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1.
研究了广东省四家温泉宾馆室内温泉水及其使用过程中对氡浓度的影响。利用RAD-7测氡仪和NR667A测氡义连续测量室内外氡浓度和水氡浓度,发现室内氡浓度受地基土壤、建筑物类型、利用方式(是否洗浴、洗浴时间长短等)、通风状况等诸多因素的影响。无人入住时宾馆室内氡浓度的变化说明土壤氡的渗入是底层房间室内氡的重要影响因素。当在浴室内使用温泉水洗浴时,浴室内平均氡浓度比没有用温泉水时高出1～8．3倍,客房内氡浓度比没有用温泉水洗浴时高出1．2～8．3倍。在使用温泉水时,某些宾馆室内氡浓度超标,可能对宾馆工作人员造成潜在的健康危害,应采取管理措施或技术手段降低其暴露水平。 相似文献
2.
大兴安岭南段赛罕乌拉石海剖面分析及其与蒙山拦马墙石河结构对比 总被引：1，自引：0，他引：1
石海（石河/冰石河）作为冰缘地貌的重要标志之一,在国内地学界尚未引起足够的重视,以至于缺少介绍石海结构特征的中文文献,更未建立判别标准,在地貌认知阶段就发生很多误判。为了揭示石海的剖面结构特征,笔者等对位于大兴安岭南段的赛罕乌拉国家级自然保护区乌兰坝石海首次进行了开挖解剖,从而归纳了原生石海的基本结构特征：岩块棱角鲜明,呈镂空状堆积,岩块直径总体上上大下小。根据野外调查确认,赛罕乌拉海拔1800 m以上的区域至少还存在着局部现代石海,也就是说,还残存着不连续冻土带,而且保持年平均气温0℃左右的气候环境。根据赛罕乌拉现今气候记录和石海分布,笔者等估算了全新世初期赛罕乌拉石海开始发育时的地表温度在0~-4℃,而今天年平均气温已经升高到2℃,升温幅度2~6℃。根据赛罕乌拉石海剖面结构特征,笔者等对山东蒙山石河进行了结构对比,认为二者剖面结构基本一致,排除了前人近年来争议明显的冰川侧碛堤和泥石流成因说。结构对比揭示山东蒙山境内全新世早期至少局部存在过冰缘气候环境,而这也为山东境内更新世冰川地貌研究提供了重要的信息。此外,本研究也为中国冰缘地貌解剖和资源调查提供了一个可以参考的研究实例。 相似文献
3.
桂南红层岩溶及其发育控制因素探讨 总被引：3，自引：3，他引：0
桂南红层岩溶形态主要表现为岩溶缓丘、地下溶洞、岩溶泉以及地下河、天窗等。在地下50m深度范围,溶洞高0.5～3m,多为无充填溶洞,发育数量随深度增加而减少。岩溶泉类型有上升泉和下降泉,泉水流量变化较大。目前尚未发现仅由红层作为含水层的地下河。桂南红层岩溶的发育程度及形态特征与岩性、构造及水文地质条件有关。红层岩溶主要发育于红层盆地边缘的钙质砾岩中。红层的层组结构可分为单一型和互层型,单一型岩溶发育相对强烈,互层型以岩溶顺层发育为特征。通常,在可溶岩与非可溶岩接触带附近红层溶洞发育;在断裂破碎带以及河谷地带红层岩溶发育强烈,溶洞规模较大。 相似文献
4.
山西大同、内蒙古鄂尔多斯冰楔、砂楔群的发现及其环境意义 总被引：7，自引：3，他引：4
研究了山西大同、内蒙古东胜和乌审旗地区发现的大量冰楔假型、砂楔、寒冻裂隙和南部白城子附近的冰卷泥.根据这些冰缘现象,并参考前人工作成果,划定了晚更新世晚期末次冰期时多年冻土的南界,并根据所获得的年代资料划分了4次冰缘期:33ka BP,30～26ka BP,20～16ka BP和8ka BP左右,当时的温度比今天分别降低8.4℃,12～13℃,10℃和7～10℃. 相似文献
5.
