JP2006349468A - Estimation system of pollution distribution of soil, estimation method of pollution distribution of soil and estimation program of pollution distribution of soil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To scientifically and rationally estimate a continuous polluted soil distribution from a small number of discrete actually measured data and to rapidly and properly performing the calculation of a purifying cost and the judge evaluation of land to disclose and transmit calculation and evaluation results to a customer through network communication. <P>SOLUTION: This estimation system 200 of the pollution distribution of soil for estimating the concentration of a pollutant in land using a computer 202 is equipped inside the computer 202 with an actually measured data memory means 204 for storing the actually measured data of the concentrations of the pollutant in a plurality of actually measuring parts of land to be evaluated, a two-dimensional estimation means 206 for estimating the concentrations of the pollutant at a plurality of the points in the horizontal plane within an estimation range including the actually measuring parts on the basis of the actually measured data of a ground surface part in the actually measured data, a parameter determining means 208 for determining an advective dispersion parameter on the basis of the actually measured data of a ground surface lower part in the actually measured data and a three-dimensional estimation means 210 for estimating the concentrations of the pollutant at a plurality of points in the estimation range on the basis of the estimated concentrations of the pollutant at a plurality of points and the determined advective dispersion parameter. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a soil contamination distribution estimation system, a soil contamination distribution estimation method, and a soil contamination distribution estimation program that estimate the contamination concentration of land using a computer.

  Some soils are contaminated by the use, discharge, or transfer from nearby facilities. Qualitative diagnosis has been conducted on the suspected soil contamination by examining the soil contamination by browsing, hearing, sampling and analysis. Moreover, a system for qualitative diagnosis is disclosed (for example, see Patent Document 1). However, since it takes a lot of labor and cost to collect survey data by conducting land surveys for the entire survey area, it is necessary to grasp the flow in the soil and based on the measured data within a certain range, It is preferable to estimate the degree of contamination.

  However, when elucidating the flow in the soil, it is often difficult to directly identify the ground structure identification and moisture permeation characteristics. This also makes it more difficult to elucidate the mechanism of transport of pollutants in the ground in relation to the soil and groundwater contamination problems. Therefore, it is necessary to estimate the aspects of moisture and pollutants flowing in a complex and diverse porous medium indirectly through laboratory experiments and field observations. In such a case, in order to make the estimation scientific and rational, it is necessary to regard a system composed of a porous medium and water as one system, and to perform objective analysis using various mathematical methods. . The ground environmental conditions and various parameters (groundwater level, seepage flow velocity, hydraulic conductivity, etc.) governing this system fluctuate in time and space, and influence each other in a complex manner. In general, in order to estimate such ground environmental conditions and various parameters, it is often difficult technically and economically to obtain a large number of observation data. In view of the above problem background, in order to grasp the spatial structure of the field from a limited amount of observation data, a method for scientifically and rationally estimating the ground environmental condition and various parameters has been demanded.

In addition, because pollutants that cause problems due to soil contamination are highly likely to remain near the ground surface due to their characteristics, excavation and removal that directly removes contaminated soil is often employed as a countermeasure against soil contamination. When calculating the amount of money necessary to excavate contaminated soil, there is a difference in the amount of money when calculating per 100 m ² as the basic unit of excavated soil and when calculating after examining the concentration distribution roughly in advance. . The impact of the real estate appraiser who appraises and evaluates the land and the financial institution that lends funds using the land as collateral changes greatly depending on the calculated amount. A calculation method, that is, a method for estimating a three-dimensional soil contamination range is required.
JP 2002-168850 A

  The purpose of the present invention is to scientifically and rationally estimate the continuous distribution of contaminated soil from a small number of discrete measured data, to quickly and appropriately calculate remediation costs and appraise land, and through network communication. To disclose and communicate to customers.

