川藏公路南线然乌-鲁朗段工程地质分区

川藏公路南线然乌-鲁朗段工程地质条件极差,致使该地区各种地质灾害十分严重.采用岩石工程系统(RES)方法对川藏公路南线然乌-鲁朗段进行了半定量的工程地质分区.首先,通过现场调查,根据地质灾害特点、工程地质条件和实践经验,对川藏公路南线然乌-鲁朗段进行了初步工程地质分区.然后在多因素相互作用关系矩阵基础上,定义了工程地质条件评价因子(EGAF),根据EGAF,对每个亚区的工程地质条件进行了半定量的评价,验证了初步工程地质分区的正确性.最后,将研究区分成了3个区和9个亚区,并绘制了相应的工程地质分区图.     

盐沼植物群落研究进展：分布、演替及影响因子

盐沼是全球温带及亚热带地区的主要滨海湿地类型之一,在我国分布广泛。盐沼湿地生态系统敏感、脆弱且具有重要的生态系统服务功能。理解盐沼植物群落时空分布动态的一般规律与生态学机制,是开展盐沼生态系统研究的基础与关键。海陆交界的特殊环境特征是影响盐沼湿地植物群落的空间分布及演替过程的主要因素。在海洋潮汐作用下,盐沼湿地中的盐度、水淹强度、氧化还原电位等非生物因子往往呈梯度分布,这也导致了生物群落中种内、种间关系的变化。在非生物及生物因子的共同作用下,盐沼植物群落也往往沿高程梯度呈带状分布。环境变化是盐沼植物群落演替的驱动因素,在海岸线相对较为稳定的盐沼,植物群落的演替多属自发演替,而在靠近的大型河口的一些持续淤涨的盐沼,植物群落演替通常属于异发演替。沿海地区的水产业、流域上游及沿海地区的工程、污染及生物入侵等直接或间接的人类活动已对盐沼湿地植物群落的产生了深刻影响。经过数十年发展,国际上盐沼植物群落学研究的热点领域主要包括盐沼植物群落与其他生物群落的相互关系、植物群落在盐沼生态系统过程中的作用等。在全球变化背景下,盐沼植物群落对气候变化与海平面升高也日益成为盐沼植物群落学相关的热点。     

沈阳黄家傍河水源地河水入渗过程中氧化还原分带规律

在分析沈阳市黄家傍河水源地地质及水文地质条件的基础上,通过场地监测-室内实验相结合的方法,对黄家水源地河水入渗过程孔隙水氧化还原分带规律进行研究.结果表明：辽河河床沉积带在河水入渗途径上存在氧化还原分带,在水流垂向入渗的初始0~20cm、20~80cm、80~90cm及后续范围内依次存在O₂-NO₃^-混和还原带、锰氧化物还原带和铁氧化物还原带;反应中河水中溶解有机碳不能提供足够的电子还原氧化剂,溶解至入渗水流中的沉积物有机碳与河水溶解有机碳一起作为碳源参与了氧化还原反应.     

USING SENSITIVITY ANALYSIS TO ASSIST PARAMETER ZONATION IN GROUND WATER FLOW MODEL1

ABSTRACT: For numerical modeling of ground water movement in a real aquifer system, the aquifer is usually divided into hydrogeologically defined zones, each with its own parameter values. The responses of the system, such as head or drawdown, are often available only in some of the zones. The estimated parameters of all the zones are based on the measured response in these limited zones. However, the estimates for some of the zones may be very uncertain, and these zones are therefore not justified by the data. In this paper, an approach is presented to understand which zone may produce uncertain parameter values and should be lumped with its neighbor. This approach is demonstrated using a regional numerical model for pumping test analysis in the Nottinghamshire aquifer, UK. A step-by-step process is used in identifying the aquifer zones and estimating their parameters based on the principle of using the smallest possible numbers of zones and parameters for adequate representation of the drawdown response. After the parameters of each zone are estimated, the sensitivity features of these parameters are examined. The results show that the parameters in one zone can be estimated properly by the drawdown in another zone only when there is significant sensitivity. For transmissivity, sensitivity between zones occurs when there is significant flow between them. For storativity, sufficient sensitivity can occur without large flows between the zones, provided that one zone causes significant drawdown in the other. This idea can be extended to the flow model for a large aquifer system. If the aquifer is divided in such a way that aquifer responses are not sensitive to the parameters in some of the zones, the parameters in those zones cannot be estimated properly and should be lumped into their neighboring zones. In this way, a simple but more reasonable model can be built.     

