岩溶地区矿井水环境影响及防治对策探讨     

牟长波 《中国煤炭地质》2013,25(3)

岩溶地区矿井水对环境的影响复杂,它不仅对地表水体产生不利影响,而且由于落水洞、地下河发育,地下水体与地表水体之间水力联系密切,若矿井水若处置不当,还将对地下水环境产生不利影响.以典型的岩溶地区——贵州省金沙县为例,通过收集目前正常生产的部分矿井水水质资料,调查区域的基本水文状况,认为研究区地表水体规模普遍较小,落水洞、暗河等较为发育,地表水体与地下水体之间的水力联系较为密切,矿井水不仅容易污染地表水,而且容易对地下水产生不利影响.针对其影响方式、范围、程度及特点提出了源头控制、源头控制、矿井水资源化、优化排放方式等一系列的综合防治对策,以供类似地区矿井水的污染防治参考.  相似文献   

松辽盆地南部局部排泄构造遥感识别与铀找矿方向探讨     

木红旭 《地质与勘探》2023,59(1):134-144

局部排泄构造对砂岩铀成矿起重要控制作用,识别局部排泄构造对砂岩铀矿勘查具有积极意义。盆地内部局部排泄构造常被土壤、植被、沙漠覆盖,隐蔽性高,地表露头尺度识别难度大,而遥感技术具备宏观观测能力,为识别隐蔽构造提供了新途径。本文以松辽盆地南部的Landsat 8遥感影像为数据源,经K-T空间变换得到可以指示地表水动力活动的亮度、绿度、湿度指数。在此基础上结合基础地质资料,对松辽盆地南部的水动力环境进行了分析,对该地区局部排泄构造进行了识别。结果表明,松辽盆地南部蒸腾作用强烈,植被分布于盆地边缘与盆内开鲁-通辽-双辽一带,土壤湿度较大,但咸水环境分布广泛。在通辽附近、开鲁北西部、双辽西部识别出多条局部排泄构造,且这些构造与已知铀矿床(矿化点)具有较好的空间相关性,显示沿局部排泄构造有很好的找矿前景。  相似文献   

Holocene environmental change on the Atlantic coast of NW Iberia as inferred from the Ponzos wetland sequence     

Luis Gómez-Orellana  Pablo Ramil-Rego  Javier Ferreiro da Costa  Castor Muñoz Sobrino 《Boreas: An International Journal of Quaternary Research》2021,50(4):1131-1145

The intertidal environment of the Ponzos beach (NW Iberian Peninsula) hosts a sedimentary sequence (including large wood fragments) deposited during the first half of the Holocene in a hygrophilous continental wetland. Pollen and macrofossil data alongside radiocarbon dating allow reconstruction of the changes that occurred during the Early and Middle Holocene in the landscape of the NW Iberia coastal lowlands, as well as the local wetland plant communities, in response to the climate variations and the eustatic sea-level oscillations. The sequence represents the evolution of a coastal wetland from its initial phases as a hygrophilous wetland towards the subsequent installation of a freshwater lagoon. Pollen data show the dominant role of Atlantic (mainly deciduous) woody taxa, the scarcity of conifers and the lack of Mediterranean elements in the coastal landscapes around the Ponzos site. The presence and abundance of some taxa such as deciduous Quercus, Castanea, Fagus, Tilia and Ulmus during the Early Holocene provides further support for the occurrence of glacial refuges in the Cantabrian-Atlantic area during the Last Glaciation. The diverse vegetation that characterizes the modern landscapes in this territory established later, spreading from these glacial reservoirs of biodiversity. In this sense, the notable and early presence of Fagus at the beginning of the Holocene, a tree also previously recorded during several phases of the Last Glacial Cycle on the NW Iberia coasts, is noteworthy. In addition, during the Early and Middle Holocene are recorded other trees that are currently extirpated as natural taxa in the area, such as Pinus, Tilia and Carpinus.  相似文献   

Permafrost Change Under Natural Sites Along the Qinghai-Tibet Railway During the Years of 2006-2015     

Zhizhong Sun  Wei Ma  Yanhu Mu  Yongzhi Liu  Shujuan Zhang  Honglei Wang 《地球科学进展》2018,33(3):248-256

