用污染指示菌评价城市水体污染的研究

选择湖南省常德市江北城区水体为代表开展本项研究。结果表明,水体中污染指示菌,总大肠菌群（ＴＣ）和粪大肠菌群（ＦＣ）密度同ＢＯＤ＿５负荷以及综合污染指数Ｐ呈高度正相关。所以,污染指示菌指标,特别是粪大肠菌群指标足综合评价城市污水,尤其是生活污水污染的一个必不可少的重要参数。对该城区水体细菌污染的评价结果是,生活污水排放愈集中的地区,细菌污染愈严重。其中护城河水的ＴＣ密度超出我国地面水Ⅲ级标准４个数量级;ＦＣ密度超过ＷＨＯ娱乐用水标准３个数量级。护城河是细菌污染最严重水体。包括滨湖公园内湖在内的接纳生活污水多或较多的水体,细菌污好也相当严重。只是远离城区的柳叮湖受污染程度较轻。     

不同氮磷比条件下浮游藻类群落变化

选取天津市小型人工湖湖水样品,调整氮磷起始质量比(分别为0.5∶1、7.2∶1、25∶1、50∶1),在水族试验箱内进行生态模拟试验,探讨城市湖水浮游藻类群落对不同氮磷比例的响应.与对照组相比,高氮磷比组绿藻种类减少,蓝藻种类变化不大;低氮磷比组蓝、绿藻种类数均减少.高氮磷比的中氮和高氮箱内,藻类生物量、细胞密度与叶绿素a都远高于对照和高磷箱;高氮箱中叶绿素a均值最高,为69.7 μg·L^-1,中氮箱次之,为54.3 μg·L^-1,对照与高磷箱分别为30.3和29.7 μg·L^-1.试验中后期,高磷箱绿藻门美丽胶网藻(Dictyosphaerium pulchellum)一直占据优势地位;而中氮箱和高氮箱主要优势藻种为皮状席藻(Phormidium corium)、细胶鞘藻(Phormidium tenue)、湖泊鞘丝藻(Lyngbya limnetica)和铜绿微囊藻(Microcystis aeruginosa)等蓝藻.对照箱内物种丰富度最高,中氮箱内生态优势度最高.     

基于三生空间质量的哈长城市群城市脆弱性时空演变格局及驱动力研究

高质量的三生空间是城市高品质空间布局、高效率功能体现的重要保障与载体。城市群作为城市三生空间矛盾的集中地,降低其城市脆弱性,是区域可持续发展的关键。因此,基于三生空间质量的哈长城市群城市脆弱性研究对国土空间协调与稳定发展具有重要意义。以哈长城市群11个地市为研究区域,基于生产空间质量、生活空间质量、生态空间质量构建城市脆弱性评价指标体系,运用熵权-TOPSIS评价模型、ArcGIS空间分析工具以及地理探测器对2010-2018年哈长城市群城市脆弱性的时空格局演变与驱动力进行分析。研究结果表明:①在时间变化上:整体来看,2010-2018年哈长城市群城市脆弱性呈下降的趋势,城市脆弱性空间上呈"先增强后减弱"的态势。城市脆弱性高等级地区数量呈现"先增强后减弱"的趋势,而城市脆弱性指数相似地区集中分布呈现"先减弱后增强"态势。②在空间布局上:形成了II、I级区"点状零散",V、IV级区的"边缘式"的空间分布格局。空间分布呈现"随机化",无明显集聚性。从其演化趋势类型特征上看,呈发散趋势的城市多于呈收敛趋势的城市,说明哈长城市群城市脆弱性空间差异呈逐渐增大态势。③基于三生空间质量哈长城市群城市脆弱性的空间分异主要是由城市生活空间质量脆弱性的差异引起,其次是城市生产空间质量脆弱性。其中,经济增长水平不高是城市生产空间质量脆弱性的首要因素;交通设施水平不完善、燃气资源供给力度不够、城乡差距偏大、教育水平程度偏低、信息化水平低下是城市生活空间质量脆弱性的关键因素;污水处理强度、城市绿化水平和生活垃圾无害化处理强度是影响哈长城市群城市生态空间质量脆弱性的基础要素。     

