A Framework to Develop Nationwide Flooding Extents Using Climate Models and Assess Forecast Potential for Flood Resilience

The methods used to simulate flood inundation extents can be significantly improved by high‐resolution spatial data captured over a large area. This paper presents a hydraulic analysis methodology and framework to estimate national‐level floodplain changes likely to be generated by climate change. The hydraulic analysis was performed using existing published Federal Emergency Management Agency 100‐year floodplains and estimated 100‐ and 10‐year return period peak flow discharges. The discharges were estimated using climate variables from global climate models for two future growth scenarios: Representative Concentration Pathways 2.6 and 8.5. River channel dimensions were developed based on existing regional United States Geological Survey publications relating bankfull discharges with channel characteristics. Mathematic relationships for channel bankfull topwidth, depth, and side slope to contributing drainage area measured at model cross sections were developed. The proposed framework can be utilized at a national level to identify critical areas for flood risk assessment. Existing hydraulic models at these “hot spots” could be repurposed for near–real‐time flood forecasting operations. Revitalizing these models for use in simulating flood scenarios in near–real time through the use of meteorological forecasts could provide useful information for first responders of flood emergencies.     

噪声地图的绘制与应用初探研究

当前噪声污染问题备受社会关注,噪声地图技术是一种直观简单的展示城市中环境噪声污染状况的方法,在城市规划、污染防治及环境保护方面发挥着越来越大的作用,噪声地图是由道路交通噪声、铁路噪声、工业噪声和机场噪声等对城市地图上每个接收点的叠加噪声值拟合图像绘制而成。本文介绍了国内外噪声地图的发展情况和应用,对噪声地图的分类、组成部分及绘制步骤进行论述,并对噪声地图的未来发展提出见解。     

利用多信息源提高半干旱地区TM影像的森林类型制图精度:以北京西部山区为例

以地处半干旱地区的北京西部山区为例,利用研究区森林类型的季相特征、已有的少部分林相图、Google Earth免费影像数据等信息选择不同坡向的相同森林类型做训练样本,通过加入其他辅助数据(海拔和坡向数据),来提高Landsat TM影像的森林类型分类精度,同时对比了基于像元和面向对象方法提取森林类型的效果。结果表明:1)就半干旱山区的森林类型划分来说,TM影像的TM4、TM5、TM4-TM2及辅助数据DEM和坡向可作为TM影像森林类型划分的最佳数据源。2)单独加入海拔信息,阔叶林的提取精度提高23%,针叶林和混交林的分类精度只提高了4%~5%;单独加入坡向信息,阔叶林的提取精度只提高21%,但是针叶林和混交林的分类精度则分别提高了13%、18%,显著优于单独加入海拔信息的效果。同时加入海拔信息和坡向信息,至少可以准确区分出约70%以上的针叶林、阔叶林和混交林。3)就本研究区而言,坡向比海拔更有效地辅助提高森林分类精度。4)就混淆矩阵数据而言,面向对象的分类方法比基于像元分类结果总体精度低3%,Kappa系数低4%,但面向对象的分类结果更加符合研究区实际情况。该研究对中分辨率影像应用于半干旱山区森林类型划分具有一定的借鉴意义。     

Implementation of the EU environmental noise directive: Lessons from the first phase of strategic noise mapping and action planning in Ireland

The first phase of noise mapping and action planning in Ireland, in accordance with EU Directive 2002/49/EC, is now complete. In total this included one agglomeration, one airport and approximately 600 km of major roads outside the agglomeration. These noise maps describe the level of noise exposure of approximately 1.25 million people. The first phase of noise mapping was dealt with by five noise mapping bodies while 26 action planning authorities were involved in the development of the associated action plans. The second phase of noise mapping, due to be completed in 2012, sees a reduction in the defined thresholds describing the required agglomerations, roads and railways that have to be mapped. This will have a significant impact on the extent of mapping required. In Ireland this will result in an increased number of local authorities being required to develop strategic noise maps for their area along with the further development of associated action plans. It is appropriate at this point to review the work process and results from the first phase of noise mapping in Ireland in order to establish areas that could be improved, throughout the noise mapping project. In this paper a review of the implementation procedures focussing on (dominant) road traffic noise is presented. It is identified that more standardisation is needed and this could be achieved by the establishment of a national expert steering group.     

