Assessment of ecological risks induced by land use and land cover changes in Xiamen City,China

The landscape ecological risk (LER) in Xiamen City, China, from 1990 to 2030 was studied using an urban land use and land cover change (LUCC) model and LER analysis. The LUCC model was used to predict the LUCC of Xiamen from 2020 to 2030. We analyzed the characteristics of LUCC and landscape pattern changes and, finally, evaluated the effect of rapid LUCC on LER. Of the six landscape types investigated, built-up land and farmland demonstrated the most significant changes. The area of built-up land increased by 1.5 times in 2010 and is predicted to increase by 2.7 times in 2030 than that in 1990. The area of farmland increased from 34.5% in 1990 to 24.5% in 2010 and is predicted to decrease to 15.1% in 2030. The number of patches (NP) of built-up land decreased with increasing area, which promoted the dominance of built-up land over other landscape types. Five landscape types, those other than built-up land, increased in NP, landscape fragmentation, segmentation, and disturbance but decreased in dominance. The LER of Xiamen in 2010 was slightly lower than that in 1990. However, with the acceleration of urbanization, the LER in 2020 and 2030 will increase by 7.6% and 12.5% than that in 2010. The LER will significantly increase in areas such as the Huandong sea area, the second urban core of Xiamen, and northern Xiang'an. For the areas, some measures (e.g. optimum urban spatial growth patterns and control of coastal reclamation) must inevitably increase to reduce the LER posed by rapid urbanization.     

长三角农田土壤中滴滴涕的污染特征与生态风险

以长江三角洲地区农田土壤为研究对象,分析了土壤和蔬菜中滴滴涕(DDTs)的残留水平和空间分布特征,评估了DDTs对土壤生态和人体健康的潜在风险。结果显示,长三角地区农田土壤中DDTs含量范围为<0.2~3 520 ng·g^-1,平均63.8 ng·g^-1,主要残留在土壤耕作层(0~30 cm)。土壤中DDTs及其代谢产物残留量较低,98.5%的点位土壤符合《中国土壤环境质量标准》的二级标准。15%的蔬菜样品中检出DDTs,其浓度为相应土壤DDTs浓度的9%~18%,土壤残留的DDTs通过食物链进入人体导致的健康风险很小。低残留DDTs对土壤微生物的群落结构和多样性无显著影响(-0.25<R<0.25,0.307<P<0.979)。应用美国环保署(USEPA)方法评估了土壤中DDTs对人体的健康风险,其中致癌风险级别为非常低,对儿童和成人具有非致癌风险的样品比例分别为1.1%和0.7%。因此,长三角地区大多数点位农田土壤DDTs残留量较低,不会对生态环境和人体健康产生危害。     

中国长江三角洲流域百菌清水生生物基准研究

通过生态毒理试验,获得百菌清对长江三角洲流域14种代表性水生生物的毒性数据。分别采用评价因子法、物种敏感度分布法和毒性百分数排序法,推导长江三角洲流域百菌清水生生物基准值。评价因子法、物种敏感度分布法和毒性百分数排序法得出的急性基准值分别是0.066μg·L~(-1)、3.00μg·L~(-1)和0.51μg·L~(-1),慢性基准值分别是0.0089μg·L~(-1)、0.40μg·L~(-1)和0.136μg·L~(-1)。比较了3种方法得出的基准值之间的差异并分析了原因,在此基础上,提出了我国长江三角洲流域百菌清水生生物基准推荐值,并与国外基准值进行了比较。研究结果可为中国农药水质标准制修订及水生生物风险评估提供科学依据。     

