performing the PROMETHEE technique based on the importance and weights derived from the indicator importance analysis unit. Claim 7 A sewer network resilience evaluation model according to claim 6, characterized in that, through the above-mentioned PROMETHEE technique, a specific preference function is selected for each indicator and parameter values ​​are defined to calculate the preference associated with the best alternative in a pairwise comparison process. Claim 8 A sewer network resilience evaluation model characterized in that, in claim 7, after determining an evaluation matrix and a preference function, a ranking for each region is derived from positive flow rate, negative flow rate, and net flow rate values ​​obtained from the evaluation. Claim 9 A method for evaluating the resilience of a sewer network for each of a plurality of regions using a sewer network resilience evaluation model according to claim 1, comprising: a step in which an indicator information collection unit specifies a region for evaluation, sets an indicator for evaluation, and collects information on the indicator for each of the regions; a step in which an indicator importance analysis unit analyzes the importance of each of the indicators; and a step in which a resilience ranking derivation unit evaluates the resilience of the plurality of regions and derives a ranking; wherein the indicators are resistance, reliability, redundancy, and response and recovery. Claim 10 A method for evaluating the resilience of a sewer network, characterized in that, in the step of analyzing the importance, the indicator importance analysis unit analyzes the importance of each indicator using the AHP technique, and when n experts designate the importance of pairwise compared indicators as Q1, Q2, Q3, Q4,,,,Qn, the geometric mean becomes the overall importance of the pairwise compared indicators, and when the hierarchical analysis procedure is completed, the importance and weight for each indicator are derived. Claim 11 A method for evaluating the resilience of a sewer network according to claim 10, wherein the above-mentioned AHP technique comprises the steps of establishing a hierarchical structure, establishing a pairwise comparison matrix using a relative measurement scale, determining a relative ranking matrix for each criterion of the hierarchy to calculate the importance of the pairwise comparison, and calculating a consistency index and a consistency ratio. Claim 12 A method for evaluating the resilience of a sewer network according to claim 10, wherein the step of evaluating the resilience and deriving a ranking comprises: a step of performing the PROMETHEE technique based on the importance and weight derived from the indicator importance analysis unit, selecting a specific preference function for each indicator, defining parameter values, and calculating the preference associated with the best alternative in a pairwise comparison process; and a step of determining the evaluation matrix and preference function, and then deriving a ranking for each region from the positive flow rate, negative flow rate, and net flow rate values ​​obtained from the evaluation. Claim 13 A method for evaluating the resilience of a sewer network, characterized in that, in Clause 12, the above-mentioned PROMETHEE technique includes the steps of defining judgment items and alternative functions, selecting a preference function corresponding to an indicator, calculating an overall preference index, calculating a preferred outflow and a preferred inflow, and calculating a net flow. Claim 14 delete

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