An empirical study of spatial-temporal growth patterns of a voluntary residential green infrastructure program

Voluntary residential green infrastructure (GI) stormwater management retrofit programs can help cities comply with environmental regulations while also improving quality of life. Previous research has identified influential factors in residents’ willingness to adopt GI, but few have simultaneously studied the spatial and temporal dynamics of GI. I use a six-year record of participation in a voluntary residential GI program in Washington DC to explore how neighborhood characteristics and social influence affect GI adoption over time. Statistical regression and Monte Carlo permutation resampling techniques are used to explain the spatial-temporal patterns of growth of the program. I demonstrate empirical evidence that participation location is increasingly determined by the locations of previous participants. These findings suggest that past participants will increasingly influence spatial clustering of GI in the city.     

南京市景观生态空间格局动态变化研究

对南京市1988年、1995年、2003年的景观空间格局动态变化研究,结果表明:南京市域的整体景观多样性指数、均匀度指数、破碎度指数逐渐增加,优势度指数、面积变异系数呈现减小的趋势;各种景观类型的景观指数在不同时期差别较大,旱地的平均斑块面积则逐年减小,其他几种景观类型的平均斑块面积都呈现增大的趋势;六个区域的景观格局特征差异较大,景观多样性指数、均匀度指数、分离度指数以南京市区为最高;聚集度指数以高淳为最高,六合次之,南京市区为最小;形状指数以江宁为最高,六合次之。     

Spatial distribution of dissolved Pb, Hg, Cd, Cu and As in the Bohai Sea

Characteristics of the spatial distribution of selected dissolved heavy metals were analyzed during large scale surveys from August 12 to 25,2003 in the Bohai Sea.Dissolved Pb was the only element with average concentrations higher than the grade-one sea water quality standard of China.The spatial distribution of dissolved Pb in surface water was similar to those of Cd,Cu and As,where the isopleths generally indicated decreasing values from the bays to the central areas.Only for Hg did the high concentrations not only appear in Liaodong Bay,Bohai Bay and Laizhou Bay,but also in the Central Area,viz.not only in inshore but also in offshore areas. Vertical distributions of dissolved Pb,Cd,Cu and As were largely uniform,while that of dissolved Hg increased with depth.We infer that the input of pollutants from land was the main influencing factor for the detected distribution patterns of dissolved heavy metals, followed by the dynamics of sea water,release from bottom sediments and biochemical processes.Comparing with historical data, average concentrations of dissolved heavy metals appear to decline in recent years.     

Relationship between air pollutants emission patterns and concentrations

Emission patterns of NO_x and S‐compounds are analyzed to study their influence on the concentrations of SO₂, NO_x, sulphate and nitrate in the air. Air mass trajectories, emission inventories and cluster analysis are used to define the emission patterns.

The scheme that characterized most of the days is defined by low emissions from 48 hours until 18 hours before the measurements and it produces average concentrations. High concentrations are due to emission peaks. The time between these emission peaks and the measurement determines the importance of the emission peak on the concentration.     

山-水-林-田-湖-草-海-城修复模式的实践应用 ——威海华夏城采石场生态修复及其效益评价

山-水-林-田-湖-草系统保护与修复强调生态系统整体性、系统性和稳定性,生态系统的健康稳定有利于生态系统服务功能的全面优化提升,对确保生态环境安全和社会经济健康协调发展至关重要.山东威海华夏城受大规模开山采石活动影响,区域生态环境遭到破坏,居民生产生活受到严重干扰,经过10余年生态修复,华夏城实现了生态效益与社会经济效...     

