STUDY FOR ABNORMAL VARIATIONS OF UNDERGROUND FLUID IN LIJIANG AREA,YUNNAN PROVINCE BEFORE LUDIAN M_S6.5 EARTHQUAKE IN 2014     

YANG Zhu-zhuan  DENG Zhi-hui  YANG Yue-wen  DENG Sheng-chang  LI Qing 《地震地质》2018,40(2):480-498

The study is based on the underground fluid observation data in Lijiang area, northwest Yunnan Province. The data include the water level and temperature in Dangxiao well and Jinjia well, and the ion measurements in Ganze spring. Combining with the data of regional hydrogeology, rainfall, well structures, and the geothermal gradient, we analyzed the variations of each measurement item before the Ludian M_S6.5 earthquake on August 3, 2014 and discussed the possible mechanism for the abnormal variations. The water levels of both Dangxiao well and Jinjia well are influenced by local rainfall, but the former shows hysteresis according to rainy seasons and is the long trend influence; while the latter shows synchronization between high water level and rainy season, indicating good connection between well water and shallow aquifer. The recharge water for Dangxiao well is in relatively low temperature, and the temperature sensor is located at the major connecting section between the well water and the aquifer; the water temperature variation is mainly affected by the discharge status and variation of water level. The Jinjia well is always in static level, and the temperature sensor is below the major connecting section between the well water and aquifer, so the water temperature is affected little by water level variations and in smooth fluctuation. The recharge source for Ganze spring can generally increase the contents of calcium and magnesium ions, so does the conductivity. The water level data of Dangxiao well since 2012 are decomposed with wavelet technique. The results, excluding such high-frequency components as the noise and the semidiurnal and daily wave components influenced by earth tide, are further processed with difference method in order to eliminate the trend effect. The results show that the relative change of water level is enhanced and in relatively rapid increase before the Ludian M_S6.5 earthquake; the corresponding water temperature values are high. The tendency of water level in Jinjia well displays descending, while the corresponding water temperature shows ascending. The content of calcium ion, magnesium ion, bicarbonate ion, and conductivity of Ganze spring are descending, while the content of fluoride ion is ascending. The abnormal variations of underground fluid in Lijiang area appeared in turns and were accompanied with minor earthquakes before Ludian M_S6.5 earthquake, which indicates enhancing of regional stress and increasing of fluid activity.  相似文献   

滇西丽江地区新生代富碱斑岩年代学、地球化学特征及其地质意义   总被引：2，自引：0，他引：2  

黄永高  罗改  张彤  熊昌利  贾小川  杨学俊 《现代地质》2018,32(1):28

滇西丽江地区新生代富碱斑岩位于滇西“三江”褶皱造山带与扬子板块西南缘结合部位,岩石类型多样,可分为碱性岩和碱性花岗岩,前者主要有正长斑岩、正长岩及粗面斑岩;后者主要包括花岗斑岩、二长花岗斑岩及石英二长斑岩。锆石LA ICP MS U Pb定年研究确定区内斑岩结晶年龄为346～371 Ma,侵位于始新世晚期。碱性岩石的SiO2含量为5454%～6770%,K2O＞Na2O,具有钾玄岩的特征;碱性花岗岩的SiO2含量为6716%～7066%,K2O＜Na2O,具有高钾钙碱性的特征。两类岩石都具有富碱(Na2O+K2O=703%～1170%)和准铝质—弱过铝质(A/CNK=064～115)的特征。富集轻稀土元素和大离子亲石元素(Sr、Ba、K、Pb等),相对亏损重稀土元素和高场强元素(Nb、Ta、Ti等),且具有高Sr、Sr/Y和La/Yb比值及低Y、Yb和镁值(Mg#＜05),表明区内斑岩兼具钾玄质岩石和埃达克质岩石的特征。综合研究认为,区内斑岩形成于印度－亚洲大陆碰撞造山的后碰撞阶段,其形成与减压熔融及幔源岩浆底侵促使增厚下地壳底部岩石发生部分熔融有关,是青藏高原东南缘构造转换带对主碰撞带造山作用过程的岩浆事件响应,进而分析确认本区具有斑岩-热液型金多金属矿床的找矿潜力,为深入认识丽江地区构造-岩浆-成矿作用提供了重要约束。  相似文献   

旅游活动与水环境耦合分析——以玉龙雪山-丽江盆地为例     

窦文康  王泽平  方金鑫  韩彤彤  蒲焘  张鹏 《冰川冻土》2021,43(4):1210-1217

玉龙雪山是我国季风海洋型冰川发育最为典型的代表性地区,也是北半球最靠近赤道的现代冰川区。丽江市的部分水源来自于玉龙雪山冰川融水,同时玉龙雪山景区每年吸引着上千万的游客来欣赏现代冰川。旅游活动与水环境息息相关且相互作用,水环境的准确刻画是指导与优化区域旅游活动的基础。以世界著名旅游城市丽江市为例,基于实地采样与数据分析,对2018年丽江市的旅游活动与水环境进行耦合分析。结果表明：丽江市旅游活动与水体污染耦合度极高,旅游活动与水体富营养化和水体毒理的耦合度较低。旅游活动与水环境存在较强的关联,特别是与水环境指标中的高锰酸盐指数,存在强烈的耦合关系。总体上,旅游活动与水环境存在相关关系,旅游旺季水环境质量较旅游淡季更差。  相似文献   

