基于微生物生物完整性指数的北京市城市河道生态系统健康评价

生物完整性指数（IBI）是河道生态系统健康评价的重要且被广泛应用的指标,然而,基于水体中分解者微生物群落构建IBI评价标准的研究较少。针对北京市城市河道生态系统健康状况开展评价,探索微生物生物完整性指数(M-IBI)评价流程与标准构建方法。基于沉积物中微生物Illumina高通量测序信息,筛选出关键环境因子（水质指标TN、TP、NH₃-N、NO₃-N和NO₂-N）确定候选生物指标,根据判别能力分析结果,确定Shannon指数、拟杆菌门（Bacteroidota）相对丰度、绿弯菌门（Chloroflexi）相对丰度、蓝藻门（Cyanobacteria）相对丰度、COD_Cr耐受属相对丰度和NH₃-N清洁属相对丰度6个指标,提出了指标标准化公式和健康评价标准。结果表明,以自然水体为补水的永定河各采样点评价结果均为健康状态,其他3条以城镇再生水厂出水为补水的河道中,清河4个采样点为健康至亚健康状态,凉水河5个采样点为健康至一般状态,大龙河4个采样点为亚健康至一般状态。M-IBI可以有效区分不同程度的受损点位,较合理地评价城市河道生态系统健康状况。

     

多重水质评价方法在地下水水质评价中的对比研究—以北京市朝阳区为例

目前地下水水质评价方法众多,选择合适的评价方法对地下水的管理与利用具有重要意义。以北京市朝阳区2020年枯水期采集的地下水水样检测结果为基础,利用改进的层次分析法、单因子指数法和综合污染指数法对地下水水质进行评价,并对比3种方法评价结果的准确性以及存在的不合理之处。结果表明：1）3种方法的水质评价结果差异较大,改进的层次分析法的水质评价结果最优,单因子指数法的评价结果最差,综合污染指数法的评价结果与其他方法的一致性最高;2）在进行水质评价时可优先选择综合污染指数法,单因子指数法适用于水质要求较高或超标污染物少的水体,改进的层次分析法适用于有多种污染物超标的水体;3）为进一步确定3种方法对地下水水质评价结果的准确性,将3种方法的评价结果与可靠性分析结果进行对比,发现改进的层次分析法、单因子指数法和综合污染指数法与可靠性分析的水质评价结果相同的占比分别为90.48%、42.86%、47.62%。因此,在对地下水水质进行综合评价时,可使用改进的层次分析法。

     

庐山不同森林植被类型土壤特性及其健康评价

土壤作为森林生态系统的一个重要因子,评价森林土壤健康状况对森林健康的维护经营以及森林系统功能的发挥具有重要意义。在系统调查和分析庐山8种森林植被类型土壤特性的基础上,评价指标分别从物种多样性以及不同的森林土壤特性中进行筛选,包括物种多样性系数、枯落物层厚度、腐殖质层厚度、土层厚度、容重、粘粒含量、有机质、p H值、阳离子交换量、全氮、水解氮、有效磷、速效钾、磷酸酶活性等指标,基于SPSS19.0软件对所获得数据进行差异性检验和相关分析,确定各项指标的权重,应用合适的土壤健康评分函数,将测得的指标值转换为对应指标的分值,最后通过加权综合法,计算其土壤健康指数,并对不同森林植被类型土壤健康状况进行评价。结果表明,8种森林植被类型下最终的土壤健康指数大小排序为:针阔混交林(0.78)常-落混交林(0.72)灌丛(0.69)常绿阔叶林(0.67)落叶阔叶林(0.64)竹林(0.59)马尾松林(0.53)黄山松林(0.46)。     

典型流域土地利用/覆被变化及对水质的影响--以太湖上游浙江西苕溪流域为例

利用1985、1995和20D0年的TM数据及水质资料，运用GIS和水质指数法研究西苔溪流域的土地利用／覆被变化及其水环境效应。结果表明：流域内耕地不断减少，建设用地持续扩大，林地前期减少后期缓慢增加；林地和耕地是流域内的主要土地利用类型，二者面积之和占流域面积的比例在三个时段均在92％以上；空间集中性及斑块碎化是土地利用空间格局变化的主要表现，建设用地斑块数量增多且斑块面积明显增大，饼地面积减少但斑块数量增多。研究时段内流域水质在时间上呈逐步恶化趋势，在空间上则表现为自上游至下游逐渐下降，其中，1996-2000年，研究河段内水质指数下降幅度达30％左右；只治理点污染源仅使水质指数增加6．5％左右，表明影响水质的主要因素是土地利用变化导致的面源污染。     

泥石流入汇的危险性判别指标

通过对比单沟和区域泥石流危险性的评估方法 ,提出了利用影响度、危险度和危害度 3项指标判别汇流区泥石流入汇危险性的设想 ,分析了泥石流入汇可能引起堵江的影响因子。作为尝试 ,给出了判别指标的计算公式 ,经实例验证具有较好的实用性 ,可作为规划设计的技术依据。     

