Influence of droughts on remote villages in the karst region of Guizhou Province,China: Causes and control

Even though the precipitation is abundant in the Karst region of Guizhou Province, remote villages in this area frequently suffer severe droughts. This paper studied the causes of droughts in this region through field investigation and references collection. Based on the cause analysis, some suggestions were provided for hazard prevention and control from an engineering perspective. Besides occasional extreme weathers, the drought in this area is primarily caused by its unique geological structures of Karst plateau and underdeveloped agricultural techniques. Meanwhile, the vicious cycle between drought and poverty, which causes the deficiency of water conservancy facilities and hazard prevention awareness, is an important reason for the frequent occurrence of agricultural and socioeconomic drought. Considering the social and economic conditions of remote villages, the long-term control of drought can only be realized if current measures are capable of bring immediate effects and benefits. Therefore, the construction of well-planned and designed water conservancy system based on each village’s natural and social conditions are the priority for current hazard prevention. Generally, the exploitation of subterranean river should be considered as the first choice to stabilize the water supply for remote villages. Meanwhile, the construction and improvement of micro water conservancy facilities, such as small water tank, small pond and so on, can effectively support the water providence during droughts as well.     

应用地理信息系统辅助山坡地潜在崩山灾害评估模式之建立

山坡地开发具有潜在的自然危险因子,人工开挖也会触动这些因子,因此,要做好土地管理工作,需从分析潜在崩山灾害类型以及开发区位两方面考虑。地形分析在工程、灾害评估等方面广为应用,本研究以张石角(1987)提出的“简确工程地质灾害调查与评估法”为依据,以山坡地丙种建地作为评估对象,利用地理信息系统所提供的空间分析及数据库功能,完成台湾省中、北部地区大范围的山坡地潜在灾害评估工作,其成果也将为政府部门所采用.     

陕南村镇住宅结构体系抗震能力评价研究——以汉中市留坝县为例

村镇住宅倒塌或损毁是造成村民财产损失和人员伤亡的直接原因，结构抗震性能是防灾减灾关注的重点。对汉中市留坝县8个行政镇75个自然村11570栋住宅结构体系、建筑年代、各组成部分损坏特征和抗震设防情况等进行调查，统计分析村镇经济水平、住宅结构体系抗震设防缺陷、空间分布特征和危险性等级；完成村镇住宅结构体系震害预测和易损性指数分析。研究结果表明:97.72%的村镇住宅满足正常使用要求，但74%的住宅结构体系存在抗震设防缺陷；村镇住宅受村镇经济水平和地理交通、施工技术及村民抗震设防知识等因素制约，既有结构体系倒塌或损毁的概率大、易损性强、抗震能力差。     

Systematic GIS-based landslide inventory as the first step for effective landslide-hazard management

The purpose of the so-called IFFI project (Inventario dei Fenomeni Franosi in Italia—Inventory of Landslides in Italy) and of many other related activities carried out by the Centro Regionale per le Ricerche Territoriali e Geologiche of ARPA Piemonte (Agenzia Regionale per la Protezione Ambientale—Regional Agency for Environmental Protection), is to map all the existing landslides in Piemonte (including both results of monitoring data and available historical data). ARPA carried out new systematic surveys using airphoto interpretation and created a specific alphanumeric geological information systems (GIS)-based database to store and process all the collected data. In order to obtain proper landslide-hazard zoning, it is necessary to provide a landslide inventory and to define the relationship between landslides and geological setting. A landslide inventory represents a fundamental base of knowledge, is a very basic tool for land planning, and strongly helps the local authorities in their decision making.     

Field monitoring of the Corvara landslide (Dolomites, Italy) and its relevance for hazard assessment

The Corvara landslide is an active slow moving rotational earth slide - earth flow, located uphill of the village of Corvara in Badia, one of the main tourist centres in the Alta Badia valley in the Dolomites (Province of Bolzano, Italy). Present-day movements of the Corvara landslide cause National Road 244 and other infrastructures to be damaged on a yearly basis. The movements also give rise to more serious risk scenarios for some buildings located in front the toe of the landslide. For these reasons, the landslide has been under observation since 1997 with various field devices that enable slope movements to be monitored for hazard assessment purposes. Differential GPS measurements on a network of 47 benchmarks has shown that horizontal movements at the surface of the landslide have ranged from a few centimetres to more than 1 m between September 2001 and September 2002. Over the same period, vertical movements ranged from a few centimetres to about 10 cm, with the maximum displacement rate being recorded in the track zone and in the uppermost part of the accumulation lobe of the landslide. Borehole systems, such as inclinometers and TDR cables, have recorded similar rates of movement, with the depths of the major active shear surfaces ranging from 48 m to about 10 m. From these data, it is estimated that the active component of the landslide has a volume of about 50 million m³. In this paper the monitoring data collected so far are presented and discussed in detail to prove that the hazard for the Corvara landslide, considered as the product of yearly probability of occurrence and magnitude of the phenomenon, can be regarded has as medium or high if the velocity or alternatively the volume involved is considered. Finally, it is also concluded that the monitoring results obtained provide a sound basis on which to develop and validate numerical models, manage hazard and support the identification of viable passive and active mitigation measures.     

基于Web-GIS构建昆明市地质灾害信息系统

简要介绍基于GIS平台的昆明市地质灾害信息系统的总体结构和功能,并对系统实现过程中几个关键问题进行讨论,为昆明市地质灾害信息的规范化管理以及地质灾害预报提供支撑。     

青海省东部农业区春季干旱分析及减灾对策

利用青海省东部农业区12个气象站的降水资料，分析了该区降水气候倾向率和近期春季、年降水变化趋势，对春季大气、土壤干旱趋势进行了探讨，并提出了相应的减灾对策。     

新疆天山地震灾害的初步分析

利用新疆天山地区丰富的地震资料，通过天山地区灾害性地震的空间分布、历史地震烈度分布、地震地表破坏特征、地震灾害损失论述了新疆天山地震灾害特征，分析了灾害成因。     

中国地质灾害危险性分析与灾变区划

根据中国崩塌一滑坡、泥石流，岩溶塌陷活动程度和形成条件，建立区域地质灾害危险性分析模型，据此，以县（市、区、旗）为单元，逐个计算地质灾害综合危险性指数，分析中国地质灾害危险性分析特征，结合区域自然条件，将中国大陆划分七大地质灾害灾变区和若干亚区，论述了各区地质灾害危险性水平和主要活动特征。