基于辐射井抽水试验的水文地质参数求解

在新疆台兰河流域冲洪积扇平原修建坎儿井式地下水库,以解决干旱区水资源合理利用分配等问题。为确定该地下水库库区的水文地质参数,本文利用研究区抽水试验资料,采用等效大井法和博尔顿法计算含水层的渗透系数和给水度,并利用MODFLOW软件建立了数值模型,进行参数反演,以验证计算结果的准确性、可靠性。利用等效大井法在已知抽水量和降深的前提下,反求含水层渗透系数;通过博尔顿法的“迟后疏干”效应,采用配线法确定给水度。计算结果表明：对于台兰河流域含水层的水文地质参数的计算,采用等效大井法和博尔顿法计算的结果较符合实际,为今后计算干旱区含水层水文地质参数提供参考依据。     

优选抽水试验观测孔井位的系统模糊决策模型研究

观测孔井位的选取在抽水试验中具有极其重要的作用。在目前实际工作中,只是定性的选择观测孔井位,决策缺少可靠性和客观合理性。该文通过建立优选抽水试验观测孔井位的多目标多层次系统模糊决策模型,综合考虑影响观测孔井位确定的观测孔与抽水孔的连线方向与地下水流方向所成的锐角度数、水文地质影响因素和观测孔与抽水孔之间的距离三项主要因素以及含水层埋深、含水层厚度和岩性三项水文地质影响子因素,优选了观测孔井位;并利用西龙河峄山断层带水源地抽水试验资料对该模型进行了验证。结果表明:采用该措施使通常的选择分析由定性描述转向定量决策,避免了主观判断偏差,有助于决策判定,所得结果是可靠的。      

时间分辨紫外脉冲荧光法测定锆矿中的铀

基于前人研究工作,开展时间分辨紫外脉冲荧光法测定天然伴生放射性锆矿样品中铀含量的方法研究。与电感耦合等离子体质谱法相比,该法正确度好、精密度高、抗干扰能力强、适应性强。实验表明体系酸碱度影响荧光强度显著,但当pH值在6.85～9.10范围时,荧光强度较高且相对稳定。对31种阳离子干扰进行实验,结果表明Sn、Cr、Sb、Tl、Rh、Mn、Ag、Bi等阳离子可使荧光强度显著降低;溶液中Zr元素质量浓度低于200μg·mL^-1时,对荧光强度影响不明显,Zr元素质量浓度为200～500μg·mL^-1时,荧光强度随Zr元素质量浓度的增加而逐渐减弱。采用过氧化钠碱熔-硝酸提取天然伴生放射性锆矿样品,样品能够消解完全。采用标准加入法,用紫外脉冲荧光法测定铀含量,检出限为0.05μg·g^-1,测定范围为0.15～4500μg·g^-1;铀含量在40～735μg·g^-1时,RSD为2.1%～7.7%;铀含量为288μg·g^-1的锆矿样品,正确度为5.2%。     

液体矿产资源估算中储卤介质孔隙（给水）度参数的计算分析

通过对盐类地层储卤介质孔隙度和给水度的室内测试和野外抽水试验、示踪法测试对比分析,得出比较客观的分析数据,提出推荐的计算参数,为盐类矿产(液体矿)的资源估算评价提供基础依据。     

塔克拉玛干沙漠腹地潜水水位对单井抽水的响应

塔里木沙漠公路防护林生态工程以地下水为灌溉水源,全线采用节水滴灌方式灌溉。全线共有108口水源井,水源井间距约4 km。以第69号水源井(38°41′12″N、83°22′16″E)为例,在距水源井120 m范围内设置了7个地下水监测井,利用潜水水位的动态观测数据,分析了抽水过程中水位的时空变化规律。研究结果表明:持续抽水过程中潜水水位变化可分为快下降和慢速下降两个阶段;潜水水位恢复过程可分为快速上升和慢速上升两个阶段。水位下降和上升的速度变化形成水位的空间差异,即降落漏斗的形成和消失。利用稳定流抽水试验计算得出含水层渗透系数为12.85 m/d。     

Response of a summertime anticyclonic eddy to wind forcing in Funka Bay,Hokkaido, Japan

Flow fluctuations inside an anticyclonic eddy in summertime Funka Bay were examined using three moorings and hydrographic data. The flow pattern above a sharp pycnocline with a concave isopycnal structure during the mooring period was characterized by high mean kinetic energy and relatively low eddy kinetic energy. The ratios of eddy to mean kinetic energy were equal to or less than one, and the mean flow field and isopycnal structure indicated the existence of a stable anticyclonic eddy above the sharp pycnocline under approximate geostrophic balance. Larger flow fluctuations with periods longer than 7 days were dominant inside the eddy. The low-frequency flow fluctuations are accompanied by north to northeastward movement of the eddy with deepening of the pycnocline and spin-up of the anticyclonic circulation. The wind field over Funka Bay is characterized by bay-scale wind fluctuations. The bay-scale winds are greatly influenced by the land topography around Funka Bay, resulting in non-uniform structure with significant wind stress curl. The bay-scale wind fluctuations are termed “locally modified wind” in the present study. The locally modified wind has a negative (positive) wind stress curl in the central–northeastern (southwestern) region of Funka Bay. The north to northeastward movement of the eddy is caused by horizontal non-uniform supply of vorticity from the locally modified wind forcing by the Ekman pumping process. Through this process, the anticyclonic circulation is enhanced (weakened) in the central–northeastern (southwestern) part of the eddy, resulting in the eddy moving north to northeastward with the pycnocline deepening and spin-up of the anticyclonic circulation. The locally modified wind forcing induces low-frequency flow fluctuations through the movement of the eddy in summertime Funka Bay.     

