地下水源热泵抽灌井优化布置及参数灵敏度

为了确定地下水源热泵的最佳布井方式,探明含水层温度场变化特征以及水文地质参数灵敏性,以石家庄地下水源热泵适宜区肖家营—东兆通为研究区,基于热储层的地热地质条件和热物性参数,利用FEFLOW软件构建了三维水-热耦合数值模拟模型。在2000 m^(3)/d的抽灌量下对不同井间距、不同布井模式-含水层温度场变化进行模拟,探讨发生热突破的可能性,并探讨温度场关于热导率、渗透系数、孔隙率等参数的灵敏度。研究结果表明:1)在单抽双灌模式下,方案C(两眼回灌井连线与地下水流向垂直,一眼回灌井位于抽水井正下游,另一眼回灌井位于沿地下水流向45°方向,即两回灌井与抽水井组成等腰直角三角形,抽水井正下游的回灌井为直角顶点)的布井方案对含水层温度场影响最小,为最优方案;2)单抽双灌模式下,抽灌量为2000 m^(3)/d时,方案C抽灌井间距设置在40~50 m较为合理;3)抽灌过程中,温度场对于渗透系数的改变灵敏度较高,而对孔隙率以及热导率的改变灵敏度较低。

山东烟台地区1956-2020年降水量变化特征分析

依据烟台市1956—2020年11个气象站点逐月降水量资料,采用线性趋势方法、Mann-Kendall法、Morlet小波分析和R/S法等方法,分析了烟台市65年来降水演变特征。结果表明:烟台市多年平均降水量为643.0 mm,中位数为642.9 mm,年降水量波动幅度较大,最大降水量(1166.36 mm)为最小降水量(389.62 mm)的2.99倍;总体呈下降趋势,年下降率为16.34 mm/(10 a);夏秋两季降水量变化趋势与年降水一致。Mann-Kendall突变分析可知,在α=0.01的显著水平下,年及夏季降水量只有1972年、2006年发生突变,且突变后降雨量都减少了;小波分析显示年及春季、夏季及秋季降水量存在显著的4~7 a的短周期和17~27 a的长周期变化,冬季无显著的周期变化;R/S法分析显示年际以及春、夏、秋三季降水量继续维持原来的下降趋势,冬季降水量Hurst指数H(0.471)<0.5,则具有反持续性,即冬季降雨量呈弱减少趋势,与趋势分析结论相反,即冬季降水量未来呈不稳定变化趋势;且由V统计量可知年及四季降水量序列均具有周期型循环特征,降水量趋势维持时间分别为8、8、6、5、5 a。

Gastroduodenal artery disconnection during liver transplantation decreases non-anastomotic stricture incidence

Background:The hepatic artery is the only blood source nourishing the biliary duct and associated with biliary complication after liver transplantation(LT).Gastroduodenal artery(GDA)disconnection increased proper hepatic artery flow.Whether this procedure attenuates biliary non-anastomotic stricture(NAS)is not clear.Methods:A total of 241 patients with LT were retrospectively analyzed.The patients were divided into the GDA disconnection(GDA-)and GDA preservation(GDA+)groups.Propensity score matching(PSM)was administrated to reduce bias.Logistic regression was conducted to analyze risk factors for biliary NAS before and after PSM.Postoperative complications were compared.Kaplan-Meier survival analysis and log-rank tests were performed to compare overall survival.Results:In all,99 patients(41.1%)underwent GDA disconnection,and 49(20.3%)developed NAS.Multivariate logistic regression revealed that GDA preservation(OR=2.24,95%CI:1.11-4.53;P=0.025)and model for end-stage liver disease(MELD)score>15(OR=2.14,95%CI:1.12-4.11;P=0.022)were risk factors for biliary NAS.PSM provided 66 pairs using 1:2 matching method,including 66 GDA disconnection and 99 GDA preservation patients.Multivariate logistic regression after PSM also showed that GDA preservation(OR=3.15,95%CI:1.26-7.89;P=0.014)and MELD score>15(OR=2.41,95%CI:1.08-5.36;P=0.031)were risk factors for NAS.When comparing complications between the two groups,GDA preservation was associated with a higher incidence of biliary NAS before and after PSM(P=0.031 and 0.017,respectively).In contrast,other complications including early allograft dysfunction(P=0.620),small-for-size graft syndrome(P=0.441),abdominal hemorrhage(P=1.000),major complications(Clavien-Dindo grade≥3,P=0.318),and overall survival(P=0.088)were not significantly different between the two groups.Conclusions:GDA disconnection during LT ameliorates biliary NAS incidence and may be recommended for application in clinical practice.

