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101.
Study on urban construction planning based on karst landscape protection contributes to sustainable development of urban construction in karst area. Jinan is a city famous for karst spring water. Karst landscape plays a decisive role in urban construction. Through hydrogeological analysis, the distribution characteristics of karst mountain, cave, gully and flat dam in Jinan are analyzed. It is revealed that various karst landforms are involved in the spring circulation process to varying degrees. Some karst landforms have been destroyed in the process of urban construction and the karst landscape has been overexploited resulting in the direct or indirect weakening of spring water recharge and infiltration capacity and the decrease of spring water flow. Through the study of the principle of organic combination of karst landscape and urban construction planning, on the basis of protecting the ecological environment of the south, paying attention to the overall protection of the karst geomorphology system and the principle of accessibility of the karst landscape, the development countermeasures guided by urban planning are put forward based on karst landforms protection. On the basis of fully considering the special karst landform conditions in Jinan, the countermeasures are that the ecological control red line of urban construction planning should be set up based on karst mountains and valleys in southern of Jinan City. It is suggested that the bare carbonate rock continuous mountain foot line in the direct recharge area should be taken as the south control red line of urban development and included in the overall planning. The urban landscape is mainly displayed in the main axis based on karst mountains and springs, constructing East-West Axis-characteristic Landscape Belt along the Wufeng Mountain-Langmao Mountain-Hero Mountain-Qianfo Mountain-Long cave-Panlong cave-Jinping Mountain line and North-South Axis Landscape Belt along the Baotu Spring- Qianfo Mountain line, Baiquan-Panlong cave line, Baimai spring-Dajian Mountain line. Based on the karst river valleys and the river system, the urban spatial pattern is constructed, forming ecological corridor, restoring infiltration function of river. The form of urban construction should be shaped based on karst landform and the river system. The main form is semi-star like radiation type and the combination of central intensive type and zonal type. Based on the whole protection of karst geomorphology system and the scientific molding of karst landscape, the ecological landscape city with the symbiosis of spring and urban can be built.  相似文献   
102.
The chemical and isotopic characteristics (oxygen, hydrogen, and strontium) of spring waters and isotopic compositions of helium (He) and neon (Ne) in gases escaping from spring waters in the Lanping–Simao Basin are studied. A total of twenty-one spring water samples (twelve hot springs, four cold springs, and five saline springs) and eleven gas samples were collected from the study area, including one spring and one gas sample from northern Laos. It is found that saline spring waters in the study area are of chloride type, cold spring waters are of carbonate type or sulfate type, and hot spring waters are of various types. High total dissolved solids levels in saline springs are significantly related to Upper Cretaceous–Paleocene salt-bearing strata. On the basis of hydrochemical geothermometry, the reservoir temperatures (Tr) for hot springs, cold springs, and saline springs are 65.5–144.1, 37.8–64.4, and 65.1–109.0 °C, respectively, and the circulation depths of saline springs are much larger than those of hot and cold springs. The oxygen and hydrogen isotopic compositions of springs in the Lanping–Simao Basin and northern Laos are primarily controlled by meteoric waters with obvious latitude and altitude effects, and are also influenced by δ18O exchange to some extent. Most Sr2+ in spring waters of the study area is derived from varied sources (carbonate, evaporite, and silicate mineral dissolution), and the Sr isotopic compositions are greatly influenced by volcanic rocks. Wide distribution of crust-derived He in the Lanping–Simao Basin and northern Laos reveal that faults in these areas may not descend to the upper mantle. It is concluded that water circulation in the study area may be limited above the upper mantle, while saline springs may originate from the Upper Cretaceous–Paleocene evaporites. Hydrochemical characteristics demonstrate affinities among the Lanping–Simao Basin, northern Laos, and Yanjing, eastern Tibet, while disaffinities are observed between these areas and Tengchong on the basis of the hydrochemical characteristics and noble gas isotopic compositions.  相似文献   
103.
廖丽荣  杜白  刘玉 《云南地质》2014,33(3):413-416
采用电感耦合等离子体质谱法(ICP-MS)对饮用天然矿泉水中的锂和锶进行测定,分析了测定过程中不确定度的主要来源,按JJF 1059-1999《测量不确定度评定与表示》对各个不确定度来源进行分析评定,给出了此法测定过程中的扩展不确定度,使得测定结果的表达更加客观和真实.  相似文献   
104.
Discontinuous tephra layers were discovered at Burney Spring Mountain, northern California. Stratigraphic relationships suggest that they are two distinct tephras. Binary plots and standard similarity coefficients of electron probe microanalysis data have been supplemented with principal component analysis to correlate the two tephra layers to known regional tephras. Using principal component analysis, we are furthermore able to bound our uncertainty in the correlation of the two tephra layers. After removal of outliers, within the 95% prediction interval, we can say that one tephra layer is likely the Rockland tephra, aged 565–610 ka, and the second layer is likely from Mt. Mazama, the Trego Hot Springs tephra, aged ~ 29 ka. In the case of the Rockland tephra, the new findings suggest that dispersal to the north was highly restricted. For Trego Hot Springs ash, the new findings extend the distribution to the southwest, with a rapid thinning in that direction. Coupled with considerations of regular tephra dispersal patterns, the results suggest that the primary dispersal direction for both tephras was to the south, and that occurrences in other directions are unlikely or otherwise anomalous.  相似文献   
105.
