Modeling the influence of urbanization on urban pluvial flooding: a scenario-based case study in Shanghai,China

Natural Hazards - Rapid urbanization has brought great productivity, prosperity and challenges to Shanghai in the last few decades. This paper focuses on the influence of urbanization on urban...     

Geochemistry, geochronology and mineralization of the rare-metal granites in the Daping Ta-Nb deposit, Fujian Province, South China

<正>1 Introduction Rare-metal granites are widely distributed in South China.The Daping porphyritic granitic Ta-Nb deposit,located in the Yongding area of south Fujian province,South China,is a large rare-metal deposit recently discovered.Few studies have been made of its petrology,mineralogy,geochemistry,chronology and metallogeny.In recent years,several exploratory drillings have been done in this deposit.These drilling holes,from 380 to 600     

The Annual Characteristics of Rainwater HCHO in Guiyang City,Southwest of China

HCHO is ubiquitous and important chemical constitutes in the troposphere. The concentrations of the HCHO (aq) in the rainwater were measured in the Guiyang city, southeastern of China from May 2006 to April 2007 and 153 discrete samples were collected. Rainwater (N = 151) HCHO (aq) concentrations ranged from lower than method detection limit (MDL) to 40.2 µmol/L with a volume weighted mean value of 7.4 ± 8.8 µmol/L. The strong correlations between HCHO (aq) and HCOO^? (r = 0.69, n = 137), HCHO (aq) and nss‐ (r = 0.74, n = 137), HCHO (aq) and (r = 0.67, n = 137), HCHO (aq) and (r = 0.74, n = 133) suggest the significant influence of the anthropogenic input for the HCHO (aq) levels. The concentration levels of rainwater HCHO (aq) was inversely proportional to the amount of rainfall, indicating the below‐cloud process is the most important mechanism for rainwater HCHO (aq) scavenging processes. More than 70% of the HCHO (aq) wet deposition took place during the early stage of the rainfall. According to the air mass back‐trajectory analysis, the rainwater with industrial back‐trajectories coming from the north had the highest levels of HCHO (aq) while the rainwater with the green‐covered or marine back‐trajectories from the southeast had the lowest concentrations, and this indicate the HCHO (aq) originated from urban or industrial regions served as an important source of the rainwater. The annual HCHO (aq) wet deposition flux was calculated as 6.96 mmol/m² per year and the total deposition flux was estimated as 24.35 mmol/m² per year, 71.4% of which was dominated by dry deposition.     

暴雨内涝危险性情景模拟方法研究——以上海中心城区为例

本文采用地理信息系统技术（GIS）与水文/水动力学相结合的方法,使用修正的SCS模型进行产流模拟,利用局部等体积法和水动力模型进行汇流模拟,建立了基于情景的城市暴雨内涝危险性模拟工具,并对相同雨强情景下不同汇流模型的模拟结果与精度进行了对比分析。结果表明：（1）局部等体积法计算简单,对降雨的时程分配较为敏感,峰前历时和雨强对结果影响显著,较适合于雨型确定的城市暴雨内涝危险性快速模拟;水动力模型计算复杂,与整个降雨历时存在明显关系,模拟精度较高。（2）利用台风“麦莎”带来强降雨导致的积水实测数据,对模拟结果进行对比和验证,表明本文建立的水动力模型法模拟结果与实测降雨积水更为接近,更适合上海中心城区暴雨内涝危险性情景模拟。     

3种典型地表风沙流通量廓线研究现状

风沙流研究越来越受到人们的重视,其中风沙流通量廓线研究起着重要作用。本文总结了3种典型地表(流沙地表、草方格地表、戈壁地表)风沙流通量廓线研究现状及存在问题。由于研究方法、研究区域及集沙效率的不同,风沙流通量廓线函数有指数函数、对数函数、幂函数、分段函数等多种,同一问题不同函数模拟结果差异可达到3倍,难以应用于实际。根据研究中存在的问题,提出风沙流通量廓线研究发展趋势。     

上海城市室内空气质量影响因素分析

本文从环境、建筑材料和装饰装修材料、时间等角度,对上海城市室内空气质量影响因素进行分析,认为不同气候条件和地域景观会对室内质量产生影响,装饰装修材料、涂料及其胶粘剂和装修水平也会对室内空气质量产生影响.精装修房的室内空气质量检查调查成果表明,装修完成后不宜立即入住,在开窗通风4个月后入住较为安全.     

