兰州市大气污染气象潜势预报研究

介绍了大气污染气象潜势预报方法和兰州市大气污染气象潜势预报系统。通过2001年9－12月兰州市空气质量预报检验分析，表明该系统对首要污染物等级预报准确率在60％以上，对兰州空气质量预报具有较好的指示性。     

兰州市空气质量预报系统研究

从潜势预报、统计预报、数值预报三方面介绍了兰州市空气质量预报系统的研究方法和结构特点,并检验分析了2001年4～10月兰州市空气质量预报,结果表明,此系统具有较强的预报能力,适用于兰州市空气质量预报业务。     

兰州市大气污染现状分析及防治对策建议

从兰州市大气污染的治理状况出发,叙述了兰州市特殊自然条件下的的大气污染现状,经过分析得出兰州市大气污染的主要类型为可吸入颗粒物;根据兰州市的具体情况得出造成兰州市大气严重污染的多方面原因,并进一步分析得出燃煤污染是兰州市大气污染的主要来源,地理气象因素是污染物难以扩散,污染持续加重的原因.同时,文章对兰州市现行的环境治理政策体系相关措施进行评价,分析了兰州市有关大气污染治理相关政策的效果.最后,根据兰州市本身具体的环境情况,提出关于兰州市大气污染治理的几点建议.     

大气污染预报技术及有关防治对策的研究

依据历史监测数据,研究了大气污染预测预报的方法及污染防治对策。利用主分量分析、多元逐步回归、拟合与逼近等方法,进行了天气预报参数与主要污染物的关系研究,建立了大气污染预测预报模型,制定了大气污染警戒值及警戒措施。模型可做４８小时内大气污染预报及１０日内大气污染趋势分析。     

兰州市区大气中TSP及其成分含量的测定与变化规律的研究

报导了兰州市一年内大气中TSP及其成分含量的监测结果、污染程度和变化规律,为兰州市进一步治理大气污染,加强环境管理,提高环境质量提供了科学依据。     

江苏省区域空气质量多模式预报预警系统研究与设计

围绕江苏省大气污染日益严峻的形势,设计了江苏省区域空气质量多模式预报预警系统,系统主要由数据中心、计算中心、分析展示中心、预报中心4个部分构成,运用了多模式集合预报、数据仓储联机分析处理、数据挖掘及智能关联等关键技术。系统的建成将为江苏省各级政府和相关单位决策层制定区域联动的大气污染防控措施,采取针对性的应急处置措施提供科学、及时的技术支撑。     

空气质量预报在世界互联网大会中的应用

为支持世界互联网大会期间大气污染管控工作，利用人工结合数值模式预报的方式在第二届到第五届世界互联网大会期间开展空气质量预报工作。多模式系统中WRF-CMAQ对乌镇及浙北区域大气污染变化的趋势模拟最好，2016—2018年对AQI日均值模拟的平均分数偏差（MFB）和平均分数误差（MFE）分别为-1.3%~1.6%和24.3%~28.3%。会前48 h、72 h和96 h空气质量等级预报准确率分别为37.5%~83.3%、33.3%~90.0%和0~89.9%。会议期间乌镇的AQI日均值48 h预报准确率为33.3%~100%，等级预报准确率为66.7%~100%。与日常空气质量预报不同，会议期间预报还应重点关注大气污染过程，如有污染可能性，需要给出污染过程的起始时间、持续范围和浓度峰值等情况及其关键时间节点，有针对性地提出大气污染管控的措施建议，为会议期间空气质量保障提供技术支撑。     

兰州市区酸雨污染的初步分析

酸雨是衡量一个城市污染的主要指标。从兰州观测站近几年的酸雨观测资料中看，兰州市区酸雨时有发生，并有逐年增加的趋势。本文从１９９２年至１９９４年的酸雨观测资料入手，分别与兰州市对应年的降尘量、ＳＯ２和ＮＯｘ浓度含量，污染综合指标等污染因子以及降水量、风、大气环流形势等气象要素之间进行了对比分析，分析结果表明，兰州市的酸雨频率大小基本上能够代表兰州市区的大气污染总体水平；气象要素是造成酸雨的重要因子     

集中供热与兰州大气污染治理

针对兰州市大气污染的现状。结合城市已有的热电联产集中供热实际和下一步发展规划。分析，阐明了集中供热对兰州市大气污染治理所发挥的作用。提醒人们认识并关心兰州市集中供热与大气污染治理问题。     

臭氧数值预报模型综述

光化学大气质量模型在研究臭氧(O_3)污染以及O_3预报方面具有核心作用,是O_3污染防治决策者的有力工具。文章结合目前中国及国际区域尺度光化学大气质量预报模型的研究与应用,重点论述与O_3有关的大气化学过程在数值预报模型中的数学表达和计算方法,阐述大气物理与大气化学过程在主流大气质量数值预报模型中的实现方法及其优势和缺陷,介绍用于数值预报模型的大气物理过程和湍流参数化方案的最新进展。就当前O_3数值模拟的主要输入资料进行讨论,强调那些易被忽视但又显著影响模型预报能力和效果的诸多因素以及模型效果评估的重要性。结合O_3与复合型大气污染的关系,强调区域大气质量数值预报模型的发展趋势与方向以及在大气环境管理方面的意义和作用。     