  The soil contamination distribution estimation system of the present invention is a soil contamination distribution estimation system that estimates the contamination concentration of a land using a computer, and the concentration of contaminants in a plurality of actual measurement parts in the evaluation target land is included in the computer. Two-dimensional estimation of pollutant concentrations at a plurality of points in a horizontal plane in the estimation range including the actual measurement part based on the actual measurement data storage means for storing the actual measurement data and the actual measurement data of the ground surface in the actual measurement data Based on the estimation means, the parameter determination means for determining the advection dispersion parameter based on the measured data of the lower surface of the ground in the measured data, the estimated concentration of pollutants and the determined advection dispersion parameter, And three-dimensional estimation means for estimating the concentration of pollutants at a plurality of points in the estimation range. A computer means a large computer, a personal computer, or the like. A terminal means a personal computer or a mobile phone. Each means performs each process according to a command to the computer or based on the judgment of the computer itself. The actual measurement part refers to a part where the contamination concentration was actually measured in the ground surface part and the ground surface lower part of the evaluation target land. The estimated range is a range in which the concentration of contamination is estimated according to the present invention, and is the entire range or a partial range of the survey target land.

In the soil contamination distribution estimation system of the present invention, in the soil contamination distribution estimation, the two-dimensional estimation means determines a plurality of pollutant concentrations Cb (x, y), and the parameter determination means includes an optimum advection dispersion parameter. tR ^OPT and pe ^OPT are determined, and the three-dimensional estimation means is based on Cb (x, y), tR ^OPT and pe ^OPT ,
C (x, y, z) = (1/2) Cb (x, y) erfc [{pe ^OPT / 4tR ^OPT (z)} ^1/2 {1-tR ^OPT (z)}] It is characterized by determining pollutant concentrations C (x, y, z) at a plurality of points in the estimation range. Here, it is assumed that the optimum value of the dimensionless advection dispersion parameter tR with respect to time is tR ^OPT and the optimum value of the Peclet number pe is pe ^OPT .

  The soil contamination distribution estimation system according to the present invention is characterized in that in the soil contamination distribution estimation, the estimation of the contaminant concentration by the two-dimensional estimation means and the determination of the advection dispersion parameter by the parameter determination means are performed simultaneously. .

  The soil contamination distribution estimation method of the present invention is a soil contamination distribution estimation method that estimates the contamination concentration of land using a computer, and the actual measurement data storage means in the computer includes a plurality of actual measurement units in the evaluation target land. Storing the actual measurement data of the pollutant concentration in the computer, and the two-dimensional estimation means in the computer, based on the actual measurement data of the ground surface in the actual measurement data, in the horizontal plane in the estimation range including the actual measurement unit Estimating a plurality of contaminant concentrations at a plurality of points in the computer, a parameter determining unit in the computer determining an advection dispersion parameter based on actual measurement data of a lower surface of the ground in the actual measurement data, and a tertiary in the computer Based on the estimated pollutant concentration at the plurality of points and the determined advection dispersion parameter, Estimating a contaminant concentration at a plurality of points in the serial estimation range, characterized in that it comprises a.

  The soil contamination distribution estimation program of the present invention is a soil contamination distribution estimation program that estimates the contamination concentration of land using a computer, and the computer measures the concentration of pollutants in a plurality of measurement units in the evaluation target land. Actual measurement data storage means for storing data, two-dimensional estimation means for estimating the concentration of pollutants at a plurality of points in a horizontal plane in the estimation range including the actual measurement part based on the actual measurement data of the ground surface portion in the actual measurement data , Parameter determining means for determining advection dispersion parameters based on the measured data of the lower surface of the ground in the measured data, based on the estimated pollutant concentrations at the plurality of points and the determined advection dispersion parameters, It is made to function as a three-dimensional estimation means for estimating the pollutant concentration at a plurality of points.

  According to the soil contamination distribution estimation system, the soil contamination distribution estimation method, and the soil contamination distribution estimation program of the present invention, the advection dispersion parameter is calculated by the parameter determination means at the same time as the pollutant concentration on the ground surface is estimated by the two-dimensional estimation means. The three-dimensional contamination concentration distribution can be estimated by the three-dimensional estimation means using these estimation results. For this reason, it is possible to efficiently estimate the three-dimensional contamination concentration distribution while using the measured data. Moreover, since the contamination degree of the whole investigation range can be estimated using the actual measurement data of the actual measurement unit, the actual measurement cost can be reduced. By using the advection dispersion parameter, it can be estimated scientifically and rationally, and the certainty of land pollution survey can be improved. In addition, the purification cost can be calculated quickly and appropriately. Furthermore, the estimation result and the calculation result can be quickly disclosed and communicated to the customer through network communication.

