环评中不同性质项目工程分析内容的探讨

根据环境影响评价中工程分析篇章的目的及要求,探讨了新建、改扩建、技术改造三种不同建设性质项目的定义,分析了这三类项目工程分析篇章应编写的内容,并重点论述了其中的区别。     

湖泊水面温度遥感定量反演研究综述

湖泊水面温度与藻类生长密切相关,通过获取水体表层温度信息来监测湖泊水面温度时空动态变化,对于蓝藻水华预警监控具有重要意义。湖泊水面温度遥感定量反演的理论方法与反演地表、海洋表面温度基本相同。本文在介绍遥感反演地表温度原理的基础上,总结了国内外基于热红外波段反演水体表面温度的单窗算法、劈窗算法、多通道算法等几种常用方法,重点分析了各算法的优缺点和反演的主要难点,并对今后在内陆水体藻华预测顸警等方面的应用趋势进行了展望。     

中国南方雨雪冰冻灾害受损森林植被研究进展

2008年年初我国南方遭受了一场极为罕见的大范围持续低温雨雪冰冻极端气候灾害,这场灾害给我国人民的生产生活造成了重大损失,其中,林业受损尤为严重。我国学者针对受损森林生态系统进行了多方面的调查与研究。对现有的调查研究工作进行综述,重点概述了森林结构、功能和经济效益的受损状况,总结了天气条件、地理因素、树种及其生长情况,分析了林分特征等方面的森林受损机制以及受损森林的恢复与重建对策,对现有的研究在内容、水平及方向上的不足之处提出建议,以期对未来的相关研究提供帮助。     

延安市污水处理厂提标改造工程设计方案与实施效果

延安市污水处理厂一期工程处理规模为5×10⁴ m³·d⁻¹,原采用以“厌氧池+氧化沟+二沉池”为核心的污水处理工艺。提标改造前,污水处理系统存在设计水质偏低而污泥负荷偏高等问题,导致冬季低温或进水水质波动较大时,出水水质难以稳定达标。对此,通过加高氧化沟池体的方式,将生化池总水力停留时间延长至19.82 h;结合MBR工艺,利用膜组件的高效固液分离能力实现泥水分离,将生化池平均污泥浓度提高至7 050 mg·L⁻¹,并在内沟好氧池中增设搅拌机及碳源投加装置,使冬季低温或进水总氮较高时,生化系统整体以AAOAO的方式运行,从而进一步控制出水总氮含量。提标改造工程实施后,一期生化处理系统反硝化污泥负荷和BOD₅污泥负荷(以每天单位MLSS的TN/BOD₅测定值计)分别降低至0.030和0.033 kg·(kg·d)⁻¹,5 ℃条件下污水处理系统的理论TN和BOD₅去除能力分别提升至44.32和286.19 mg·L⁻¹,达到了污染物去除需求。提标改造后污水处理系统运行良好,出水可稳定达到《陕西省黄河流域污水综合排放标准》(DB 61/224-2018)中的A标准,可为该地区同类型污水处理厂提标改造提供参考。     

干旱荒漠区植被恢复与重建的探讨

西北干旱荒漠区生境严酷，物种贫乏，植被稀疏低矮，加上不合理的开发利用，致生境恶化。利用当地有限的水源来实现干旱荒漠区的植被恢复，防止流沙蔓延，可以从以下两方面入手：一方面，以裸地为立地条件，利用当地的关键种(keystone specics)或优势种(dominant species)，选择合适的生境，采用人工种子库和幼苗移植等方法，促使已缺失的植物种在目的地重新定居；另一方面，利用灌丛效应选择合适物种加以配合，提高干旱荒漠区的植被盖度。研究表明：以上两种途径对实现干旱荒漠区的植被恢复和重建是可行的。     

The State of Protected Forest Communities in the European Forest–Steppe Zone of Russia and Prospects for Their Reconstruction: A Case Study of Specially Protected Areas of Penza Oblast

The structure of most forest communities in the European forest–steppe, including protected areas, has been disturbed. The adverse consequences of these disturbances include the incomplete age structure of the populations of cenosis-forming species and the irreversibility of successions. The conservation of biodiversity in the structurally disturbed communities is impossible without human intervention, which must be aimed at restoring their age heterogeneity with regard to their specific ecological features.     

