构建生态安全格局是保障城市生态安全的必要手段，科学识别生态源地是构建生态安全格局的基础。以高度城市化的大都市区——上海市为研究对象构建生态源地识别体系，探究不同土地利用数据源与指标权重对生态源地识别的影响。在此基础上，基于最小累积阻力模型（MCR）与电路理论构建生态阻力面，识别生态保护与修复优先区域，对已有研究仅关注保护/修复的情况进行补充。结果表明：（1）自然生态本底仍是识别生态源地的重要指标，加入人类需求指标可填补已有研究对高度城市化源地识别针对性和丰富性的不足。生态系统服务格局、生态环境安全格局与环境友好格局权重为5∶2∶1时，源地识别效果最佳。（2）上海市生态源地空间和数量分布极不均匀，破碎化是首要问题。上海市现有（2017年）生态源地202个，共920.96 km~2,占总面积14.53%,其中微型源地（面积＜3 km~2）数量高达82.67%。城市化水平影响生态源地分布，外环是源地数量与总面积的分水岭，郊环是源地平均面积的重要界线。（3）上海市以“面（源地）-线（廊道）-点（优先点）”组成生态保护网络，其中生态廊道442条，生态保护优先点306个，重要点线分布集中于中心城区边界。上海市生态修复优先区域325.47 km~2,其中障碍点309.78 km~2,需优化的非生态斑块95个（15.69 km~2）,大都市区的生态修复重点区域应聚焦于城市化扩散的阻力区域，且应多关注生态价值适中的草地与耕地。研究工作可为其他高度城市化区域，以及处于高速城市化发展进程城市的国土空间生态修复关键区识别提供借鉴与参考。

Black carbon (BC) is an important component of airborne fine particulate matter, with significant impacts on global climate change and human health. Taking Minhang District of Shanghai as the study area, a microaethalometer (MA200) and GPS were installed on the electric taxi to form a mobile observation platform to identify the spatial distribution and hot spots of atmospheric BC in urban environment. We analyzed the sources and influencing factors of BC. The results showed that the overall characteristics of the spatial distribution pattern of near surface atmospheric BC in Minhang District of Shanghai were high in the north and low in the south. The average BC concentration was (4.11±4.87) μg·m-3. The average concentrations of BC in working days and non-working days were (4.22±1.49) and (3.52±2.26) μg·m-3. The variability of BC concentration in the high value area was large, indicating that the increases of BC concentration in mobile observation were related to traffic accidents in the road section. In addition to human activities, large-scale dense vegetation might inhibit BC diffusion. The Absorption ngström Exponent (AAE) was (0.82±0.54), which was closer to that of fossil fuel combustion. The contributions of fossil fuel emissions, biomass combustion, and mixed sources to BC sources were 67.5%, 4.9% and 27.6%, respectively.

Air pollution has seriously endangered human health and the natural ecosystem during the last decades. Air quality monitoring stations (AQMS) have played a critical role in providing valuable data sets for recording regional air pollutants. The spatial representativeness of AQMS is a critical parameter when choosing the location of stations and assessing effects on the population to long-term exposure to air pollution. In this paper, we proposed a methodological framework for assessing the spatial representativeness of the regional air quality monitoring network and applied it to ground-based PM2.5 observation in the mainland of China. Weighted multidimensional Euclidean distance between each pixel and the stations was used to determine the representativeness of the existing monitoring network. In addition, the K-means clustering method was adopted to improve the spatial representativeness of the existing AQMS. The results showed that there were obvious differences among the representative area of 1820 stations in the mainland of China. The monitoring stations could well represent the PM2.5 spatial distribution of the entire region, and the effectively represented area (i.e. the area where the Euclidean distance between the pixels and the stations was lower than the average value) accounted for 67.32% of the total area and covered 93.12% of the population. Forty additional stations were identified in the Northwest, North China, and Northeast regions, which could improve the spatial representativeness by 14.31%.

2013年我国正式开展了113个环境保护重点城市和国家环境保护模范城市细颗粒物等项目监测，目前已建成国家环境空气质量监测网络.为了较好地将空气质量国控环境监测点（简称国控点）监测结果提升到区域和全球水平，须了解当前空气质量环境监测网络的空间代表性.本文以长三角地区为研究区域，基于国控点空间分布信息，结合区域第二产业比重（POSI）、地区生产总值（GDP）、人口（POP）、风速（WDSP）、降水量（PRCP）、气温（TEMP）、增强型植被指数（EVI）和数字高程模型（DEM）8个影响细颗粒物（PM2.5）相关变量，在1 km×1 km空间分辨率下计算长三角地区129个国控点与研究区域中其他位置（像元）的多维欧氏距离，并结合K均值聚类方法开展区域国控点PM2.5监测的空间代表性评价及优化.结果表明：①长三角地区129个国控点代表区域面积差异明显，其中，上海市淀山湖站点的代表面积最大，为37933 km2，南京市迈皋桥站点的代表面积最小，仅为4 km2；②长三角地区国控点能较好地代表整个区域的PM2.5空间分布，现有国控点对PM2.5空间分布代表的有效范围（即像元与国控点多维欧氏距离低于全区平均值的区域）占总面积的63.23%；③难以被现有国控点代表性的区域主要集中在江苏省太湖、洪泽湖等水域、上海市中心城区与崇明沿海地区及浙江西南部山地地区；④在浙江省绍兴市与衢州市新增2个国控点，中东部丘陵地区的区域代表性可得到明显改善，长三角地区国控点可代表区域面积占比整体提高16.4%.

