“8.8”大地震后九寨沟世界遗产地湖泊淤积与沼泽化现状评价     

蒋先逞豪  李瑞利  杜杰  江鎞倩  石聪  毛鹏  邱国玉  沈小雪 《湖泊科学》2021,33(6):1832-1843

地震及其伴生地貌过程破坏山体植被和土壤,产生的松散物源进入湖泊可能会带来泥沙淤积与沼泽化的风险.为探明九寨沟"8.8"大地震后湖泊淤积与沼泽化现状,以及松散物源的影响,本研究选取九寨沟景区内4个淤积与沼泽化程度不同的湖泊,进行了实地勘查,采用植被指标为主、促淤效应为辅的沼泽化综合评价方法进行现状评价;同时,结合无人机获取的湖泊周边环境和受灾程度信息,探讨了地震后伴生地貌过程及产物对九寨沟湖泊淤积与沼泽化的影响.结果表明：（1）四个湖泊的沼泽化发展模式均是由岸边向湖心推进.（2）各湖淤积与沼泽化程度空间分布特征存在差异,按发展程度从高到低依次表现为：五花海沼泽化程度最高,西北侧处于沼泽化后期（沼泽化指标值为[3,4]）;镜海次之,局部处于沼泽化盛期（沼泽化指标值为[1.5,3]）;犀牛海再次,仅出入水口处于沼泽化前期（沼泽化指标值为[1.5,2.5]）;箭竹海最低,整体处于沼泽化前期（沼泽化指标值为[0,1.5]）.（3）松散物源输入造成湖岸淤积程度增加、促进水生植被扩张,是造成九寨沟湖泊淤积和沼泽化发展的重要原因.管理者需重点关注小微湖泊、出入水口、受灾点的沼泽化发展情况.  相似文献   

基于MGE的勘测信息系统升级方法的研究     

张珊珊  梁子震 《测绘与空间地理信息》2007,30(2):46-48

随着社会各界对大比例尺空间数据的获取、共享、建库和应用等方面要求的提高,基于MGE平台开发的广州市勘测信息系统,其图形与属性数据分离管理的数据管理模式在数据安全性、数据共享以及数据动态更新等方面已经不能满足当前数据服务的要求,面临升级与改造。文章针对广州市城市勘测信息系统的现状特点,提出了广州市城市勘测信息系统升级的解决方案。  相似文献   

坚固体孕震模式下地下流体异常时空演化的数值模拟   总被引：10，自引：0，他引：10       下载免费PDF全文

张慧  梁子彬 《地震学报》2000,22(2):176-182

利用固液二相介质平面应变问题的有限元方法,研究了倾滑型地震地下流体场兆、源兆特征及时空演变过程．结果表明:孕震的早期阶段,即弹性积累和非线性阶段,地下流体缓慢变化,异常不明显;中期阶段,即硬化及局部膨胀阶段,震源区出现膨胀,地下流体异常主要集中在震源区,源兆出现得早,场兆出现得晚;进入中短期阶段,即大范围膨胀阶段,震源区异常继续发展,异常区不断扩大,在震源区以外出现新的异常值较大的地区．   相似文献   

南流江出海口海上工程地质钻探施工方法     

梁子山 《南方国土资源》1992,(1)

海上及海上滩涂钻探都必须借助于钻探船才能施工。钻探船的选择、钻探船的拼装、钻探船的抛锚定位、钻探施工的孔口装置等对海上钻探的安全施工关系极大,本人对上述几个方面进行较详细的介绍和探讨,可供同行进行江、河、湖、海等水域进行钻探时借鉴。南流江出海口海上工程地质钻探施工是成功的，取得了较好的经济和社会效益。  相似文献   

没有电器的“树上”旅馆     

梁子 《地理教学》2011,(6):2+65-F0002,F0003

很早前,曾经听一位英国朋友说,他在肯尼亚工作期间,住过一个别具特色的旅馆,那旅馆是上世纪初,一对英国夫妇凭借一部戏剧的灵感和天真的想像,突发奇想地在一片荒无人烟的大草原中,在几棵大树的树叉上,搭建了几闻简陋的、“吊脚楼”式的“树顶”小屋。  相似文献   

美国大规模调水的经济效益问题     

C.W.豪  云浦 《地理科学进展》1984,3(4):19-23

Ⅰ.现有的与予计的调水情况美国的降水分布是很不均匀的。粗略地说,这个国家的东部水资源丰沛而西部则干旱少雨。所以,毫不足怪,东部的水质问题比较突出,而高部水量问题则占首要地位。因而,西部地区对跨流域调水抱有极大的兴趣。  相似文献   

湖南近五年来之雾     

欧阳楚豪 《气象学报》1943,(Z1)

一、日之天气 雾之形成,须有待於静隐层结乏气团。於时风力微弱,对流不盛。故凡以足以扰动气团层结之因子,如风力增大气温升高等,均类能防础雾之发生,尤以辐射类为然。兹将湘省之长沙、常德、衡阳三地雾日之天气状况分述於下:  相似文献   

