层次分析-熵值定权法在城市建设用地适宜性评价中的应用

在前人评价经验的基础上,采用层次分析-熵值定权法和模糊综合评价法进行了建设用地适宜性评价,该定权方法所采用的三标度法在一定程度上解决了传统九标度法难以通过的一致性检验问题,且便于把握打分尺度,可操作性强;建设用地评价要素及因子的变异程度对指标的权重有很大的影响,引入熵值的概念能更合理地确定评价指标的权重。文中以天津中心...     

Architecture of turbidite channel systems on the continental slope: Patterns and predictions

The study of many slope channel systems has led to the development of rules in the form of observations, measurements, and hypotheses. For example, we hypothesize that high abandonment relief can strongly influence the location of the subsequent channel element and will result in an organized channel stacking pattern in which the path of the younger channel element approximates the path of the former element. The rules were developed with the objective of constructing forward models of petroleum reservoirs that are internally consistent, reproducible, and quantifiable. Channelized turbidite deposits can be interpreted to be the product of multiple cycles of waxing-waning flow energy at multiple scales. Systematic changes in the volume and caliber of turbidity flows through time trigger a fall of the equilibrium profile, which drives erosion and sediment bypass across the slope, followed by a rise of the equilibrium profile, which allows deposition on the slope of increasingly mud-rich sediments through time. In most turbidite successions, at least three scales of waxing-waning cyclicity can be interpreted: element, complex set, and sequence. The stacking pattern of channel elements within a complex set-scale cycle tends to be sequential: (1) erosion and sediment bypass; (2) amalgamation of channel elements associated with a low rate of aggradation; (3) a disorganized stacking pattern of channel elements associated with a moderate rate of aggradation; and (4) an organized stacking pattern of channel elements associated with a high rate of aggradation. Stages 1 and 2 may be absent or minor in mud-rich systems but prominent in sand-rich systems. Conversely, stage 4 may be prominent in mud-rich systems but absent in sand-rich systems. Event-based forward modeling, utilizing rules, can produce realistic architectures, such as the four stages described above. Multiple realizations and multiple alternative models can be constructed to quantitatively examine the probability of specific parameters of interest such as pore volume and connectivity.     

Mountain pastures and grasslands in the SW Tien Shan, Kyrgyzstan �� Floristic patterns, environmental gradients, phytogeography, and grazing impact

Vast grasslands are found in the walnut-fruit forest region of southern Kyrgyzstan,Middle Asia.Located above the worldwide unique walnutfruit forests and used for grazing,they play a pivotal role in the mixed mountain agriculture of local farmers.Accordingly,these pastures are subject to an increasing utilization pressure reflecting the changing political and social conditions in the transformation process from a Soviet republic to an independent state.A first detailed analysis of mountain pasture vegetation in the Ferghana Range answers the following questions:What are the main plant community types among Kyrgyzstan’s mountain pastures? What are the main environmental gradients that shape their species composition? Which phytogeographical distribution types are predominant? How does grazing affect community composition and species richness in these grasslands? Species composition was classified by cluster analysis;underlying environmental gradients were explored using DCA.A dataset of 395 relevés was used for classification,and a subset of 79 relevés was used in a DCA to analyze the correlation between vegetation,environment,and grazing impact.The investigated pastures were classified into four distinctive plant communities.The site factors altitude,heat load,inclination and grazing impact were found to be the major determinants of the vegetation pattern.A significant overlap between floristic composition and structural and spatial properties was shown.The majority of the species pool consisted of Middle Asian endemics and Eurosiberian species.However,disturbance-tolerant species played a significant role with respect to species composition and coverage of the herbaceous layer in vast areas of southern Kyrgyzstan’s mountain pastures.In general,an intense grazing impact is clearly reflected by both species composition and structural variables of plant communities.The highly diverse and unique ecosystem is modified by an increasing utilization pressure.In order to maintain vital processes and functioning of this valuable ecosystem-in both economical and ecological terms-,it is indispensable to adopt appropriate pasture management strategies.     