惠济河底泥重金属污染特征及潜在生态风险评价

连续5 a对惠济河(开封市区段)8个断面的底泥样品中Cu、Zn、Pb、Cd及Cr 5种重金属的浓度进行分析,并采用单因子污染指数法、综合污染指数法、地积累指数法、潜在生态风险指数法进行生态风险评价。监测结果表明:8个断面中除最上游孙李唐庄桥断面底泥未受重金属污染外,其余断面底泥均有不同程度的污染,以皮屯桥断面底泥污染最重,达严重污染。综合污染指数法评价结果表明:惠济河底泥Cd为重度污染,Cu和Pb为轻度污染,Zn为轻微污染,Cr为无污染;除皮屯桥断面底泥综合污染指数高达6.74外,其他断面综合污染指数为0.55~1.89。地积累指数法评价结果表明:惠济河底泥首要重金属污染物为Cd,平均流域地积累指数高达3.50,处于污染等级4,即偏重度污染;此外,Cu、Pb偏中度污染,Zn轻度污染,Cr无污染。潜在生态风险指数法评价结果表明:惠济河底泥中Cd为强生态危害,其他重金属为轻度生态危害;重金属污染综合评价为强生态危害,这主要是Cd浓度过高造成的,其最高潜在生态风险因子达2 233.50,出现在皮屯桥断面。     

有机磷类杀螺增效剂在土壤中的吸附行为

通过测定16个有机磷类杀螺增效剂在安徽省宿县土壤中的有机硕吸附系数（Koc),研究了该类化合物的环境行为;并用碎片分子连接性指数（FMCIs)和线性溶剂化能参数（LSERs)结构描述符,与土壤有机碳吸附系数之间进行了定量结构-性质相关（QSPR）分析,所得到的两组预测方程,可用于该类化合物的生态风险评价。     

城市河流水质常规评价技术研究

运用综合水质标识指数法,对我国河流水质评价面临的关键技术问题,包括水质评价方法、水质评价项目,水质级别评价,水环境功能区达标评价、水质定性评价、河流及水系整体水质比较、水质随时间和空间变化等作了明确界定,并介绍了在上海河流水质评价中的应用。     

Remote sensing of the urban heat island and its changes in Xiamen City of SE China

World-wide urbanization has significantly modified the landscape, which has important climatic implications across all scales due to the simultaneous removal of natural land cover and introduction of urban materials. This resulted in a phenomenon known as an urban heat island(UHI). A study on the UHI in Xiamen of China was carried out using remote sensing technology. Satellite thermal infrared images were used to determine surface radiant temperatures. Thermal remote sensing data were obtained from band 6 of two Landsat TM/ETM^ images of 1989 and 2000 to observe the UHI changes over l l-year period. The thermal infrared bands were processed through several image enhancement technologies. This generated two 3-dimension-perspective images of Xiamen‘s urban heat island in 1989 and 2000, respectively, and revealed heat characteristics and spatial distribution features of the UHI. To find out the change of the UHI between 1989 and 2000, the two thermal images were first normalized and scaled to seven grades to reduce seasonal difference and then overlaid to produce a difference image by subtracting corresponding pixels. The difference image showed an evident development of the urban heat island in the 11 years. This change was due largely to the urban expansion with a consequent alteration in the ratio of sensible heat flux to latent heat flux. To quantitatively compare UHI, an index called Urban-Heat-Island Ratio Index(URI) was created. It can reveal the intensity of the UHI within the urban area. The calculation of the index was based on the ratio of UHI area to urban area. The greater the index, the more intense the UHI was. The calculation of the index for the Xiamen City indicated that the ratio of UHI area to urban area in 2000 was less than that in 1989. High temperatures in several areas in 1989 were reduced or just disappeared, such as those in old downtown area and Gulangyu lsland. For the potential mitigation of the UHI in Xiamen, a long-term heat island reduction strategy of planting shade trees and using light-colored, highly reflective roof and paving materials should be included in the plans of the city planers, environmental managers and other decision-makers to improve the overall urban environment in the future.     

Progress in quantitative research on the relationship between atmospheric oxidation and air quality

Atmospheric oxidizing capacity (AOC) is an essential driving force of troposphere chemistry and self-cleaning, but the definition of AOC and its quantitative representation remain uncertain. Driven by national demand for air pollution control in recent years, Chinese scholars have carried out studies on theories of atmospheric chemistry and have made considerable progress in AOC research. This paper will give a brief review of these developments. First, AOC indexes were established that represent apparent atmospheric oxidizing ability (AOIe) and potential atmospheric oxidizing ability (AOIp) based on aspects of macrothermodynamics and microdynamics, respectively. A closed study refined the quantitative contributions of heterogeneous chemistry to AOC in Beijing, and these AOC methods were further applied in Beijing-Tianjin-Hebei and key areas across the country. In addition, the detection of ground or vertical profiles for atmospheric OH·, HO₂·, NO₃· radicals and reservoir molecules can now be obtained with domestic instruments in diverse environments. Moreover, laboratory smoke chamber simulations revealed heterogeneous processes involving reactions of O₃ and NO₂, which are typical oxidants in the surface/interface atmosphere, and the evolutionary and budgetary implications of atmospheric oxidants reacting under multispecies, multiphase and multi-interface conditions were obtained. Finally, based on the GRAPES-CUACE adjoint model improved by Chinese scholars, simulations of key substances affecting atmospheric oxidation and secondary organic and inorganic aerosol formation have been optimized. Normalized numerical simulations of AOIe and AOIp were performed, and regional coordination of AOC was adjusted. An optimized plan for controlling O₃ and PM_2.5 was analyzed by scenario simulation.