基于洪灾发生频率的辽宁省汛期分期研究

以辽宁省近55年(1956-2010年)历史洪涝灾害为研究对象,依据洪涝灾害在年内各时段的发生频率,进行汛期划分.从55年的洪灾资料中共摘录洪灾44次,其中一般灾害27次,严重灾害17次.根据各候一般灾害和严重灾害次数,确定辽宁省汛期为6月1日-9月5日,主汛期为7月11日-8月20日.55年的洪涝灾害统计表明,汛期一般洪灾和严重洪灾所占比例达到100％,主汛期严重灾害比例达到100％,一般洪灾比例达到70.4％.汛期降水和径流占全年60％以上,主汛期占全年30％～40％.与辽宁省主要流域代表性水文站点降水和径流汛期分期结果的对比分析表明,洪涝灾害的发生时间、频率、等级能够反映降水和径流的年内变化特征,重大灾害的出现与主汛期的出现具有同步性.     

两宋时期自然灾害的文学记述与地理分布规律

两宋320年间共发生灾害1739次,灾害种类14种,如此深重的灾害是导致两宋"积贫积弱,国力不强"的一大主要因素.由于宋朝时期的地理气候特点,水灾、旱灾接连不断发生,并且成为两宋最主要的自然灾害.古代自然灾害研究主要依据史书记载,中国是世界上少数灾害多发的国家之一,文学作品中反映出来的灾难与救世观念可以给人们很多启发.以王禹偁为代表的宋代文学家给后世留下了许多记述灾害的文学作品,从文学作品的记述中可以提取古代灾害的准确信息.北宋都城位于开封,南宋京都在杭州,由于史料对当时中央政府所在地省份的记述颇为翔实,两宋自然灾害的省区分布,以河南、浙江灾害次数最多.     

环境政策评估：一个宏观经济分析框架的综述

环境动态随机一般均衡（E-DSGE）模型以其良好的扩展性和预测性逐渐被环境宏观经济学者接纳。环境因素的引入包括经济系统对环境系统的作用、环境系统的演化过程、环境系统对经济系统的反作用等方式。E-DSGE模型中的不确定性冲击包括经济不确定性冲击、政策不确定性冲击和环境不确定性冲击。E-DSGE模型中环境政策的讨论重点包括环境税、限额与交易、强度管制等。多重环境政策的组合效应、环境影响的国际传导以及环境政策与宏观经济政策的融合等是E-DSGE模型研究的重要前沿课题。加强新凯恩斯框架下E-DSGE模型的构建与应用,加强跨流域和跨界的环境问题、水的问题、碳的问题等研究是下一阶段E-DSGE建模的重点。     

关于黄沙研究与进展

该文介绍了黄沙研究的历史,包括自公元前1150年开始我国历史资料中关于黄沙的记载,第四纪地质学和环境科学中与黄沙有关的研究概况,近年来国内外对黄沙研究的新进展,以及采用卫星云图、激光雷达探测仪等遥测新技术。      

南京城市全面跨江发展初探

南京是我国长江尾闾著名的历史文化名城,自周元王四年（公元前472年）始筑“越城”至今已有2 482 a的历史。在南京城市发展过程中,由于自然、政治、经济等因素的综合影响,历代在此建设城廓,都以江南向西北开口的簸箕形盆地作为基础,而向北跨江发展自历史上以来都非常缓慢。在实地踏勘研究区和梳理分析历史地理资料的基础上,重建了南京城市跨江发展的历史过程,划分出4个发展时期：沿江发展期、跨江发展的萌芽期、跨江发展的初期、跨江发展的全面和加速推进期。基于城市跨江发展的原因与机制等理论,分析论证了当前南京选择全面和加速推进跨江发展的可行性。依据国内外跨江发展的经验教训,提出南京实施全面和加速推进跨江发展的主要策略是：(1)加快构建合理的跨江交通格局;(2)处理好江北新市区与南京城市整体功能的互补性与独立性关系;(3)做到空间布局优化与开发重点突出并举,江北老城镇保护性改造与新市区开发建设并重;(4)充分利用大型产业项目的非树型效应;(5)实施沿江岸段的合理功能分区与生态环境综合整治;(6)省市政府提供持续的政策支持,完善体制机制改革。〖 〖HT5”     