长江中游城市群生态系统健康时空演变特征分析

城市群地区生态系统健康状况关乎城市群的可持续发展,科学测度城市群地区生态系统健康水平对城市群地区生态系统健康宏观调控政策制定具有重要的实践意义,然而当前生态系统健康评价仍存在不足之处。生态系统服务是反映生态系统健康状况的重要组成部分,如何把生态系统服务纳入生态系统健康评估框架中,成为了当前研究讨论的热点话题。拟把基于InVEST模型评估的生态系统服务纳入生态系统健康评估框架中,构建了基于"生态系统活力-生态系统组织力-生态系统弹性-生态系统服务"的评估框架,结合多源数据对1995—2015年长江中游城市群生态系统健康水平时空特征进行测度。结果显示:(1)研究期间长江中游城市群地区生态系统健康状况总体有所恶化,恶化区域主要分布在城市群的核心地区;(2)研究期间长江中游城市群地区生态系统健康存在显著的空间依赖性,生态系统健康高值区主要分布在周边山区以及中部的罗霄山脉,生态系统健康低值区主要分布在平原地区、大城市周边地区以及主要的交通线路沿线地区。本研究结果可以为其他地区生态系统健康评估以及长江中游城市群地区生态系统健康保护政策制定提供科学借鉴。     

辽宁中部城市群城市非点源污染负荷评估

过去几十年我国经历了快速城市化过程,这使得不透水面大幅度增加,导致地表径流和洪峰流量增加,进入水体的污染物增多。城市非点源污染已成为河流水体恶化、生态系统退化的重要原因。在快速城市化过程中,城市群已成为城市化发展的新阶段。位于同一流域的各城市所产生的城市非点源污染导致城市群流域水环境问题越来越突出,成为制约城市群流域可持续发展的关键因素之一。现有的关于城市非点源的研究多集中于城市内部小尺度,对城市群大尺度的研究亟需发展。以位于浑河太子河流域的辽宁中部城市群为例,在沈阳市不同功能区和不同下垫面进行降雨径流采样,基于事件平均浓度(EMC)法和SWMM(Storm Water Management Model)模型相结合的方式,定量评估城市群流域城市非点源污染负荷。研究结果表明：路面径流中城市非点源污染物浓度、负荷量及其单位面积负荷要高于屋面径流和透水面径流。辽宁中部城市群TP、TN、COD、TSS的年均城市非点源污染负荷分别为265.52、852.89、2249.71、192496.74 t/a,重金属Cd、Ni、Pb、Cr、Cu、Zn的年均城市非点源污染负荷分别为347.99、9932....     

珠三角城市群生态空间分区方法与管控对策

生态空间管控是维护区域生态安全,解决区域生态供需矛盾的重要手段。生态空间分区一直是生态管控的热点问题,对促进城市群可持续发展具有重要意义。以珠三角城市群为例,基于政策目标、民众需求、专家知识等方面综合构建评价体系,开展了基于生态空间质量和生态系统健康评价的生态空间分区的探索研究。结果表明：珠三角城市群生态空间约占城市群面积的82.8%,生态空间质量好,但生态系统健康水平低。城市尺度肇庆市、深圳市生态空间质量较高,珠海市、中山市生态空间质量较低;惠州市、肇庆市生态系统健康水平较高,佛山市、中山市生态系统健康水平较低。综合生态空间质量和生态系统健康,区域尺度将城市群生态空间分为重点保护区、重点修复区、潜在修复区和生态保育区。重点保护区占生态空间总面积的10.1%,是区域生态源地,应实行最严格的环境保护制度,划定生态保护红线和自然保护地,加强生态建设和生物多样性保护,并加强生态连通性建设,提升区域整体生态系统服务;重点修复区占生态空间总面积的21.6%,以生态修复,实施生态治理工程,推进生态产业为主;潜在修复区占生态空间总面积的13.1%,以保护优先、自然恢复为主,对生态空间进行全面的养护,保护和提升品质,重点提升生态系统服务;生态保育区占生态空间总面积的55.2%,重点实施生态廊道建设,同时加强区域高标准农田建设,在保护生态空间的基础上合理开展生产建设活动。对生态空间分区管控的研究可方便决策者对生态修复空间和生态保护空间进行识别和分类管理,有效指导国土空间规划和区域生态环境管理体系的完善。     

