Scatterscore: A Reconnaissance Method To Evaluate Changes In Water Quality

Water quality data collected in periodic monitoring programs are often difficult to evaluate, especially if the number of parameters is large, the sampling schedule varies, and values are of different orders of magnitude. The Scatterscore Water Quality Evaluation was developed to yield a quantitative score, based on all measured variables in periodic water quality reports, indicating positive, negative or random change. This new methodology calculates a reconnaissance score based on the differences between up-gradient (control) versus down-gradient (treatment) water quality data sets. All parameters measured over a period of time at two or more sampling points are compared. The relationship between the ranges of measured values and the ratio of the medians for each parameter produces a data point that falls into one of four sections on a scattergram. The number and average values of positive, negative and random change points is used to calculate a Scatterscore that indicates the magnitude and direction of overall change in water quality. The Scatterscore Water Quality Evaluation, a reconnaissance method to track general changes, has been applied to 20 sites at which coal utilization by-products (CUB) were used to control acid mine drainage (AMD).     

A FAST RECURSIVE GIS ALGORITHM FOR COMPUTING STRAHLER STREAM ORDER IN BRAIDED AND NONBRAIDED NETWORKS1

ABSTRACT: Stream ordering is a useful property of every river network, having a wide range of applications. A method for determining stream orders that quickly and easily addresses various network topologies and magnitudes is therefore needed. This paper introduces a general recursive stream ordering framework for vector hydrography. It also presents a linear, O(n), stream ordering procedure for braided river networks, which is a major improvement to the existing quadratic, O(n²), procedure. The discussion includes results and interpretations, and the appendices present procedure pseudocodes and thorough line by line explanations.     

塑料排水技术及其在环境岩土工程中的应用

介绍了常用塑料排水材料及其技术要求和性能;阐述了目前国内塑料排水技术在环境岩土工程中的应用状况,并就应用塑料排水技术解决岩土工程中的安全、生态和环境保护等问题提出了思路。笔者认为在岩土工程建设中,根据工程场地的地理、地质和生态环境条件,合理采用塑料排水材料,充分应用塑料排水技术,可以有效地保证工程设施的安全,实现环境岩土工程系统的相互促进和协调发展。文中同时介绍了塑料排水带真空和堆载预压地基固结渗透量的计算方法,可供参考。     

DETERMINISTIC-SYSTEMIC RELATIONSHIPS IN OVERLAND FLOW ANALYSIS1

ABSTRACT: An analysis of storm runoff is presented, giving primary attention to deterministic-systemic relationships. So that system aspects can be emphasized, other aspects are kept simple; analysis is made for uniform rainfall on a strip of uniform width, limiting direct applicability to small areas. Two relationships between excess rain and time of concentration, one based on hydraulic parameters, the other on hydrologic characteristics, are combined in a solution for peak discharge. The hydraulic expression gives the interrelationship of time of concentration, excess rain, friction, length, and slope. The hydrologic relationship is achieved by converting ordinary intensity-duration curves to corresponding excess rain intensity-duration curves, thereby interrelating excess rain, time of concentration, and loss characteristics. The resulting solution for peak discharge allows for systemic feedback among both hydraulic and hydrologic parameters.     

A MODEL OF THE BEHAVIOR OF pH DETERMINING PARAMETERS IN IMPOUNDMENTS1

ABSTRACT: A computer model capable of describing the behavior of pH-determining parameters in an impoundment is presented. The steady-state model, based upon principles of water chemistry, applies the complete-mix concept to the routing of the chemical quantities, alkalinity and CO₂ acidity. An iterative procedure is used to account for surface mass transfer of carbon dioxide. A fourth-degree polynomial is solved for the hydrogen ion concentration at each point of routed alkalinity and CO₂ acidity concentrations. Field data required to verify and apply the model are described, including an example application to the Loyalhanna Creek Reservoir.     