Crustacean habitat potential mapping in a tidal flat using remote sensing and GIS

To make a macrofaunal (crustacean) habitat potential map, the spatial distribution of ecological variables in the Hwangdo tidal flat, Korea, was explored. Spatial variables were mapped using remote sensing and a geographic information system (GIS) combined with field observations. A frequency ratio (FR) and logistic regression (LR) model were employed to map the macrofauna potential area for the Ilyoplax dentimerosa, a crustacean species. Spatial variables affecting the tidal macrofauna distribution were selected based on abundance and biomass and used within a spatial database derived from remotely sensed data of various types of sensors. The spatial variables included the intertidal digital elevation model (DEM), slope, distance from a tidal channel, tidal channel density, surface sediment facies, spectral reflectance of the near infrared (NIR) bands and the tidal exposure duration. The relation between the I. dentimerosa and each spatial variable was calculated using the FR and LR. The species was randomly divided into a training set (70%) to analyse habitat potential using FR and LR and a test set (30%) to validate the predicted habitat potential map. The relations were overlaid to produce a habitat potential map with the species potential index (SPI) value for each pixel. The potential habitat maps were compared with the surveyed habitat locations such as validation data set. The comparison results showed that the LR model (accuracy is 85.28%) is better in prediction than the FR (accuracy is 78.96%) model. The performance of models gave satisfactory accuracies. The LR provides the quantitative influence of variables on a potential habitat of species; otherwise, the FR shows the quantitative influence of a class in each variable. The combination of a GIS-based frequency ratio and logistic regression models and remote sensing with field observations is an effective method to determine locations favorable for macrofaunal species occurrences in a tidal flat.     

基于知识图谱的土壤重金属快速监测技术进展

为了解当前国际土壤重金属快速监测研究现状及趋势，以Web of science数据库为基础，以X射线荧光光谱法（XRF）为例利用CiteSpace进行知识图谱可视化分析，并在此基础上对国际土壤重金属快速监测进行研究综述.结果表明，从Web of science数据库资料来看，当前对土壤重金属快速监测的研究机构以中国科学院和西班牙国家科学研究委员会发文量最多，而发文从属国家以美国为最多，中国和德国居其次；研究热点主要集中于快速监测仪器的技术开发、实际应用、定量化监测影响因素的识别及校正等方面；针对土壤重金属污染快速监测的未来研究趋势主要集中于监测仪器的小型化智能化研发、农田土壤重金属快速监测、区域土壤重金属空间分布监测等方面.认清和了解当前国际土壤重金属快速监测研究状况，可为国内相关研究提供参考.     

STREAMFLOW TRENDS IN WISCONSIN'S DRIFTLESS AREA1

ABSTRACT: Trends in streamflow characteristics were analyzed for streams in southwestern Wisconsin's Driftless Area by using data at selected gaging stations. The analyses indicate that annual low flows have increased significantly, whereas annual flood peaks have decreased. The same trends were not observed for forested areas of northern Wisconsin. Streamflow trends for other streams in southeastern Wisconsin draining predominantly agricultural land were similar to trends for Driftless Area streams for annual low flows. The causes for the trends are not well understood nor are the effects. Trends in annual precipitation do not explain the observed trends in streamflow. Other studies have found that erosion rates decreased significantly in the Driftless Area, and have attributed this reduction to a change of agricultural practices, which increase infiltration, decrease flood peaks, and increase low flows.     

基于人工智能的深潜耐压球壳应力场映射

目的 针对深潜耐压球壳在真实下潜过程中全局应力场难以直接获取的问题,提出一种基于人工智能的深潜耐压球壳应力场映射算法。方法 构建深潜耐压球壳有限元模型,并开展仿真分析。提出深潜耐压球壳监测布点方案,进而利用长短时记忆神经网络(Long-short Term Memory Network,LSTM),将测点应力信息作为输入,将全局应力场信息作为输出,构建深潜耐压球壳应力场映射模型。最后,对不同测点下的映射结果进行分析。结果 与模型试验结果相比,仿真误差小于2%。与DNN模型及BP模型相比,映射误差分别下降94.92%与97.76%。结论 所提映射算法可在部分测点失效的情况下仍可以保持较高精度。     

牛栏江污染物源解析与空间差异性分析

牛栏江-滇池补水是缓解滇池生态用水短缺的重要工程,对牛栏江流域主要污染源与空间差异性的识别分析,将有助于进一步改善牛栏江的水质. 采用CFA(对应分析)对牛栏江流域污染源进行解析识别,结果表明流域内TN、NH₃-N(氨氮)等污染物主要来源于嵩明县境内,TP、氟化物等污染物主要来源于寻甸县境内. 在CFA分析的基础上,采用HCA(层次聚类分析)和SOM(自组织映射神经网络)对4个监测点、10种污染物指标进行分析,以识别空间分布的差异性和相似性,并且评价各指标的空间分布特征及监测点代表性. 结果表明:4个监测点中,TP、氟化物、砷化物、Vph(挥发酚)在寻甸县境内的七星桥污染最严重;TN、NH₃-N在牛栏江上游嵩明县境内的四营污染最重. 结合流域污染负荷调查可知,寻甸县的磷负荷最大,占流域总负荷的58.73%,七星桥的TP污染贡献大于其他3个监测点,与七星桥TP污染最为严重相符合. 该研究结果可为牛栏江流域实施进一步的分段治理提供决策支撑.