Fluctuation of NO3-N in groundwater of the reservoir of the Sunagawa Subsurface Dam, Miyako Island, Japan

Ishida, Satoshi; Tsuchihara, Takeo; Imaizumi, Mitsuru

doi:10.1007/s10333-006-0037-7

Cited by 24 publications

(20 citation statements)

References 14 publications

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“…Good hydraulic connectivity and rapid groundwater movement caused by pumping facilitated nitrate transportation and equalized its distribution in the reservoir. A similar observation was documented in the study of the nitrate contamination of the Sunagawa artificial underground reservoir by Ishida, S. et al [36,37]. Due to pumping a large amount of groundwater for irrigation, an extensive uniform area of NO3−-N concentration in the Sunagawa artificial underground reservoir was developed.…”

Section: Resultssupporting

confidence: 77%

“…Long-term monitoring of the nitrate concentration in the artificial underground reservoir of the Sunagawa subsurface dam before and after the dam’s construction indicated that the subsurface dam and pumping stored water greatly affected groundwater flow and water mixing in the reservoir area. The NO3−-N concentration decreased gradually and harmonized with the decrease in cultivation acreage [36,37]. Yoshimoto, S. et al [38] proposed a numerical model consisting of a water balance sub-model and nitrogen balance sub-model to predict the long-term changes of groundwater nitrate in the reservoir area of the Komesu subsurface dam.…”

Section: Introductionmentioning

confidence: 99%

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Impacts of Artificial Underground Reservoir on Groundwater Environment in the Reservoir and Downstream Area

Sun

Kang

et al. 2019

IJERPH

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Artificial underground reservoirs have changed the hydrological cycle from its natural condition. This modification may trigger a series of negative environmental effects both at the local and regional levels. This study investigated the impact of the Wanghe artificial underground reservoir on groundwater flow and quality in the reservoir and its downstream area. Wanghe is a typical artificial underground reservoir scheme in China, which assumes the dual function of fresh-water preservation and control of seawater intrusion. The groundwater flow pattern has changed after the reservoir construction, and the water level in the reservoir rose rapidly. Evaluation of long-term groundwater level fluctuation suggested that the reservoir deprived the downstream aquifer of the runoff, which it received under the natural flow regime. A preliminary isotopic evaluation using 3H was developed to understand the groundwater flow and renewal rates in the study area. The uniform distribution of tritium levels in the reservoir indicated that the stored water was well-mixed in both horizontal and vertical directions. The intervention on groundwater circulation also made differences in groundwater renewal rates between stored and downstream water. Field investigations on groundwater nitrogen pollution showed that the construction of the artificial underground reservoir resulted in nitrate accumulation in the stored water. Agriculturally derived nitrate was the largest contributor, and NO 3 − concentration varied considerably over time due to fertilization and irrigation activities, rainfall, and denitrification. NO 3 − -N distributed homogeneously in the reservoir, which was attributed to the construction of the subsurface dam, land use pattern and artificial groundwater flow.

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Section: Resultssupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Impacts of Artificial Underground Reservoir on Groundwater Environment in the Reservoir and Downstream Area

Sun

Kang

et al. 2019

IJERPH

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“…In this study, first, the authors propose a remote online detection method to measure ground water quality parameters that are composed of chemical oxygen demand (COD) [20], total organic carbon (TOC) [21], nitrate nitrogen (NO 3 –N) [22], and turbidity (TURB) [23,24]. Section 2 describes the principle of UV spectrophotometry and the data processing methods in detail.…”

Section: Introductionmentioning

confidence: 99%

Study on an Online Detection Method for Ground Water Quality and Instrument Design