浙江省数字流域规划灾害治理技术研究

介绍了系统模块的基本功能、系统属性和空间数据库设计 ,以及自主开发的空间数据库引擎(SpatialDatabaseGuide)的基本概念。对系统中的几个关键技术的实现方法进行了详细讨论。系统已在浙江省数几十个市县的水利部门得到推广应用 ,为该省“数字流域”规划和灾害治理发挥了积极作用。     

基于深度学习的空气质量预报方法新进展

空气质量预报与人们的日常生活密切相关,其基本思想是分析历史空气质量数据,发现其内在的时空相关性,结合未来气象信息以及污染源排放量,对未来的空气质量进行预测。目前,环境管理和社会公众服务对空气质量预报提出了长时间、多维度、高精度的预测要求,一些新型的空气质量预测方法仍处于起步探索阶段。近年来,随着人工智能的普及与推广(特别是云计算与大数据的发展),深度学习这项基于传统人工神经网络的技术被国内外研究者所重视。笔者对现有典型的空气质量预报方法进行了阐述,包括数值预测模型方法、统计预报模型方法、基于机器学习模型的预测方法等,并重点介绍了该领域最新进展:基于深度学习模型的预测方法,并在此基础上进行了总结与展望。     

基于地层条件下煤层瓦斯流动模拟研究

为了研究地层条件下瓦斯流动特点,通过建立瓦斯吸附-解吸、扩散和渗流综合流动数学模型,分析不同埋深条件下瓦斯流动机制,并模拟吸附层和滑脱效应对瓦斯流动的影响。结果表明:随煤层埋深增加,部分纳米孔隙内瓦斯流动机制由扩散过渡到渗流,这有利于瓦斯运移;在煤层深部,瓦斯吸附层和滑脱效应对瓦斯渗流作用影响不大;随埋深增加,瓦斯吸附层对瓦斯运移影响逐步增大,而滑脱效应则逐步弱化;在埋深相同时,两者对瓦斯运移的影响都随孔隙直径增大而减小。研究有助于深入了解瓦斯在深部煤层流动的机制,提高深部煤层瓦斯抽采效果。     

基于瓦斯抽采关键封孔参数及新型封孔材料应用研究

针对煤层瓦斯抽采封孔参数选取不合理,传统封孔材料封堵钻孔周边裂隙效果差等主要问题,采用数值模拟、实验室试验及工程实践等多种手段,分析不同封孔方式的漏气效果,研究封孔时效性对瓦斯抽采的影响,完成最优实验配比及性能测试,验证了现场瓦斯抽采效果。结果表明:全封孔方式抽采效果优于半封孔,合理控制封孔时效性,钻孔周边围岩破坏减少,封孔效果提高;正交试验确定材料最优配比即复合早强剂0.3%、复合缓凝剂0.5%、膨胀剂0.03%、水灰比1.2;试样周围充斥着交叉、贯通的“网状结构”钙矾石,且呈现多而密的粗棒状结构;材料具备塑性变形特性,持续变形量大;与矿方原封孔材料相比,新型封孔材料封孔后瓦斯抽采浓度提高193.3%,抽采周期明显延长,抽采效果显著提高。     

共同管沟深基坑现场变形监测与数值模拟分析

为了分析共同管沟深基坑边坡的变形规律及其对邻近建筑物的影响作用,以三星深基坑工程为例,采用数值模拟分析并进行现场变形监测验证。结果表明:降水措施对深基坑开挖引起的水平位移作用不大,而对竖向位移作用较大;随着深基坑开挖深度的不断加大,边坡土体的水平位移和竖向位移总体呈现增大的趋势,最大水平位移值表现为从坡脚向坡脚上方移动;原地下水位线以上所开挖边坡的最大竖向位移都发生在坡脚处,采用降水措施后,原地下水位线以下所开挖边坡的最大竖向位移出现在原地下水位附近。现场变形监测与数值模拟计算结果吻合度较高,说明土体参数的选取合理。研究成果可提升城市共同管沟深基坑建设安全设计及施工水平、降低工程风险损失。