玉龙雪山冰川变化对ENSO事件的响应   总被引：1，自引：1，他引：0  

张忠林  何元庆  庞洪喜 《冰川冻土》2004,26(3):294-297

应用独立性检验方法就ENSO事件对我国云南丽江地区降水、温度和冰川变化影响进行了相关分析. 结果表明丽江降水与ENSO事件有密切关系, MEI值为负时下一年降水量增加, MEI正值与下一年降水量减少相对应. 丽江气温与ENSO事件关系显著, MEI值为负时下一年气温降低, MEI正值与下一年气温增加对应. 利用夏季降水量和气温设计了冰川积累量指数并与MEI进行对比分析, 发现当年MEI值与下一年的冰川积累指数存在一定相关关系, 并影响未来的冰川的变化, MEI为正时冰川将会退缩, MEI值为负时冰川将会前进.  相似文献   

丽江东部地区黑泥哨组铜矿成矿规律及潜力分析     

王平  刘辉龙  罗波  陈雪峰 《沉积与特提斯地质》2017,37(4):77-83

丽江东部地区广泛分布的黑泥哨组(P3h)是区域上一个重要的含铜层位,在该地区大公山、铜厂河、宝坪等地均发现有工业铜矿床。该地层中发现的铜矿床具有两种类型:产于火山沉积夹层中的火山沉积-热液型铜矿及产于构造破碎带中的构造热液型铜矿。主要控矿因素为二叠纪晚期古地理环境、火山活动、成矿前构造及喜山期岩浆活动。本文通过分析这些控矿因素之间的关系,总结该区域内黑泥哨组铜矿化规律,为今后的找矿工作提出一些建议。  相似文献   

漓江流域水环境综合治理对策     

成官文 《南方国土资源》1999,12(2):27-30

文章概述了漓江流域水环境现状,分析了存在的主要问题,阐明了流域水灾频繁、水环境污染的成因,指出了流域森林结构欠合理,调蓄能力不足,导致了流域洪涝、干旱频繁,枯水期长,水资源短缺;流域生活与生产排污,造成枯水期水污染。因而需进行深入的科学研究、绿化、兴修水利工程、实施节水技术、严格管理、科学调配水资源等综合举措,实现流域的可持续发展。  相似文献   

Characteristics of the Variation of Cross Fault Short-Baseline and Short-Range Leveling in Western Yunnan Earthquake Test Site Before Lijiang M_S7.0 Earthquake     

Li Zhonghua  Su Youjing  and Liu ZhuyinSeismological Bureau of Yunnan Province  Kunming  China 《中国地震研究》1998,(4)

Results of analysis of variation of cross fault short-baseline and short-range leveling in Western Yunnan Earthquake Test Site (WYETS), results show that among five observation stations of cross fault short-baseline and short-range leveling in WYETS before the Lijiang MS7.0 Earthquake occurred in February 1996 only Yongsheng observation station (epicentral distance 82 km) located at Chenghai fault shows great variation about one year before the earthquake. And the nearest observation station, Lijiang (epicentral distance 42 km); presents great coseismic variation, but does not show obvious anomalous variation before the earthquake. There are no significant variations related to the earthquake at the other three observation stations. Two methods are used in analysis of the observed data and some valuable results have been obtained.  相似文献   

丽江市地质灾害易发性遥感影像判译   总被引：2，自引：0，他引：2  

JIANG Qin  杨世瑜 《云南地质》2008,27(1):114-119

丽江市地质灾害多发,在滇西北旅游城市中较典型。应用遥感技术对丽江市地质灾害易发性的遥感研究,可突破传统方法,发挥宏观、综合、直观、快速特点,取得较好效果。  相似文献   

1951~2010年云贵高原大理和丽江气温、降水的气候特征分析   总被引：2，自引：0，他引：2  

刘翔卿  王雷  刘阳  孙绩华 《气候与环境研究》2018,23(5):513-523

利用大理和丽江气象站1951~2010年的逐日气象资料,分析了横断山脉东部气温、降水的气候特征。结果表明,1991年以后,大理和丽江地区均存在显著增温的趋势（0.58和0.55℃/10 a）,明显高于同时期中国平均气温的增加幅度;而在1991年之前,大理和丽江的年平均气温呈现下降或微弱上升的趋势（-0.14和0.07℃/10 a）。与夏季平均气温的增温幅度相比,冬季平均气温的增温更显著,且其变化趋势与年均气温的气候特征是一致的。大理和丽江年总降水及各季节降水量在1951~2010年并没有明显增加或减少的趋势。大理和丽江雨季开始的时间分别为第28候和第30候,持续时间分别约为5.5和4.5个月。20世纪80年代以后,丽江年平均风速的减小强度明显大于大理,这是因为丽江站地处城区,城市化剧烈,地表粗糙度增加显著。日照时数与云量呈反相的季节变化,降水量的多年平均的逐候变化与日照时数、总云量、尤其是低云云量相关,随风速增大而减小。  相似文献   

Study on simulating strong ground motion by fractal stochastic method     

GUO Meng-qiu  WANG Bin  XU Zhao-yong 《地震学报(英文版)》2005,18(4):490-495

The time history of strong ground motion can be synthesized by empirical Green's function (EGF) method.Firstly a large seismic event is discretized into a series of subevents; secondly recordings of earthquakes with proper size and spatial distribution are chosen as time history (EGF) of those subevents; finally the EGFs are summated to get the time history of ground motion caused by the large event.  相似文献