中国洪水灾后恢复重建行动与理论探讨

基于中国洪水灾后恢复重建的实践 ,总结了中国洪灾灾后恢复重建的结构体系 ,并依此讨论了洪水灾后恢复重建的若干理论和实践问题。文章指出 ,应明确洪水灾后恢复重建与备灾和防灾的关系 ,并提出了洪水灾后恢复重建的结构体系与程序。     

LONG-TERM RECONSTRUCTION OF WATER LEVEL CHANGES FOR LAKE ATHABASCA BY ANALYSIS OF TREE RINGS1

ABSTRACT: The fact that dendrochronology can be a useful tool in water resources management is demonstrated by a study of past changes in lake levels. The study was necessitated by the recent (1967) closure of the gates on the W.A.C. Bennett Dam on the Peace River in British Columbia, causing a drop in water levels of Lake Athabasca, the lake levels control water level undulations in a series of smaller lakes which lie in the 1.5 million acre delta area along its western edge in Alberta. The W.A.C. Bennett Dam has by its regulation of the Peace River affected the river's historical role of creating a hydraulic dam during early summer flood stages thereby preventing outflow from Lake Athabasca and inducing annual inundation of the delta area. Because the ecololgy of the lake and adjacent delta region has depended on the now attenuated snow-melt flooding from the Upper Peace River Basin, it became necessary to consider some means of artificially inducing this annual inundation. It was not known, however, what the long-term water level changes were around which the present ecology had developed. Continuous historical lake level records exist only for the period 1935–1967. Was this period one of anomalously high or low water levels? Relatively old white spruce trees growing along natural levees of the channels in the delta region were found to contain tree-ring records that reflected the water stages in the channels. Because the water levels in the channels could be correlated with lake levels, it was possible to use the three-ring series to extend the known 33-year record of lake level changes to 158 years. By using canonical analysis and 10-day mean lake levels for three different subperiods in the 33-year period of calibration, along with tree-ring series from appropriately chosen stands of white spruce, reconstructions were made of the long-term record for late May, early July, and late September. The reconstructed record shows that the May 21–30 lake levels have been three times as variable in the past as in the period of historical record (1935–1967), the July 11–20 levels twice as variable, and the September 21–30 levels 10% less variable. However, the mean water level for each of the three subperiods for the long-term record is very close to the means for the period of historical record. The reconstructed record shows that, before the dam gates were closed, there was only one three-year period (1866–1868) in which the lake levels were as low as they have been since closure of the gates (that is, 1967–1970). (Levels were nearly as low, however, during the period 1942–1945.     

混沌理论在河流溶解氧预测中的应用初探

基于混沌理论、相空间重构思想和嵌入理论分析涟水流域溶解氧的时间序列，计算吸引子维数和最大的Lyapunov指数，研究河流水质系统的复杂性特征。结果表明，河流溶解氧时间序列具有混沌特性，其外在表现为貌似随机的无规则特点；但系统本身内在的、固有的规律(表现在最大的Lyapunov指数)，表明短期预测河流水质变化是可行的，并应用混沌相空间模线性回归模型进行了预测，其预测结果对涟水流域的水质管理和控制具有一定的参考价值。     

两种应用场景下NDVI时间序列数据拟合方法研究

植被覆盖指数（NDVI）时间序列数据集包含地表植被的长势、生长周期、时空变化等信息,其拟合重建结果可应用于物候信息提取、生态质量评价、人类活动扰动识别、覆被变化动态监测等方面。基于TIMESAT软件,选取物候参数提取和扰动识别2个应用场景,结合地面站点数据和Jacknife法模拟数据,对比分析非对称高斯函数拟合法（AG法）、双Logistic函数拟合法（D-L法）和Savitzky-Golay滤波法（S-G法）3种方法的拟合效果。结果表明：（1）3种方法拟合重建后提取的生长开始时间（SOS）、生长结束时间（EOS）、生长周期（LOS）等物候参数接近站点数据,AG法和D-L法保持NDVI时序曲线整体变化特征的能力较强,提取的SOS和EOS更接近站点数据;（2）人类活动扰动识别应用场景中,S-G法在滤波时能够最大限度地保留时序曲线细节变化,恢复速率相关系数达到0.618,回归估计标准差低于AG法和D-L法,因此识别精度最优。