基于改进灰色关联法的现代地裂缝影响因素分析——以衡水地区为例

衡水地区现代地裂缝呈现快速发展趋势,影响地裂缝发育的因素众多,然而对地裂缝主控因素的研究存在争议,且以定性分析为主。论文根据调查和统计数据,利用改进的灰色关联法定量分析了各影响因素的关联度及影响度。结果表明,形成地裂缝的影响因素关联度排序为:深层地下水埋深>第四系沉积厚度>地面沉降量>浅层地下水埋深>地形地貌>距活动性构造距离,其影响度分别为37.36%、24.14%、15.92%、8.77%、7.79%、6.02%。通过对影响度的分析,认为衡水地区现代地裂缝不仅具有自然属性,也具有社会属性,超采深层地下水、第四系沉积厚度及地面沉降为该区地裂缝形成的主控因素。研究方法及结果可以为华北平原其它地区的地裂缝影响因素分析及研究区灾害防治提供参考。

基于模糊综合法的烟台市栖霞中桥岩溶塌陷易发性评价

在分析烟台市栖霞中桥区地质条件及岩溶塌陷产生条件的基础上,选择岩溶发育条件、构造条件、覆盖层条件、水文条件和人类活动条件共5个因子,构建层次型指标体系。同时为增加评价结果的客观性和准确性,选择采用模糊数学法构建各指标的隶属函数,并借助ArcGIS软件,最终实现对研究区岩溶塌陷灾害的易发性评价。分区评价结果表明:已发生岩溶塌陷点分布在岩溶塌陷的极易发生区和易发生区,说明本次评价分区具有合理性;对岩溶塌陷灾害极易发区和易发区应严格控制地下水的开采,以防止岩溶塌陷灾害的发生。

Distribution and evolution features of salinized soil in Hebei Plain

In order to study the distribution and evolution features of saline soil, the correlations between the groundwater depth, salinity and salinization of soil are examined through analyzing the hydrometeorological data and distribution maps of saline soil, groundwater depth and salinity in 1957 and 2005. The results show that the area of salinization has generally decreased. The area of salinization decreases with the increasing groundwater depth, and the dynamic evolution characteristics appeared between the groundwater depth and area of salinization. The area of heavy salinization is greatest when the groundwater salinity is > 5 g/L, the area of moderate salinization is greatest when the groundwater salinity is between 2-5 g/L, the area of light salinization is greatest when the groundwater salinity is 1-2 g/L and the area of non-salinization is greatest when the groundwater salinity is <1 g/L. The area of heavy salinization was characterized with groundwater depth <2.5 m and salinity >1.8 g/L. The area of non-salinization was characterized with groundwater depth >4.0 m and salinity 0.2-1.5 g/L.

A Study of the Groundwater Reservoirs and Regulation in the Alluvial Fan of the Hutuo River

Based on analysis of the geology and hydrogeology of the alluvial fan of the Hutuo River,Hebei province of China,this paper studies the groundwater reservoir’s regulated space,storage capacity and regulated water in system.On this basis,a groundwater numerical simulation model was established.Using this model and taking into account specific regulating schemes,this paper evaluates the regulation and storage capacity of groundwater reservoirs and the effect of conjuncttive operation of surface water and groundwater.Results show that the funnel area of the study area status storage space is 12.83×108 m^3.Groundwater level after the regulation has clearly rebounded;improving groundwater supply and ensuring stable water supply in Shijiazhuang city of Hebei province,this clearly has important practical significance.

地下水应急水源地综合研究——以唐山市平原区为例

为规范地下水应急水源地勘查、评价和研究内容及程序,以唐山市平原区地下水应急水源地为例,运用综合分析和数值模拟法,针对应急水源地的供水特征和生态环境约束,总结了地下水应急水源地的选址原则,探讨了地下水应急水源地研究内容和研究步骤,提出了地下水应急开采量概念。通过研究查明了水文地质条件,确定应急水源地位置;建立了地下水流模型;以地质环境为约束,以可持续开发利用为前提条件,评价了应急开采量和地下水资源恢复能力。对唐山市平原区地下水应急水源地的研究表明,该水源地距离现有水源地较远,水文地质条件、补给条件和水质较好,地下水应急水源地的应急开采量约9×10^(4) m^(3)/d,停采后地下水资源恢复能力较好。研究成果对地下水应急水源地的勘查和评价具有指导意义。