基于WebGIS的地质灾害数据库系统的设计

基于对地质灾害及其WebGIS技术的认识和了解,结合目前国内外对地质灾害和WebGIS的研究现状,从WebGIS的特点出发,设计了基于WebGIS的地质灾害数据库系统,实现WebGIS对地质灾害数据的管理,实现数据管理、图层管理、地质灾害点的动态监测、用户管理4个功能,从而对地质灾害数据进行有效管理,方便用户获取数据.     

林芝市公路地质灾害易发性区划及气象预报模型

[目的]对西藏自治区林芝市公路地质灾害易发性区划及气象预报模型进行研究,为实施该市境内公路沿线地质灾害气象预报提供理论依据。[方法]首先,选取了林芝市公路沿线15 km缓冲区内的断层密度、土壤类型、坡度、沟谷密度、年降水量、土地利用、裸岩率和距河流的距离8个地质灾害易发性区划因子,通过信息量及逻辑回归方法确定各区划因子的系数,得到了地质灾害易发性区划模型;再进一步依据地质灾害发生当日、前1日、前2日和前3日的日降水数据,使用逻辑回归方法建立了地质灾害气象预报模型。[结果]林芝市公路沿线15 km缓冲区内的大部分地区地质灾害易发性概率小于0.4,且离道路越近,地质灾害易发性概率越大。将该预报模型用于历史地质灾害点数据进行检验,发现该模型的预报准确率为85.71%,漏报率为14.29%。[结论]受地形地貌、降水资料等影响,该模型预报结果可能与实际情况存在一定的偏差,但能反映基本趋势。     

地质灾害易发山区新农村房屋建设选址理论与方法

过去农村房屋建设,大多未进行科学选址,随意烂挖乱建,致使不少房屋建在陡坡、陡崖脚、滑坡、崩塌、泥石流等地质灾害易发区内,存在严重的灾害隐患.新农村建设应彻底转变过去落后的建房方式,建房前应进行科学的选址.对拟建房区域的自然地质环境、地质灾害现状进行详细调查、评估,进行灾害危险性分区、建房地基环境分类.把新建房屋选在Ⅰ类地基环境区,若Ⅰ类区较少;满足不了新建房屋需要,可选少量条件较好的Ⅱ类地基环境区,但需加强对环境的保护,开挖边坡应及时加固,对可能引发、遭受的地质灾害进行治理.     

海南农垦农产品产地土壤重金属污染分布特征及评价

以海南农垦农产品产地土壤为研究对象,研究了土壤中As、Hg、Pb、Cd、Cr等5种重金属的含量特征,并利用单因子污染指数法、内梅罗污染指数法及潜在生态危害指数法,对该地区土壤重金属污染程度和潜在生态危害进行评价。结果表明:As、Hg、Cr平均含量高于海南省表层土壤背景值,重金属污染累积值分别为4.90、2.00、7.73;该地区土壤重金属污染空间分布不均匀,位于海南省北部地区的红明、东昌、南海、东路、南阳等基地内梅罗污染指数和Cr的单因子污染指数均大于1.00,土壤处于Cr轻度污染状态;土壤重金属潜在生态危害指数为168.70,整体表现为中等生态危害,潜在生态危害主要来自于As和Hg。     

A survey of contaminated ground with illustrative case histories

Contaminated ground represents a problem in all the industrialized countries of the world. Contaminated ground may give rise to hazards and that implies a degree of risk which also involves a problem of definition. The investigation of a site which is suspected of being contaminated differs somewhat from a routine site investigation. Sampling of soils, groundwater and gas producing material may be required. Various precautions may be necessary in doing this and operatives may have to wear protective clothing. The first case history considered involves a site investigation for a relief sewer in Glasgow, Scotland. As the site investigation progressed it ran into made‐ground which contained chemical waste. The presence of this waste meant that the nature of the investigation changed and much more stringent safety precautions had to be taken. It also meant that the initial location of the sewer tunnel had to be repositioned at greater depth in uncontaminated sandstone rather than in the superficial deposits above. Two further case histories associated with coal mining in the Ruhr district of Germany are included. The methods involved in investigating these two sites are described, as is their rehabilitation. Copyright © 2000 John Wiley & Sons, Ltd.