Assessment of non-point source pollution using a spatial multicriteria analysis approach

Eutrophication caused by the enrichment of nutrients from diffusing sources is degrading surface water quality throughout the world. Assessing the potential contributions of different land areas in diffuse nutrient export has become an important task in non-point source (NPS) pollution control. Existing methods were often limited by the availability of local data and the complexity of model formulation. This study developed a spatial multicriteria method to evaluate the nitrogen loss potential at the basin level. Four criteria were formulated to characterize the source capacity of nitrogen export, the flow path to water body, the efficiency of runoff generation and the climatic driving force. The proposed method is a low-effort approach since the required data is either already available in a global context or easily produced with limited inputs. Being implemented in GIS environment, this method generates maps that can be easily interpreted to provide decision support. The method was applied to the Huai River Basin, China. The results were validated based on the correlation between the nitrogen loss potential of sub-basin and the water quality class of river. The maps of nitrogen loss potential were helpful for examining the regional pattern of diffuse nitrogen loss, and could facilitate the decisions of NPS pollution management at the provincial or basin level.     

改进遗传算法在污水处理工艺优选决策指标权值确定中的应用

构建了基于模糊聚类的改进遗传算法（简称FMGA）,用于污水处理工艺优选决策指标权值的确定。FMGA的数值仿真结果表明,该算法能有效避免早熟收敛,能在较短时间内获取指标权值并且运算过程稳定。最后,将FMGA用于确定三峡库区城镇污水处理工艺优选决策指标的权值。结果表明,经济（0．2602）〉技术（0．2094）〉能耗（0．...     

城市轨道交通噪声测试分析

采取1/3倍距法布设测点,使用多通道噪声分析系统,对城市轨道交通噪声进行地面和轨面上的水平测试及垂向测试,取得其距离衰减规律、声级垂向分布等特性,新的测试点位布设方案取得了比传统测试方案更详细的测试结果。研究结果对于城市轨道交通噪声特性的研究及其控制方法的确定具有重要的学术意义和工程价值,同时对城市轨道交通噪声的测试方案进行了有益的探索。     

Methods for estimating the uncertainty in emergy table-form models

Emergy studies have suffered criticism due to the lack of uncertainty analysis and this shortcoming may have directly hindered the wider application and acceptance of this methodology. Recently, to fill this gap, the sources of uncertainty in emergy analysis were described and analytical and stochastic methods were put forward to estimate the uncertainty in unit emergy values (UEVs). However, the most common method used to determine UEVs is the emergy table-form model, and only a stochastic method (i.e., the Monte Carlo method) was provided to estimate the uncertainty of values calculated in this way. To simplify the determination of uncertainties in emergy analysis using table-form calculations, we introduced two analytical methods provided by the Guide to the Expression of Uncertainty in Measurement (GUM), i.e., the Variance method and the Taylor method, to estimate the uncertainty of emergy table-form calculations for two different types of data, and compared them with the stochastic method in two case studies. The results showed that, when replicate data are available at the system level, i.e., the same data on inputs and output are measured repeatedly in several independent systems, the Variance method is the simplest and most reliable method for determining the uncertainty of the model output, since it considers the underlying covariance of the inputs and requires no assumptions about the probability distributions of the inputs. However, when replicate data are only available at the subsystem level, i.e., repeat samples are measured on subsystems without specific correspondence between an output and a certain suite of inputs, the Taylor method will be a better option for calculating uncertainty, since it requires less information and is easier to understand and perform than the Monte Carlo method.     

桂牧1号杂交象草研究进展

系统综述了桂牧1号杂交象草(Pennisetum purpureumcv.Guimu-1)生物学特性、丰产栽培技术、营养品质、饲喂效果等方面的研究状况,并针对生产实际中存在的问题,提出了桂牧1号杂交象草今后生产和研究的主要方向.     

三峡库区(重庆段)菜地土壤重金属污染特征、潜在生态风险评估及源解析

为探究三峡库区菜地土壤重金属的污染特征、潜在生态风险和污染物的来源,于2021年10月采集了库区（重庆段）14个蔬菜种植区（县）菜地的表层土壤样品,分析了样本中7种重金属元素（As、Cd、Cr、Cu、Ni、Pb和Zn）的含量,分别利用单因子指数法、内梅罗综合污染指数法和潜在生态风险评价法对土壤重金属的富集状况和潜在风险进行了评估,并分析了蔬菜种植年限和栽培方式（露天和大棚）对土壤重金属累积的影响.结果表明,库区菜地土壤中重金属的含量高于重庆市三峡库区土壤背景值,但均低于《农用地土壤污染风险管控标准（试行）》（GB 15618-2018）规定的土壤污染风险管制值;单因子污染评价结果表明,区域土壤Pb、Zn、Cu和Cd处于轻微污染水平;内梅罗综合污染指数法表明,研究区处于轻度污染水平,主要污染因子为Cd和Ni,有91.4%的土壤样品存在不同程度的污染（P_N>1）,其中9.19%的样品处于重度污染;潜在生态风险评估结果指出,研究区以轻度生态风险为主,Cd中度生态风险的土壤样本数占比为9.77%,存在一定的生态风险.聚类分析结果显示Cd-Cu-Pb-Zn和As-Cr-Ni分别具有相同的污染源.菜地土壤中重金属含量随着种植年限的增加均呈上升趋势;总体上大棚土壤中重金属含量均高于露天菜地土壤.     