  The soil contamination distribution estimation system, soil contamination distribution estimation method, and soil contamination distribution estimation program of the present invention will be described in detail below with reference to the drawings.

  The soil contamination distribution estimation system 200 according to the present invention is a soil contamination distribution estimation system that estimates the concentration of land contamination using a computer 202. As shown in FIG. Based on the actual measurement data storage means 204 for storing the actual measurement data of the pollutant concentration in the plurality of actual measurement parts and the actual measurement data on the ground surface part in the actual measurement data, a plurality of points in the horizontal plane in the estimation range including the actual measurement part Two-dimensional estimation means 206 for estimating the pollutant concentration, parameter determination means 208 for determining the advection dispersion parameter based on the actual measurement data below the ground surface in the actual measurement data, the estimated pollutant concentrations at the plurality of points and the determined advection And three-dimensional estimation means 210 for estimating the concentration of pollutants at a plurality of points in the estimation range based on the dispersion parameter. To have.

  Therefore, the soil contamination distribution estimation program of the present invention is a program that causes the computer 202 to function as the actual measurement data storage unit 204, the two-dimensional estimation unit 206, the parameter determination unit 208, and the three-dimensional estimation unit 210.

The two-dimensional estimation means 206 determines a plurality of pollutant concentrations Cb (x, y), the parameter determination means 208 determines optimal advection dispersion parameters tR ^OPT and pe ^OPT , and the three-dimensional estimation means 210 determines Cb. (x, y), based on tR ^OPT and pe ^OPT ,
C (x, y, z) = (1/2) Cb (x, y) erfc [{pe ^OPT / 4tR ^OPT (z)} ^1/2 {1-tR ^OPT (z)}] Determine pollutant concentrations C (x, y, z) at a plurality of points in the estimated range. As is well known, erfc (x) = 1−erf (x) and erf (x) = (2 / π ^1/2 ) ∫ (t = 0 to ∞) {eexp (−t ² )} dt. However, ∫ (t = 0 to ∞) means integration from 0 to ∞.

  The results and information evaluated by the soil contamination distribution estimation system 200 of the present invention are provided to customers such as land owners, real estate companies, real estate appraisers, or financial institutions via network communication. The providing method is not particularly limited, such as a method for posting on a home page or a method for downloading data.

  Here, a description will be given of the results of the study by the present inventor regarding the influence of the mass transfer parameter on the contamination concentration distribution shape in the contamination concentration distribution evaluation in the horizontal direction. When considering the distribution of contamination near the ground surface, the spread of contamination in the horizontal direction is considered to be affected by the molecular diffusion coefficient and the delay coefficient. Then, the influence of the mass transfer parameter on how the pollutants spread was examined using the diffusion equation shown in FIG. Contaminants were continuously injected from a contamination source having a predetermined concentration cp, and the influence of the molecular diffusion coefficient Dm and the delay coefficient R on the temporal change of the concentration distribution and the concentration distribution characteristics were examined.

  As a result, in consideration of the delay coefficient of the pollutant that is a problem in soil contamination, the distance ΔL at which the pollutant diffuses is about 1 m at the longest. High nature. For this reason, it is considered that the advection dispersion characteristics have little influence on the expansion of pollutants in the horizontal direction. Considering the survey interval of 10 mm defined in the Soil Contamination Countermeasures Law, it is difficult to estimate the concentration distribution of pollutants based on the movement characteristics (molecular diffusion phenomenon and adsorption phenomenon) of pollutants from the concentration values detected at each survey point. I found out.

  On the other hand, as a result of the inventor's investigation on estimation of the contamination concentration distribution using statistical analysis, the kriging analysis described later is considered to be a very effective means. In other words, Kriging analysis using established statistical theory is considered to be a very effective means for estimating the contamination concentration distribution on the ground surface that is hardly affected by advection dispersion characteristics.