世界自然遗产-四川黄龙钙华景观的形成与演化 总被引：15，自引：4，他引：11
本文对作者十余年来在四川黄龙(世界遗产地)的钙华研究成果和最新的一些监测发现进行了综述, 目的是为公众更好地了解黄龙、保护黄龙提供科学基础。主要结果和结论是: (1)黄龙钙华的形成是由于地球深部高分压的CO2在碳酸盐岩补给区产生富含碳酸氢钙的地下水, 当其以泉的形式出露地表时, 由于泉水的CO2分压远远高于空气, 泉水中的CO2大量逸出, 结果导致碳酸钙过饱和而发生沉积; (2)黄龙钙华的颜色以黄色为主色调, 主要是在雨季因雨水冲刷土壤向水中混入泥沙的缘故; 而在旱季, 钙华主要形成于清亮干净的泉水, 因此, 钙华的颜色呈现出纯净碳酸钙沉积的本色-白色。这也是黄龙洞钙华剖面年层中出现黄-白相间亚层的原因; (3)高精度的铀-钍同位素测年表明, 黄龙钙华主体是全新世以来形成的; (4)地表水向地下河的漏失是黄龙地表水日益减少, 导致钙华体表面干涸, 从而气生蓝藻大量滋生, 致使某些钙华变黑的主要原因, 因此, 有必要尽早采取防渗补水措施; (5)旅游活动已对黄龙钙华景观产生影响, 包括上游人为践踏使下游钙华池淤塞, 以及磷酸盐污染使硅藻等过度繁殖和钙华沉积速率可能降低等, 因此, 必须尽早采取相应防控措施。 相似文献
6.
7.
黄河上游地区气候变化及其对黄河水资源的影响 总被引：34，自引：0，他引：34
通过对1961年以来黄河上游地区气候变化的分析,发现黄河源区进入80年代中后期以后,年平均气温上升趋势非常明显,特别是1998年的年平均气温竟达到-2.1℃,是40年来年平均气温最高的一年;进入90年代,春季和夏季温度急剧回升.黄河上游地区年平均降水量及秋季降水量无明显的变化趋势,且其年际间的波动趋于缓和;冬季(12～2月)和春季(3～5月)降水量的变化趋势呈现出逐年增多的趋势;夏季(6～8月)降水量变化趋势却表现出显著的减少趋势.同时,分析了38年黄河上游径流量及其与流域降水、气温的关系,着重分析了干旱气候对黄河水资源的影响.结果表明,黄河上游地区水资源呈减少趋势,其减少趋势进入90年代后尤为明显.这一变化趋势与黄河上游地区夏季降水量变化趋势有着一致性,说明汛期降水量的减少是黄河上游流量减少的最直接的气候因子. 相似文献
8.
利用青藏高原东南边缘核心区迪庆地区3个站的蒸发皿蒸发、降水、径流深观测资料,分析了各要素年内、年际变化规律,检验了突变点,探讨了区域蒸发、降水、径流深相关关系。结果表明：（1）研究区蒸发量年内四季分布相对均衡,其次为径流深及降水量;径流深年际离散系数低,其次为降水量、蒸发量;径流深年内季节分布年际离散系数低,其次为蒸发量、降水量。（2）研究区年度蒸发量的增加主要因春季蒸发增加,年度降水量的减少主要因冬季降水量减少,年度径流深的增加主要因夏季、秋季、冬季径流深增加所致,夏季径流深增加主要因夏季蒸发减少,秋季径流深增加主要因秋季降水增加、蒸发减少、夏季径流增加、蒸发减少所致,冬季径流深增加主要因秋季径流增加所致。（3）研究区年度、春季蒸发量下降趋势显著,年度干旱、春旱风险呈降低趋势;降水量年内占比趋向于向夏季、秋季集中,径流深夏、秋季呈增加趋势,区域内洪涝灾害风险有增大趋势。2000年以来,区域内年度蒸发量出现较为明显增加趋势,年度降水量、年度径流出现明显减少趋势,该趋势与线性趋势出现背离,且年度和四季降水量、径流深在2014年左右均检测出变少突变信号,该现象可能对区域生态环境及水资源状况产生较大影响。 相似文献
9.