A novel environmental indicator for monitoring of pesticides

The identification of an indicator for monitoring pesticides is a very effective analytical approach because it allows one to schedule and simplify the analytical routine. In this study, a new indicator has been designed, which has to be able to define a scale of priorities in the pesticides monitoring. A starting equation was developed involving the escaping tendency of a given substance from a phase (based on the Mackay model I level). The reliability of the indicator was tested by application to a model system, consisting of a defined and limited area, choosing water as matrix over a period of 6 years. A group of marker compounds was also defined to implement the predictive efficacy of the indicator. The results obtained by modeling were compared to those obtained by experimentation of the same model system. The indicator was subsequently and appropriately modified creating a new equation, including a kinetic factor, which considers the environmental degradation processes. The effect of the rectified indicator was consistent with the sales data list of compounds, when applied to the markers. The indicator developed in this study, tested as a model on specific area-phase-period (Province of Siena, water phase, 2000?C2006), is applicable to any other area-phase-period, adjusting the partition value of the Mackay model for the case under study.     

Development and Testing of 2D Finite Difference Model in Open Channels

This study develops a depth-averaged two-dimensional (2D) numerical model using a finite difference method (FDM) on a staggered grid. The governing equations were solved using the Marker and Cell method that was developed at the Los Alamos laboratories by Harlow and Welch in 1965. In the paper, an explicit FDM was used to solve the governing equations. A first-order approximation was used for the temporal derivative. Second-order central difference approximations were used for space discretization. The time step is limited by the Courant–Friedrichs–Lewy (CFL) condition. The time step used in this study depends on the grid spacing and velocity components in the x- and y-directions. The study is divided into two steps: the first step is to develop a depth-averaged 2D numerical model to simulate the flow process. The second constructs a module to calculate the bed load transport and simulate the river morphology in the areas that have steep slopes, torrents, and mountain rivers. Developed model was applied to the artificial channel and a flood event in the Asungjun River section of the mountainous Yangyang Namdae River (South Korea). General simulation results showed that the developed model was in good agreement with the observed data.     

A Simulation Study to Assess the Sensitivity of a Forest Health Monitoring Network to Outbreaks of Defoliating Insects

The sensitivity of the United States Forest Health Monitoring network to outbreaks of defoliating insects was examined by means of a simulation study. A model constructed specifically for the study was used to generate a wide variety of defoliation patterns in forested landscapes. Forest configuration was that of Minnesota, USA, as expressed by the GAP land cover classification. Combinations of model parameters were based on a Latin Hypercube sample. The relationship between the average number of plots defoliated and outbreak characteristics was then examined via multiple regression. Both theoretical and model results pointed to a strong, linear relationship between the average number of plots defoliated and outbreak size. Model results provided additional insight, suggesting a significant relationship between the average number of plots defoliated and other outbreak characteristics after outbreak size was taken into account.     

Treatment of Urban Areas within a Regional Transport Model of Sulphur and Nitrogen Oxides

The air pollution transport model UGEM (The University of Greenwich Evaluation Model) has been developed to evaluate medium-range transport and deposition of sulphur and oxidised nitrogen from all types of sources of emissions in the UK and to estimate their average annual deposition and concentrations across the UK. The model has been tested for its predictions against the available measurements.This study was focused on a possibility of applying the UGEM model to the assessment of air quality on a local scale. One parameter in the model is crucial, the local deposition fraction. The effect of this parameter on quality of the model predictions has been studied for different scales of UGEM output, such as the whole territory of the UK, a rural region and an urban area.The results of the study show that the magnitude of the local deposition fraction should be different for each grid square to reach the best agreement of predictions of concentrations with measurements. Applying a local value of the parameter to each grid square will improve the model predictions of the concentrations in urban areas in particular and will not affect the quality of model predictions of the wet deposition.     

An experimental method to verify soil conservation by check dams on the Loess Plateau, China

A successful experiment with a physical model requires necessary conditions of similarity. This study presents an experimental method with a semi-scale physical model. The model is used to monitor and verify soil conservation by check dams in a small watershed on the Loess Plateau of China. During experiments, the model–prototype ratio of geomorphic variables was kept constant under each rainfall event. Consequently, experimental data are available for verification of soil erosion processes in the field and for predicting soil loss in a model watershed with check dams. Thus, it can predict the amount of soil loss in a catchment. This study also mentions four criteria: similarities of watershed geometry, grain size and bare land, Froude number (Fr) for rainfall event, and soil erosion in downscaled models. The efficacy of the proposed method was confirmed using these criteria in two different downscaled model experiments. The B-Model, a large scale model, simulates watershed prototype. The two small scale models, D_a and D_b, have different erosion rates, but are the same size. These two models simulate hydraulic processes in the B-Model. Experiment results show that while soil loss in the small scale models was converted by multiplying the soil loss scale number, it was very close to that of the B-Model. Obviously, with a semi-scale physical model, experiments are available to verify and predict soil loss in a small watershed area with check dam system on the Loess Plateau, China.     

