A Streamflow Forecasting Framework using Multiple Climate and Hydrological Models1

Abstract: Water resources planning and management efficacy is subject to capturing inherent uncertainties stemming from climatic and hydrological inputs and models. Streamflow forecasts, critical in reservoir operation and water allocation decision making, fundamentally contain uncertainties arising from assumed initial conditions, model structure, and modeled processes. Accounting for these propagating uncertainties remains a formidable challenge. Recent enhancements in climate forecasting skill and hydrological modeling serve as an impetus for further pursuing models and model combinations capable of delivering improved streamflow forecasts. However, little consideration has been given to methodologies that include coupling both multiple climate and multiple hydrological models, increasing the pool of streamflow forecast ensemble members and accounting for cumulative sources of uncertainty. The framework presented here proposes integration and offline coupling of global climate models (GCMs), multiple regional climate models, and numerous water balance models to improve streamflow forecasting through generation of ensemble forecasts. For demonstration purposes, the framework is imposed on the Jaguaribe basin in northeastern Brazil for a hindcast of 1974‐1996 monthly streamflow. The ECHAM 4.5 and the NCEP/MRF9 GCMs and regional models, including dynamical and statistical models, are integrated with the ABCD and Soil Moisture Accounting Procedure water balance models. Precipitation hindcasts from the GCMs are downscaled via the regional models and fed into the water balance models, producing streamflow hindcasts. Multi‐model ensemble combination techniques include pooling, linear regression weighting, and a kernel density estimator to evaluate streamflow hindcasts; the latter technique exhibits superior skill compared with any single coupled model ensemble hindcast.     

电网规划环境影响评价应关注的几个要点

广州市城市高压电网规划环境影响评价是国家环境保护总局全国规划环境影响评价的试点项目,结合该专项规划环境影响评价在评价指标体系设计、评价标准、评价技术方法等方面的探索和研究成果,提出电网规划环境影响评价应关注的几个要点。     

电网安全风险管理

随着电网建设的高速发展和电网事故影响的扩大,电网安全引起了各方面的高度重视.从2006年起,国家电网公司正式开展安全风险管理工作.根据风险管理的理论和电网事故的特点,系统地探讨了电网安全的风险管理并提出了改进措施,以形成安全生产预防机制,规避和化解安全风险,保障电网安全运行.     

The aqueous solubility of twenty‐seven insecticides and related compounds.

Abstract

The aqueous solubilities of 27 insecticides and related compounds were determined. Diazinon, fensulfothion and paraoxon had solubilities greater than reported in the literature. The presence of impurities and/or additional components in the mixture altered the measured solubility values. Addition of acetone in amounts up to 1% (volume) produced increases in parathion solubility up to 11%. The pH values of the equilibrated solubility systems were, in most instances, acidic and, in several instances, were in the pH 3–4 range.     

电网建设项目竣工环保验收的常见问题及解决方案

电网项目属于非污染型生态项目,具有该类型项目特有的影响因子单一、项目涉及范围广及环境敏感点分布不均等特点。该类项目竣工环保验收中存在6种主要问题,针对验收率、验收监测、公众参与等方面,通过制定规范、加强管理、落实环保治理措施等层面,给出了相对的解决方案。通过方案的实施,主要常见问题可得到解决或改善。     

IEC61850通讯规约在500kV芝堰变电站的应用

随着用户对电能可靠性和质量要求的不断提升,智能电网、互动电网等技术逐步兴起。数字化变电站是智能电网的物理基础,国际电工委员会发布的IEC61850标准为数字化变电站技术奠定了理论基础。本文探讨了IEC61850规约在智能化一次设备以及数字化通信技术的发展及在500KV芝堰变电站的具体应用。     

基于格网单元的县级土地利用总体规划生态环境影响评价方法与应用

土地利用总体规划的生态环境影响评价对于保护区域生态环境、减少土地利用总体规划对环境的负面影响具有重要的意义。以格网单元为基础,结合PSR模型和生态安全评价法,通过相关性分析筛选指标,构建评价指标体系。通过GIS空间分析,定量评价县级土地利用总体规划环境影响。以张家界市永定区为例,综合评价了规划实施前后区域生态环境的状况。评价结果表明：新一轮的土地利用总体规划后,全区生态环境状况有改善的地区占全区总面积的7819%,说明新的规划对全区大部分地区的生态环境有积极影响。其中,水土流失指数处于安全和较安全的区域占全区总面积的6017%,全区水土流失状况略有好转,加强水土保持工程建设仍是用永定区生态环境保护的首要任务之一     

土地网格化管理关键技术探讨

基于土地网格化管理的思想,提出了对土地实施网格化管理过程中的网格划分方案和编码方案,并通过对上海市嘉定区土地网格化管理实例总结出具体土地网格划分方法,对比了城市网格与土地利用网格划分的异同,同时构建了网格化土地管理信息平台总体框架,认为3S技术、构件技术、中间件技术和地理编码技术是土地网格化管理信息系统构建的关键技术,为进一步完善网格化土地管理新模式以及土地网格化精细管理提供实施方案、数据保障和政策支持。     

焦炉烟气中复杂有机污染物筛选研究(I):采样技术与方法

借鉴国内外典型烟气采样装置 ,设计出多级串联采样装置。它将多种过滤、吸附材料联合使用 ,具有一次采集有机污染物种类全 ,数量多 ,结构简单 ,操作方便 ,适用范围广等特点 ,实际采集鞍钢焦炉烟气样品 ,效果很好。     

重庆城市电网工频电磁环境现状及安全性分析

在现场实测的基础上,分析研究了重庆城市电网中各种电压等级、各种类型变电站周边环境,多种形式架空线路下方区域以及地下电缆周围工频电磁环境的现状,对比国家现行标准限值,评价重庆城市电网的工频电磁环境的安全性,同时也指出随着架空线密度的增加,周围工频电场不但不增加,反而有降低的现象.目前擅自在输电线路下建房或增加房屋高度是危及电磁环境安全的主要问题,应加大监管力度,减少日后不必要的环保纠纷.