Dr. J. Karte 《GeoJournal》1983,7(4):329-340
As formed by frost-action and the presence of intensely frozen ground periglacial phenomena, especially microrelief features, are good examples for geomorphic phenomena as being clearly dependent upon specific climatic conditions. Whereas climate controls and delimits the formation and occurrence of periglacial phenomena at a zonal and regional scale, non-climatic vegetational, topographical and edaphic factors are significant within the climatically defined boundary conditions at a smaller scale. It can be shown that each type of periglacial phenomenon is dependent on specific climatic and edaphic conditions. Data on these conditions are compiled in several tables. On the other hand, because of this dependence on specific environmental conditions periglacial phenomena are at the same time diagnostic indicators for such conditions. As to climate they are indicators for specific climatically defined types of frozen ground and for thermal conditions in terms of mean values, such as mean air temperatures, freezing and thawing indexes. Spatial associations of genetically different types of periglacial phenomena indicate the extent and regional subdivision of the periglacial environment and its climatic limits. The definition of the climate-diagnostic value of present periglacial phenomena is an essential perequisite for the palaeoclimatic interpretation phenomena are sensitive to climatic variations of small amplitude and as such they are also indicators of recent short-term climatic changes. As to edaphic conditions they indicate frost-action potential of the groud and various soil properties which have practical implications. As edaphic indicators periglacial phenomena are of significance for terrain evaluation programmes in the Arctic for practical purposes. 相似文献
10.
保温处理措施在多年冻土区道路工程中的应用 总被引：26，自引：11，他引：26
阐述了保温处理措施保护多年冻土的原理, 认为保温材料下部地温年变幅的减小是保温处理措施保护多年冻土上限下降的主要效果. 青藏公路昆仑山越岭地段保温处理试验路段路基、路肩及天然地表下的地温观测资料证实, 保温处理处理措施并不能改变因修筑路基而引起的路基吸热趋势, 但是保温处理后浅层地温下降; 地温年变幅明显减小, 多年冻土上限比无保温处理路段高. 青藏铁路北麓河试验段保温处理试验路段半年的观测资料表明, 保温层上下面温度存在巨大差异, 充分体现了保温材料的热阻效应, 可望大幅度减小保温材料下部地温的年变幅, 起到保护或延缓多年冻土融化的效果. 相似文献
11.
ERICH DRAGANITS CHRISTOPH JANDA 《Boreas: An International Journal of Quaternary Research》2003,32(2):436-442
Subaqueous, bowl-shaped depressions found in a Himalayan pond formed in an abandoned river channel in the Lingti Valley (Spiti, NW India) are spring pits (Quirke 1930 ). The occurrence of the spring pits is restricted to the western end of the pond, where coarse-grained, highly permeable alluvial fan material continues below lacustrine mud deposits. The spring pits formed by active vertical discharge of ground water from an underlying artesian alluvial fan aquifer, confined by the overlying fine-grained lacustrine sediments. The aquifer is continuously recharged by down-slope ground-water flow in the alluvial fan. These small artesian springs are comparable with much larger artesian springs described in the literature and a similar mechanism of formation is proposed. Some similarities in their shapes and mechanisms of formation may indicate that spring pits represent small, nearshore examples of pockmarks. The differences of these features, formed by persistent fluidization from short-lived seismic liquefaction processes, are discussed and the utility of the structures for palaeo-environmental and palaeo-ground-water interpretation is evaluated. 相似文献
12.
