"珠三角"地区城市化对地下水水质影响案例研究

以珠海市东部沿海地区为例,探讨城市化地区地下水化学特征及污染状况的关系.结果表明土地利用类型与地下水水质变化密切相关.香洲区地下水化学组分差异较大,电导率范围为49.4~971 μS/cm.大部分地下水呈弱酸性,林地及果园用地地下水电导率较低,水化学类型多属于Na-HCO3型;老城区及新住宅区地下水类型多属于Ca-Mg-HCO3类型,电导率较高,受NO3-及Cl-污染较为严重.新住宅区地下水NO3-污染状况较老城区更为严重可能与旧村改造及市政排水设施不完善有关.除少数采样点外,地下水化学类型受季节变化影响不大.人为污染与自然风化过程是影响地下水化学类型的重要因素.     

Acute toxicity assessment of drinking water source with luminescent bacteria: Impact of environmental conditions and a case study in Luoma Lake,East China

• Acute toxicity assessment was conducted in Luoma lake watershed, East China. • Impacts of environmental factors on the toxicity testing was fully evaluated. • Dissolve oxygen had a weak positive correlation with luminescence inhibition rate. Protecting the quality of lake watersheds by preventing and reducing their contamination is an effective approach to ensure the sustainability of the drinking water supply. In this study, acute toxicity assessment was conducted on the basis of acute bioluminescence inhibition assay using the marine bacterium Vibrio fischeri as the test organism and Luoma Lake drinking water source in East China as the research target. The suitable ranges of environmental factors, including pH value, organic matter, turbidity, hardness, and dissolved oxygen of water samples were evaluated for the toxicity testing of bioluminescent bacteria. The physicochemical characteristics of water samples at the selected 43 sites of Luoma Lake watershed were measured. Results showed that the variations in pH value (7.31–8.41), hardness (5–20 °d) and dissolved oxygen (4.44–11.03 mg/L) of Luoma Lake and its main inflow and outflow rivers had negligible impacts on the acute toxicity testing of V. fischeri. The luminescence inhibition rates ranged from -11.21% to 10.80% at the 43 sites. Pearson’s correlation analysis in the experiment revealed that temperature, pH value, hardness, and turbidity had no correlation with luminescence inhibition rate, whereas dissolved oxygen showed a weak statistically positive correlation with a Pearson correlation coefficient of 0.455 (p<0.05).     

Simulating spatiotemporal dynamics of urbanization with multi-agent systems—A case study of the Phoenix metropolitan region, USA

Urbanization is a human-dominated process and has greatly impacted biodiversity, ecosystem processes, and regional climate. To understand the socioeconomic drivers of urbanization and project future urban landscape changes, multi-agent systems provide a powerful tool. We develop an agent-based model of urban growth for the Phoenix metropolitan region of the United States, which simulates the behavior of regional authorities, real estate developers, residents, and environmentalists. The BDI (Beliefs-Desires-Intentions) structure is employed to simulate the agents behavior and decision models. The heterogeneity of agents is reflected by adjusting parameters according to the agents’ beliefs, desires and preferences. Three scenarios, baseline, economic development priority and environmental protection, are developed and analyzed. The combination of multi-agent system and spatial regression model is employed to predict the future urban development of the Phoenix metropolitan region. Landscape metrics are used to compare the spatial patterns of the urban landscape resulting from different scenarios in different times. In general, with the rapid urban expansion, the shape of urban patches will become more regular as many of them become coalesced. The spatial analysis of urban development through modeling individual and group decisions and human-environment interactions with a multi-agent systems approach can enhance our understanding of the socioeconomic driving forces and mechanisms of urban development.     