基于钻孔抽水试验和示踪试验的岩溶地区含水层结构研究

岩溶含水层具有强异质性和各向异性特征,其空间结构的调查和认识是地下水流动和污染物迁移研究的重要基础。然而,岩溶含水层特殊的地质结构导致岩溶区水文地质调查非常困难。为了更好地掌握研究区岩溶含水层结构特征,本文在进行抽水试验的同时开展多示踪剂（荧光素钠、罗丹明、荧光增白剂）示踪试验。利用Theis标准曲线对比法分析抽水试验数据,计算试验场地渗透张量,根据示踪试验结果分析含水层结构性质。计算出研究区渗透张量主方向的导水系数分别为:0.297 m2·h-1和0.028 m2·h-1,给水度为1.19E-04,优势方向为东偏南18.47°。抽水条件下示踪试验获得3种示踪剂的回收率分别为:荧光素钠97.98%,罗丹明B47.34%,荧光增白剂39.54%;平均流速分别为:0.378 m·h-1、0.3 m·h-1和0.14 m·h-1,反映研究区岩溶孔隙、裂隙较小,示踪剂运移慢、时间长。荧光素钠和荧光增白剂的BTC曲线表现为单峰型,罗丹明B的BTC曲线表现为多峰型,表明研究区既发育优势流裂隙,又发育相对均匀裂隙。同时,示踪剂最大回收率方向与抽水实验所得渗透张量主方向相符。研究结果为岩溶含水层精细结构的刻画,水文模型物理参数的确定提供了方法和依据。      

中宁县黄河滩地傍河取水工程辐射井设计与施工

中宁县地处黄河中游,黄河滩地地下水受黄河补给,是具有巨大开采潜力的水源地。针对中宁黄河滩地第四系含粘粒土砂卵石地层的傍河水源地,选择辐射井作为取水建筑物,完成5眼辐射井。集水井成孔采用反循环方法,并配有专用钻头打捞含水层中粒径＞200 mm的漂石,用具有扭力、推力、拉力和振冲力的全液压水平钻机进行水平辐射管施工。采用“等效大口井法”计算辐射井抽水量。对抽水试验的数据及相关资料进行分析,比较辐射井、管井和大口井的稳定出水量和降深,结果表明采用辐射井开采类似水源地是有效的取水方式。     

The influence of the geostrophic wind advection approximation on a well-mixed layer

Numerical results indicate that advection of momentum in the boundary layer may significantly alter both the structure of the planetary boundary layer and its influence on the overlying free atmosphere. However, due to the nonlinearity of the inertial terms, it is always difficult to obtain the analytical solution of the boundary-layer model that retains the flow acceleration. In order to overcome this difficulty, the geostrophic momentum (hereafter GM) approximation has been introduced into boundary-layer models. By replacing the advected momentum with the geostrophic wind, the effect of the flow acceleration is partially considered and the original nonlinear partial differential equation set is converted to ordinary differential equations, the solutions of which can be obtained easily with standard techniques. However, the model employing GM fails to capture the features of the boundary layer when the spatio-temporal variation of the boundary-layer flow cannot be properly approximated by the geostrophic wind. In the present work, a modified boundary-layer model with the inertial acceleration in a different approximate form is proposed, in which the advecting wind instead of the advected momentum is approximated by the geostrophic wind (hereafter GAM).Comparing the horizontal velocity and boundary-layer pumping obtained from the classical Ekman theory, and the model incorporating (i) GM and (ii) GAM, it is found that the model with GAM describes most facets of the steady well-mixed layer beneath a north-westerly flow with embedded mesoscale perturbations that is considered in the present work. Inspection of the solution of the model with GAM shows that, within the limit of the validation of the model (i.e., the Rossby number R_O is not very large and the drag coefficient C_D is not too small), the horizontal convergence (divergence) is strengthened by the effect of the inertial acceleration in the region of maximum positive (negative) geostrophic vorticity. Consequently, the boundary-layer pumping there is intensified. It is found that the intensification is firstly strengthened and then weakened as R_O or C_D increases.     

大口径群孔抽水试验成果在评价赵固一井水文地质条件中的应用

位于焦作矿区东南部的赵固一矿因岩溶裂隙水患、基岩厚度薄和新生界盖层厚等三大因素制约了开采而长期搁置.在以往勘探成果基础上,利用大口径群孔抽水试验成果资料,对矿区边界条件、岩溶水的连通性、水动力特征、和水化学特征等诸方面进行了分析,通过评价认为处在二1煤底板的L8岩溶含水层富水程度中等,其二1煤层可以开采,较客观地认识了水患问题.