长三角地区饮用水源地沉积物中有机氯农药污染特征

2015年4月采集长江三角洲地区河流型、河网型和湖泊型饮用水源地沉积物,采用同位素稀释高分辨气相色谱-高分辨质谱法测定了22种有机氯农药(OCPs).结果表明,采集的沉积物中测定的22种有机氯农药都有检出,滴滴涕(DDTs)、六氯苯、六六六(BHCs)、五氯苯的检出率为100%;有机氯污染水平依次为:嘉兴河网(浓度范围为1.71-61 ng·g-1,中值为12.4 ng·g-1)>长江下游(浓度范围为0.46-93 ng·g-1,中值为8.59 ng·g-1)≈钱塘江(浓度范围为1.02-69 ng·g-1,中值为8.1 ng·g-1)>太湖(浓度范围为1.76-8.65 ng·g-1,中值为3.53 ng·g-1). DDT及其降解产物的浓度与其他地区的含量相当.依据DDTs和BHCs的同分异构体比值的变化和主成分分析结果对污染源进行解析,结果表明嘉兴河网主要以氯丹、九氯和六六六为主要污染特征,该地区有氯丹的使用和六六六的历史残留.钱塘江主要以BHCs、氯丹和DDTs为主要污染特征,有林丹的输入.太湖主要污染特征为DDTs和BHCs,并有新源输入.长江下游主要以o,p'-DDT和BHCs为污染特征,有些采样点表明有三氯杀螨醇的使用,六六六为历史残留.对长三角地区水源地沉积物进行生态评价发现,滴滴涕类有机氯农药存在潜在生态风险,其中DDTs具有潜在生态风险的采样点占74%,具有生态风险的采样点占2%.     

Survival of faecal coliforms and hygiene risks in soils treated with municipal sewage sludges

An incubation experiment was conducted to monitor effect of sewage sludge application on changes in numbers of faecal coliforms in soils over time after sludge application and evaluate the hygiene risks. Soil faecal coliform counts were made after 1, 7, 14, 28, 56 and 84 days of incubation. The faecal coliform counts in the sludge-treated soils decreased substantially with time and were similar to those in the untreated controls after incubation for 56 days. Land application of air-dried sludges increased the hygiene risks due to the re-growth of faecal coliforms, and the counts of faecal coliforms in soil treated with air dried sludge from Suzhou (91% DM) were 50 times higher than in soils with fresh dewatered sludge from Suzhou (15% DM) after 7 days of incubation. The main factors affecting the changes in faecal coliform counts were sludge type and incubation time. Sludge type determined the faecal coliform counts and the ability of the faecal coliforms to re-establish, and indigenous microorganisms competed with the faecal coliforms for nutrients during the incubation process.     

土地资源对珠三角地区人口增长的约束分析

改革开放以来,随着经济高速发展,大量外来人口涌入珠三角地区。1979─2012年间,珠三角地区的常住人口从1797.42万人增至5681.70万人。大规模的人口增长使得珠三角地区的资源供给压力增大,特别是土地资源。2010年珠三角地区已开发的建设用地面积为8867 km2,其中深圳、东莞等城市的建设用地规模已经接近其土地资源的适宜开发上限,土地资源对人口增长的约束作用也日趋显著。为了评判珠三角地区土地资源压力对人口增长的影响,利用Malthus模型和Logistic模型分别对该地区9个城市的人口变化进行拟合,结果表明,2组模型对2000年前各城市的人口变化均有较高的拟合精度且拟合结果与实际情况较为相近,主要是由于该地区早期发展阶段的资源压力对人口增长的约束作用较小。2000年以后不同城市的Logistic模型与Malthus模型对人口变化预测呈现出不同的趋势,主要与各城市的土地资源压力密切相关。根据2组模型模拟结果的差异和土地资源的压力,将9个城市分为3组。其中深圳、东莞为第一组,这2个城市的人口增速最快、土地资源压力最大,相应的Malthus模型的估计值分别在2003年、2005年超过了实际人口,且其后估计值与实际值的差距逐渐增大。依据Malthus模型2020年深圳、东莞的人口预测值分别为6469.58万人、2386.81万人,这大大超过了这2个城市的资源环境承载极限。这一结果说明在深圳、东莞的人口高速增长已经不可持续,Malthus模型已不能反映其未来人口的变化趋势。第二组包括广州、佛山、珠海和中山4个城市。这组城市的人口增速相对缓慢,Malthus模型的估计值与实际人口较为接近,但2010年以来这4个城市人口的增长呈放缓趋势,Malthus模型估计值逐渐偏大。第三组城市包括人口增速最慢的江门、惠州和肇庆3个城市。这组城市的人口?     

