81011519

open access

Version of Record

地下水揚水による汚染物質回収範囲と回収所要時間の確率的評価

Stochastic approach for estimating time-related capture zones of solute and travel time distributions in pumping wells

Japanese (日本語)

神戸大学都市安全研究センター研究報告

20

173-186

神戸大学都市安全研究センター

2016-03

2019-05-30

The objectives of this study were to demonstrate two stochastic methodologies using backward particle tracking and random walk particle tracking to estimate time-related groundwater capture zones and time-related solute capture zones, respectively, in pumping wells and to apply these methodologies to a contaminated site by tetrachloroethylene (PCE) in Hyogo Prefecture, Japan. As for backward particle tracking, lattice cells with a certain length were introduced to assign binary values corresponding to particle pathlines within a certain travel time. Also, for the purpose of time-related solute capture zone estimation, ensemble of the particle evolutions toward pumping wells from a cell was conducted as the ensemble travel-times and was presented another aspect relevant to spatial distributions of travel-times of cells. Based on the particle travel histories in geostatistically generated hydraulic conductivity fields, ensemble of the lattice cell values provided the probability distributions of time-related capture zones in terms of groundwater flow and solute transport. These methodologies were investigated for a two-dimensional geometry with single and multiple wells in heterogeneous aquifers under steady state flow conditions. The probability of each lattice cell was applied to the calculation of a quantitative measure expressing the uncertainty relevant to the probability distributions of the groundwater and solute capture zones, demonstrating the effect of the heterogeneity on the uncertainty of time-related capture zones. In addtion, these methodologies provided some proper outcomes corresponding to the pumping rates and pumping locations. Furthermore, entropy was introduce d to evaluate the uncertainty of time-related capture zones and exhibited an increase tendency with the increase of magnitude of capture zones.

揚水井

紀要論文