Groundwater Quality and Potential Pollution in the Southern Shimabara Peninsula, Japan
Nakagawa, Kei LU
; Amano, Hiroki
LU
; Yu, Zhi Qiang
and Berndtsson, Ronny
LU
(2022)
In Water (Switzerland)
14(24).
- Abstract
Nitrate pollution in groundwater is a severe problem in Shimabara Peninsula, Nagasaki Prefecture, Japan. Previous studies have investigated water quality characteristics in the northern part of the peninsula and shown serious effects of nitrate pollution in the groundwater. The present study aimed to investigate the groundwater quality in the southern areas of the peninsula for improved understanding of the water quality status for the entire peninsula. Groundwater samples were collected at 56 locations in Minami-Shimabara City from 28 July to 4 August 2021. The spatial distribution of water quality constituents was assessed by Piper-trilinear and Stiff diagrams for major ion concentrations. One agricultural area in the western parts... (More)
Nitrate pollution in groundwater is a severe problem in Shimabara Peninsula, Nagasaki Prefecture, Japan. Previous studies have investigated water quality characteristics in the northern part of the peninsula and shown serious effects of nitrate pollution in the groundwater. The present study aimed to investigate the groundwater quality in the southern areas of the peninsula for improved understanding of the water quality status for the entire peninsula. Groundwater samples were collected at 56 locations in Minami-Shimabara City from 28 July to 4 August 2021. The spatial distribution of water quality constituents was assessed by Piper-trilinear and Stiff diagrams for major ion concentrations. One agricultural area in the western parts exceeded Japanese recommended standards for water. According to the Piper-trilinear diagram, 44 sampling sites (78.6%) were classified as alkaline earth carbonate type, nine sites (16.1%) as alkaline earth non-carbonate type, and three sites (5.3%) as alkaline carbonate type. Stiff diagrams displayed Ca-HCO3 water type for most of the sites. Na-HCO3 and Mg-HCO3 types were found in coastal areas. Principal component analyses showed that the first component corresponded to dissolved constituents in groundwater and denitrification, the second effects of ion exchange and low nitrate pollution, and the third effects of severe nitrate pollution. Hierarchical cluster analysis was used to classify the groundwater into five groups. The first group included sites with relatively high nitrate concentration. The second group had relatively low ion concentration, distributed from center to eastern parts. The third group included intermediate ion concentration, distributed at lower altitudes along the coastal line. The fourth and fifth groups had a higher ion concentration, especially characterized by high sodium and bicarbonate concentration.
(Less)
- author
- Nakagawa, Kei
LU
; Amano, Hiroki
LU
; Yu, Zhi Qiang
and Berndtsson, Ronny
LU
- organization
- publishing date
- 2022-12
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- groundwater, hierarchical cluster analysis, principal component analysis
- in
- Water (Switzerland)
- volume
- 14
- issue
- 24
- article number
- 4106
- publisher
- MDPI AG
- external identifiers
-
- scopus:85144605097
- ISSN
- 2073-4441
- DOI
- 10.3390/w14244106
- language
- English
- LU publication?
- yes
- id
- 2b915b88-4e0f-41c4-ba42-8732063654ee
- date added to LUP
- 2023-01-09 10:40:17
- date last changed
- 2023-10-09 03:09:50
@article{2b915b88-4e0f-41c4-ba42-8732063654ee,
abstract = {{<p>Nitrate pollution in groundwater is a severe problem in Shimabara Peninsula, Nagasaki Prefecture, Japan. Previous studies have investigated water quality characteristics in the northern part of the peninsula and shown serious effects of nitrate pollution in the groundwater. The present study aimed to investigate the groundwater quality in the southern areas of the peninsula for improved understanding of the water quality status for the entire peninsula. Groundwater samples were collected at 56 locations in Minami-Shimabara City from 28 July to 4 August 2021. The spatial distribution of water quality constituents was assessed by Piper-trilinear and Stiff diagrams for major ion concentrations. One agricultural area in the western parts exceeded Japanese recommended standards for water. According to the Piper-trilinear diagram, 44 sampling sites (78.6%) were classified as alkaline earth carbonate type, nine sites (16.1%) as alkaline earth non-carbonate type, and three sites (5.3%) as alkaline carbonate type. Stiff diagrams displayed Ca-HCO<sub>3</sub> water type for most of the sites. Na-HCO<sub>3</sub> and Mg-HCO<sub>3</sub> types were found in coastal areas. Principal component analyses showed that the first component corresponded to dissolved constituents in groundwater and denitrification, the second effects of ion exchange and low nitrate pollution, and the third effects of severe nitrate pollution. Hierarchical cluster analysis was used to classify the groundwater into five groups. The first group included sites with relatively high nitrate concentration. The second group had relatively low ion concentration, distributed from center to eastern parts. The third group included intermediate ion concentration, distributed at lower altitudes along the coastal line. The fourth and fifth groups had a higher ion concentration, especially characterized by high sodium and bicarbonate concentration.</p>}},
author = {{Nakagawa, Kei and Amano, Hiroki and Yu, Zhi Qiang and Berndtsson, Ronny}},
issn = {{2073-4441}},
keywords = {{groundwater; hierarchical cluster analysis; principal component analysis}},
language = {{eng}},
number = {{24}},
publisher = {{MDPI AG}},
series = {{Water (Switzerland)}},
title = {{Groundwater Quality and Potential Pollution in the Southern Shimabara Peninsula, Japan}},
url = {{http://dx.doi.org/10.3390/w14244106}},
doi = {{10.3390/w14244106}},
volume = {{14}},
year = {{2022}},
}