Permafrost changes under natural sites along the Qinghai-Tibet Railway were investigated based on the ground temperature monitored from the year of 2006 to 2015. Among these sites, mean permafrost table was 3.54 m, with a range of 0.88 to 9.14 m. Among the sites with decreasing permafrost table, mean decreasing amplitude of permafrost table was 0.51 m, with a range of 0.05 to 2.22 m; mean decreasing rate of permafrost table was 0.07 m/a, with a range of 0.01 to 0.25 m/a. Decreasing amplitude and decreasing rate of permafrost table in high temperature regions were 0.47 m and 0.06 m/a greater than those in low temperature regions, respectively. In general, ground temperatures at permafrost table and 15 m depth presented rising tendency. Mean rising amplitude of ground temperature at permafrost table was 0.16 ℃, with a range of 0.01 to 0.60 ℃; mean rising rate of ground temperature at permafrost table was 0.018 ℃/a, with a range of 0.001 to 0.067 ℃/a. Rising amplitude and rising rate of ground temperature at permafrost table in low temperature regions were 0.12 ℃ and 0.014 ℃/a greater than those in high temperature regions, respectively. Mean rising amplitude of ground temperature at 15 m depth was 0.10 ℃, with a range of 0.01 to 0.48 ℃; mean rising rate of ground temperature at 15 m depth was 0.011 ℃/a, with a range of 0.002 to 0.054 ℃/a. Rising amplitude and rising rate of ground temperature at 15 m depth in low temperature regions were 0.11 ℃ and 0.012 ℃/a greater than those in high temperature regions, respectively. Due to the effect of local factors, increasing of permafrost table and decreasing of ground temperature were observed under several sites.  相似文献   

Field report: Sailing around the exhumed roots of the Mesozoic Patagonian paleo-accretionary wedge(Diego de Almagro Island,Chile)     

Samuel Angiboust  Jesus Mu?oz 《地学前缘(英文版)》2018,9(5):1591-1594

We undertook a boat expedition to explore the geological framework of a very remote, lesser-known island, in the Chilean Patagonia: the Diego de Almagro Island(latitude S51°330'). This uninhabited, ca.400 km~2 Island is one of the very rare exposures of the Mesozoic accretionary subduction complex along the Chilean margin. Unstable weather, strong winds, steep topography, and very dense vegetation make an on-land mission difficult. Careful preparation based on high-resolution satellite images is advised to optimize shore access and minimize risks of injury. Despite a relatively important degree of regional reequilibration of metamorphic assemblages due to sluggish exhumation through the forearc crust, our results have shown that the island is composed of a nappe stack of ocean-floor derived slivers of metasedimentary units that exhibit very different pressure-temperature-time paths during burial by subduction under the Chilean margin and subsequent exhumation. These rocks are witness to a complex thermal evolution of the subduction zone between Jurassic and Cretaceous times from granulite facies to blueschist facies conditions as well as multiple episodes of accretion at ca. 35 -40 km in depth for almost100 Ma over the Mesozoic era.  相似文献   

Spatio-temporal evolution and dynamic simulation of the urban resilience of Beijing-Tianjin-Hebei urban agglomeration     

Mu  Xufang  Fang  Chuanglin  Yang  Zhiqi 《地理学报(英文版)》2022,32(9):1766-1790

Journal of Geographical Sciences - The continuous growth of urban agglomerations in China has increased their complexity as well as vulnerability. In this context, urban resilience is critical for...  相似文献   

Similarities between optimal precursors for ENSO events and optimally growing initial errors in El Niño predictions     

Mu Mu  Yanshan Yu  Hui Xu  Tingting Gong 《Theoretical and Applied Climatology》2014,115(3-4):461-469

With the Zebiak–Cane model, the relationship between the optimal precursors (OPR) for triggering the El Niño/Southern Oscillation (ENSO) events and the optimally growing initial errors (OGE) to the uncertainty in El Niño predictions is investigated using an approach based on the conditional nonlinear optimal perturbation. The computed OPR for El Niño events possesses sea surface temperature anomalies (SSTA) dipole over the equatorial central and eastern Pacific, plus positive thermocline depth anomalies in the entire equatorial Pacific. Based on the El Niño events triggered by the obtained OPRs, the OGE which cause the largest prediction errors are computed. It is found that the OPR and OGE share great similarities in terms of localization and spatial structure of the SSTA dipole pattern over the central and eastern Pacific and the relatively uniform thermocline depth anomalies in the equatorial Pacific. The resemblances are possibly caused by the same mechanism of the Bjerknes positive feedback. It implies that if additional observation instruments are deployed to the targeted observations with limited coverage, they should preferentially be deployed in the equatorial central and eastern Pacific, which has been determined as the sensitive area for ENSO prediction, to better detect the early signals for ENSO events and reduce the initial errors so as to improve the forecast skill.  相似文献   