Water Quality Modeling for a Typical Urban Lake Based on the EFDC Model

Urban lakes are typically characterized by fragile ecological capacities and complex management of their hydrospheric ecosystems. The aims of this study are to establish a reliable hydrodynamic-water quality model for an urban lake, to investigate the responses of water quality to different extreme hydrological conditions associated with rainstorms, and to explore the results from different modeled scenarios surrounding the pollution threats associated with a sewage leak. A three-dimensional hydrodynamic water quality model was developed in this study. The model was calibrated and validated using observed data. The model results agreed well with the observed data, and the averaged relative root mean-squared error (RRMSE) for all of the compared variables was 33.3 %. The validated model was applied to analyze water quality responses for different extreme historical rainfall scenarios from January 1, 2012 to December 31, 2012. The model results indicate that for Lake Tianyinhu, rainstorms adversely affect water quality due to larger nutrient loads, generated by larger rainfall events, and the limited water storage capacity of the lake. Moreover, the responses of water quality to sewage leak events were studied through four scenarios with different leak intensities and durations. The model results indicate that sewage leaks have measureable negative effects on water quality and that it is vital to inspect and promptly eliminate any possible leaks within pipes surrounding the lake. This study may provide a useful tool for hydrological ecosystem protection and management techniques for similar urban lakes.     

基于人工神经网络的夜光藻密度预测模型

利用人工神经网络 BP算法 ,对各种理化因子与赤潮中夜光藻密度建立了人工神经网络预报模型 ,并利用该模型对各种理化因子与夜光藻密度的非线性对应规律进行了研究。结果表明 ,模型较好地反映了存在的对应规律     

北京市公交车噪声测试与分析

公交车已成为当前北京市道路交通噪声的主要束源之一,针对公交车声源模型缺乏而沿用大型车声源模型所致的噪声预测误差问题,在北京市选取了两类常见公交车进行了537辆车的单车通过噪声测试,在无效数据剔除和背景噪声修正后,利用回归分析法获得了北京市公交车声源模型,通过与现有《公路建设项目环境影响评价规范》中大型车声源模型的比较,显示出建立北京市公交车噪声声源模型的必要性。基于《公路建设项目环境影响评价规范》中的道路交通噪声预测方法,提出了符合北京市实际情况的道路交通噪声预测模型。     

Application of artificial neural network approach and remotely sensed imagery for regional eco-environmental quality evaluation

Eco-environment quality evaluation is an important research theme in environment management. In the present study, Fuzhou city in China was selected as a study area and a limited number of 222 sampling field sites were first investigated in situ with the help of a GPS device. Every sampling site was assessed by ecological experts and given an Eco-environment Background Value (EBV) based on a scoring and ranking system. The higher the EBV, the better the ecological environmental quality. Then, three types of eco-environmental attributes that are physically-based and easily-quantifiable at a grid level were extracted: (1) remote sensing derived attributes (vegetation index, wetness index, soil brightness index, surface land temperature index), (2) meteorological attributes (annual temperature and annual precipitation), and (3) terrain attribute (elevation). A Back Propagation (BP) Artificial Neural Network (ANN) model was proposed for the EBV validation and prediction. A three-layer BP ANN model was designed to automatically learn the internal relationship using a training set of known EBV and eco-environmental attributes, followed by the application of the model for predicting EBV values across the whole study area. It was found that the performance of the BP ANN model was satisfactory and capable of an overall prediction accuracy of 82.4%, with a Kappa coefficient of 0.801 in the validation. The evaluation results showed that the eco-environmental quality of Fuzhou city is considered as satisfactory. Through analyzing the spatial correlation between the eco-environmental quality and land uses, it was found that the best eco-environmental areas were related to forest lands, whereas the urban area had the relatively worst eco-environmental quality. Human activities are still considered as a major impact on the eco-environmental quality in this area.     

Ecological study of river Suswa: modeling DO and BOD

In this paper limnological status of river Suswa was observed for a period of two years. A water quality Beck modified Khanna Bhutiani model (BMKB model) was developed to calculate DO (dissolved Oxygen) and BOD (biochemical oxygen demand). The model was developed to calculate DO and BOD by using DO/BOD of same place and upstream in previous season which results in Single output. This model gives the seasonal value on the basis of previously taken upstream and downstream observations/concentrations of DO and BOD. The model was calibrated and verified for the water quality data (Physico-chemical data) of samples collected from river Suswa in different seasons. The model gave good agreement between data observed by it and the data observed manually, thus substantiating the validity of the model. Only minor differences were observed in physical, chemical and heavy metals of all the four sampling stations during the course of study.