大口径深层曝气井地下竖井构筑物施工风险管理

深层曝气井地下竖井构筑物的施工风险与拟建场地工程地质勘察、成孔钻进、外管下放、管外回填固化等环节风险相关。利用层次分析-模糊评判方法把深层曝气井地下竖井构筑物施工风险表示为有序的递阶层次结构,通过确定各施工环节的风险权重,对施工环节的风险进行排序,确定各施工环节的风险程度。把层次分析的量化结果与模糊数学中的综合评判方法结合起来,对深层曝气井地下竖井构筑物施工进行全面的风险评价、管理。     

Environmental Impact Assessment of High Pressure Water Scrubbing Biogas Upgrading Technology

The aim of this work was to assess the burdens of a process in terms of environmental and health impacts, resource depletion issues, and energy demand based on the ability of the Life Cycle Assessment methodology to link the environmental impacts with the mass and energy flows. The analysis was done in terms of process and environmental performances of high pressure water scrubbing (HPWS) system applied for biogas upgrading. The application of process simulation based on the Aspen Plus® software has been considered as supportive for the calculation of mass and energy balances. Data processed using GaBi 4: Software showed that global warming, acidification, and human toxicity potentials were the main impact categories associated with the HPWS process. These indicators are largely related to the exhaust gas from the desorption column and the indirect emissions generated during energy consumption. The life cycle inventory study resulted in the development of a database with a vast inventory of data regarding HPWS technology. A basis for assessing potential improvements in the environmental performance of the system is provided. Future studies in this area will address the economical evaluation of the HPWS technology, so as to maximize economic efficiency and minimize environmental impacts.     

1961—2019年中国区域连续性暴雨过程的危险性区划

利用暴雨区连续追踪的思路和全国2481个气象站逐日降水资料对1961—2019年全国区域连续性暴雨过程（Regional Continuity Rainstorm Process,RCRP）进行客观识别,并根据RCRP的持续时间、影响范围、最大日降水量和最大过程降水量建立和改进危险性评估模型和危险性区划。结果显示：1961—2019年中国共发生2294次RCRP,危险性排名前十强的RCRP与历史记录相符;其危险性空间分布特征与我国降水气候态分布相似,由东南向西北逐级递减;我国RCRP的高危险性区域位于华南和江南地区;危险性的季节空间分布与同季节的降水特征相关,春季华南地区的RCRP高危险性等级体现了我国华南前汛期的影响;夏季华北和东北地区的RCRP危险性高于其他季节,沿海地区的高危险性体现了台风暴雨的影响;秋季四川北部的危险区主要体现了华西秋雨的影响;单次RCRP危险性区划表征本次暴雨洪涝受灾程度大小的分布情况,可以直观地判断此次RCRP对我国相应区域造成暴雨洪涝灾害的大小分布情况。其研究结果增进了对于RCRP演变规律的认识,对于预测未来RCRP季节或次季节内等不同时间内的区域危险性强度大小及其相关的暴雨洪涝灾害风险防范具有重要意义。     

市政管道状况评价技术研究

本文首先对管道缺陷状况进行了总结分类,并对管道缺陷状况评价方法进行了探讨,以此为基础,用VB6．0开发了相应的管道状况评价软件,然后,采用层次分析法对管道各类缺陷严重性进行了分析,得出管道修复优先次序,为市政管道的评价与维护提供了一定的参考意见。     

AN EXPERIMENTAL STUDY ON BEDMAKING AND CATASTROPHIC PROCESSES IN ISLAND BRAIDED CHANNEL

LINTRODUCTIONAstudyonevolutionandpredictionofthefluvialgeomorphicsystemhasdevelopedinthe1970's(Scheideggef,1975),andisstillapplied.Fromthemiddleofthe1980'son,researchofcatastrophicprocessesinthefluvialgeomorphicSystem(catatrophism,hazards)hasbeenfocusedon(SchummandChorley,1983,ShenandSchumm,1981,Chorley,SchununandSugden,1985).WhenafluvialgeomorphicSystemislocatedatthelinearregionofanollequilibriumstatebutveryclosetoequilibriumone,theboundaryconditionprotectstheSystemfromequilibrium,an…     

南北地震带中段地震活动的板块动力学研究

在大陆造山带研究的最新成果基础上论述了南北地震带中段地壳的定变过程，结合造山带内部的高温韧性滑脱构造及地球物理深部探测成果和新生代以来的板块运动探讨了南北地震 段地震的地壳动力学过程及成因机制。