Incorporating spectral data into logistic regression model to classify land cover: a case study in Mt. Qomolangma (Everest) National Nature Preserve

Only few models for land-cover classification incorporated spectral data into ordinary logistic regression (OL model) in the Mt. Qomolangma (Everest) National Nature Preserve (QNNP) in China. In this study, spectral variables were incorporated into OL model and autologistic regression (AL) model to classify six main land covers. Twelve environmental variables and seven spectral variables of 10,000 stratified random sites in the QNNP were quantified and analyzed; OL model, AL model, OL model with spectral data (OLM model), and AL model with spectral data (ALM model) were estimated. The OLM and ALM models produced better estimates of regression coefficients and significantly improved model performance and overall accuracy for the grassland, sparsely vegetated land, and bare land compared with OL and AL models.     

破坏性地震应急信息处置研究现状简述

结合地震应急实例,分析了对破坏性地震应急信息处置的认识,并对国内外有关方面的研究现状进行了简要介绍.     

Status of Macrobenthic Community and Its Relationships to Trace Metals and Natural Sediment Characteristics

Laizhou Bay, located in the northwest of Shandong Peninsula, has complex transitional environments between terrestrial and marine ecosystems. In the present study, a total of 122, 131, and 139 species were collected in spring, summer, and autumn 2011, respectively. Species constitutions of macrobenthos were grouped into four phyla, of which annelida were the most abundant phylum, the average biomass proportion of echinodermata was the lowest, and the proportion of important species for mollusca was the highest. The structure of the macrobenthic community showed significant differences between sites, and greater divergence was observed between the third site (S03) and other stations. The ABC plots showed that the biomass curve lay below the abundance curve, and the W‐statistic value was negative. The result of the BOPA index showed that two stations had moderate ecological status in spring and that there were two heavily polluted sites and one moderately polluted site in summer. The BIO‐ENV analyses indicated that the grain‐size fractions together with trace metals (Hg, Pb, Zn, Cu, and Cr) could be considered as the major environmental variables influencing the macrobenthic patterns. The results together demonstrated that the macrobenthic communities in Laizhou Bay were negatively affected, perhaps by the tremendous impact of heavy metals in the sediments.     

Late Quaternary (30.7–9.0 cal ka BP) vegetation history in Central Asia inferred from pollen records of Lake Balikun, northwest China

Surface and fossil pollen samples were collected to reconstruct the vegetation and environment since 30.7 cal ka BP in the Lake Balikun Basin, northwest China. This record demonstrates that the region was occupied by four vegetation communities during the interval 30.7–9.0 cal ka BP, including desert steppe (30.7–25.1 cal ka BP), Amaranthaceae-Asteraceae desert (25.1–17.7 cal ka BP), Amaranthaceae-Artemisia-Asteraceae desert (17.7–12.8 cal ka BP) and Amaranthaceae desert (12.8–9.0 cal ka BP), corresponding to relatively humid, the coldest and driest, cold and dry, and colder and drier conditions, respectively. The reconstructions of vegetation and environmental changes around Lake Balikun do not support the interpretation of an extremely humid LGM in Central Asia, challenging the cold-moist (glacial), warm-dry (interglacial) pattern of late Quaternary environmental change in Central Asia. The Last Glacial Maximum was cold and dry, and similarly harsh conditions continued into the early Holocene.