三峡水库典型消落带土壤DOM组分特征及其对有效态镉释放影响

重金属镉（Cd）是三峡水库蓄水后消落带土壤中主要的重金属污染物之一.为研究三峡水库反季节调蓄条件下溶解性有机质（DOM）对有效态Cd在土壤固-液相间释放行为及其再补给过程的影响,以三峡水库香溪河消落带为研究对象,分别于2019年10月和2020年10月采集土壤样品,利用紫外-可见吸收光谱、三维荧光光谱技术和荧光区域积分法分析土壤DOM光谱特性,同时结合梯度扩散薄膜技术（DGT）和土壤扩散通量模型（DIFS）综合探究土壤有效态Cd及其释放动力学过程.此外,测定了消落带土壤基本理化特性以及土壤中Cd含量和赋存形态.结果表明,研究区土壤DOM以富里酸为主,腐殖质特征较弱,具有陆源为主和内源较弱的混合特征,与2019年相比,2020年土壤DOM中富里酸类物质占比更高;2019年和2020年土壤ω（Cd）平均值分别为（0.474±0.301） mg·kg^-1和（0.249±0.058） mg·kg^-1,土壤中Cd的赋存形态均以非残渣态为主;DGT测定结果显示2020年土壤中有效态Cd含量较2019年呈下降趋势,进一步通过DIFS模型拟合结果表明,土壤中Cd的吸附速率大于解吸速率,土壤对有效态Cd的再补给能力较弱,表明三峡消落带土壤中有效态Cd的潜在释放风险较低,低分子量DOM和DOM中富里酸类物质是抑制土壤中有效态Cd释放的重要因素.研究结果揭示了三峡水库水文情势变化下DOM对重金属Cd环境地球化学行为的影响,为三峡库区重金属污染防治提供科学理论依据.     

三峡库区澎溪河不同高程消落带土壤磷形态及磷酸酶活性分布特征

磷酸酶可将有机磷矿化为无机磷,对土壤有机磷转化具有重要作用,然而目前鲜见关于三峡库区消落带土壤磷酸酶及其与磷形态转化的相关报道.研究澎溪河流域落干期不同高程消落带土壤磷形态及磷酸酶活性的分布特征,分析了磷酸酶活性与磷形态之间的相关性及其对磷形态的影响.结果表明,不同高程消落带土壤的H₂ O-P_i、NaHCO₃-P_i和NaOH-P_i含量均高于岸边土壤,生物可酶解磷含量和NaOH-P_o含量随高程增加而升高.冗余分析显示有机质和无定形铁锰含量是影响不同高程土壤有机磷形态的主要原因.消落带土壤酸性磷酸酶、碱性磷酸酶、磷酸二酯酶（以p-NP计）和植酸酶（以P计）活性均值分别为1.40、2.60、0.44和11.43 μmol ·（g ·h）^-1,且消落带土壤各磷酸酶活性随高程增加而增大,植物量和微生物量差异是导致消落带磷酸酶活性空间分布差异的重要原因.整体上消落带土壤磷酸酶活性与各有机磷形态含量呈显著正相关,而与生物可利用磷含量呈负相关.较高高程消落带土壤磷酸酶活性较高而生物可利用磷含量较低,在淹水初期磷酸酶介导的矿化有机磷为无机磷速率相对较高,向上覆水体释放磷的风险也较大.研究成果有助于全面理解三峡库区消落带土壤磷的地球化学循环.     

气候变化对长江三角洲海岸带的可能影响

本文利用长江三角洲海岸带的历史资料，讨论了长江三角洲海岸带的历史演变，并对未来海岸的变化作了估计。着重讨论了未来气候变化对长江三角渡海堤、江口通航、江口淡水资源的影响，指出未来全球气候变暖、长江流域降水增加都可能增加对长江三角洲海岸带的影响。最后提出了适应气候变化和减轻影响的措施。     

利用生物模拟采样技术研究第二松花江中的难降解有机污染物

利用生物模拟被动采样研究第二松花江吉林市段的有毒有机污染物种类，并与鱼的生物富集及沉积物的吸附作用进行了比较。对采样器，鱼类及沉积物样品中难降解有机物的分析可以看出、难降解有机污染物在三者之间的分布有较好的对应关系。生物模拟被动采样技术一定程度上模拟了具有生物有效性的难降解有机污染物的富集过程。