Phyt'Eaux Cités: application and validation of a programme to reduce surface water contamination with urban pesticides

This paper presents first results of Phyt’Eaux Cités, a program put in place by the local water supply agency, the SEDIF (Syndicat des Eaux d’Ile-de-France), in collaboration with 73 local authorities, private societies and institutional offices (365 km²). The challenges included: measurement of the previous surface water contamination, control of urban pesticide applications, prevention of pesticide hazard on users and finally a overall reduction of surface water contamination. An inquiry on urban total pesticide amount was coupled with a surface water bi-weekly monitoring to establish the impact of more than 200 molecules upon the Orge River. For 2007, at least 4400 kg and 92 type of pesticides (essentially herbicides) were quantified for all urban users in the Phyt’Eaux Cités perimeter. At the outlet of the Orge River (bi-weekly sampling in 2007), 11 molecules were always detected above 0.1 μg L⁻¹. They displayed the mainly urban origin of pesticide surface water contamination. Amitrole, AMPA (Aminomethyl Phosphonic Acid), demethyldiuron, diuron, glyphosate and atrazine were quantified with a 100% of frequency in 2007 and 2008 at the Orge River outlet. During the year, peaks of contamination were also registered for MCCP, 2,4 MCPA, 2,4 D, triclopyr, dichlorprop, diflufènican, active substances used in large amount in the urban area. However, some other urban molecules, such as isoxaben or flazasulfuron, were detected with low frequency. During late spring and summer, contamination patterns and load were dominated by glyphosate, amitrole and diuron, essentially applied by cities and urban users. Both isoproturon and chlortoluron were quantified during autumn and winter months according to upstream agricultural practices. In conclusion, 3 years after the beginning of this programme, the cities reduced the use of 68% of the total pesticide amount. An improvement on surface water quality was found from 2008 and during 2009 for all pesticides. In particular, glyphosate showed a decrease of the load above 60% in 2008, partly related to the Phyt’Eaux Cités action.     

天津市夏季城区道路不同车道积尘负荷的关系

采用改进的移动式铺装道路积尘采样方法于夏季采集天津市城区不同类型道路各车道的道路积尘样品,计算出积尘负荷,并分析积尘负荷的变化规律。结果表明：天津市区外环线、快速路、主干道、次干道和支路的路面积尘负荷分别为0.06、0.10、0.21、0.22和0.28 g·m-2,天津市道路路面积尘污染强弱顺序为支路 >次干道 >主干道 >快速路 >外环线;对于次干道与支路,不同车道路面积尘负荷差异不大;对于外环线（1车道除外）、快速路和主干道,越接近道路中央积尘负荷越小,且4车道（即慢车道）积尘负荷与其他各车道积尘负荷之间存在线性关系。     

平原感潮河网地区不同土地利用下营养盐迁移特征

分别在南通平原河网地区选择典型非圩区开展野外原位试验,用野外观测和室内分析相结合的方法,研究平原非圩区典型试验小区不同土地利用下营养盐在自然降雨—径流驱动下迁移的时空分布特征.结果表明,导致营养盐迁移时空分布存在显著差异的主要原因为不同的土地利用类型、施肥条件及植被覆盖度等,不同土地利用下的径流量差异是导致营养盐迁移通...     

对城市道路交叉口左转专用车道设计的探讨

在参考国内外设计经验的基础上,从左转车道设置的原则、设置左转车道的常用方式、左转车道的长度和宽度等角度对左转车道的设计问题进行了探讨,提出对左转车道进行合理偏移可有助于提高驾驶员的视距.     

中亚热带红壤区不同土地利用土壤田间持水量估测

田间持水量是衡量土壤保水性的重要指标,也是进行农田灌溉、作物水管理和水文模型的重要参数,但其测定繁琐而耗时,迫切需要一种简捷精确的估测方法。采集了50个来自稻田和旱地的1 m深原状土壤剖面样,然后基于土壤基本理化性质,利用多元逐步回归方法对土壤田间持水量进行模型预测。结果显示:(1)对于稻田土壤,田间持水量主要受容重和有机碳影响,而对于旱地则主要受土壤质地影响;(2)构建的田间持水量传递函数,对于稻田土壤预测精确度较高,调整的确定系数达到0.79,对于旱地则相对较弱。研究表明土地利用方式对田间持水量精确估测影响较大,利用土壤传递函数法对田间持水量的快速获取有一定参考价值。     

