输气管道建设项目景观及生态系统影响评价—以广东省天然气管网一期工程为例

广东省天然气一期总长约466．5km,其中干线长度约369．1km,支干线长约97．4km。项目建设区域包括广州、佛山、肇庆、惠州、韶关、清远和东莞6市。天然气管道建设因其工程特性、施工方式,不可避免对土地利用类型、土壤、植被、动物、农业等方面带来影响,其表征为景观生态的直接影响,由此带来生态系统结构和功能的改变。以广东省天然气一期为例,采用遥感解译和GIS分析技术进行生态影响评价。通过地貌、植被、土地利用现状和现代地理过程等要素的组合,结合景观破碎度、多样性、优势度等指标,定量评价管道建设造成的景观生态影响。选取植被、土壤亮度、湿度、热度等指数,确立各指数权重分后,建立生态评价模型,对生态系统质量进行综合评价,分析管道建设可能造成的生态系统影响。评价区内景观生态类型可分为水域、旱地、水田、林地、草地、建设用地6种,各占6．5％、9．9％、51．2％、25．2％、2．8％和4．3％,破碎度为0．298,均匀度0．743,优势度0．594;生态环境质量可分为良好、中等、较差3类,各占39．8％、26．0％和34．2％。     

Performance of CH4MOD wetland for the case study of different regions of natural Chinese wetland

Reliable national estimates of CH₄ emissions from natural wetlands depend on model validation based on site observations. We therefore evaluated the performance of the CH4MOD_wetland model in simulating CH₄ emissions from 11 representative wetland sites in five regions of China. Model performance analysis showed that this method effectively simulates differences in the CH₄ fluxes between different sites and regions. The model efficiency for estimating the daily CH₄ fluxes in the northeastern China (NE), Inner Mongolia and northwestern China (NW), the North China plain and the Middle-Lower Yangtze Plain (E) and the Qinghai Tibetan Plateau (SW) was 0.51, 0.20, 0.52 and 0.65, respectively. The efficiency for estimating the annual mean CH₄ fluxes in southern China (S) was 0.99. Systematic negative deviation between the simulated and observed CH₄ emissions existed in all regions, especially in the NW region, which had a mean deviation (RMD) value of − 36.7%. On the national scale, the root mean square error (RMSE), the RMD, the model efficiency (EF) between the simulated and observed seasonal values were 28.7%, − 7.8% and 0.93, respectively. The CH₄ emissions showed the highest sensitivity to air temperature in the NE and SW regions, and to water table depth in the E region. Based on the sensitivity analysis, future climate warming and wetting are likely to increase the wetland CH₄ emissions at different levels in all regions of China.     

陕西省区域性自然灾害脆弱性评价研究

自然灾害脆弱性评价研究对于提高区域防灾减灾能力具有重要现实意义。以陕西省10市1区为例,选取6个子系统29项指标,运用均方差赋权法对陕西区域性自然灾害脆弱性进行评价研究。结果表明:自然条件、经济和基础设施3个子系统是影响陕西省区域性自然灾害脆弱性的主要因素;经济、社会和基础设施等因素是区域应灾能力的重要表现,直接影响着区域自然灾害脆弱性的高低;陕西省区域性自然灾害脆弱性具有显著的时空分布特征,关中平原及陕南秦巴山区各地级市、区自然灾害脆弱性高于陕北地区。     

Removal of natural organic matter by cationic hydrogel with magnetic properties

Magnetic cationic hydrogel (MCH) was synthesized, and its removal efficiency and mechanisms in regard to natural organic matter (NOM, represented by humic acid and fulvic acid) from the aqueous environment were studied. The effects of time, adsorbent dosage, initial pH, ionic strength, background ions, and NOM types were also investigated. MCH was characterized and found to have a strong magnetic character, yielding an extra advantage for recycling and reuse. Batch studies showed that the removal of Aldrich humic acid (AHA) by MCH was effective. The main mechanism for the removal of NOM is believed to be due to electrostatic interaction. NOM with larger molecular weight tended to be preferentially removed. Solutions with low pH, high ionic strength, and background electrolytes containing calcium, sulfate and bicarbonate were unfavorable for AHA removal. The adsorption-desorption of MCH was evaluated in three cycles, and demonstrated high regeneration rates.     