The widening urbanization gap between the Three Northeast Provinces and the Yangtze River Delta under China’s economic reform from 1984 to 2014

Urbanization has created a significant gap between the Three Northeast Provinces (TNP) and the Yangtze River Delta (YRD) since China’s reform and opening-up. In this study, we explain this problem by employing an urban expansion index, spatial hierarchical clustering, the Zipf-PLE model, fractal theory, and time-series analysis. Statistical data on the built-up area, population, and gross domestic product were downloaded from the National Bureau of Statistics of China. The results revealed the following. (1) During the stage of the planned economy, as a result of the significant government investment in development, the urban built-up areas in the TNP and the YRD reached 1867 and 757 km², respectively, in 1984. (2) During the stage of the socialist market economy, the urban built-up area of the YRD experienced rapid growth over the 30 years from 1984 to 2014 with a rate of increase of 668.8%, which was higher than that of the TNP (139.9%). In 2014, the urban built-up areas of the TNP and the YRD were 4479 and 5820 km², respectively. (3) Locational advantages had significant effects on urban development after China’s economic reform. The coastal cities of the YRD had higher rates of increase of the built-up areas. By contrast, the border cities of the TNP had lower rates of increase. Finally, this paper finds that the socialist market economy exhibited more efficiency in promoting urban expansion and economic development. The results are significant for generating balanced and sustainable regional development strategies in the future.     

红河哈尼梯田世界文化景观遗产的遥感监测与土地覆盖变化

红河哈尼梯田是中国重要的世界文化景观遗产,以森林、梯田、村寨、水系四度同构的人与自然高度协调的生态系统而著称。随着经济与旅游的发展,哈尼梯田自申报世界遗产以来,其文化景观不可避免地遭受干扰。遗产监测有助于及时了解遗产本体的保存现状和风险影响因素,确定遗产突出普遍价值以及制定规避风险的有效措施。文章基于红河哈尼梯田独特的文化景观特征,利用高分辨率卫星遥感影像对申遗前后的文化景观遗产要素进行遥感监测,分析其土地覆盖现状与变化趋势,探究遥感手段在遗产要素变化监测中的可行性与可靠性,对遥感在文化遗产监测中的应用具有一定的指导意义。结果表明,(1)红河哈尼梯田申遗后,景观格局基本没有发生改变,仍然以森林和梯田为主,其遗产要素的变化均在可控范围内。主要申遗范围坝达片区各遗产要素面积变化共为93.78 hm²,水田变化约占总变化面积的80%,其次是林地约占18%,其他遗产要素面积变化不大。(2)各遗产要素之间的面积变化以水田转变为林地和灌木林地为主,占总变化面积的57%,部分房屋建筑物拆迁变为灌木林地,说明申遗后相关的退耕还林政策与生态环境保护规划起到了明显成效。(3)随着旅游业的发展,以及村民生活条件改善的需求,部分梯田转变为道路和房屋建筑,但这些规划的合理性还需进一步核实与确认。(4)依据哈尼梯田的文化景观特征,监测文化景观遗产要素时的精细化程度比土地利用变化要求高,因此首选高分辨率遥感影像,建议空间分辨率达到1 m以上。     

长江三角洲流域保护水生生物优先控制农药品种筛选

以长江三角洲流域为研究区域,首先明确了以保护水生生物为目标的优先控制农药品种的筛选原则,并以模型预测为基础,根据农药对水生生物的风险性,筛选形成了长江三角洲流域保护水生生物优先控制农药品种名录。名录共包含15种农药有效成分,一方面可为我国地表水农药生态基准的制定提供优先次序,另一方面对于长江三角洲流域地表水体农药污染控制具有重要的指导意义。     