典型城市土壤中重金属锑(Sb)的含量分布特征及风险评价

为探讨重金属锑（Sb）在城市土壤中的分布特征和潜在风险,基于上海市102个地块1670个不同深度剖面土壤样品数据,分析4种典型土地利用类型土壤重金属Sb的含量分布特征,并通过潜在生态风险指数法和健康风险评价模型进行风险评价.结果表明,研究区域土壤ω（Sb）的平均值为0.52 mg·kg^-1,并呈现明显的聚集分布特性;土壤Sb含量随着土壤深度的增加逐渐降低,表层土壤Sb存在一定程度的富集,人类活动影响了土壤中Sb的分布.工业用地表层土壤Sb含量相较于其它3种类型土壤差异显著,其累积程度高于住宅用地和商服用地,农用地Sb含量水平最低.区域整体上处于清洁至尚清洁水平,但工业用地的单项污染指数相对最高,达到轻度污染水平,住宅用地、商服用地和农用地分别为尚清洁或清洁水平;潜在生态风险指数范围为4.23~7.61,区域整体表现为轻微潜在生态风险.工业用地潜在生态风险等级为中等,需引起重视.健康风险评价结果显示土壤Sb非致癌风险较小或可忽略.     

城市景观娱乐水体微生物风险评价

随着城市居民亲水娱乐活动日益增加,开展景观娱乐水体微生物风险评价,并以此为基础开展有效的风险管理,对于人口密集的城市区域尤为重要.以我国南方某城市3个典型景观娱乐水体为案例,采用定量微生物风险评价的方法框架,综合运用水质监测、社会调查、文献调研等方法开展暴露评价,并由此开展基于粪大肠菌(FC)、大肠埃希氏菌(EC)和肠球菌(ENT)的多微生物指标人体健康风险评价.结果表明,基于FC、EC和ENT的多指标微生物风险评价结果具有一定的一致性和可比性;位于城市居住区的B河段不宜作为人体直接或非直接接触的娱乐水体,其对公众健康的风险主要来源于用作家庭杂用水;位于城市公共开放空间的C河段和风景旅游区的E湖可以满足现有的景观娱乐功能要求,其对公众健康的风险主要来源于各种休闲娱乐活动;应重视与城市景观娱乐水体功能不匹配的无序利用(如作为家庭杂用水)对公众健康的风险.     

Hurricane Katrina‐linked environmental injustice: race,class, and place differentials in attitudes

Claims of environmental injustice, human neglect, and racism dominated the popular and academic literature after Hurricane Katrina struck the United States in August 2005. A systematic analysis of environmental injustice from the perspective of the survivors remains scanty or nonexistent. This paper presents, therefore, a systematic empirical analysis of the key determinants of Katrina‐induced environmental injustice attitudes among survivors in severely affected parishes (counties) in Louisiana and Mississippi three years into the recovery process. Statistical models based on a random sample of survivors were estimated, with the results revealing significant predictors such as age, children in household under 18, education, homeownership, and race. The results further indicate that African‐Americans were more likely to perceive environmental injustice following Katrina than their white counterparts. Indeed, the investigation reveals that there are substantial racial gaps in measures of environmental injustice. The theoretical, methodological, and applied policy implications of these findings are discussed.     

面向驾驶员辅助系统的换道意图辨识方法研究

为提高先进驾驶员辅助系统工作效能,通过差异性分析选取了人-车-路特征参数,建立了支持向量机换道意图辨识模型.基于驾驶模拟器采集的数据,运用ROC曲线对比分析了不同参数组合、时窗、数据表达形式下模型的分类效果,结果表明以方向盘转角、加速度、车辆距车道线距离和驾驶人头动信息为特征参数,时窗为1.5s,以时窗内信息均值和方差表述特征参量可获得最优辨识效果.研究表明,模型在保证1 s前瞻性的同时辨识率可达93％.     

Patterns of bird abundance along the agricultural gradient of the Pampean region

Bird and land-use surveys were conducted along the agricultural gradient covering from pure croplands through mixed-farming to pure pastoral-farming scenario in the Pampean region of Argentina. Simple regression analyses were performed to analyse the responses of bird abundance to the percentage of land devoted to crop-production. The specific variables associated to bird abundance within both the crop and pastoral-farming landscapes were identified by running redundancy analyses (RDA). The abundance of 20 out of 43 species (47%) was significantly related to the percentage of cropland, finding negative (65%), positive (25%) unimodal (5%) and bimodal (5%) responses of birds to increasing intensity of crop production. The results showed three types of negative and two types of positive responses of bird abundance to the agricultural gradient. RDA revealed the importance of crop-field types in the crop-production scenario and of cattle presence and grass height in the pastoral-farming scenario for the structuring of the grassland bird community. As most species were negatively affected by crop production, the current land-use homogenisation towards high-intensity croplands will most likely result in population decline of many birds in the region.