贵阳花溪养牛村暗河枯水期岩溶水动态特征分析

贵阳市花溪区养牛村一带岩溶发育,地下水资源丰富。为了解该区域在枯水季地下河流量、水位变化情况以及地下水受污染状况,特开展了本研究。研究区域为构造变形复杂的岩溶槽谷地貌,通过野外调查、实测、室内实验等途径获取数据,利用CAD绘图和Excel数据统计,分析了暗河流量、水位、水质、水温、pH值动态特征。结果表明,养牛村地下河岩溶水枯水季流量季调节系数为6.83,平均流量0.102 m3·s-1,处于较稳定状态;水位变化幅度值为2.7,处于稳定状态,水温与pH均呈缓慢上升趋势。根据《地下水质量标准》（GB/T 14848-2017）,该区地下水水质处于III-V类水,不宜作为饮用水资源开采。本次研究结果可为该区地下水资源的开发利用和水环境评价与保护提供参考。      

我国中西部表层沉积物中微炭屑记录的火活动信息

微炭屑作为植物体不完全燃烧的产物, 是良好的火活动代用指标。目前, 国内外更多地关注微炭屑对不同时间尺度上火的重建, 对现代微炭屑的分布特征及其与火的关系缺少系统分析。本研究采集了35个跨越我国中西部约2950 km的表层沉积样品, 利用孢粉流程法获取微炭屑, 结合采样点周边50 km、100 km及200 km范围内卫星火点数量以及植被、降水、湿度及温度等指标, 分析不同空间范围微炭屑的粒径、形态及浓度特征, 探讨其与火活动频率的关系。结果表明: 陆表(表土、湖泊与其他水体表层沉积物)微炭屑浓度可有效地反映区域火活动特征, 其浓度高值往往与区域内火点高值相对应; 现代火活动频繁区域主要分布在植被、降水与温度条件偏好的半湿润-半干旱区(也是人类农业活动密集区); 据二者对比结果推测, 微炭屑的来源范围可能主要为50~100 km以内; 同时, 长条形与近圆形微炭屑的比值与50 km范围内草地火活动有较好的对应关系(r=0.61, p＜0.05), 对燃烧的草本与木本植物比例具有较好的指示意义。考虑到区域环境条件差异, 未来拟将更大空间范围内微炭屑记录与火点数量和燃烧面积相结合, 进一步揭示微炭屑与现代火活动的关系, 为地层古火重建提供现代过程基础。

     

分期设计洪水标准计算方法研究

针对水库分期设计和调度运用所涉及的分期情况下如何定义水库防洪标准,以及如何在不突破水库防洪标准的前提下合理确定分期设计洪水标准等关键问题,本文基于概率论中独立事件的概率组合原理,提出了水库分期运用情况下的水库防洪标准的等价表达形式,并以一个水库作为分析案例,在确保水库分期运用情况下的等价防洪标准不突破水库防洪标准的前提下,分别确定了各个分期设计洪水标准以及相应的汛限水位。     

Carbonate Sequence Stratigraphy of a Back-Arc Basin： A Case Study of the Qom Formation in the Kashan Area, Central Iran

The Qom Formation comprises Oligo-Miocene deposits from a marine succession distributed in the Central Basin of Iran. It is composed of five members designated as A-F. Little previous work exists on the sequence stratigraphy. Based on an integrated study of sequence stratigraphy with outcrop data, wells and regional seismic profiles, the Qom Formation is interpreted as a carbonate succession deposited in a mid-Tertiary back-arc basin. There are two second-order sequences (designated as SS1 and SS2) and five third-order sequences (designated as S1-S5). Five distinct systems tracts including transgressive, highstand, forced regressive, slope margin and lowstand have been recognized. The relationship between the sequences and lithologic sub-units has been collated and defined (S1 to S5 individually corresponding to A-C1, C2-C4, D-E, the lower and upper portions of F); a relative sea level change curve and the sequence stratigraphic framework have been established and described in detail. The coincidence of relative sea level change between that of the determined back-arc basin and the world indicates that the sedimentary cycles of the Qom Formation are mainly controlled by eustatic cycles. The variable combination of the systems tracts and special tectonic-depositional setting causally underpin multiple sequence stratigraphic framework styles seen in the carbonates of the back-arc basin revealing: (1) a continental margin basin that developed some form of barrier, characterized by the development of multiple cycles of carbonate-evaporites; (2) a flat carbonate ramp, which occurred on the southern shelf formed by the lack of clastic supply from nearby magmatic islands plus mixed siliciclastics and carbonates that occurred on the northern shelf due to a sufficient clastics supply from the land; and (3) a forced regressive stratigraphic stacking pattern that occured on the southern shelf and in basin lows due to the uplifting of the southern shelf. Thick and widespread aggradational framework limestone usually occurs in the initial sequences (S1 and S3) of the supersequence, which led to preferential oil reservoir deposition but a lack of source and cap rocks, whereas the retrogradational and progradational framework limestone usually occurs in the later sequences (S2 and S4-S5) of the supersequence, which results in two perfect sets of source, reservoir and cap rock assemblies, so that the limestone in sub-member C2-C4 and the F-Member can be predicted as important objects for oil exploration.     

应用短期停蓄法计算涝区排水模数

本文简要介绍了涝区排水模数不同计算方法,提出了应用短期停蓄法计算涝区排水模数过程,并用实例加以论证.事实说明,该方法理论依据充分,符合实际,计算结果合理.     

深层搅拌桩复合地基沉降计算理论研究

为了寻找深层搅拌桩复合地基沉降计算的简便方法，根据已有的研究成果，进行了桩与桩周土间摩擦力分布规律的假设和简化，运用单位元法推导了深层搅拌桩复合地基沉降计算公式和设计用曲线，同时采用轴对称有限元法，对一实际工程的实测成果进行了分析。计算结果表明：文中理论计算的中级荷载下的沉降量值介于分层总和法与有限元法计算值之间，但文中方法比有限元计算法简单，比分层总和法更合理。     

浅析GIS在岩溶地区公路建设土地利用中的应用

在岩溶地区公路建设中，受复杂地形地貌的影响，将不可避免地产生占用耕地、破坏植被等环境问题，使得岩溶地区本来就脆弱的生态环境日趋恶化。因此，合理利用土地资源，维护生态平衡，将成为岩溶地区公路建设必须考虑的重要议题。在文中结合岩溶地区公路建设的实际情况，利用先进的GIS技术，针对公路建设的不同阶段，分别提出了各种不同的技术手段和工程措施，既指导了岩溶地区的公路建设．也保护了有限的土地资源。     

巧家松梁铅锌矿床Ⅰ号矿体分布区1260中段构造岩地球化学特征

云南巧家松梁铅锌矿床系滇川黔铅锌成矿域内赋存于震旦系灯影组白云岩中的富铅锌矿床,它严格受构造控制.文章在讨论矿床地质特征的基础上,选择Ⅰ号矿体1260中段36个断裂构造岩样品进行研究.认为NW向断裂带内铅锌矿脉的形成早于NE向顺层产出的铅锌矿脉,构造岩存在Zn-Pb-Fe、caO-MgO-Na,O和Al2O3-K2O三种元素组合.Zn-Ph-Fe组合和CaO-MgO-Na2O组合呈负相关关系.前者为铅锌成矿作用的元素组合,后者代表了沉积作用和热液蚀变作用的复合产物;Al2O3-K,O元素组合反映了断裂作用产生的黏土矿物.微量元素分析结果表明,自矿体中心向外存在Zn-Cd-Ga、Pb-Ag-Ge元素分带,这对成矿预测具有重要意义.