在岩溶含水系统中,作为主要排水通道的管道对泉流量动态具有一定的控制作用,而管道特征参数对流量变化亦有影响。为确定管道各参数的影响,前人以管道发育的岩溶水系统为研究对象,进行了短时间序列泉流量响应的分析探讨,而对岩溶管道不十分发育的岩溶水系统的研究较薄弱。为此,本研究结合北方岩溶水系统的发育特征,借助CFP管道流模型对管道各参数对岩溶系统流量和流态的影响程度及各参数的敏感性进行了分析,而后基于河南鹤壁许家沟泉域岩溶水文地质特征构建了泉域的MODFLOW-CFP模型,对泉域岩溶地下水渗流进行了模拟,并对不同降水保证率下的泉流量进行了预测。结果表明:管道流量与管壁渗透系数、管道坡度和管径呈正相关,而随弯曲度和埋深的增加管道流量呈先增大后减小的趋势。管壁粗糙度对流量的影响较小,且呈现出一定的波动性,尤其是当管壁粗糙度较小时,波动比较明显。经敏感性分析发现,管壁渗透系数和埋深的敏感性最高,其次为弯曲度和管道坡度,而管道直径和管壁粗糙度敏感性最低。许家沟泉域在25%降水保证率下,年最大泉流量为0.45 m3/s,平均泉流量为0.36 m3/s;在75%降水保证率下,年最大泉流量为0.41 m3/s,平均泉流量为0.31 m3/s,与实际情况吻合。该法可为我国北方岩溶区水资源评价及泉域水资源开发保护提供借鉴。 相似文献
13.
晋祠泉断流与地下水资源保护关系 总被引：4，自引：0，他引：4
通过对晋祠泉域岩溶地下水水文地质条件的分析,阐述了晋泉形成机理和断流原因,认为晋泉断流是多种因素的综合效应。说明地下水资源保护是一项系统工程,应采取统一的、科学的、多层次的全面管理,才能有效地保护有限的地下水资源,唤醒人们在进行经济建设的同时,要注意保护我们赖以生存的地球环境。 相似文献
14.
Climate and material controls on periglacial soil processes: Toward improving periglacial climate indicators 总被引：1，自引：0，他引：1
Norikazu Matsuoka 《Quaternary Research》2011,75(2):356-365
One of the distinguished efforts of A.L. Washburn was to reconstruct mean annual air temperature using periglacial features as climate indicators. This paper reviews existing periglacial indicators and proposes a strategy to improve their thermal resolution based on recent periglacial process studies, with a focus on solifluction and thermal contraction cracking and associated landforms/structures. Landforms resulting from solifluction reflect both the depth subjected to freeze-thaw and the thickness of frost-susceptible soils. The thickness of a solifluction structure can be used to infer the dominant freeze-thaw regime and minimum seasonal frost depth. Ice-wedge pseudomorphs have limited potential as a climate indicator because (1) they mainly reflect extreme winter temperatures, (2) their thermal thresholds depend on the host material, and (3) they need to be distinguished from frost wedges of other origin produced under different thermal and/or material conditions. Monitoring studies of currently active ice wedges suggest that ice-wedge cracking requires a combination of low temperature and large temperature gradients in the frozen active layer. Further field monitoring of periglacial processes and their controlling factors under various climate conditions and in various materials are needed, however, to improve the resolution of periglacial paleoclimate indicators. 相似文献
15.
This review article is intended to introduce periglacial environment present and past in Japan, and to summarize some studies on it. The periglacial climate in Japan is characterized by a wide annual range of air temperature and much snow accumulation in winter. This makes for local variability in appearance of periglacial processes on the mountain slopes near crests. In Japan, the main interest in periglacial studies concerns the above-mentioned variability and its causes, that is, how periglacial processes relate to vegetation, local climate especially snow accumulation and its seasonal duration, soil, micro-relief, properties of bed rock etc.Seasonal soil freezing was measured in lowlands of Hokkaido. Depth of frost penetration without snow cover increases proportionally to the increments of accumulated degree-days. Depth of frost penetration on natural conditions is affected not only by the degree-days but also by the depth of snow cover which differs locally even within a small area.The oldest frozen ground phenomena was recognized in a horizon about 50,000 years old in the lowlands of Hokkaida. Involutions about 40,000 years ago exceeded active earth hummocks in size. And the phenomena reached the maximum phase is represented by icewedge casts of the En-a pumice (ca. 15,000 abp). Most of fossil features are covered with undisturbed Ta-d pumice (cz. 9,000 abp), but earth hummocks and vertical stones have been still formed in the Holocene tephra layers. 相似文献
16.