一株高效阿特拉津降解菌株的筛选及其降解能力和机理

在江苏省某玉米农田土壤中筛选出以阿特拉津（ATZ）为唯一碳源和氮源的菌株D2,经16S rDNA基因序列分析,将其鉴定为土壤芽孢杆菌（Solibacillus）,菌株D2的生长曲线符合SGompertz模型和Slogistic模型. 不同ATZ初始浓度、pH和培养温度条件下对ATZ的降解实验表明,菌株D2对ATZ具有极高的耐受性（>200 mg·L⁻¹）,在温度为20—30 ℃、pH值为5—9的条件下降解率均能达100%,可将100 mg·L⁻¹的ATZ在18 h内完全去除,ATZ去除量与D2菌株的数量呈显著的负相关（r=−0.983,P＜0.01）. 对ATZ的降解中间产物测定表明,菌株D2可通过脱氯羟基化、加氢脱烷基化、甲基化、脱烷基化和水解等过程将阿特拉津转化为羟基阿特拉津（HA）、阿特拉通（atraton）、脱乙基阿特拉津（DEA）、西玛津（DMA）、羟基西玛津（HDMA）和脱乙基脱异丙基阿特拉津（DACT）. 因此,D2是一株高效降解菌株,环境适应能力高于大部分已报道菌株,能够广泛应用于ATZ污染废水和污染土壤修复等领域.     

The urban growth, size distribution and spatio-temporal dynamic pattern of the Yangtze River Delta megalopolitan region, China

As one of the six megalopolitan regions in the world, the Yangtze River Delta is one of the most populated and developed regions of China. The spatial and temporal dynamic pattern of the urbanization process of the megalopolitan region is investigated. This work compared the spatial and temporal dynamic pattern of the urban growth for the five urban areas (Shanghai, Nanjing, Suzhou, Wuxi and Changzhou) in this region. During the 15 years, urban growth patterns were dramatically uneven over three 5-year periods. The size distribution of the five urban areas became more even with the rapid urbanization process. The patterns of urban expansion reflected policy adjustment and economic development throughout the time. Landscape metric analysis across concentric buffer zones was conducted to elucidate the area, shape, size, complexity and configuration of urban expansion. The study indicates the coalescence process occurred during the rapid urban growth from 1990 to 1995 and the moderate growth period from 2000 to 2005, but different urban growth period between 1995 and 2000. The urban growth pattern was coalesced for the Nanjing and Wuxi metropolitan areas and diffused for Shanghai, Suzhou and Changzhou. This approach indicates that the coalescence process was the major growth model for this region in the recent 15 years despite their different size, economic growth and population growth. The diffusion-coalesce dichotomy represent endpoints rather than alternate states of urban growth. This work will be beneficial in understanding the size distribution and urbanization process of the megalopolitan region in China.     

Remote sensing of global change: growth in China's Jiangsu Province

SUMMARY

This paper examines how remote-sensing data and regional social and economic data can be used together to identify changes in land-use patterns in particular regions. Study of the spatiotemporal dynamics of remote-sensing data can identify trends in competing uses of land, water and other natural resources for agriculture, industrial development and urban settlements. When combined with information on trends in industrial production, population, agricultural production, pollutant releases, water usage and natural forest coverage, these data reveal patterns of anthropogenic disturbance that can provide early signals of problems in resource decline or land-use management. This study focuses on land-cover changes in southern Jiangsu Province of the People's Republic of China between 1976 and 1984. This region, to the west of Shanghai and to the south of the Yangtze River, experienced unprecedented economic growth after the end of the Cultural Revolution. Remote-sensing imagery reveals the rapid growth of urban centres, commensurate declines in surface water area, and changing patterns of agriculture. The observed changes cast doubt on the ability of the region to sustain such rapid and intense land-use conflicts over a long period.     

