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黄河上游某滑坡坝渗透稳定性评价 总被引:1,自引:0,他引:1
为了对黄河上游某滑坡坝的渗透稳定性进行较深入研究,作者首先通过试验资料确定了坝体与湖底纹泥渗透稳定的可能破坏形式、临界水力坡降和允许水力坡降,在此基础上应用数值模拟方法(Modflow程序)对滑坡坝在正常湖水位与极限湖水位两种工况进行了渗透稳定性评价。具体评价方法为,在每种工况下先评价计算范围内最大水力坡降方向每一格点(计算剖分网格)的渗透稳定性,进而评价整个坝体的渗透稳定性。研究结果表明,在正常湖水位与极限湖水位两种工况下,坝体均不会出现渗透稳定性问题,在极限湖水位下,坝体的渗漏量变化不大(由2775m^3/d增加为3138m^3/d)。说明在漫长的历史过程中,堰塞湖已形成了很好的防渗铺盖,当水位高于溢洪道时,湖水主要通过溢洪道向外排泄。研究结果为下游某大型水电站的设计、施工与安全运营提供了理论依据。 相似文献
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结合甘肃省民勤红沙岗矿区疏干水利用实例,基于Visal Modflow4.1软件对矿区第四系疏干水可利用量进行了数值模拟计算,并对矿区第四系松散岩类孔隙水的补给及储量进行了研究。研究结果表明:矿区第四系松散岩类孔隙水天然补给源为沟谷雨洪水入渗量和基岩裂隙水的侧向流入量之和98.41×10~4m~3/a(2 696.16 m~3/d),其储存量为2 798.45×10~4 m~3;设计矿区疏干水开采时间为30年、40年及50年时,与其对应第四系可利用疏干水量分别为281.98×10~4m~3/a(7 725.48 m~3/d)、225.32×10~4m~3/a(6 173.15 m~3/d)和183.55×10~4m~3/a(5 028.77 m~3/d),矿区疏干水不能满足计划用水量600.00×10~4 m~3/a,需寻找新的供水水源;计算结果较真实地反映了矿区疏干水储量,具有较好的实用性;所建模型为其它类似矿区疏干水可利用量的计算提供了借鉴。 相似文献
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基于Modflow的岩溶管道概化与模拟探讨 总被引:2,自引:0,他引:2
在复杂岩溶介质中,由于岩溶形态存在小尺度的溶缝到大尺度的岩溶管道的变化,岩溶地下水流呈现为层流-紊流多种流态共存的复杂系统。对含水层中岩溶管道的准确概化是精确模拟复杂岩溶介质地下水流动的前提。在较为成熟的三维有限差分地下水流动模型(等效多孔介质)条件下寻找一种概化岩溶管道的方法,基于Modflow地下水流动模型,分别讨论模型软件中的单元渗流计算子模块( BCF )、排水沟子模块( DRN )、河流子模块( RIV )以及溪流子模块( STR)对岩溶管道的概化模拟效果,发现河流子模块( RIV)与溪流子模块( STR)是概化岩溶管道的最优模块。 相似文献
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Modeling of groundwater flow for Mujib aquifer, Jordan 总被引:4,自引:0,他引:4
Jordan is an arid country with very limited water resources. Groundwater is the main source for its water supply. Mujib aquifer
is located in the central part of Jordan and is a major source of drinking water for Amman, Madaba and Karak cities. High
abstraction rates from Mujib aquifer during the previous years lead to a major decline in water levels and deterioration in
groundwater quality. Therefore, proper groundwater management of Mujib aquifer is necessary; and groundwater flow modeling
is essential for proper management. For this purpose, Modflow was used to build a groundwater flow model to simulate the behavior
of the flow system under different stresses. The model was calibrated for steady state condition by matching observed and
simulated initial head counter lines. Drawdown data for the period 1985–1995 were used to calibrate the transient model by
matching simulated drawdown with the observed one. Then, the transient model was validated by using drawdown data for the
period 1996–2002. The results of the calibrated model showed that the horizontal hydraulic conductivity of the B2/A7 aquifer
ranges between 0.001 and 40m/d. Calibrated specific yield ranges from 0.0001 to 0.15. The water balance for the steady state
condition of Mujib aquifer indicated that the total annual direct recharge is 20.4 × 106m3, the total annual inflow is 13.0 × 106 m3, springs discharge is 15.3 × 106 m3, and total annual outflow is 18.7 × 106 m3. Different scenarios were considered to predict aquifer system response under different conditions. The results of the sensitivity
analysis show that the model is highly sensitive to horizontal hydraulic conductivity and anisotropy and with lower level
to the recharge rates. Also the model is sensitive to specific yield 相似文献
