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Numerical simulation of groundwater flow for a coastal plain in Japan: data collection and model calibration 总被引:1,自引:0,他引:1
Using a three-dimensional finite element model, this study characterizes groundwater flow in a costal plain of the Seto Inland
Sea, Japan. The model characterization involved taking field data describing the aquifer system and translating this information
into input variables that the model code uses to solve governing equations of flow. Geological geometry and the number of
aquifers have been analyzed based on a large amount of geological, hydrogeological and topographical data. Results of study
demonstrate a high correlation between the ground surface elevation and the groundwater level in the shallow coastal aquifer.
For calibrating the numerical groundwater model, the groundwater flow was simulated in steady state. In addition, the groundwater
level and trend in the transient state has also been elucidated. The numerical result provides excellent visual representations
of groundwater flow, presenting resource managers and decision makers with a clear understanding of the nature of the types
of groundwater flow pathways. Results build a base for further analysis under different future scenarios. 相似文献
2.
Distributions of the surface brightness and the surface color of five barred spiral galaxies expressed in the form of digital maps are presented. This is the first step to determine the composition of the components of barred spiral galaxies — bar, spiral arm, inner ring and outer ring — and to obtain an accurate picture of the dynamical model of a barred spiral galaxy. We have found that (a) the bar is redder than the spiral arm and has a color similar to that of the disk and (b) the inner ring of theSB(r) type galaxy is bluer than the bar and rather resembles the spiral arm. 相似文献
3.
Comparison of the soil physical properties and hydrological processes in two different forest type catchments 总被引:1,自引:0,他引:1
Water Resources - Soil physical properties and hydrological processes were analyzed in two experimental catchments with different forest types: one catchment is covered mostly with conifer type... 相似文献
4.
A semi-distributed groundwater recharge model for estimating water-table and water-balance variables 总被引:1,自引:0,他引:1
A semi-distributed groundwater recharge model is presented, which estimates water-table fluctuation and water-balance variables. The model is expressed by the water-balance concept linking atmospheric and hydrogeological parameters to different water uses (industrial, agricultural, domestic, etc). It was calibrated and validated using 5 years of data collected in the Dogo Plain in Japan. A 3-year dataset, from 2000 to 2002, was used in the calibration, while a 2-year dataset, from 2003 to 2004, was used for the validation. Calibration of the model was achieved by the shuffled complex evolution automatic optimization of model parameters to match simulated results with measured water-table depth. Square roots of relative error (R2) are 0.88 and 0.90 for calibration and validation processes, respectively. Monthly evolution of water storage change was then estimated and the water-table drawdown in different pumping scenarios was simulated. Finally, the groundwater-pumping amount planned by the government for future sustainable groundwater utilization was evaluated. The government-planned groundwater-pumping amount is feasible in most regions while the midstream region should be paid more attention. This study offers a scientific basis to control and prevent depletion of groundwater resources. 相似文献
5.
Omar R. Salinas Villafane Toshifumi Igarashi Mitsuru Kurosawa Toshio Takase 《Applied Geochemistry》2012
Potentially toxic metals, such as Cu, Pb and Zn, are leached from weathered rocks at many closed mine sites due to the acidic environments and mineralogical modifications. The mobilized toxic metals may cause contamination of surrounding water bodies. In this study, both laboratory column experiments and field observations at a former mine located in the north of Japan were carried out to compare the leaching behavior of Cu, Pb and Zn. The thickness of the surface weathered rock was varied (10, 20 and 30 cm) for the columns experiments while porous cups for porewater sampling were set up at different depths (GL-15, -45, -70, and -95 cm) for the field observations. Deionized water was added once a week over 75 weeks to the columns to simulate rainfall while porewater was extracted by a vacuum pump in several sampling campaigns (over 18 months). Similar low pH and leaching behavior of potentially toxic metals were observed for column experiments and field observations. A moderate increase in concentration with depth was observed for Cu and Zn. However, no increase in concentration was observed for Pb. This suggests that the leaching of Cu and Zn is enhanced by the length of the flow pathway through the weathered rock layer while Pb concentration is restricted by the precipitation of insoluble Pb sulfate. Thus, the thickness of the weathered rock layer is an important parameter that should be taken into consideration to estimate the loads of some potentially toxic metals, which is important when designing remediation schemes. 相似文献
6.
Bunshiro Takase 《Astrophysics and Space Science》1986,118(1-2):35-37
On 1 October, 1974 the 105 cm Schmidt-telescope was dedicated at the Kiso Observatory. Since then it has been used for several galactic and extragalactic studies. The main works are described here together with some data on the telescope.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984. 相似文献
7.
A. V. Konoplev Y. Wakiyama T. Wada V. N. Golosov K. Nanba T. Takase 《Water Resources》2018,45(4):589-597
The article presents the results of studying radiocesium concentration and distribution between dissolved and particulate forms in ponds in the near zone of Fukushima Dai-ichi NPP NPP after the 2011 accident. The total concentration of 137Cs in pond water and its variations are shown to be largely governed by the concentration of particulate matter being as high as 68 Bq/L, compared with 5 Bq/L in solution. The values of the distribution coefficient Kd in the ponds are similar to those in rivers and in large flow-through lakes in the accidentally polluted zone at Fukushima Dai-ichi NPP. The contributions of the main competing ions K+ and NH 4 + to radiocesium desorption from solid particles into solution were similar for the ponds; however, their relative effect on dissolved radiocesium concentration varied over time because of variations in ammonium concentration. 相似文献
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