长江三角洲地区复合生态系统生态承载力研究

利用生态压力与生态弹性力之间的相互作用关系构建了生态承载力评价的指标体系,并以长江三角洲地区为例,对复合生态系统生态承载力进行评价。结果显示,上海市、江苏省、浙江省的生态压力指数在过去的10 a中虽略有起伏,但整体都在缓慢增大,生态弹性力指数也基本保持持续增长的态势,生态承载力水平基本向好的趋势发展,但依然处于高压平衡甚至失衡状态。     

论制约21世纪城市园林绿化发展的因素

改革开放以来，我国城市园林绿化事业虽然取得了长足进展，但仍面临着人多地少、资金严重缺乏的窘境，本文分析了产业这些问题的症结，提出了相应的对策与建议。     

城市景观生态特点与建设途径——以佛山市为例

城市景观生态设计是城市生态规划的基本内容,以广东省佛山市为例,运用景观生态学原理,分析了佛山市景观生态现状和生态设计内函,对佛山市景观生态建设提出了一些思路与对策。     

Can the 2050 zero land take objective of the EU be reliably monitored? A comparative study

The European Union has defined an ambitious objective for the future concerning sustainable land use to stop the process of land take by 2050. But can this objective be reliably monitored? In this paper, which is based on the case study of Luxembourg and the neighbouring regions, we show that the tools that are used to monitor land-take produce different results that prevent from comparing the figures from one region to another. Moreover, a comparison of the strategic documents related to land use in this cross-border region shows that land-use policies are the product of very different contexts and relationships towards land as a resource, which need to be addressed with tailored strategies.     

杭州及绍兴大气中羰基化合物的污染特征、来源及影响

长江三角洲地区是我国“三区十群”大气污染防治重点区域之一,城市大气光化学污染严重,但对其形成机制研究较少. 本论文采用2,4-二硝基苯肼固相吸附采样,高效液相色谱法（HPLC）分离检测技术,测定了杭州和绍兴两个长三角典型城市大气羰基化合物,研究了羰基化合物的时空分布特征及其对大气光氧化的贡献,并利用比值法初步分析了羰基化合物的来源. 结果表明,杭州市和绍兴市大气中主要羰基化合物都是甲醛、乙醛和丙酮,其在杭州市的质量浓度分别是（3.81±1.15）μg·m⁻³、（4.71±2.18）μg·m⁻³、（10.34±10.20）μg·m⁻³（n=209）,在绍兴市的质量浓度分别为（5.85±3.93）μg·m⁻³、（3.88±1.97）μg·m⁻³、（8.30±6.87）μg·m⁻³（n=499）,这3种化合物占杭州市和绍兴市羰基化合物总量分别是76.2%、80.5%. 绍兴市夏季羰基化合物的平均总浓度明显高于其他季节,大气光化学污染可能是绍兴大气羰基化合物的主要来源. 2021年4月28日—5月5日,在绍兴的一次臭氧轻度污染过程期间,臭氧污染的节假日期间羰基化合物总量高于工作日,且夜间高于白天. 对杭州和绍兴臭氧生成潜势（OFP）贡献较大的羰基化合物是甲醛和乙醛,它们对杭州市秋季大气中OFP的贡献达53.4%,对绍兴市全年大气中总OFP的贡献值为55.8%—78.2%. 本研究结果有助于认识大气羰基化合物对杭州市和绍兴市臭氧的贡献.     

长三角地区水体中全氟化合物的污染特征及风险评价

为探究长三角地区水环境中全氟化合物（PFASs）的污染分布特征及风险水平,对长三角地区水环境中11种PFASs进行了研究. 通过固相萃取结合液相色谱-三重四极杆串联质谱的方法对该地区水环境中PFASs污染水平进行分析,并运用环境风险熵值法对该地区水环境中PFASs污染进行了风险评估. 结果表明PFASs在长三角地区广泛存在,Σ₈PFASs浓度为8.64—736.74 ng·L⁻¹,其中主要污染物为全氟辛酸（PFOA）、全氟己酸（PFHxA）和全氟己烷磺酸盐（PFHxS）,其浓度范围分别为4.49—517 ng·L⁻¹、0.92—688 ng·L⁻¹和0.51—260 ng·L⁻¹. 源解析结果表明长三角大部分地区水环境中PFASs污染来源于前体化合物降解所形成的面污染源,少部分地区水环境PFASs污染来源于部分行业直接排放形成的点污染源. 风险评估结果显示该地区水环境中PFASs的生态风险值和健康风险熵值均低于参考值,对生态环境和人体健康的风险水平较低.