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根据某火电厂建设项目自身性质及其对地下水环境影响的特点,采用数值模拟法进行预测与评价,建立能够正确刻画评价区地下水流动特征的地下水数值模型,并预测评价项目厂区在建设阶段、运行阶段及服务期满后等3个情景下地下水环境的影响和危害情况。认为本项目废水设计为零排放,不会对场址所在的地下水系统造成新的影响。在正常工况下,建设项目不会对当地地下水产生明显影响。在考虑发生风险事故且防渗措施失效情况下,建设项目对场区及下游地下水环境造成轻微影响,不会引起地下水质量标准降低,在及时采取防渗堵漏措施后,对场区及下游地区地下水不会产生影响。旨在为有效预防和控制电厂区域的地下水环境恶化,保护地下水资源,为电厂工程设计和环境管理提供科学依据。 相似文献
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Prediction of inflow from overlying aquifers into coalmines: a case study in Jinggezhuang Coalmine,Kailuan, China 总被引:1,自引:0,他引:1
Aquifers overlying coal seams are common water sources in coalmines. The unexpected inflow of water can flood mines and threatens
the mine safety. Mine flooding caused by the overlying aquifers has occurred more frequently in recent years in China. Proposed
in this paper is a new method that involves three basic maps and two predictions to tackle this geo-hazard. This new approach
is based on the water abundance in the overlying aquifer and risk analysis of the roof collapse. It couples groundwater flow
models with rock mechanics analysis. The method was successfully applied to prediction of the water intrusion from the overlying
aquifer at Jinggezhuang Coalmine in Kailuan, China. The areas with high risk of water intrusion were delineated. Visual Modflow
(version 2.61) was used to simulate the inflows at two active working faces. The developed approach can predict the total
inflow for a working face and the transient inflow as the working face advances. 相似文献
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The groundwater table has been declining at a rate of 0.65 m/yr in Luancheng County since large scale groundwater extraction carried out in the 1960s. The drop of precipitation, substantial increase in agricultural output, variations of crop planting structure and construction of water conservancy projects in the headwater area all tie up with the decline of the groundwater table. On the basis of analyzing the hydrogeological conditions and the water resources utilization of Luancheng County, a three-dimensional groundwater flow model was developed to simulate the county’s groundwater flow through finite-difference method using Visual Modflow software. We divide the research field into four parts after analyzing the hydrogeological condition. Based on parameter calibration and adjustment using measured data, the hydraulic conductivity and specific yield were simulated. Using the calibrated model, we analyze the agricultural water saving potentiality and its influence on the groundwater. The results are as follows: (1) if we decrease the amount of water extracted by 0.14×108 m3, the average groundwater table of the five observation wells in December will rise by 0.33 m; (2) if we decrease the water by 0.29× 108 m3, the average groundwater table of the five observation wells in December will rise by 0.64 m; and (3) if we increase the water by 0.29×108 m3, the average groundwater table of the five observation wells in December will decline by 0.45 m. So we can draw a conclusion that controlling the agricultural water use is an important way to prevent the decline of groundwater table. 相似文献