典型天然吸附剂对重金属的吸附性能研究

天然吸附剂由于其本身结构的特殊性,对重金属离子有一定的吸附效果,但是原始的吸附剂在工程处理应用中有一定的局限性,如耐酸碱性不高、吸附量不大等,因此在实际应用中采用较多的典型吸附剂多为改性材料,改性后的吸附剂提高了对环境的耐受性和对金属离子的吸附量,对于去除和回收水体中重金属有很大的优势和发展前景。     

高含硫天然气钻探工程环境监理要点探讨

对高含硫天然气钻探工程的主要环境影响进行了分析,针对大气环境、水环境、声环境、固体废弃物、生态环境及水土流失、环境风险等环境要素,对其环境监理要点进行了探讨.     

云南山地自然灾害类型及防治对策

本文从灾害成因的角度将云南山地自然灾害分为:坡面重力作用、沟谷泥石流、沟谷洪水、气象灾害、地震、流域水土流失、森林火灾等七个类型,并对各种灾害特征作了描述,系统地分析了山地灾害的形成因素,提出了一些防治对策。     

Use of polymeric sub-micron ion-exchange resins for removal of lead, copper, zinc, and nickel from natural waters

This research investigated the removal capacity of polymeric sub-micron ion-exchange resins(SMR) for removal of lead, copper, zinc, and nickel from natural waters in competition with natural organic matter(NOM). Polymeric SMR particles were created and tested to ensure that they were adequately dispersed in the solution. They removed little NOM(10%or less) from river water and wastewater, indicating that competition from NOM was not a major concern. SMR were able to remove 82% ± 0.2% of lead, 46% ± 0.6% of copper, 55% ±20% of zinc, and 17% ± 2% of nickel from river water spiked with 500 μg/L of each. Similarly,in wastewater, they were able to remove 86% ± 0.1% of lead, 38% ± 0.8% of copper, 28% ± 1%of zinc, and 11% ± 1% of nickel.     

Towards real-time detection of wastewater in surface waters using fluorescence spectroscopy

The presence of municipal wastewater at the intake of a major drinking water treatment facility located on Lake Ontario was examined using fluorescence data collected during a period of continuous monitoring. In addition, controlled mixing of lake water and wastewater sampled from a local treatment facility were conducted using a bench-scale fluorescence system to quantify observed changes in natural organic matter. Multivariate linear regression was applied to components derived from parallel factors analysis. The resulting mean absolute error for predicted wastewater level was 0.22% (V/V, wastewater/lake water), indicating that wastewater detection at below 1.0% (V/V) was possible. Analyses of sucralose, a wastewater indicator, were conducted for treated wastewater as well as surface water collected at two intake locations on Lake Ontario. Results suggested minimal wastewater contribution at the drinking water intake. A wastewater detection model using a moving baseline was developed and applied to continuous fluorescence data collected at one of the drinking water intakes, which agreed well with sucralose results. Furthermore, the simulated addition of 1.0% (V/V) of wastewater/wastewater was detectable in 89% of samples analyzed, demonstrating the utility of fluorescence-based wastewater monitoring.     

云南省农业自然灾害区划指标之探讨

自然灾害区划是防灾减灾和灾害科学研究的重要内容，而正确地选取区划指标是进行区划工作的关键环节。本文作为《云南省农业自然灾害区划研究》课题的一部分，在探讨各单项灾害（干旱、洪涝、低温霜冻、风雹、水土流失）区划指标的基础上，提出了综合农业自然灾害区划的基本指标－即“综合农业自然灾害指数”，并对指标进行了分级，为区划工作提供了依据。