Building contraventions and incidence of flood in the Lagos Metropolis,Nigeria

Frequent floods have led to loss of lives and destruction of property in both coastal and landlocked cities across the globe, particularly where floodplains have been developed without recourse to space standards. This paper investigated the contributions of contravention of building codes to flooding in flood-prone areas in the Lagos metropolis. Global Positioning Systems (GPSs) were used to determine the location and elevation above sea level of 1,025 buildings situated in 211 streets that were prone to flooding. The distance of buildings from drainage channels/the lagoon was determined in ArcGIS 10.2 environment. Findings revealed that building code contravention contributed significantly to flooding (r = 0.926). About 63.5% and 63.3% of sampled buildings contravened building-plot ratio and statutory setbacks from drainage channels/the lagoon, respectively. Proactive urban planning, strict enforcement of building codes and development control regulations are required to reduce flooding and its consequences in cities of developing nations where flooding has become an annual occurrence.     

长江三角洲都市连绵区边界界定研究

都市连绵区的边界界定对象包括两个方面,都市连绵区的整体空间范围边界界定和内部结构边界界定。对长江三角洲及其周边地区所有的238个县、市、区的就业人口结构和空间分布特征进行主成分分析和聚类分析,探讨相应都市区的结构特征以及都市区的空间组合特征等,进而确定了长江三角洲地区的整体范围边界和内部结构边界。其结论包括①长三角都市连绵区的整体空间范围包括苏州、无锡、宁波的全部以及上海、南京、常州、杭州、镇江、扬州、泰州、南通和绍兴、舟山的部分县市区;②长三角的内部结构可分为三大部分,以上海为中心的环太湖城镇密集区,以南京为中心形成沿长江城镇区,以杭州、宁波为中心形成环杭州湾城镇密集区,其内部边界界线分别以镇江丹徒区、嘉兴—湖州为边界地带。从核心城市上海角度看,整个长江三角洲都市连绵区的内部结构呈现“圈层推进+轴线延伸”的空间特征。     

网络分析法在城市绿网优化中的应用

2005-2020年天津总规之绿地系统规划(总规绿网),由于缺乏绿网优化配置,其生态效益仍将不尽如人意。为此,采用图论和网络分析法(ANP),构建、评价了4个具有不同连接度和生态水平的绿网方案。ANP模型计算结果表明,绿网4最大化地利用现状和潜在廊道、连接各斑块,效益排序最优,成本次优,综合效益最高,且敏感度分析证明当效益与成本比大于0.25时,首位排序稳定。协调土地利用与交通等相关规划要素,给出基于网络4的绿地系统规划方案,为总规绿网优化提供依据。ANP适用于多目标、多因子、多方案决策,可解决以往网络指数与景观指数分离问题,实现不同顶点位置的网络评价,是绿网优化的有力工具。     

现代城郊农业的功能定位及其评价研究——以北京市为例

现代城市郊区化趋势下的城郊农业功能发生了质的转变,由提供农副产品的单一性功能逐渐转变为多样性功能,为城乡一体化布局和城市功能互补发挥了独特的作用。剖析了现代城郊农业的功能定位问题,并从生产服务功能、生态保育功能、景观文化功能三个方面构建了评价指标体系。采取类比法评价了北京市城郊农业的功能特征,估算其总经济价值量约为1100亿元,其中生产服务功能占28%,生态保育功能占66%,景观文化功能占6%。在此基础上,提出了北京市城郊农业发展模式应以生产服务为基础,生态保育为重点,景观文化为特色,探讨了京郊农业可持续发展的相应对策。     

大城市郊区土地利用结构类型区评价：以南京市为例

通过对南京市郊区土地利用结构类型区划分指标的模糊聚类分析，将南京城郊划分为８个类型区，并比较分析了各个类型区的土地利用特征及集约经营程度，土地利用效益，最后指出：为了优化配置郊区土地资源，南京市郊区土地利用必须采取因地制宜，综合利用，集约经营，增加投入，保护耕地，持续利用的措施。     

京津冀都市圈休闲旅游开发研究

随着我国经济发展和旅游需求的增长，休闲旅游消费日益成为我国居民的重要消费构成。京津冀都市圈休闲旅游的发展将有助于提升生活质量，带动相关产业发展，吸引内部休闲客源，提升都市圈及内部城市旅游竞争力，改善区域生态环境。分析了京津冀都市圈经济和旅游发展状况、休闲旅游发展条件、休闲旅游需求变化及开发潜力。在此基础上，论述了休闲地开发布局及相应的策略。     

基于贝叶斯公式的地下水污染源及含水层参数同步反演

针对非均质地下含水层污染源识别及含水层参数反演过程中监测方案优化问题,提出一种基于贝叶斯公式及信息熵最小的累进加井的多井监测方案优化方法.首先,构建假想案例下的二维非均质各向同性潜水含水层水流及溶质运移模型,运用GMS软件进行数值模拟求解.采用最优拉丁超立方抽样方法和Kriging法建立数值模拟模型的替代模型.然后以参数后验分布的信息熵最小为目标函数,采用累进加井的方式进行多井监测方案优化设计.最后根据优化后的监测方案,采用差分进化自适应Metropolis算法进行污染源及含水层参数的同步反演.算例研究表明：在兼顾反演精度及监测成本,并保证每个参数分区内至少有1眼监测井的条件下,5眼井组合监测方案（6,5,1,2,8）为最优监测方案.与信息熵最小的10眼井组合监测方案（1,2,3,4,5,6,7,8,9,10）的参数反演结果相比,5眼井组合监测方案对11个参数α=（X_S,Y_S,T₁,T₂,Q_s,K₁,K₂,K₃,DL₁,DL₂,DL₃）的后验均值偏离率的平均值虽增大1.2%,但监测成本却是10眼井组合监测方案的50%.     

Microplastic contamination in Great Lakes fish

Freshwater ecosystems, generally adjacent to human population and more contaminated relative to adjacent marine ecosystems, are vulnerable to microplastic contamination. We sampled 7 species of fish from Lake Ontario and Lake Superior and assessed their gastrointestinal (GI) tracts to quantify ingested microplastics and other anthropogenic particles. A subset of the microparticles were chemically analyzed to confirm polymer types and anthropogenic origins. We documented the highest concentration of microplastics and other anthropogenic microparticles ever reported in bony fish. We found 12,442 anthropogenic microparticles across 212 fish (8 species) from nearshore Lake Ontario, 943 across 50 fish (1 species) from Humber River, and 3094 across 119 fish (7 species) from Lake Superior. Fish from Lake Ontario had the greatest mean abundance of anthropogenic microparticles in their GI tracts (59 particles/fish [SD 104]), with up to 915 microparticles in a single fish. Fish from Lake Superior contained a mean [SD] of 26 [74] particles/fish, and fish from Humber River contained 19 [14] particles/fish. Most particles were microfibers. Overall, ≥90% of particles were anthropogenic, of which 35-59% were microplastics. Polyethylene (24%), polyethylene terephthalate (20%), and polypropylene (18%) were the most common microplastics. Ingestion of anthropogenic particles was significantly different among species within Lake Ontario (p < 0.05), and the abundance of anthropogenic particles increased as fish length increased in Lake Ontario (ρ = 0.62). Although we cannot extrapolate the concentration of microplastics in the water and sediments of these fish, the relatively high abundance of microplastics in the GI tracts of fish suggests environmental exposure may be above threshold concentrations for risk.