洞庭湖区退田还湖生态补偿机制

以洞庭湖区退田还湖的生态补偿为例,初步探讨了有关生态补偿的3个基本问题,即补偿支付者和接受者的问题,补偿强度的问题和补偿渠道的问题。     

城市化与生态环境响应研究综述

城市化是学者们一直比较关注的重点问题,他们从不同视角对城市化及其过程进行了大量而富有创新的研究,并取得了丰硕的成果。伴随着城市化进程的加快,人们对生态环境问题的关注,城市化与生态环境的响应关系是城市地理新的关注点。文章分别就国内外学者对城市化、城市生态环境、城市化与生态环境响应的研究进行了综述,认为国内外学者对城市化、城市生态环境的研究起步早,成果多,近年来研究范围日益拓展,研究程度日益加深,并加强了新技术新方法的应用。国内学者对城市化的研究集中于城市化道路选择问题的探讨、城市化水平测度以及城市化的动力机制三个方面。对城市生态环境的研究多集中于社会一经济一自然复合生态系统及生态城市的研究。对于城市化与生态环境响应关系的研究则多见于生态学家、经济学家及地理学家的成果中,主要集中在单方面的城市化对生态环境的影响研究,而对于生态环境是怎样反过来影响城市化进程的研究则比较少见。另外,学者们的研究以微观单个影响因子的研究居多,从宏观综合角度出发进行的研究较少。这将是今后研究的一个重点问题。     

Impact of energy structure adjustment on air quality: a case study in Beijing, China

Energy consumption is a major cause of air pollution in Beijing, and the adjustment of the energy structure is of strategic importance to the reduction of carbon intensity and the improvement of air quality. In this paper, we explored the future trend of energy structure adjustment in Beijing till 2020, designed five energy scenarios focusing on the fuel substitution in power plants and heating sectors, established emission inventories, and utilized the Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality Model (CMAQ) to evaluate the impact of these measures on air quality. By implementing this systematic energy structure adjustment, the emissions of PM₁₀, PM_2.5, SO₂, NO _x , and non-methane volatile organic compounds (NMVOCs) will decrease distinctly by 34.0%, 53.2%, 78.3%, 47.0%, and 30.6% respectively in the most coalintensive scenario of 2020 compared with 2005. Correspondingly, MM5-Models-3/CMAQ simulations indicate significant reduction in the concentrations of major pollutants, implying that energy structure adjustment can play an important role in improving Beijing??s air quality. By fuel substitution for power plants and heating boilers, PM₁₀, PM_2.5, SO₂, NO _x , and NMVOCs will be reduced further, but slightly by 1.7%, 4.5%, 11.4%, 13.5%, and 8.8% respectively in the least coal-intensive scenario. The air quality impacts of different scenarios in 2020 resemble each other, indicating that the potential of air quality improvement due to structure adjustment in power plants and heating sectors is limited. However, the CO₂ emission is 10.0% lower in the least coal-intensive scenario than in the most coal-intensive one, contributing to Beijing??s ambition to build a low carbon city. Except for energy structure adjustment, it is necessary to take further measures to ensure the attainment of air quality standards.     

城市化与生态环境响应研究综述

城市化是学者们一直比较关注的重点问题,他们从不同视角对城市化及其过程进行了大量而富有创新的研究,并取得了丰硕的成果。伴随着城市化进程的加快,人们对生态环境问题的关注,城市化与生态环境的响应关系是城市地理新的关注点。文章分别就国内外学者对城市化、城市生态环境、城市化与生态环境响应的研究进行了综述,认为国内外学者对城市化、城市生态环境的研究起步早,成果多,近年来研究范围日益拓展,研究程度日益加深,并加强了新技术新方法的应用。国内学者对城市化的研究集中于城市化道路选择问题的探讨、城市化水平测度以及城市化的动力机制三个方面。对城市生态环境的研究多集中于社会—经济—自然复合生态系统及生态城市的研究。对于城市化与生态环境响应关系的研究则多见于生态学家、经济学家及地理学家的成果中,主要集中在单方面的城市化对生态环境的影响研究,而对于生态环境是怎样反过来影响城市化进程的研究则比较少见。另外,学者们的研究以微观单个影响因子的研究居多,从宏观综合角度出发进行的研究较少。这将是今后研究的一个重点问题。     