条件非线性最优扰动法在大气与海洋目标观测研究中的应用   总被引：3，自引：0，他引：3  

穆穆  王强  段晚锁  姜智娜 《气象学报》2014,72(5):1001-1011

对近年来用条件非线性最优扰动法研究大气与海洋目标观测问题的部分工作进行了总结,主要涉及厄尔尼诺-南方涛动（ENSO）事件、黑潮路径变异事件以及阻塞事件。通过研究这些事件发生的最优前期征兆（OPR）和最快增长初始误差（OGE）,发现这些事件的最优前期征兆和最快增长初始误差分别具有空间的高度相似性及其伴随的局地性特征。理想回报试验表明,如果在ENSO事件和黑潮路径变异事件的最快增长初始误差和最优前期征兆所确定的扰动大值区减小初始场误差,上述事件的预报技巧会大幅度提高;最优前期征兆和最快增长初始误差的空间相似性使得在同一敏感区域增加额外观测,不仅有助于捕捉上述异常事件的前期信号,还可以有效减小初始误差,从而提高对该事件的预报技巧。阻塞事件爆发的最优前期征兆和最快增长初始误差的空间相似性和局地性特征在其目标观测研究中的应用,应该是深入研究的课题。  相似文献   

Comparison of sparse‐grid geometric and random sampling methods in nonlinear inverse solution uncertainty estimation     

Michael J. Tompkins  Juan Luis Fernández Martínez  Zulima Fernández Muñiz 《Geophysical Prospecting》2013,61(1):28-41

A new uncertainty estimation method, which we recently introduced in the literature, allows for the comprehensive search of model posterior space while maintaining a high degree of computational efficiency. The method starts with an optimal solution to an inverse problem, performs a parameter reduction step and then searches the resulting feasible model space using prior parameter bounds and sparse‐grid polynomial interpolation methods. After misfit rejection, the resulting model ensemble represents the equivalent model space and can be used to estimate inverse solution uncertainty. While parameter reduction introduces a posterior bias, it also allows for scaling this method to higher dimensional problems. The use of Smolyak sparse‐grid interpolation also dramatically increases sampling efficiency for large stochastic dimensions. Unlike Bayesian inference, which treats the posterior sampling problem as a random process, this geometric sampling method exploits the structure and smoothness in posterior distributions by solving a polynomial interpolation problem and then resampling from the resulting interpolant. The two questions we address in this paper are 1) whether our results are generally compatible with established Bayesian inference methods and 2) how does our method compare in terms of posterior sampling efficiency. We accomplish this by comparing our method for two electromagnetic problems from the literature with two commonly used Bayesian sampling schemes: Gibbs’ and Metropolis‐Hastings. While both the sparse‐grid and Bayesian samplers produce compatible results, in both examples, the sparse‐grid approach has a much higher sampling efficiency, requiring an order of magnitude fewer samples, suggesting that sparse‐grid methods can significantly improve the tractability of inference solutions for problems in high dimensions or with more costly forward physics.  相似文献   

渤海湾西岸的几道贝壳堤   总被引：2，自引：1，他引：1  

岳军  Dong yue  张宝华  耿秀山  刘雪松  赵希涛  牟林  张百鸣  韩芳 《地质学报》2012,86(3):522-534

渤海湾西岸出露或埋藏了多道贝壳堤,通过地质调查发现:贝壳堤的平面分布结构是沿着(或随着)渤海湾海岸由老至新(从岸—海)与海岸呈大致平行排列。贝壳堤的划分方案有两种,一种是从新至老,另一种是从老至新,本文采取后一种划分方法:即第Ⅰ道(老)—第Ⅵ道(新)贝壳堤。本文对每道贝壳堤的物质(岩性特征)组成与堆积特征进行了描述(图2～图7);对贝壳堤的几何形态特征进行了数理统计(表2);对贝壳堤形成的年代特征进行了对比分析(表3);对贝壳堤的生物组合特征等资料进行了归纳和整理;对贝壳堤的分道方案进行了对比分析(表1),揭示了贝壳堤的赋存状态、形成的年代及第Ⅰ道—第Ⅵ道贝壳堤所处的潮位变化(图8)。以形成贝壳堤这一独特的地质载体为基础,试图从渤海湾宏观整体的角度分析并揭示贝壳堤的成因机制(表4,图9),笔者认为广义的渤海湾是内陆的半泻湖(海),也可以视为局部海:山东庙岛列岛—辽东半岛构成了渤海的障壁海岸,在障壁海岸这样的自然地理和地貌条件下,通过大量的资料综合分析认为只有障壁海岸才是形成"科珀河型三角洲与喙状三角洲"的必然条件,而"科珀河型三角洲与喙状三角洲类型"等是形成障壁砂坝(障壁岛,障壁滩)—贝壳堤的或然条件,这就是贝壳堤成因的主要机制。  相似文献