  Further, the present inventor examined the influence of the mass transfer parameter on the contamination concentration distribution shape in the evaluation of the contamination concentration distribution in the vertical direction. This examination was performed using the advection dispersion equation shown in FIG. 3B for the one-dimensional movement of the contaminant that permeates in the depth direction. As a result, the influence of the osmotic flow velocity and dispersion length (dispersion coefficient) on the contamination concentration distribution characteristics is considered to be large.

  The operation of the soil contamination distribution estimation system 200 will be described below to describe the soil contamination distribution estimation method of the present invention.

  First, actual measurement data is collected at an easily measurable portion in the evaluation target land, and as shown in FIG. 2, the actual measurement data is arranged for each depth, and the actual measurement data is input to the actual measurement data storage means 204. Thereafter, the computer 202 performs the following processing.

  The computer 202 causes the actual measurement data storage unit 204 to function and calculates a representative value (average value, median value, etc.) for each depth. It is desirable to determine the calculation method of the representative value after creating the frequency distribution. The class that is the horizontal axis of the frequency distribution has a great influence on the shape of the frequency distribution, so sufficient attention has been paid to the way of class classification (whether it is organized by constants or logarithmic values) and the hierarchy width. Is set. The actual measurement data in the ground surface portion (Z = 0) stored in the actual measurement data storage means 204 is used to estimate the contamination concentration distribution on the ground surface portion, and the actual measurement data in the lower ground surface (Z <0). The data is used to determine the advection dispersion parameters TR and Pe.

Next, the computer 202 evaluates the spatial structure of the actual measurement data by the two-dimensional estimation means 206. That is, in order to evaluate the spatial structure of the measured data distributed on the ground surface,
2γ (h) = (1 / n) Σ (i = 1 to n) [Z (Xi) −Z (Xj)] ^{2 The} variogram γ (h) is calculated using the equation (Equation 1). The variogram represents the dispersion of the measured data separated by a predetermined distance h, and there is no dispersion when the variogram is zero. That is, it means that the measured data is uniform. In this specification, Σ (i = 1 to n) means adding from i = 1 to i = n. Here, Z (Xi) is various quantities relating to actually measured data, and must have a normal distribution that does not depend on other parameters. According to the results of the sensitivity analysis, it is clear that the contamination concentration distribution on the ground surface is hardly affected by the infiltration characteristics and advection dispersion characteristics of pollutants. It seems to be independent of parameters. In addition, since the logarithmic value of the actually measured data has normal distribution, it is treated here as Z (Xi) = log10C (Xi) (Formula 2). Here, Xi is actually measured data at the survey point i (concentration or adsorption amount, and the unit is not particularly limited, such as mg / kg, mg / m ^3, etc.). The calculated variogram γ (h) is fitted to a spherical model or an exponential model, and the variogram is functionalized.

Next, the computer 202 causes the two-dimensional estimation means 206 to function to estimate the contamination concentration on the ground surface. That is, the contamination concentration cb (x, y) at an arbitrary ground surface position (x, y) is determined using the calculated variogram. Kriging analysis is performed using various quantities Z (Xi) obtained by logarithmically converting measured data, and various quantities Z (x, y) at the ground surface position (x, y) are estimated. Z (x, y) = Σ (i = 1 to n) λiZ (Xi) (formula 3) is a linear combination of the measured data Z (Xi) at the survey point. It can be calculated by the following formula. The weight λi is −Σ (i = 1 to n) λiγ (|| Xi-Xj ||) + μ = −γ (|| Xi-X (x, y) ||), i = 1, 2, 3 · .., N, [Sigma] (j = 1 to n) [lambda] j = 1 (equation 4) is calculated by solving the simultaneous linear equations. μ represents a Lagrangian constant, and X (x, y) represents a position vector (coordinate value) at an arbitrary position (x, y). By calculating the weight λi, the contamination concentration Cb (x, y) at an arbitrary position (x, y) is calculated from the above equations 2 and 3. If the measured data C (Xi) in Equation 2 is the liquid layer concentration, Cb (x, y) = 10exp [Σ (i = 1 to n) λiZ (Xi)], and the measured data C (Xi) is adsorbed. If it is a quantity, it is (1 / Kd) 10exp [Σ (i = 1 to n) λiZ (Xi)]. Here, Kd is a distribution coefficient [L ³ / M].