东北区低温冷害风险评估及区划

从变异系数、正态分布风险概率、风险指数三方面对东北区热量条件的稳定性和低温冷害的风险进行了讨论和评估;并将上述三种风险指标极差化,以求取低温冷害的综合风险指数,最后以综合风险指数为指标,并参考变异系数、正态分布风险概率、风险指数,给出了东北区低温冷害风险区划。     

华南地区荔枝寒害风险分析与区划

以荔枝种植面积最大的广东、广西为代表，依据自然灾害风险分析原理、历年气候、种植面积和产量资料，分别就华南地区各县荔枝的灾损率、易灾性和防寒抗灾能力进行了分析，并以综合的风险指数为区划指标，对华南地区荔枝寒害风险进行了空间区域分划和分区评述。     

基于典型线路地质灾害调查成果进行地质灾害区划评价的研究

根据影响区域地质灾害发生的地质因素、地形因素、诱发因素和人为因素,在工作区上选取典型线路开展地质灾害发生发育状况调查,根据调查成果总结规律,提取影响因子,建立区域地质灾害评价指标体系,对典型线路穿越的评价试验区进行地质灾害区域评价,验证线路成果应用于区域地质灾害评价的可行性,对于调查人员无法涉足、遥感技术难以应用的地区的地质灾害的评价工作有重要价值。     

库区移民新城滑坡灾害危险性区划研究

三峡库区地质灾害发育,已威胁到移民新城的城市规划与地方经济的发展。为解决这一问题,论文以巴东县新城区为研究对象,分析了滑坡的发育特征,开展滑坡灾害危险性区划研究,以MAPGIS软件为平台,根据斜坡坡向和斜坡坡度将全区共划分成223个不规则单元,采用层次分析方法构建评价指标体系,在得到信息量预测模型的基础上,对各影响因素...     

Modelling of iron cycling and its impact on the electron balance at a petroleum hydrocarbon contaminated site in Hnevice, Czech Republic

Over a period of several decades multiple leaks of large volumes from storage facilities located near Hnevice (Czech Republic) have caused the underlying Quaternary aquifer to be severely contaminated with nonaqueous phase liquid (NAPL) petroleum hydrocarbons. Beginning in the late 1980's the NAPL plume started to shrink as a consequence of NAPL dissolution exceeding replenishment and due to active remediation. The subsurface was classified geochemically into four different zones, (i) a contaminant-free zone never occupied by NAPL or dissolved contaminants, (ii) a re-oxidation zone formerly occupied by NAPL, (iii) a zone currently occupied by NAPL, and (iv) a lower fringe zone between the overlying NAPL and the deeper underlying contaminant-free zone. The study investigated the spatial and temporal variability of the redox zonation at the Hnevice site and quantified the influence of iron-cycling on the overall electron balance. As a first step inverse geochemical modelling was carried out to identify possible reaction models and mass transfer processes. In a subsequent step, two-dimensional (forward) multi-component reactive transport modelling was performed to evaluate and quantify the major processes that control the geochemical evolution at the site. The study explains the observed enrichment of the lower fringe zone with ferrihydrite as a result of the re-oxidation of ferrous iron. It suggests that once the NAPL zone started to shrink the dissolution of previously formed siderite and FeS by oxygen and nitrate consumed a significant part of the oxidation capacity for a considerable time period and therefore limited the penetration of electron acceptors into the NAPL contaminated zone.