Limits...
Applying factor analysis combined with kriging and information entropy theory for mapping and evaluating the stability of groundwater quality variation in Taiwan.

Shyu GS, Cheng BY, Chiang CT, Yao PH, Chang TK - Int J Environ Res Public Health (2011)

Bottom Line: Groundwater quality demonstrated apparent differences between the northern and southern areas of Taiwan when divided by the Wu River.Approximately 52% of the monitoring wells in southern Taiwan suffered from progressing seawater intrusion, causing unstable groundwater quality.The method proposed in this study for analyzing groundwater quality inspects common stability factors, identifies potential areas influenced by common factors, and assists in elevating and reinforcing information in support of an overall groundwater management strategy.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Management, Tungnan University, Taipei County 222, Taiwan. gsshyu@mail.tnu.edu.tw

ABSTRACT
In Taiwan many factors, whether geological parent materials, human activities, and climate change, can affect the groundwater quality and its stability. This work combines factor analysis and kriging with information entropy theory to interpret the stability of groundwater quality variation in Taiwan between 2005 and 2007. Groundwater quality demonstrated apparent differences between the northern and southern areas of Taiwan when divided by the Wu River. Approximately 52% of the monitoring wells in southern Taiwan suffered from progressing seawater intrusion, causing unstable groundwater quality. Industrial and livestock wastewaters also polluted 59.6% of the monitoring wells, resulting in elevated EC and TOC concentrations in the groundwater. In northern Taiwan, domestic wastewaters polluted city groundwater, resulting in higher NH(3)-N concentration and groundwater quality instability was apparent among 10.3% of the monitoring wells. The method proposed in this study for analyzing groundwater quality inspects common stability factors, identifies potential areas influenced by common factors, and assists in elevating and reinforcing information in support of an overall groundwater management strategy.

Show MeSH
Overlay map of factor scores and information entropy values: (a) South, North-F1; (b) South-F2, North-F4; (c) South, North-F3; (d) South-F4, North-F2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC3118879&req=5

f4-ijerph-08-01084: Overlay map of factor scores and information entropy values: (a) South, North-F1; (b) South-F2, North-F4; (c) South, North-F3; (d) South-F4, North-F2.

Mentions: Figure 4(a) shows the overlaying map of the distribution of Factor 1 scores and the ranks of information entropy values for the northern and the southern areas. For the northern area, the ranks of information entropy values for only five of the monitoring wells vary noticeably. Unstable monitoring wells occupy 2.9% (5/175) of the total number of monitoring wells, located in Taipei City, Miaoli County, and Yilan County. The regions with high scores of Factor 1 conformed to the locations of these five unstable monitoring wells. In the southern area, the ranks of information entropy values showed that 103 monitoring wells had noticeable variation with 52.0% (103/198) of the monitoring wells being unstable. The overlay map reveals that the regions with high Factor 1 scores corresponded with monitoring well locations having the upper rankings of information entropy values. A higher concentration of the groundwater quality parameter contained in Factor 1 less stability. This is common to both the southern and the northern areas, but the problem is more serious in the southwestern coast of Taiwan because Factor 1 represents the extent of groundwater salinization. Thus, the information is useful to obtain the spatial distribution of groundwater salinization. Figure 4(a) reveals that the monitoring wells that have unstable groundwater quality located in potential areas of groundwater salinization are polluted.


Applying factor analysis combined with kriging and information entropy theory for mapping and evaluating the stability of groundwater quality variation in Taiwan.

Shyu GS, Cheng BY, Chiang CT, Yao PH, Chang TK - Int J Environ Res Public Health (2011)

Overlay map of factor scores and information entropy values: (a) South, North-F1; (b) South-F2, North-F4; (c) South, North-F3; (d) South-F4, North-F2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3118879&req=5

f4-ijerph-08-01084: Overlay map of factor scores and information entropy values: (a) South, North-F1; (b) South-F2, North-F4; (c) South, North-F3; (d) South-F4, North-F2.
Mentions: Figure 4(a) shows the overlaying map of the distribution of Factor 1 scores and the ranks of information entropy values for the northern and the southern areas. For the northern area, the ranks of information entropy values for only five of the monitoring wells vary noticeably. Unstable monitoring wells occupy 2.9% (5/175) of the total number of monitoring wells, located in Taipei City, Miaoli County, and Yilan County. The regions with high scores of Factor 1 conformed to the locations of these five unstable monitoring wells. In the southern area, the ranks of information entropy values showed that 103 monitoring wells had noticeable variation with 52.0% (103/198) of the monitoring wells being unstable. The overlay map reveals that the regions with high Factor 1 scores corresponded with monitoring well locations having the upper rankings of information entropy values. A higher concentration of the groundwater quality parameter contained in Factor 1 less stability. This is common to both the southern and the northern areas, but the problem is more serious in the southwestern coast of Taiwan because Factor 1 represents the extent of groundwater salinization. Thus, the information is useful to obtain the spatial distribution of groundwater salinization. Figure 4(a) reveals that the monitoring wells that have unstable groundwater quality located in potential areas of groundwater salinization are polluted.

Bottom Line: Groundwater quality demonstrated apparent differences between the northern and southern areas of Taiwan when divided by the Wu River.Approximately 52% of the monitoring wells in southern Taiwan suffered from progressing seawater intrusion, causing unstable groundwater quality.The method proposed in this study for analyzing groundwater quality inspects common stability factors, identifies potential areas influenced by common factors, and assists in elevating and reinforcing information in support of an overall groundwater management strategy.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Management, Tungnan University, Taipei County 222, Taiwan. gsshyu@mail.tnu.edu.tw

ABSTRACT
In Taiwan many factors, whether geological parent materials, human activities, and climate change, can affect the groundwater quality and its stability. This work combines factor analysis and kriging with information entropy theory to interpret the stability of groundwater quality variation in Taiwan between 2005 and 2007. Groundwater quality demonstrated apparent differences between the northern and southern areas of Taiwan when divided by the Wu River. Approximately 52% of the monitoring wells in southern Taiwan suffered from progressing seawater intrusion, causing unstable groundwater quality. Industrial and livestock wastewaters also polluted 59.6% of the monitoring wells, resulting in elevated EC and TOC concentrations in the groundwater. In northern Taiwan, domestic wastewaters polluted city groundwater, resulting in higher NH(3)-N concentration and groundwater quality instability was apparent among 10.3% of the monitoring wells. The method proposed in this study for analyzing groundwater quality inspects common stability factors, identifies potential areas influenced by common factors, and assists in elevating and reinforcing information in support of an overall groundwater management strategy.

Show MeSH