快速城市化进程中城市扩张对景观格局分异特征的影响

在中国快速城市化背景下,大部分研究仅是单一的利用景观指数分析城市景观格局,往往只侧重于对景观斑块或格局的几何特征进行简单分析和描述,忽略了城市扩张与城乡景观格局动态变化过程之间的内部联系,研究城市扩张与城乡景观格局动态变化过程之间的内部联系对揭示城市化规律有着重要意义。文章以江苏省昆山市（县）范围为研究对象,基于全市1985—2008年间多期TM影像图,在采用遥感与地理信息系统相结合的技术方法获取昆山市景观格局动态变化以及相关景观生态学指数分析的基础上,探讨城市扩张对城乡景观格局的影响。结果表明：23年间自然景观类型的面积基本保持不变;人工景观面积显著增涨了4倍。斑块密度、景观斑块数量破碎度指数受人工景观类型影响基本呈上升趋势;斑块密度、景观破碎度、最大斑块、边缘密度等指数与建设用地增长之间存在明显相关性,表明城市扩张是城乡景观格局特征变化的重要驱动力。     

Impact of gasoline engine deposits on light duty vehicle emissions: in-use case study in Beijing, China

Tailpipe emissions from light-duty gasoline vehicles usually deteriorate over time. The accumulation of engine deposits due to inadequate gasoline detergency is considered to be one of the major causes of such emission deterioration. Six in-use light-duty gasoline vehicles in Beijing were tested to investigate the impact of engine deposits on emissions of hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NO _x ). Emissions under cold start and hot running test conditions from the six light duty vehicles were measured before and after engine deposits were removed. Results show that although individual vehicles reacted differently for each of the pollutants, elimination of engine deposits on average reduced HC emissions under hot running conditions by 29.4%, CO emissions under cold start conditions by 23.0% and CO emissions under hot running conditions by 35.5% (t < 0.05 in all cases). No pollutant emissions increased with statistical significance (t < 0.05) after the removal of engine deposits. Variations of emission changes upon removal of engine deposits were observed. Such variations are in line with previous studies, implying that the impact patterns of engine deposits on vehicle emissions may be subject to many influencing factors that are not fully understood and difficult to control under all conditions. A statistical view of the impact of engine deposits on vehicle emissions may be appropriate for evaluation of emissions reductions across a city or a country. It is necessary to maintain sufficient and effective gasoline fuel detergency in practice to keep the engines clean and in turn reduce vehicle emissions.     

Water environmental planning and management at the watershed scale: A case study of Lake Qilu, China

Water environmental planning and management has become essential for guiding the water pollution control activities. Past water pollution control activities have been site specific, with little thought on water quality standard reaching at the watershed scale. Based on the watershed approach, a seven-step methodological framework for water environmental planning and management was developed. The framework was applied to water environmental planning and management of the Lake Qilu watershed in Yunnan Province, China. Results show that the reduction amount of total nitrogen (TN) under the plan is 1,205 tons per year so that the target of environmental capacity can be reached in 2020. Compared with traditional methods, the framework has its prevalence and could be generalized to analogous watersheds.     

城市湖泊流域面源污染的源-汇效应研究--以武汉市东湖为例

随着城市点源污染控制不断完善,城市面源污染已成为危害中国城市水体的重要污染源.由城市土地利用变化引起的地表径流污染是导致湖泊水质恶化和富营养化的主要因素,加强面源污染的源-汇效应研究是控制、管理流域污染的重要途径之一.研究选取中国最大的城市湖泊武汉市东湖为研究对象,运用遥感和GIS技术,进行流域划分和地类解译,建立土地利用基础数据库,后对水质统计数据进行定量化处理,通过建立了地类——湖泊水质关系模型,科学地分析了用地与水质的关系,并对城市湖泊水质的季节动态、影响因素进行了初步探索.研究结果表明土地利用和气候变化对流域内湖泊水质的影响显著.其中,农田和建设用地是城市湖泊面源污染的主要来源,绿地和坑塘水面能够有效的截流、吸收污染物,起到保护湖泊水质的作用;受降水、温度等气候因子的影响,湖泊水质状态呈现季节性波动.研究选取东湖为研究对象,研究面源污染的源-汇效应,具有代表性,对于更好保护城市湖泊,合理利用湖泊资源提供了理论依据.     

