1:45 PM - 3:15 PM
[O06-P14] Groudwater level measurement and groundwater quality investigation using a borehole
Keywords:Izu peninsula, ground water, water level
An all-core borehole survey was conducted last year to investigate the impact of volcanic mudflow deposits from the Kawagodaira volcano on the Tagata Plain, where our high school located. We used this borehole as a well to investigate whether the groundwater level and by investigated ground water quality.
We measured the groundwater level using a water level gauge and examined the relationship between the water level and precipitation. We found that precipitation causes groundwater levels to rise. We also found that the water level has been decreasing significantly since October, which is thought to be due to the drainage of water from the paddy fields.
We sampled water in the borehole and tested the water quality for pH, conductivity, COD, nitrite nitrogen, nitrate nitrogen, ammonia nitrogen, and nitrate-form nitrogen, and phosphate phosphorus. Ammonia-based fertilizers were administered to the flower beds above the study borehole in August. The values of ammonium-form nitrogen, nitrite-form nitrogen, and nitrate-form nitrogen increased in turn in September. Thus, we can see the activation of nitrate bacteria in the soil. The pH dropped below 6.80 after more than 5mm of rain fell on the previous day, suggesting that the soil was affected by the weakly acidic rainwater. Conductivity increases with the sum of the values of phosphoric acid, ammonium nitrogen, nitrite nitrogen, and nitrate nitrogen, so we consider that correlates with the amount of dissolved electrolytes in the ground water.
For further data collection, we constructed a new apparatus to collect water samples and measure water temperature at different depths.
Overall, we found that rainfall and water management in the surrounding rice paddies affect ground water level fluctuations, and that fertilizers, strata, and soil bacteria affect ground water quality. In the future, we found like to investigate the deeper interior of the well, continuously observe water level and water quality data compare the composition of the water with rain water, and investigate the effects of soil composition.
We measured the groundwater level using a water level gauge and examined the relationship between the water level and precipitation. We found that precipitation causes groundwater levels to rise. We also found that the water level has been decreasing significantly since October, which is thought to be due to the drainage of water from the paddy fields.
We sampled water in the borehole and tested the water quality for pH, conductivity, COD, nitrite nitrogen, nitrate nitrogen, ammonia nitrogen, and nitrate-form nitrogen, and phosphate phosphorus. Ammonia-based fertilizers were administered to the flower beds above the study borehole in August. The values of ammonium-form nitrogen, nitrite-form nitrogen, and nitrate-form nitrogen increased in turn in September. Thus, we can see the activation of nitrate bacteria in the soil. The pH dropped below 6.80 after more than 5mm of rain fell on the previous day, suggesting that the soil was affected by the weakly acidic rainwater. Conductivity increases with the sum of the values of phosphoric acid, ammonium nitrogen, nitrite nitrogen, and nitrate nitrogen, so we consider that correlates with the amount of dissolved electrolytes in the ground water.
For further data collection, we constructed a new apparatus to collect water samples and measure water temperature at different depths.
Overall, we found that rainfall and water management in the surrounding rice paddies affect ground water level fluctuations, and that fertilizers, strata, and soil bacteria affect ground water quality. In the future, we found like to investigate the deeper interior of the well, continuously observe water level and water quality data compare the composition of the water with rain water, and investigate the effects of soil composition.