In addition, the computer 202 causes the parameter determination unit 208 to function to determine the advection dispersion parameter. That is, the advection dispersion parameters tR and pe representing the site are determined using the measured data under the ground surface (z <0) stored in the measured data storage unit 204. For the fitting data, use the representative value of the measured data at each depth,
C (tR, pe) = (1/2) Cberfc [(pe / 4tR) ^1/2 (1-tR)] (Formula 5) Here, tR and pe are parameters depending on the depth z, tR = (vt / R) (1 / z), and pe = (v / RD) · z. The optimum parameters tR ^OPT and pe ^OPT that minimize the error between the above equation 5 and the representative value of the measured data are identified. If the identified tR ^OPT and pe ^OPT are considered as advection dispersion parameters representing the site, the contamination concentration distribution in the deep part from the contamination concentration Cb in the ground surface part is expressed as C (z) = (1/2) Cberfc [{pe ^OPT / 4tR ^OPT (z)} ^1/2 {1-tR ^OPT (z)}] (Equation 6) is calculated and estimated.

Next, the computer 202 causes the three-dimensional estimation unit 210 to function to calculate a three-dimensional contamination concentration distribution. In order to determine the contamination concentration distribution in the depth direction from the above equation 6, it is sufficient that the contamination concentration Cb at the ground surface is known. Concentration distribution on the ground surface is calculated from Kriging analysis by Cb (x, y) = 10exp [Σ (i = 1 ~ n) λiZ (Xi)] and (1 / Kd) 10exp [Σ (i = 1 ~ n) λiZ (Xi)] can be estimated. Therefore, C (x, y, z) = (1/2) Cb (x, y) where the contamination concentration at an arbitrary ground surface position (x, y) estimated from kriging analysis is set as Cb (x, y). y) erfc [{pe ^OPT / 4tR ^OPT (z)} ^1/2 {1-tR ^OPT (z)}] is used to calculate the three-dimensional concentration distribution.

  Further, the computer 202 calculates the amount of excavated soil based on the estimated three-dimensional concentration distribution. When the microelements in the target site are taken out, the contamination concentration C in the microelements is Min (i = 1-8) {Ci} or more and Max (i = 1-8) {Ci} or less. Here, Ci represents the contamination concentration at each vertex of the microelement. Therefore, when the microelement is equal to or lower than the reference concentration Ctarget, Max (i = 1 to 8) {Ci} is equal to or lower than Ctarget. Conversely, when Max (i = 1 to 8) {Ci} exceeds Ctarget, the target microelement exceeds the reference concentration Ctarget, and is treated as the amount of excavated soil. That is, the target site is divided into minute elements, and the amount of contaminated soil contained in the target site (the amount of soil to be excavated) is calculated by performing such discrimination for each minute element.

  Further, the computer 202 calculates the purification cost using the estimated three-dimensional concentration distribution and the amount of contaminated soil. The estimation result and calculation result by the computer 202 are transmitted from the survey terminal 204 to the server. The transmitted estimation result and calculation result are posted on the homepage. Alternatively, it can be downloaded from the customer. In addition, you may transmit directly to the customer from the survey terminal 204.

As described above, the advection dispersion parameters (osmotic flow velocity, dispersion coefficient, delay coefficient, and elapsed time) are summarized with the two parameters of the optimum advection dispersion parameters tR and pe, and fitted to the measured data for each depth, These two parameters can be determined. By reducing the number of parameters from 4 to 2, it is possible to grasp the contamination concentration distribution characteristics in the depth direction reasonably and quantitatively. Moreover, the contamination concentration distribution in the depth direction can be calculated by reflecting tR ^OPT and pe ^OPT obtained from the fitting to the actual measurement data in the theoretical opening of the advection dispersion equation.

  In addition, it is possible to estimate the three-dimensional contamination concentration distribution by determining the contamination concentration at the ground surface by kriging analysis and calculating the contamination concentration distribution in the deep portion from the theoretical solution of the advection dispersion equation. In addition, by developing a method for estimating the three-dimensional concentration distribution, it is possible to quantitatively evaluate the amount of contaminated soil to be excavated in the site.

  Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment. In addition, the present invention can be implemented in a mode in which various improvements, modifications, and changes are made based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

  According to the soil contamination distribution estimation system, the soil contamination distribution estimation method, and the soil contamination distribution estimation program of the present invention, a continuous and contaminated soil distribution is scientifically and reasonably estimated from a small number of discrete measured data, Calculation of remediation costs and appraisal of land can be performed quickly and appropriately, and disclosed and communicated to customers via network communication. For this reason, it can be used universally for soil contamination investigations.

It is a connection diagram which shows the structure of the soil contamination distribution estimation system of this invention. It is a flowchart figure of the soil contamination distribution estimation system of FIG. It is a figure which shows the importance of an advection dispersion | distribution parameter in the soil contamination distribution estimation system of FIG.

Explanation of symbols

200 soil contamination distribution estimation system 202 computer 204 measured data storage means 206 two-dimensional estimation means 208 parameter determination means 210 three-dimensional estimation means

Claims (5)

A soil contamination distribution estimation system that estimates the contamination concentration of land using a computer,
Actual measurement data storage means for storing actual measurement data of pollutant concentrations in a plurality of actual measurement units in the evaluation target land,
Two-dimensional estimation means for estimating pollutant concentrations at a plurality of points in a horizontal plane in the estimation range including the actual measurement part based on the actual measurement data of the ground surface part in the actual measurement data;
Parameter determining means for determining advection dispersion parameters based on the measured data of the lower surface of the ground in the measured data;
Three-dimensional estimation means for estimating a plurality of contaminant concentrations at a plurality of points in the estimation range based on the estimated plurality of contaminant concentrations and the determined advection dispersion parameter;
Soil pollution distribution estimation system equipped with. The two-dimensional estimation means determines a plurality of pollutant concentrations Cb (x, y),
The parameter determining means determines optimal advection dispersion parameters tR ^OPT and pe ^OPT ;
The three-dimensional estimation means is based on the Cb (x, y), tR ^OPT and pe ^OPT ,
C (x, y, z) = (1/2) Cb (x, y) erfc [{pe ^OPT / 4tR ^OPT (z)} ^1/2 {1-tR ^OPT (z)}]
The soil pollution distribution estimation system according to claim 1, wherein the pollutant concentration C (x, y, z) at a plurality of points in the estimation range is determined. The soil contamination distribution estimation system according to claim 1 or 2, wherein the estimation of the pollutant concentration by the two-dimensional estimation unit and the determination of the advection dispersion parameter by the parameter determination unit are performed simultaneously. A soil contamination distribution estimation method that estimates the contamination concentration of land using a computer,
A step of storing actual measurement data of pollutant concentration in a plurality of actual measurement units in the evaluation target land, the actual measurement data storage means in the computer;
Two-dimensional estimation means in the computer, based on actual measurement data of the ground surface portion in the actual measurement data, to estimate the pollutant concentration at a plurality of points in the horizontal plane in the estimation range including the actual measurement unit;
Parameter deciding means in the computer determines an advection dispersion parameter based on the measured data of the lower surface of the ground in the measured data;
A three-dimensional estimation means in the computer for estimating a plurality of pollutant concentrations in the estimation range based on the estimated pollutant concentrations at the plurality of points and the determined advection dispersion parameter;
Soil contamination distribution estimation method. A soil contamination distribution estimation program that estimates the contamination concentration of land using a computer.
Actual measurement data storage means for storing actual measurement data of pollutant concentrations in a plurality of actual measurement units in the evaluation target land,
Two-dimensional estimation means for estimating the concentration of pollutants at a plurality of points in a horizontal plane in the estimation range including the actual measurement part based on the actual measurement data of the ground surface part in the actual measurement data;
Parameter determining means for determining advection dispersion parameters based on the measured data of the lower surface of the ground in the measured data,
Three-dimensional estimation means for estimating a plurality of pollutant concentrations in the estimation range based on the estimated pollutant concentrations at the plurality of points and the determined advection dispersion parameter;
Soil contamination distribution estimation program to function as.

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