Tong

Wang

et al. 2019

Sensors

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The online measurement of ground water quality, as one important area of water resource protection, can provide real-time measured water quality parameters and send out warning information in a timely manner when the water resource is polluted. Based on ultraviolet (UV) spectrophotometry, a remote online measurement method is proposed and used to measure the ground water quality parameters chemical oxygen demand (COD), total organic carbon (TOC), nitrate nitrogen (NO3–N), and turbidity (TURB). The principle of UV spectrophotometry and the data processing method are discussed in detail, the correlated mathematical modeling of COD and TOC is given, and a confirmatory experiment is carried out. Turbidity-compensated mathematical modeling is proposed to improve the COD measurement accuracy and a confirmatory experiment is finished with turbidity that ranges from 0 to 100 NTU (Nephelometric Turbidity Unit). The development of a measurement instrument to detect the ground water COD, TOC, NO3–N, and TURB is accomplished; the test experiments are completed according to the standard specification of China’s technical requirement for water quality online automatic monitoring of UV, and the absolute measuring errors of COD, TOC, and NO3–N are smaller than 5.0%, while that of TURB is smaller than 5.4%, which meets the requirements for the online measurement of ground water quality.

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“…For example, numerous studies have reported extensive nitrate groundwater contamination in the Ryukyu limestone aquifer in the southern part of Okinawa Island, and most of these studies have concluded that chemical fertilizer is the major source of this nitrogen (e.g., Agata, Satake, & Tokuyama, 2001;Nakano, Yasumoto, Terasawa, & Nawa, 2013;Tokuyama, Yonaha, & Ohde, 1990;Yoshimoto, Tsuchihara, Ishida, & Imaizumi, 2007). In the unsaturated zone of the Ryukyu limestone aquifer on Miyako-jima Island in Okinawa Prefecture, the lag time for groundwater recharge from the ground surface (10 m) with fertilizer-derived nitrogen was estimated to be 7 years (Ishida, Tsuchihara, & Imaizumi, 2006;Tashiro & Takahira, 2001).…”

Section: Introductionmentioning

confidence: 99%

Hydrochemical behaviour of an underground dammed limestone aquifer in the subtropics

Nakaya

Yasumoto

et al. 2018

Hydrological Processes

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In an island area with limited surface water resources, the conservation of fresh groundwater resources is important for the maintenance of the water supply and irrigation system to be used in agricultural activity. In a limestone aquifer used for irrigation on a subtropical island, the progress of the dissolution behaviour of the aquifer and the effects of CO2 storage and chemical weathering of the aquifer must be understood to ensure sustainable groundwater use. In this study, hydrochemical behaviour of the Ryukyu limestone aquifer was investigated using the residence time of slowly flowing groundwater, which is contained by a 2.3‐km‐long underground man‐made dam constructed in 2005 located at the southern edge of Okinawa Island, Japan. Groundwater dating and horizontal flow velocity measurements indicate that the groundwater horizontal flow is slow in the underground dam area, whereas the saturation index (SI) for calcite indicates that the majority of the limestone exists in a supersaturated condition. The range of SI for gypsum was indicative of subsaturation, and the SI increased with the groundwater residence time, suggesting that the dissolution of CaSO4 tends to proceed slowly through the common ion effect. The dissolution of CaCO3, however, tends to be in suspension within about a residence time of 20 years. The apparent dissolution rate of Ca in the Ryukyu limestone aquifer in this area was estimated to be approximately 2.70–4.06 nmol cm−2 year−1, a value much lower than that of the early stages of the limestone dissolution. The estimated groundwater CO2 (gas) concentrations are two order high (about 0.3–7%) relative to atmospheric CO2 (about 0.04%), and the groundwater pH shows a tendency to decrease from 7.4 to 6.9 over the last approximately 20 years, indicating that the hydration reaction of CO2 occurs in the Ryukyu limestone aquifer. These findings imply that high CO2 produced in the subtropical zone is consumed slower than CO2 production during limestone dissolution, with the exclusion of the early stage of the chemical weathering process, and causes groundwater acidification in the underground dammed limestone aquifer.

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Fluctuation of NO3-N in groundwater of the reservoir of the Sunagawa Subsurface Dam, Miyako Island, Japan

Cited by 24 publications

References 14 publications

Impacts of Artificial Underground Reservoir on Groundwater Environment in the Reservoir and Downstream Area

Impacts of Artificial Underground Reservoir on Groundwater Environment in the Reservoir and Downstream Area

Study on an Online Detection Method for Ground Water Quality and Instrument Design

Hydrochemical behaviour of an underground dammed limestone aquifer in the subtropics

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