近年来人类活动影响下长江河口的变化模式     

王成龙  赵一飞  邹欣庆  许鑫王豪  葛晨东 《海洋学报(英文版)》2017,36(4):87-96

To evaluate the controlling factors for coastline change of the Changjiang(Yangtze River) Estuary since 1974,we extracted the mean high tide line from multi-temporal remote sensing images that span from 1974 to 2014 at 2-year intervals.We chose 42 scenes to constrain the changing pattern of the Changjiang Estuary coastline,and implemented GIS technology to analyze the area change of the Changjiang(Yangtze) Subaerial Delta.Runoff,sediment discharge and coastal engineering were withal considered in the analysis of the coastline changes.The coastline has transgressed seaward since 1974,and a part of it presents inter-annual variations.The area of the Changjiang Subaerial Delta increased by 871 km2,with a net accretion rate of 21.8 km2/a.Based on the change of sediment discharge due to the major projects in the Changjiang River Basin,we divided the changing pattern of the coastline into three stages:the slow accretion stage(1974–1986),the moderate accretion stage(1987–2002),and the rapid accretion stage(2003–2014).Liner regression analysis illustrated that there is a significantly positive correlation between the area changes and sediment discharge in the Chongming Eastern Shoal and Jiuduansha.This suggested that sediment load has a fundamental effect on the evolution of the Changjiang Estuary.Construction of Deep Waterway in the North Passage of the Changjiang River(1998–2010) led to a rapid accretion in the Hengsha Eastern Shoal and Jiuduansha by influencing the hydrodynamics in North Passage.Coastal engineering such as reclamation and harbor construction can also change the morphology of the Changjiang Estuary.We defined a contribution rate of area change to assess the impact of reclamation on the evolution of Changjiang Estuary.It turned out that more than 45.3% of area increment of the Changjiang Estuary was attributed to reclamation.  相似文献   

苏北滨海湿地互花米草潮滩CO₂,CH₄和N₂O通量的日变化规律     

许鑫王豪  傅光翮  邹欣庆  葛晨东  赵一飞 《海洋学报(英文版)》2017,36(4):105-113

The invasions of the alien species such as Spartina alterniflora along the northern Jiangsu coastlines have posed a threat to biodiversity and the ecosystem function.Yet,limited attention has been given to their potential influence on greenhouse gas(GHG) emissions,including the diurnal variations of GHG fluxes that are fundamental in estimating the carbon and nitrogen budget.In this study,we examined the diurnal variation in fluxes of carbon dioxide(CO_2),methane(CH_4),and nitrous oxide(N2O) from a S.alterniflora intertidal flat in June,October,and December of 2013 and April of 2014 representing the summer,autumn,winter,and spring seasons,respectively.We found that the average CH_4 fluxes on the diurnal scale were positive during the growing season while negative otherwise.The tidal flat of S.alterniflora acted as a source of CH_4 in summer(June) and a combination of source and sink in other seasons.We observed higher diurnal variations in the CO_2 and N_2O fluxes during the growing season(1 536.5 mg CO_2 m~(–2) h~(–1) and 25.6 μg N_2O m~(–2) h~(–1)) compared with those measured in the non-growing season(379.1 mg CO_2 m~(–2) h~(–1) and 16.5 μg N_2O m~(–2) h~(–1)).The mean fluxes of CH_4 were higher at night than that in the daytime during all the seasons but October.The diurnal variation in the fluxes of CO_2 in June and N_2O in December fluctuated more than that in October and April.However,two peak curves in October and April were observed for the diurnal changes in CO_2 and N_2O fluxes(prominent peaks were found in the morning of October and in the afternoon of April,respectively).The highest diurnal variation in the N_2O fluxes took place at 15:00(86.4 μg N_2O m~(–2) h~(–1)) in June with an unimodal distribution.Water logging in October increased the emission of CO_2(especially at nighttime),yet decreased N_2O and CH_4 emissions to a different degree on the daily scale because of the restrained diffusion rates of the gases.The seasonal and diurnal variations of CH_4 and CO_2 fluxes did not correlate to the air and soil temperatures,whereas the seasonal and diurnal variation of the fluxes of N_2O in June exhibited a significant correlation with air temperature.When N_2O and CH_4 fluxes were converted to CO_2-e equivalents,the emissions of N_2O had a remarkable potential to impact the global warming.The mean daily flux(MF) and total daily flux(TDF) were higher in the growing season,nevertheless,the MF and TDF of CO_2 were higher in October and those of CH_4 and N_2O were higher in June.In spite of the difference in the optimal sampling times throughout the observation period,our results obtained have implications for sampling and scaling strategies in estimating the GHG fluxes in coastal saline wetlands.  相似文献   

建立地震信息服务系统的网络安全管理体系的探索          下载免费PDF全文

郝柽  梁子斌  李少华  郝臻  张立红 《地震工程学报》2007,29(2):165-169

以国际信息安全标准BS7799/ISO17799为信息安全管理体系的准则,根据《中国地震局信息安全等级保护建设方案》的相关要求和规定,通过分析信息网络的层次关系,在科学的安全框架之上,探讨建立以防火墙系统、VPN应用系统、网络反病毒软件,以及入侵检测系统(IDS)安全策略为核心的地震信息服务系统网络安全管理体系构。  相似文献