道路绿化种植抗污染植物模式研究

在广州市广花公路黄石路段建立了 3个道路绿化抗污染模式进行研究 ,生长 2年后测定各模式对NOx、CO和TSP等大气污染物质的净化效果。结果表明 ,若植物种类相同、配置方式基本相似 ,则种植密度与净化效果密切相关 ,密度适宜能适当通风的林带的净化效果最好     

Differences in distributions,assembly mechanisms,and putative interactions of AOB and NOB at a large spatial scale

● Nitrifiers in WWTP were investigated at large spatial scale. ● AOB populations varied greatly but NOB populations were similar among cities. ● Drift dominated both AOB and NOB assembling processes. ● DO did not show a significant effect on NOB. ● NOB tended to cooperate with AOB and non-nitrifying microorganisms. Ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) play crucial roles in removing nitrogen from sewage in wastewater treatment plants (WWTPs) to protect water resources. However, the differences in ecological properties and putative interactions of AOB and NOB in WWTPs at a large spatial scale remain unclear. Hence, 132 activated sludge (AS) samples collected from 11 cities across China were studied by utilizing 16S rRNA gene sequencing technology. Results indicated that Nitrosomonas and Nitrosospira accounted for similar ratios of the AOB community and might play nearly equal roles in ammonia oxidation in AS. However, Nitrospira greatly outnumbered other NOB genera, with proportions varying from 94.7% to 99.9% of the NOB community in all WWTPs. Similar compositions and, hence, a low distance–decay turnover rate of NOB (0.035) across China were observed. This scenario might have partly resulted from the high proportions of homogenizing dispersal (~13%). Additionally, drift presented dominant roles in AOB and NOB assembling mechanisms (85.2% and 81.6% for AOB and NOB, respectively). The partial Mantel test illustrated that sludge retention time and temperature were the primary environmental factors affecting AOB and NOB communities. Network results showed that NOB played a leading role in maintaining module structures and node connections in AS. Moreover, most links between NOB and other microorganisms were positive, indicating that NOB were involved in complex symbioses with bacteria in AS.     

Above and below ground biomass patterns in arid lands

Regular vegetation patterns have been observed in many arid zones around the word. This particular spontaneous arrangement of the vegetation optimizes the use of the scarce water resources and could be imitated to restore vulnerable ecosystems; at the same time, the patterns of vegetation act as an early warning signal of the fact that fragile ecosystems may suddenly undergo irreversible shifts, thus, they deserve a special attention. The formation of vegetation patterns is the object of many theoretical and experimental studies, nevertheless, in previous works, the interest that is deserved to below ground biomass allocation is minor as compared to the effort that is spent to describe the organization of vegetation above ground.     

应对气候变化关键技术创新差异的时空格局——以“一带一路”沿线国家为例

技术是应对气候变化的重要手段,关键技术创新差异的扩大将不利于各国应对气候变化的协同发展。以技术产出的专利为数据源,运用大数据挖掘工具、泰尔熵指数及空间计量学的方法和理论,分析了"一带一路"沿线国家应对气候变化关键技术创新差异的时空格局演变情况。研究结果表明:(1)沿线国家应对气候变化关键技术创新差异整体上呈现下降态势,并以初期震荡向后期平稳有升过度。(2)按地理位置划分的区域技术创新差异呈现高的空间集聚效应,且强强集聚与弱弱集聚具有一定时期内的稳定性,部分地区面临陷入技术贫困陷阱风险。(3)沿线各国应对气候变化技术创新差异存在趋同俱乐部现象,个别国家随时间推移可能经历不同俱乐部过度。针对这种趋同特征及各国技术需求特点可划分为4种类别:技术转出区、技术转入区、技术扩散区和技术承接区。技术转出区多集中在东欧某些经济发达、能源依存度高的国家。为此,本文提出如下建议:(1)各国根据自身情况制定减排政策的同时,需要国际社会制定与其相适应的差异化且有侧重的援助方案。(2)技术创新强国在涉及应对气候变化技术转移知识产权等事项上应该给予技术需求国让步。同时,技术转移应考虑区域协同及地理邻近的扩散。(3)中国应发挥好南南合作援助基金的作用,加强特定区域内共性技术的帮扶力度,建立与适宜国家间关键技术联合研发与示范机制,树立大国形象。(4)中国应加快沿线战略布局,根据不同区域各国应对气候变化的现状及其技术能力制定差异化的产业和技术转移的政策,加强与沿线国家的技术合作与贸易往来,形成优势互补的产业链。