摘要: | 摘 要 翡翠及石門水庫為大台北都會區及台灣北部最重要的水資源,然而目前在有關水庫水質優養化及水質污染之評價上,仍然缺乏一個可靠的綜合評判指標;本文之目的,即為制定一套新的水庫優養化程度及水質污染之綜合評價方法。過程針對翡翠及石門水庫為研究案例,以灰關聯分析方法,進行水庫優養化程度及水質污染之綜合評價。 在水庫優養化程度部份,利用灰關聯分析方法,並藉由層級分析法(AHP)算出各個因子之權重,來進行多指標的綜合評判。分析結果指出:1)簡單、明確的多指標水庫水質優養化之等級和評估模式可依灰關聯分析建立。2)灰關聯分析在等級分類上採用層級分析法(AHP)的權重,較能合理反應出事實來進行水庫水質優養化的分級,據以評估比較優養化情況。3)翡翠及石門水庫經後颱風侵襲後,水庫水質優養化程度大多呈普至優養狀況,但在歷經旱災時,水庫水質優養化程度並無明顯的惡化現象。4)從歷年來看,除了1992、1996、1998、1999、2000年的AGRA值,等級為水質差的優養外,翡翠水庫水質大部份為貧至普養;從歷月來看,除了6、7及10、11、12月份的AGRA值,等級為水質欠佳的優養外,翡翠水庫水質大部份為貧至普養。 在水庫水質污染程度部份,利用灰關聯分析方法結合NCKU WQI8方法算水質因子權重,以進行水質污染綜合評判。分析結果指出:1)翡翠及石門水庫在歷經旱災時,水庫水質呈現明顯的惡化現象。2)灰關聯分析在水庫水質污染綜合評估時,其因子的權重採用NCKU WQI8方法,較能合理反應出水庫水質污染的程度。3)從歷年水質情況來看,翡翠水庫的水質有逐年惡化的趨勢;而石門水庫水質似有逐年好轉的趨勢。 Grey Relational Analysis for the Synthetic Evaluation of Reservoir Water Quality : Case Studies of Feitsui and Shihmen Reservoir Shao-Wei Chiu ABSTRACT Feitsui and Shihmen Reservoir are the most important water resource for the metropolitan Taipei city as well as northern Taiwan. Although water quality assessment is such an critical issue, a reliable synthetic evaluation index concerning eutrophic reservoir and water pollution are still lacking at present. The purpose of this study is to establish a new evaluation method for the eutrophic and water pollution conditions of reservoir. Grey relational analysis was processed by using Feitsui and Shihmen Reservoir as case studies, so as to perform a multi-indices synthetic evaluation. For the eutrophic condition of reservoir, Grey relational analysis and Analytic Hierarchy Process (AHP) were employed to calculate the weighting of each parameter(Chl-a, SD and TP), so as to perform a synthetic evaluation with multi-indices. The analytic results indicate that 1) a simple, clear classification and evaluation model for the eutrophic reservoir can be successfully established. 2) Grey relational analysis with Analytic Hierarchy Process (AHP) of weighting in classification exhibits a reasonable and appropriate classification. Furthermore, the eutrophic condition of reservoir can thus be evaluated in a quantitative way. 3) The water quality of both Feitsui Reservoir and Shihmen Reservoir were turning mostly to mesotrophic or eutrophic after typhoon; On the other hand, their eutrophic condition did not exhibit any significant variation in the drought season of 2002. 4) Among the monthly and annual data evaluated, most of the water quality of Feitsui Reservoir were concluded as oligo- to mesotrophic, except for the months of June, July, October, November and December; in addition to the years of 1992, 1996, 1998, 1999 and 2000, which were classified as eutrophic in AGRA value. This conclusion is furthered confirmed by field observaton. As for the water pollution of reservoir, Grey relational analysis and NCKU WQI8 method were further combined to perform a synthetic evaluation with multi-indices. The analytic results indicate that 1)The water quality of both Feitsui Reservoir and Shihmen Reservoir turned to worse in the drought season of 2002. 2) Grey relational analysis basing on NCKU WQI8 of weighting in classification exhibits a reasonable and appropriate evaluation for water pollution. Again, the water pollution condition of reservoir can thus be evaluated in a quantitative way. 3) Among the annual data evaluated, the water quality of Feitsui Reservoir is getting worse and Shihmen Reservoir is getting better in recent years. This conclusion needs to be further confirmed by future studies. |