城镇体系等级结构的分形维数及其测算方法*

文章探讨了城镇体系等级结构的分形研究方法。首先,讨论了区域城镇规模分布的Zipf模型,并通过分形退化分析将其应用范围加以拓广,从而与非分形研究接口;第二,引进了分形结构因子,以此开创了城镇体系等级结构的FSF分析;第三,提出了表征城镇体系等级差异的差异度概念和度量方法。文章给出实例说明了各种方法的应用,并比较了三种方法的异同。     

泰山JMZ-150型锚杆钻机的研制

泰山ＪＭＺ－１５０型钻机是一种新型的、液－机结合的锚杆钻机。介绍了钻机的设计要求、结构、参数、特点及实际施工情况。     

孔兹岩系及其研究概况

作为地壳早期演化阶段的一套变质沉积建造,孔兹岩系在原岩、成矿作用方面具其独有的特征和专属性。世界各地孔兹岩系的研究资料表明,其多数形成于太古代末及早元古初期,并经历了复杂的变质变形作用。同时含丰富的晶质石墨、富铝矿物、磷等非金属矿产,故孔兹岩系的系统研究对开发利用其矿产资源及推断地壳早期历史的演化,具有重大意义。本文对孔兹岩系原岩建造、变质作用、成矿作用及形成时代的研究现状作了概括介绍和评述。     

推进国土资源信息化建设若干问题的探讨

加快推进国土资源信息化建设,是构建国土资源保障科学发展新机制的基础性工程之一。本文针对我国西部经济欠发达地区国土资源信息化建设现状和存在问题,对如何加快推进国土资源信息化建设若干问题进行了探讨,提出了一些建议,以期加快推进国土资源信息化的建设与发展,保障国土资源事业又好又快发展。     

灾后城镇重新选址的地震地质灾害评估纲要

纲要概括了地震地质灾害评估在重要基础设施选址中的目的和重要意义,给出了地震地质灾害评估的流程、评估内容、评估方法,其中包括场址位置和调查区域的确定,历史和现代仪器地震记录,断层和活断层的鉴定、活动性评价及其方法.讨论了地震引起的地表破裂、滑坡、崩塌等地质灾害估计的内容及方法,及相应的避让距离和加固措施.     

汶川8.0级地震滑坡、崩塌机制

本文总结了汶川8．0级地震引起的滑坡、崩塌的破坏特征,分析了地震地质灾害的外因和内因。鉴于本次地震导致的大量人员伤亡和巨大的财产损失,在进行城镇灾后重建工作或类似山区城镇规划时,强烈建议进行地震地质灾害评估工作。     

Study on runoff simulation of the upstream of Minjiang River under future climate change scenarios

Climate change is one of the main factors that affect runoff changes. In the upstream of Minjiang River, the temperature increased significantly in the last 50 years, while the precipitation decreased on the contrary. In order to analyze the effect of climate change on site runoff, watershed runoff depth and evaporation, nine climate scenarios are assumed based on rainfall and temperature indicators. A SWAT model of Minjiang River is constructed, and runoff simulation is carried out with the nine scenarios. The results show that if precipitation increases or decreases 20 %, the change rate of runoff depth will increase or decrease 28–32 %; if temperature increases or decreases 2 °C, the change rate of runoff depth will decrease or increase 1–6 %; if temperature increases or decreases 2 °C, the change rate of the potential evaporation will increase or decrease 5–16 %, and the actual evaporation rate of variation will increase or decrease 1–6 %. Overall, precipitation variation has greater effect on simulated runoff than temperature variation dose. In addition, temperature variation has more obvious effect on the runoff simulation results in dry years than in wet years. The actual evaporation of watershed depends on evaporation capacity and precipitation and increases with the increasing of the potential evaporation and precipitation. The study also shows that the climate change scenarios analysis technology, combined with SWAT hydrological model, can effectively simulate the effect of climate change on runoff.

     

Frozen subduction in the Yangtze block: insights from the deep seismic profiling and gravity anomaly in east Sichuan fold belt

The Sichuan basin is the main part of the middle-upper Yangtze block, which has been experienced a long-term tectonic evolution since Archean. The Yangtze block was regarded as a stable block until the collision with the Cathaysia block in late Neoproterozoic. A new deep seismic reflection profile conducted in the eastern Sichuan fold belt (ESFB) discovered a serials of south-dipping reflectors shown from lower crust to the mantle imply a frozen subduction zone within the Yangtze block. In order to prove the speculation, we also obtain the middle-lower crustal gravity anomalies by removing the gravity anomalies induced by the sedimentary rocks and the mantle beneath the Moho, which shows the mid-lower crustal structure of the Sichuan basin can be divided into eastern and western parts. Combined with the geochronology and Aeromagnetic anomalies, we speculated the Yangtze block was amalgamated by the West Sichuan and East Sichuan blocks separated by the Huayin-Chongqing line. The frozen subduction zone subsequently shifted to a shear zone accommodated the lower crustal shortening when the decollement at the base of the Nanhua system functioned in the upper plate.     

利用专家评估法作未来10年（2000～2010年）广州市气象灾害影响趋势展望

将气象灾害（主要是风灾、涝灾和旱灾）对广州市的影响程度分成轻微、偏轻、中等、偏重和严重五个级别，在时间上将未来10年分成三个时期：近期（2000～2002年）、中期（2003～2006年）、远期（2007～2010年），通过对广州市57名长期从事灾害研究的专家的调查，再运用专家评估法，结果表明：在三种灾害中，对广州市影响最大的是风灾，未来10年几乎每年都有热带气旋影响广州，造成较大程度的损失，其损失程度约比中等年份偏多10～15%;涝灾对广州市的影响在近期比台风小，中期与台风的影响接近，至远期的影响超过台风，整个预测期内比中等年份偏多10%左右。对广州市影响最小的是旱灾（特别在近期和远期），比中等年份偏少5%左右。