The braided outwash of Wartanian age near Bełchatów, central Poland, was formed synchronously by two river systems: glacier streams flowing from the northwest and west and periglacial rivers flowing from the south and southwest. An extensive alluvial fan was formed which later developed into a highly aggrading fan due to a rising water level in the proglacial lake to the north. Braided streams were represented by relatively low-energy systems with shallow-channel and/or transverse bar deposition. Sporadically, rapid inflows of meltwater caused more energetic conditions and formation of large scours. The latter were found only in the glacier streams and this was confirmed by palaeocurrent measurements and analyses of quartz roundness. 相似文献
17.
利用多年观测资料,结合地下水补、径、排条件,分析娘子关岩溶地下水动态变化特征及成因。结果表明:（1）娘子关泉群流量在1980-2004年前总体表现为下降状态,2004年之后趋于稳定并略有回升;（2）岩溶地下水位动态空间上表现为地下水补给区比径流区变化大,时间上则分为两个不同时间段:1980-2004年表现为持续下降状态,2005-2014年表现为波动缓慢下降,部分地区水位小幅回升;龙庄岩溶地下水1998年1月到2004年1月水位下降22.9 m,平均年变幅3.82 m,2005年5月到2014年5月水位升高1.5 m,年均变化-0.17 m。 相似文献
18.
Hydrologic and geochemical influences on the dissolved silica concentration in natural water in a steep headwater catchment 总被引：1，自引：0，他引：1
The dissolved silica concentrations in groundwater, springwater, and streamwater were measured on an unchanneled hillslope in the Tanakami Mountains of central Japan. The effects of preferential flowpaths, including lateral and vertical flow in the soil layer and flow through bedrock fractures, on the variation in the dissolved silica concentrations in runoff and groundwater were examined, as were the effects of the mixing of water from geochemically diverse water sources on the dissolved silica concentrations. The mean dissolved silica concentrations in water sampled from 40 cm below the soil surface and in transiently formed groundwater above the soil-bedrock interface during rainfall events were relatively constant, independent of the variation in the mixing ratio of pre-event water and incoming throughfall. These waters were mostly supplied by the vertical infiltration of water in soil. The mean dissolved silica concentrations were similar, regardless of sampling depth, although the mean residence time of the water increased with depth. These results indicated that the dissolved silica concentrations in soil water and transient groundwater were independent of contact time between the water and minerals. The mean dissolved silica concentration in perennially saturated groundwater above the soil-bedrock interface, which was recharged by water infiltrating through soil, and water emerging from bedrock in an area near the spring was more than twice that of transient groundwater, and the variation was relatively large. The mean dissolved silica concentration increased significantly downslope, from perennial groundwater to spring from soil matrix to stream, and the spring and stream concentrations also showed large variations. The dissolved silica concentration was highest in the spring from a bedrock fracture and was relatively constant. The mixing of water from two geochemically diverse water sources, soil and bedrock, controlled the dissolved silica concentrations of the perennial groundwater, the spring from soil matrix, and the stream. Our results demonstrated that in most areas of this headwater catchment, the preferential flowpaths have only a small effect on the dissolved silica concentrations. In a small area, which was < 2% of the total catchment area near the spring, the dissolved silica concentration was controlled by the mixing of water from geochemically diverse water sources. 相似文献
19.