2013年岷县漳县6.6级地震前甘肃天水花牛的水氡出现了与汶川8.0级地震极为相似的异常变化并在震前已被重点跟踪.为了对花牛水氡2013年出现的异常与岷县漳县地震的关系给出合理的判断,本文分析了花牛水氡正常的趋势背景和年变化形态,给出了正常背景和异常变化的判别指标;分析了花牛水氡的主要影响因素,认为气温是花牛水氡出现年变的主要因素,日降雨量达到一定量级才能引起水氡的短暂变化;着重从水氡测值的可靠性、影响因素的不一致性、多学科前兆变化的协调性、异常的重现性、异常与岷县地震的时空相关性等方面对2013年4月以来的异常进行了详细的分析和论证.研究结果可以判定,2013年4月以来天水花牛水氡出现的异常作为岷县漳县6.6级地震的异常是可信并可靠的.  相似文献   
106.
随着经济的快速发展和工业化、城市化进程的不断加快和人口的剧加,人类活动产生的污染物对济南市局部地下水造成了一定的污染。该文分析论述了济南市泉域的水文地质条件,地下水污染现状及综合评价,提出了防治地下水污染的措施。  相似文献   
107.
收集了1963—1996年长江口外海域水温的观测数据,分析了该海域冬、春季表层、10m层、20m层和30m层不同层次水温的季节和年际变化规律,以及其间水温垂向结构的变化。季节变化上,表层多年平均水温在8月最高,3月最低,底层多年平均水温9月最高,3月最低。年际变化上,冬季在1979年存在一个由冷到暖的跃迁;4月水温的年际变化较冬季复杂,表层、10m层、20m层和30m层水温分别在1979、1973、1973和1975年发生从冷到暖的跃迁。水平分布上,冬季除东南角小范围表层水温降低外,沿岸及北部海区表层水温均升高,春季北部和南部中间海域水温升高,升温幅度由表层至30m层逐渐变小。垂向结构上,冬季表底混合均匀,表层与20m层的年际变化相关系数高达0.97,春季表层与20m层的水温差存在10年左右的变化周期。本文将一些可能影响春季水温年际变化的因素与海温进行了比较并发现,在冷期,春季表层海温与长江口外海域气温相关较暖期好,相关指数为0.79;而暖期的春季表层与20m层的水温差与净热通量相关系数较高,为0.65。  相似文献   
108.
对月牙泉外围沙山表面沉积物进行系统采样,结合区域风况,分析了沙山典型部位的粒度分布及其参数特征。月牙泉北侧金字塔沙丘沙粒较粗,分选性较差,正偏趋势显著;月牙泉南侧线形沙丘以细沙为主,分选性较好,分布属正偏态。北侧金字塔沙丘从西南和西北两个坡面到东侧坡面,粗颗粒减少、分选性变好,但趋势不明显,说明金字塔沙丘未发生明显移动;而南侧线形沙丘自南侧坡面向北侧坡面沙粒粒径变小、分选变好,较细的沙粒被搬运并沉积北侧坡面,搬运作用十分明显,即线形沙丘向月牙泉方向发生明显移动。通过粒度分析风沙动力环境表明,月牙泉风沙危害主要来自南侧沙山北移。  相似文献   
109.
金字塔沙丘近地表流场及其对月牙泉影响研究   总被引:1,自引:0,他引:1  
对月牙泉景区气象站点资料和积沙量统计分析以及月牙泉北侧金字塔沙丘近地表流场野外观测表明:受地形影响,月牙泉景区和金字塔沙丘各点起沙风玫瑰和输沙势玫瑰在监测期内差别较大。在金字塔沙丘影响下,不同风向下气流发生多次分离和汇集,沙丘近地表气流发生明显变化,携沙气流行进方向发生改变。金字塔沙丘坡面上各点合成输沙势和起沙风与坡面走向呈垂直角度,气流沿坡面爬越沙丘时,动能发生损耗,携沙能力减弱,减少了进入月牙泉的风沙量,减弱了月牙泉的风沙灾害。  相似文献   
110.
MJO对中国春季降水影响的数值模拟研究   总被引:2,自引:0,他引:2  
白旭旭  李崇银  李琳 《气象学报》2012,70(5):986-1003
利用IAP-AGCM4.0模式,通过多初值集合数值模拟研究了赤道附近的大气季节内振荡(MJO)传播的两个关键位相期对中国东部春季降水的影响.当在赤道中东印度洋及赤道西太平洋引进异常非绝热加热(强MJO活动)强迫时,模式很好地模拟出了中国东部地区春季降水的异常形势,模式模拟与先期所作的诊断分析结果极为相似,即在MJO的第2-3(6-7)位相,中国长江中下游地区多雨(中国东部大部分地区降水偏少).对模式输出的高度场、风场、散度和涡度场以及水汽输送场的分析表明,中国春季降水异常的发生分别与异常非绝热加热在东亚/西北太平洋地区所造成的异常大气环流形势密切相关.对逐日响应场的分析表明,就MJO活动影响中国春季降水的可能物理过程及机制进行的讨论表明,赤道附近的异常对流加热不仅可以在赤道附近激发产生大气的罗斯贝波和开尔文波型响应,而且,还会在大气中激发产生从热带到中高纬度的罗斯贝波列遥响应.但是,由于异常对流加热发生的地区不同,大气遥响应场的形势也会十分不同,它所导致的影响也就很不一样.当异常对流加热发生在赤道中东印度洋(对应MJO的第2-3位相)时,大气的罗斯贝波列遥响应将在东亚/西太平洋地区形成有利于中国东部(尤其是长江中下游地区)春季降水偏多的形势;当异常对流加热发生在赤道西太平洋(对应MJO的第6-7位相)时,大气的罗斯贝波列遥响应将在东亚/西太平洋地区形成不利于中国东部春季降水的形势.  相似文献   
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