湿地功能变化与生态系统管理--以洞庭湖区双退垸为例

以调控湿地生态功能为途径,在分析双退垸次生湿地功能动态变化、现阶段功能特点及管理现状基础上,提出了洞庭湖区双退垸湿地生态系统可持续管理方案,并针对现阶段存在的管理问题提出具体对策.     

Impact of climate factors on cyanobacterial dynamics and their interactions with water quality in South Taihu Lake,China

Cyanobacterial bloom events in South Taihu Lake cause serious water quality problems and disturb aesthetic view of lake’s environment. In this study, correlations between cyanobacterial blooms and hydro-meteorological factors, including water quality, temperature and precipitation were investigated. Results demonstrated that South Taihu Lake was heavily affected by cyanobacteria and the proliferation of cyanobacteria due to variations in hydro-meteorological factors and water quality conditions. Water quality parameters, including COD, NH₃-N, TN and TP improved significantly since 2008 even at an elevated cyanobacterial bloom situation. Correlation analyses have shown that the development of cyanobacterial density and chlorophyll a concentration was sensitive to a wider temperature variation. The optimum temperature for cyanobacteria was 20°C, while extremely low and high temperatures were found to suppress their growth. Moreover, unusual rainfall patterns were measured during the study period (2003–2009), which showed an adverse impact on cyanobacterial development. Findings from this study suggested that seasonal lake’s water quality monitoring; suitable treatment of cyanobacterial blooms and strict policy implementation can solve the water quality issues in highly eutrophic lakes like Taihu.     

Freshwater lakes--a potential source for aquaculture activities--a model study on Perumal Lake, Cuddalore, Tamil Nadu

The freshwater Perumal lake located at Cuddalore was assessed for its suitability and potential for aquaculture practices. Various hydrobiological parameters determined reveals that the various physicochemical characteristics are with in normal range of values. The DO level, BOD and COD values determined in the lake revealed the consequences of community activities and pollution possibilities. The primary productivity data revealed maximum productivity during March which infer that the lake is unaffected by anthropogenic disturbance and community contamination. The bacterial count remained higher during the monsoon periods, which characterize profuse rainfall and storm water discharge into the lake. The microfauna includes zooplankter such as cladocerans, copepods, rotifers and ostracods. Benthos include carps, catfishes, mullets and prawns. The above study revealed that the various parameters in the lake conform to the levels suited for freshwater fish culture and represents a resource for scientific management.     

土地利用/覆被变化对土地生态系统有机碳库的影响——以吉林省通榆县为例

土地利用/覆被变化对陆地碳循环影响显著.文章基于实地采集的土壤、植物样品的测试数据和1989、2004两年8月陆地卫星TM遥感影像数据,采用生态系统类型法分析吉林省通榆县1989-2004年耕地、林地、草地、盐碱地、沙地等11 种地类之间土地利用变化对土地生态系统有机碳库的影响.计算结果表明1989-2004年通榆县土地生态系统有机碳库共损失了3.18 TgC(1Tg=106t),年均损失约为0.265 Tgc.其中,湿地、草地有机碳库分别损失5.54 TgC和3.71 TgC,盐碱地面积的增加导致有机碳库损失4.75 TgC.林地面积增加和沙地面积减少分别使有机碳库增加了4.58 TgC和3.75 TgC.研究区总体上为一个碳失汇,草地退化、湿地萎缩、土地沙化和盐碱化造成了有机碳库的碳损失,而植树造林、草地植被的恢复和重建等活动则可以显著增加土壤有机碳储量.该研究对于评估自然环境与人为活动影响下,特别是大规模土地整治与生态修复对土壤有机碳的增汇潜力和固碳效应的影响具有重要的理论意义和应用价值.     