Spatial distribution of dissolved Pb, Hg, Cd, Cu and As in the Bohai Sea

Characteristics of the spatial distribution of selected dissolved heavy metals were analyzed during large scale surveys from August 12 to 25,2003 in the Bohai Sea.Dissolved Pb was the only element with average concentrations higher than the grade-one sea water quality standard of China.The spatial distribution of dissolved Pb in surface water was similar to those of Cd,Cu and As,where the isopleths generally indicated decreasing values from the bays to the central areas.Only for Hg did the high concentrations not only appear in Liaodong Bay,Bohai Bay and Laizhou Bay,but also in the Central Area,viz.not only in inshore but also in offshore areas. Vertical distributions of dissolved Pb,Cd,Cu and As were largely uniform,while that of dissolved Hg increased with depth.We infer that the input of pollutants from land was the main influencing factor for the detected distribution patterns of dissolved heavy metals, followed by the dynamics of sea water,release from bottom sediments and biochemical processes.Comparing with historical data, average concentrations of dissolved heavy metals appear to decline in recent years.     

Simulation modelling for sustainability: a review of the literature

This article is a review of work published in various journals and conference proceedings on the topics of Simulation Modelling for Sustainability between January 2000 and May 2015. A total of 192 papers are reviewed. The article intends to serve three goals. First, it will be useful to researchers who wish to know what kinds of questions have been raised and how they have been addressed in the areas of simulation modelling for sustainability. Second, the article will be a useful resource for searching research topics. Third, it will serve as a comprehensive bibliography of the papers published during the period. The literature is analysed for application areas, simulation methods and dimensions of the triple bottom line model of sustainable development.     

Spatial and Temporal Evaluation of Hydrological Response to Climate and Land Use Change in Three South Dakota Watersheds

This study analyzed changes in hydrology between two recent decades (1980s and 2010s) with the Soil and Water Assessment Tool (SWAT) in three representative watersheds in South Dakota: Bad River, Skunk Creek, and Upper Big Sioux River watersheds. Two SWAT models were created over two discrete time periods (1981‐1990 and 2005‐2014) for each watershed. National Land Cover Datasets 1992 and 2011 were, respectively, ingested into 1981‐1990 and 2005‐2014 models, along with corresponding weather data, to enable comparison of annual and seasonal runoff, soil water content, evapotranspiration (ET), water yield, and percolation between these two decades. Simulation results based on the calibrated models showed that surface runoff, soil water content, water yield, and percolation increased in all three watersheds. Elevated ET was also apparent, except in Skunk Creek watershed. Differences in annual water balance components appeared to follow changes in land use more closely than variation in precipitation amounts, although seasonal variation in precipitation was reflected in seasonal surface runoff. Subbasin‐scale spatial analyses revealed noticeable increases in water balance components mostly in downstream parts of Bad River and Skunk Creek watersheds, and the western part of Upper Big Sioux River watershed. Results presented in this study provide some insight into recent changes in hydrological processes in South Dakota watersheds. Editor's note: This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series.     

Small farm ponds: overlooked features with important impacts on watershed sediment transport

Despite their size, small farm ponds are important features in many landscapes. Yet hydrographical databases often fail to capture these ponds, and their impacts on watershed processes remain unclear. For a 230‐km² portion of central Texas, United States (U.S.), we created a historical inventory of ponds and quantified the accuracy of automated detection methods under varying drought conditions. In addition, we documented pond dredging/enlargement events and identified sites that had been abandoned. We also analyzed sediment cores from downstream reservoirs to track changes in watershed sediment transport. Over 75 years, pond densities increased more than 350% — to among the highest documented in the U.S. — and the ability of automated methods to detect these ponds was highly dependent on drought severity (R² = 0.96). Approximately 5% of ponds present in the 1950s were no longer present in 2012, while 33% were dredged between 1937 and 2012. Downstream reservoir sedimentation has decreased by an average of 55% as ponds have increased in number. These findings suggest that small ponds and the maintenance of trapping efficiency have large‐scale impacts on sediment dynamics. Accurately accounting for these storage effects is vital to water resource planning efforts.     

历史时期人类活动对环境影响强度的定量研究

本文通过对河西走廊人口和耕地面积的重建和经济史相关研究成果,利用人类活动对环境影响公式I=PAT,定量重建了河西走廊地区历史时期人类活动对环境影响强度。重建结果显示,可将近2000年以来河西走廊地区的人类活动划分为三个主要阶段,即清代中期以前、清代中期至民国、新中国成立以来。标准化后的环境影响值2千年来平均为6.20,清代中期以前平均为2.79,清代中期以来达到22.50,而近50年来为69.70。