Assessment of heavy metal in the water,sediment, and two edible fish species of Jamshedpur Urban Agglomeration,India with special emphasis on human health risk

The city of Jamshedpur, nicknamed the “industrial capital of Jharkhand,” is one of the oldest industrial settlements in India, nestled amidst the mineral-rich Chota Nagpur plateau, with its diverse tribal population. Heavy metal contamination from industrialization and urbanization can pose a serious health risk to the resident population of the city. Metal concentrations in water and sediment of various water bodies (rivers, canals, and lakes) were determined using ICP-MS. Pollution indices indicate heavy metal contamination at Jamshedpur Urban Agglomeration, mainly because of Cr (23–1111.6 mg/kg), Hg (0.08–4.11 mg/kg), and Pb (5.2–248 mg/kg). Labeo rohita and Punitus sarara, the two popular edible fishes, also have high concentration of Cr, Hg, and Pb. Health risk to human population due to consumption of metal contaminated edible fishes (L. rohita and P. sarara) was determined by target hazard quotient (THQ) and hazard index (HI). THQ value of fish consumption (most popular protein supplement in the area) was found higher for Cr and Pb when compared with previous literature on fish consumption. Also, HI value ranged from 1.4 to 3.9, suggesting that the children have higher health risks than adults, due to consumption of metal contaminated fishes (especially L. rohita).     

A decision support tool for evaluating the wildlife corridor design and conservation performance using analytic network process (ANP)

A recent issue highlights the need for a wildlife corridor to mitigate habitat fragmentation and biodiversity degradation caused by intensive urbanization in the country, such as the development of infrastructure, roads, and highways. Indeed, the issues of frequent road and vehicle-animals collisions are ever-increasing in urban corridors. As a result, flora and fauna populations can become isolated, leading to an unbalanced ecosystem. This study developed the Wildlife Corridor Design and Conservation (WCDC) index, assessment model. The study has investigated the wildlife corridor design and conservation features through a systematic literature review, clustered them into three criteria (biophysical, structural, and environmental designs) and twenty-one sub-criteria. The study applied the Analytic Network Process method to measure the weights of features; habitat preservation (W_C1.1 = 0.280), species varieties control (W_C1.2.=0187), and conduit for movement (W_C1.3. = 0.100) play critical roles in wildlife corridor design and conservation. The Weighted Sum Method verified the WCDC model through a case study (Red Earth overpass, Canada). The model assigns certification labels (Gold, Silver, Bronze, or not-certified); accordingly, it ranked the evaluated site as Gold, which means the Red Earth overpass performs intimately in biophysical, structural, and environmental preservation of mammal habitat. The study conducted regression analysis for model validation, determining a significant association between the base and case-study models.     

Air temperature and humidity and human comfort index of some city parks of Mexico City

A series of air temperature (Ta) and relative humidity (HR) measurements were carried out in five urban parks and their surroundings in Mexico City. It was found thatTa is lower andRH is higher inside the parks. There were differences (P<0.05) between the parks and surroundings in air temperature, relative humidity, vapour pressure (e), vapour pressure deficit (VPD) and the thermohygrometric human comfort index (THI).Ta differences were more marked during the early afternoon. Maximum differences ofTa, e, andDPV were 5.6°C, 0.6 and 1.2 mbar. There is strong evidence that the magnitude of differences inTa are directly proportional to the surface of urban parks.