Black carbon (BC), an important component of atmospheric aerosols, has a great influence on regional and global radiation balance, climate and human health due to its small particle size, large specific surface area and radiation forcing. The long-term variation of atmospheric BC over China during 1980-2019 was investigated through MERRA-2 reanalysis data. MERRA-2 BC generally presented a good correlation (average R = 0.61) with 852 monthly samples from ground-based observations at 64 stations around China. In recent 40 years, the annual-averaged atmospheric BC concentration derived from MERRA-2 reanalysis data was 1.10 +/- 0.22 mu g/m(3), with an average annual growth rate of 1.52%. The monthly BC concentrations showed a "W-shaped trend. Based on the Mann-Kendall trend analysis, the BC concentration can be roughly divided into three stages: (1) the "low value" stage with slow growth rate (1.68%) (1980-1999, 0.91 +/- 0.10 mu g/m(3)), (2) the fluctuating "median value" stage with high growth rate (4.44%) (2000-2007, 1.28 +/- 0.13 mu g/m(3)), and (3) the "high value" stage with slow downtrend (-0.87%) (2008-2019, 1.32 +/- 0.06 mu g/m(3)). Peak times and multi-year average growth rates of BC concentration and emission were not synchronized. The spatial distribution, dividing by the Hu Line, a line dividing the population density and urbanization of China, formed three BC high-value areas in Sichuan Basin, Northern Henan area and Beijing-Tianjin-Hebei (BTH). The altitude where the concentration of BC increased fastest at an average annual growth rate of 3.47% during 1980-2019 was between 0 and 500 m. The growth rate of BC concentration was close to zero as the altitude increased. During the past 40 years, significant overall uptrends were detected in MERRA-2 BC concentration with Mann-Kendall trend analysis at pixel scale, especially during 1980-1999 and 2000-2007. This increasing trend was more obvious in the eastern Hu Line. Whereas, a downward trend was appeared in the plains and basins of southeast China during 2008-2019.

As an important component of atmospheric aerosols, black carbon (BC) has a great influence on the regional and global radiation balance, climate, and human health due to its small particle size, large specific surface area, and radiative forcing potential. Here, the spatio-temporal characteristics of atmospheric BC were investigated based on modern-era retrospective analysis for research and applications version 2 (MERRA-2) reanalysis data and ground observation data during 1980-2019 in Shanghai, a highly urbanized city in mainland China. The influences of local emissions and regional transmission on regional-scale BC concentrations were examined using the M-K trend test, backward trajectory analysis, and the potential source contribution function (PSCF). The results showed that:① MERRA-2 BC and ground observation datasets showed good consistency (R∈[0.68, 0.72]), indicating that MERRA-2 reanalysis data can be used to reveal long-term changes in ground-level atmospheric BC concentrations; ② Atmospheric BC concentrations in Shanghai over the past 40 years can be divided into three stages:a "low value" stage of slow growth[1980-1986, (1.75±0.17) μg·m-3], a relatively stable "median value" stage[1987-1999, (2.18 ±0.07) μg·m-3], and a fluctuating "high value" stage[2000-2019, (3.07±0.31) μg·m-3]. Seasonally, Shanghai's BC concentrations generally show a "U" pattern with low concentrations in summer and high concentrations in winter. As a result of black carbon emissions from marine diesel engines and other engines used for water transportation, a small peak also occurs in July; ③ The diagnostic quality ratio of air pollutants and the bivariate correlation analysis[R(BC-NO2)>R(BC-CO)>R(BC-SO2)] indicated that traffic emissions were the main sources of atmospheric BC in Shanghai, especially by heavy diesel vehicles; ④ The backward trajectory and PSCF analyses found that the air mass of Shanghai in summer was dominated by a clean sea breeze, accounting for 77.18%. In contrast, during the other seasons, more than 50% of the air mass came from the north. The potential source regions of atmospheric BC in Shanghai are mainly distributed in eastern China, expanding outwards and centering on the Yangtze River Delta, and the expansion direction is consistent with the directions of the backward trajectories.