100年度地下水水質檢測分析與評估

Author

財團法人農業工程研究中心

Language

English

Publisher

Water Resources Agency, Ministry of Economic Affairs

Pages

700

Publication Date

2011/12

Binding

ISBN/Barcode

9789860307573

Collection

Product Dimensions

Book Description

To comprehend the groundwater quality of Taiwan and provide valuable information for development, protection, and research of groundwater resources, the groundwater samples of 380 monitoring wells in Taiwan are collected and analyzed. The major achiecements of this project including:
1. Over-pumping of groundwater in coastal area of southwestern Taiwan may cause the seawater intrusion, accompanying with high EC values in most wells.
2. The characteristics of groundwater in mountain area were O2-riched and oxidation, whereas those in downstream area were anaerobic and reductive conditions.
3. Major characteristics of groundwater in Taiwan includes degradation of organic C/formation of inorganic C, nitrate/nitrite redox cycling, reductive dissolution of As, Fe, and Mn, and generation of sulfides.
4. The dissolution of metals from deposits and borehole materials may result the groundwater contamination of Cu, Pb, Zn, Cr, Ni,Cd in some wells.
5. Extensive use fertilization of agriculture may lead to critical nitrate pollution of groundwater, especially in the uppermost aquifer. The nitrate concentrations in wet season are higher than those in dry season, which is caused by the hydrogeological characteristics and groundwater flow direction.
6. Critical salinalization of groundwater was found in Chianan plains, causing by modern seawater intrusion and sulfate reduction. The saline groundwater are also found in part of groundwater of Choushui river alluvial fan and Pindong plain.
7. The reductive condition has caused the elevated nitrite, Fe, and Mn concentrations in most groundwater samples. The adsorbed As may be liberated during the reductive dissolution of Fe/Mn minerals, especially in coastal areas of Yunlin, Pindong and Lanyan plains, and Chianan plain.
8. The urgent wells for drought period or wartime of Taipei basin, Taichung area, Chianan plain, Pindong plain are located in mountain area, whereas those of Choushui river alluvial fan and Lanyan plains are located in shallow groundwater aquifer.
The further investigations of the havey metals pollution, seawater intrusion, nitrate pollution are needed to achieve the goal of the sustainable operation of monitoring wells.