Impact of community-based approaches to wildlife management: case study of the CAMPFIRE programme in Zimbabwe

The objective of this study was to elicit community perceptions on the effectiveness of the CAMPFIRE programme, a community initiative, designed to benefit rural communities in Gonono ward in the Zambezi valley. Five villages and 76 respondents were selected from the ward using simple random sampling. Data collection included a structured questionnaire administered to households, semi-structured interviews with key informants, such as chiefs, headmen and local council staff, transect walks and participant observations. The results of the study revealed that, although the CAMPFIRE concept has been instrumental in creation of employment and infrastructure, the local community considers that no significant changes have occurred to their livelihoods. The findings suggest that the current model of wildlife conservation in Zimbabwe is not promoting total community participation. Future models need to focus on total involvement and independence from government structures. However, this can only happen when there is sufficient capacity building in communities on a wide number of issues, including general management, to ensure long-term sustainability.     

Implementation of ecological modeling as an effective management and investigation tool: Lake Kinneret as a case study

The need for scientifically based management of lakes, as key water resources, requires the establishment of quantitative relationships between in-lake processes responsible for water quality (WQ) and the intensity of major management measures (MM, e.g. nutrient loading). In this paper, we estimate the impact of potential changes in nutrient loading on the Lake Kinneret ecosystem. Following validation of the model against a comprehensive dataset, we applied an approach that goes beyond scenario testing by linking the lake ecosystem model DYRESM–CAEDYM with a set of ecosystem variables included in a pre-assessed system of water quality indices. The emergent properties of the ecosystem predicted from the model simulations were also compared with lake data as a form of indirect validation of the model. Model output, in good agreement with lake data, indicated differential effects of nitrogen and phosphorus nutrient loading on concentrations, and major in-lake fluxes, of TN and TP, and dynamics and algal community structure. Both model output and lake data indicated a strong relationship between nitrogen loading and in-lake TN values. This relationship is not apparent for phosphorus and only a weak relationship exists between phosphorus loading and in-lake TP. The modeling results, expressed in terms of water quality, allowed establishment of critical/threshold values for the nutrient loads. Implementation of the ecological modeling supplemented with the quantified set of WQ indices allowed us to take a step towards establishment of the association between permissible ranges for water quality and major management measures, i.e. towards sustainable management.     

城市化对土壤呼吸作用影响的研究进展

土壤呼吸是指土壤产生CO2的所有代谢作用,是碳素由陆地生态系统进入大气的主要途径和大气CO：的重要来源,是影响全球碳循环的途径之一,它的变化可能会对大气CO2浓度产生显著的影响。城市化的推进引起世界范围内土地利用／覆盖方式的变化,这种变化对土壤的理化性质、生物学特性等产生深刻影响,从而影响土壤的呼吸作用。因此,研究城市化引起的土壤呼吸变化对于精确地估测陆地碳循环有着重要意义。国外在20世纪90年代就开始了城乡梯度上土壤碳动态的研究,而我国在这这方面的研究还处在起步阶段,尤其是关于由自然土壤转变为城市土壤后,土壤呼吸变化的机制研究较少。已有的研究表明,在干旱和半干旱地区,城市化引起土壤呼吸降低,而非干旱区则相反。此外,城市化过程中,土壤呼吸变化的方向和强度因所处的气候区域、利用的土地来源、城市内部的土地利用方式及植被类型的不同等而存在差异,但仍存在许多不确定的影响因素,如与气候变化的耦合作用等。因此,在未来城市化过程对土壤呼吸作用的研究中,应加强土壤呼吸作用的直接影响因子和间接影响因子、时空差异及其他更精细的研究。