Human activities in the karst Ozark Plateaus can impact water quality of springs where surface water is rapidly transferred
to subsurface conduits. Bennett Spring, in southern Missouri, is the fourth largest spring in the state and supports local
tourism activities. Questions regarding poorly functioning on-site wastewater systems (OWS) have raised concerns over the
long-term water quality of the spring. This study reports the results of a surface water quality monitoring program in the
recharge area where monthly samples were collected at base flow to identify potential pollution sources to the spring. Base
flow hydrology of the recharge area was highly variable over the study period, which was drier than normal, causing an incomplete
sampling record due to no flow conditions at some sites. For most of the year, nutrient levels were less than the eutrophic
threshold (ET) of 0.075 mg/l total phosphorus (TP) and 1.5 mg/l total nitrogen (TN). Sites that consistently displayed concentrations
of TP and TN higher than the ET were influenced by wastewater treatment plants (WTP) or OWS. Sites with nutrient concentrations
above the ET were likely influenced by the re-release of nonpoint source related TP and TN delivered to streams during storm
events. Water quality and discharge at the spring outlet remained consistent over the sampling period suggesting diffuse recharge
from a deep aquifer source is able to dilute shallow ground water sources carrying nonpoint pollutants at base flow. Historical
and regional data comparisons show these trends have been consistent over at least the last two decades. 相似文献
20.
地表水与地下水相互转化是中国西北干旱内流盆地水循环的显著特征,转化机制研究是盆地水循环规律认知和水资源可持续管理的重要基础。以我国西北干旱内流河黑河流域中游的张掖盆地和盐池盆地为研究区,建立了黑河主干河道时变水平衡模型和地表水地下水耦合数值模型,研究了长周期水文变化和人类活动双重影响下地表水与地下水转化机制,得到如下认识:（1）补给条件由以天然条件下河流渗漏为主的线状补给演变为以河流与引水渠道渗漏的线状补给和灌区田间入渗面状补给,排泄条件由以泉水溢出和天然湿地排泄演变为以泉水溢出与地下水开采为主的排泄。（2）张掖盆地黑河干流河道入渗段和溢出段大致以G312 大桥为界,亦称为地表水与地下水转化的转折点。莺落峡—G312 大桥段为悬河渗漏段,河道入渗补给主要受控于进入河道的实际过水量。其中,莺落峡—草滩庄段河道入渗补给率为28.20 %;草滩庄—G312 大桥段河道入渗补给量与河道过水量的关系可用分段函数表达,河道过水量大于或等于0.37×108 m3/mon时呈幂函数关系,小于则呈线性函数关系。G312 大桥—正义峡段为地下水溢出段,其中G312大桥—平川大桥段地下水溢出量约占全部溢出量的70%,溢出峰值出现在高崖水文站下游约6 km处,其单长溢出量可达0.46 m3/(s·km)。（3）研究区是一个相对完整的河流—含水层系统,近31年来经历了连枯和连丰的水文变化,地下水补给排泄条件及与地表水转化机制均发生了相应的变化。地表水与地下水转化最强烈的地区为张掖盆地中部的黑河—梨园河倾斜平原。1990—2001 年连枯期,灌区引水量总体逐年减少,以河道入渗和渠系渗漏为主的补给量平均以0.06×108 m3/a速率减少,农田灌溉面积增加导致灌溉用水增加,地下水开采量显著增加,地下水水位逐年下降,储存量累计减少5.77×108 m3,地下水溢出量平均减少0.16×108 m3/a;而2002—2020 年连丰期,灌区引水量总体逐年减少,河道入渗量呈增加趋势,地下水总补给量平均增加0.15×108 m3/a,灌溉面积继续扩大,农灌开采量随之增加,以河道入渗量增加为主导,地下水水位持续上升,储存量累计增加5.45×108 m3,地下水溢出量平均增加0.08×108 m3/a。总之,补给和排泄条件变化较大,地下水储存量先减后增,地下水溢出总量变化较为平缓,反映了该区巨厚含水层系统的巨大调蓄功能。（4）位于张掖盆地东部的诸河倾斜平原地下水水位长期处于持续下降状态,这是由于地表水开发过度,补给量锐减。黑河侵蚀堆积平原地下水水位基本稳定。30 多年来盐池盆地倾斜平原地下水水位长期处于持续下降状态,这是由于移民开垦导致地下水过量开采。（5）内流盆地天然悬河入渗段是珍贵的地下水补给通道,无论连枯期还是连丰期,河道实际过水量是河道渗漏补给量的关键,保护上游天然河道和一定的河道实际过水量是内流盆地水资源可持续管理的关键。 相似文献