{"title":"利用气压引起的周期性地下水位变化估算含水层分类和气动扩散系数","authors":"Heejun Yang, T. Shibata","doi":"10.3178/HRL.14.111","DOIUrl":null,"url":null,"abstract":": To classify the aquifer type and to estimate the pneu‐ matic diffusivity using harmonic analysis and analytical expressions, we measured groundwater levels and baro‐ metric pressure in an unconfined aquifer with a thick un‐ saturated zone at a southern part of the Beppu volcanic fan, Japan. The groundwater level was inversely related to the barometric pressure, with little or no time lag behind baro‐ metric pressure. The groundwater level and barometric pressure exhibit periodic changes with prominent spectra at K 1 (lunar-solar diurnal) and S 2 (main solar semidiurnal) tidal constituents but not at O 1 (main lunar diurnal) and M 2 (main lunar semidiurnal) tidal constituents, which are the motions of solar and lunar relative to the earth. It indicates that the aquifer is an unconfined aquifer type with no earth tide effect. Pneumatic diffusivity in the unsaturated zone was estimated as 7.6 × 10 –2 to 5.7 × 10 –3 m 2 /s using changes between the groundwater level and the barometric pressure. The pneumatic diffusivity and the unsaturated zone thick‐ ness strongly affect amplitude ratios and phase lags between the groundwater level and the barometric pressure in the unconfined aquifer.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":null,"pages":null},"PeriodicalIF":0.6000,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":"{\"title\":\"Aquifer classification and pneumatic diffusivity estimation using periodic groundwater level changes induced by barometric pressure\",\"authors\":\"Heejun Yang, T. Shibata\",\"doi\":\"10.3178/HRL.14.111\",\"DOIUrl\":null,\"url\":null,\"abstract\":\": To classify the aquifer type and to estimate the pneu‐ matic diffusivity using harmonic analysis and analytical expressions, we measured groundwater levels and baro‐ metric pressure in an unconfined aquifer with a thick un‐ saturated zone at a southern part of the Beppu volcanic fan, Japan. The groundwater level was inversely related to the barometric pressure, with little or no time lag behind baro‐ metric pressure. The groundwater level and barometric pressure exhibit periodic changes with prominent spectra at K 1 (lunar-solar diurnal) and S 2 (main solar semidiurnal) tidal constituents but not at O 1 (main lunar diurnal) and M 2 (main lunar semidiurnal) tidal constituents, which are the motions of solar and lunar relative to the earth. It indicates that the aquifer is an unconfined aquifer type with no earth tide effect. Pneumatic diffusivity in the unsaturated zone was estimated as 7.6 × 10 –2 to 5.7 × 10 –3 m 2 /s using changes between the groundwater level and the barometric pressure. The pneumatic diffusivity and the unsaturated zone thick‐ ness strongly affect amplitude ratios and phase lags between the groundwater level and the barometric pressure in the unconfined aquifer.\",\"PeriodicalId\":13111,\"journal\":{\"name\":\"Hydrological Research Letters\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.6000,\"publicationDate\":\"2020-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"2\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Hydrological Research Letters\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.3178/HRL.14.111\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"WATER RESOURCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Hydrological Research Letters","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3178/HRL.14.111","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"WATER RESOURCES","Score":null,"Total":0}
Aquifer classification and pneumatic diffusivity estimation using periodic groundwater level changes induced by barometric pressure
: To classify the aquifer type and to estimate the pneu‐ matic diffusivity using harmonic analysis and analytical expressions, we measured groundwater levels and baro‐ metric pressure in an unconfined aquifer with a thick un‐ saturated zone at a southern part of the Beppu volcanic fan, Japan. The groundwater level was inversely related to the barometric pressure, with little or no time lag behind baro‐ metric pressure. The groundwater level and barometric pressure exhibit periodic changes with prominent spectra at K 1 (lunar-solar diurnal) and S 2 (main solar semidiurnal) tidal constituents but not at O 1 (main lunar diurnal) and M 2 (main lunar semidiurnal) tidal constituents, which are the motions of solar and lunar relative to the earth. It indicates that the aquifer is an unconfined aquifer type with no earth tide effect. Pneumatic diffusivity in the unsaturated zone was estimated as 7.6 × 10 –2 to 5.7 × 10 –3 m 2 /s using changes between the groundwater level and the barometric pressure. The pneumatic diffusivity and the unsaturated zone thick‐ ness strongly affect amplitude ratios and phase lags between the groundwater level and the barometric pressure in the unconfined aquifer.
期刊介绍:
Hydrological Research Letters (HRL) is an international and trans-disciplinary electronic online journal published jointly by Japan Society of Hydrology and Water Resources (JSHWR), Japanese Association of Groundwater Hydrology (JAGH), Japanese Association of Hydrological Sciences (JAHS), and Japanese Society of Physical Hydrology (JSPH), aiming at rapid exchange and outgoing of information in these fields. The purpose is to disseminate original research findings and develop debates on a wide range of investigations on hydrology and water resources to researchers, students and the public. It also publishes reviews of various fields on hydrology and water resources and other information of interest to scientists to encourage communication and utilization of the published results. The editors welcome contributions from authors throughout the world. The decision on acceptance of a submitted manuscript is made by the journal editors on the basis of suitability of subject matter to the scope of the journal, originality of the contribution, potential impacts on societies and scientific merit. Manuscripts submitted to HRL may cover all aspects of hydrology and water resources, including research on physical and biological sciences, engineering, and social and political sciences from the aspects of hydrology and water resources.