Quality of life in selected slums of Kolkata: a step forward in the era of pseudo-urbanisation

Urbanisation is the proportionate increase in the urban population with respect to the total population. In India urbanisation was never a result of a strong economic base of cities. It was distress and poverty in rural areas that resulted in a huge influx of rural migrants into urban areas. The pace of urbanisation gained momentum after 1941 with the percentage of people living in urban areas increasing to 31.16% in 2011. The pattern of urbanisation is characterised by continuous concentration of population in the megacities and in Class I cities. India’s urbanisation is best described as pseudo-urbanisation, a condition in which a large city is formed without a functional infrastructure to support it. Migration and pseudo-urbanisation lead to demographic explosion and a progressive concentration of poor migrants in the cities, followed by misery, poverty, unemployment, exploitation, rapid growth of slums and degradation in the quality of urban life. Slums are usually characterised by poor housing conditions, inadequate physical infrastructure, deprivations in socio-economic conditions, health, hygiene and lack of safety and security. Two slums were chosen within the Kolkata Municipal Corporation for assessing the quality of life. Despite government initiatives the condition of the slum dwellers has not improved much.     

玄武湖挺水植物区与敞水区浮游甲壳动物昼夜水平迁移初探

浮游甲壳动物昼夜垂直迁移(DVM)是深水湖泊中的一种常见的现象,在浅水湖泊中,没有明显的下层滞水层为浮游甲壳动物提供避护所,浮游甲壳动物的垂直迁移活动不明显。但浅水湖泊挺水植物的存在为浮游甲壳动物提供了区别于敞水带的生境,结合理化、浮游植物和鱼的因素,对浅水湖泊玄武湖挺水植物区与敞水区浮游甲壳动物的昼夜水平迁移进行了研究。结果得出：浅水湖泊玄武湖中理化环境（如温度、溶解氧和pH)在荷花区、敞水区、荷花区与敞水区的交界区差异不大,对浮游甲壳动物的昼夜水平迁移不起主导作用。荷花区的浮游植物在质量和数量上低于敞水区,浮游甲壳动物在夜间捕食压力小的情况下会向敞水区移动。敞水区、交界区浮游甲壳动物在白天被捕食的风险要大于荷花区,因而白天时间浮游甲壳动物会迁移到荷花区聚集.     

Ecogenetic features and functions of solods in transural forest-steppes (within Sverdlovsk Oblast)

Specific ecogenetic features of solods in the forest-steppe zone has been studied, and the role of biotic and abiotic factors of soil formation has been estimated. Differentiation of soil horizons with respect to the physical clay fraction accounts for specific features of their moistening, which is reflected in the ratio of strongly and weakly crystallized forms of iron. Periodic changes in redox conditions results in iron segregation, and a high content of fulvic acids accounts for its eluvial migration. These processes are controlled by soil geochemical barriers.     

Attitudes towards relocation following Hurricane Sandy: should we stay or should we go?

This study explores the dilemma of whether to rebuild or relocate from the areas devastated by Hurricane Sandy in 2012. Since disasters represent the discernible manifestation of other complex coastal hazards, they offer a window of opportunity to engage residents in the dialogue on relocation as sometimes the most effective risk reduction strategy. The following research evaluates attitudes towards relocation and willingness to consider buyout among 46 surveyed households located in highly‐affected communities five months after Sandy. It also gauges perceptions of coastal risks and recovery concerns as drivers of relocation, the level of support for different adaptation strategies, and preferences related to the relocation process itself on how and where to relocate and with what type of assistance. Responses indicate that, even though residents prefer structural solutions to address coastal hazards, they are not fully opposed to the possibility of relocation mostly for personal health and safety reasons.     

水位波动带氮素迁移转化规律

为考察水位波动对非饱和-饱和土层中氮素迁移转化的影响,设计土柱实验装置Ⅰ和Ⅱ分别模拟水位稳定与波动两种情景,测定一个水位波动周期内地下水中NO₃^--N、NO₂^--N和NH₄⁺-N浓度变化情况。结果表明,柱Ⅱ水位第1次下降柱内1^#,2^#,3^#,4^#采样点NO₃^--N浓度均增大,增幅分别为6.5%、14.9%、15.33%和19.8%。水位上升时结果相反,分别降低17.3%、26.15%、50.29%和44.61%。第2次水位下降至初始位置4个采样点NO₃^--N浓度再次增大,幅度分别为7.1%、10.6%、13.89%和7.76%。铵态氮呈相反趋势不同程度的变化。水位波动柱Ⅱ连通水槽内总氮量增加显著高于柱I水槽,即水位波动有利于波动带地下水中氮素垂向迁移,加重波动带以下地下水硝酸盐污染。因此,水位波动对氮素迁移转化的影响不容忽视。     

基于多中心理论的辽宁沿海经济带环境治理模式研究

辽宁沿海经济带是我国沿海地区生态环境较为脆弱的地区之一,环境污染和破坏问题较突出。而环境治理直接关系到经济与社会的持续发展,环境治理模式则是决定环境治理绩效的重要因素之一。运用多中心模式分析辽宁沿海经济带环境治理存在的问题及其原因,构建该区域的多中心治理模式,并在此基础上提出相应的策略措施,为辽宁省沿海经济带发展规划的实施提供参考。     

城市生活垃圾焚烧处理过程中重金属迁移规律研究

通过采集厦门2个垃圾焚烧发电厂进厂垃圾、渗滤液、飞灰、炉渣和烟气样品,分析垃圾组成成分及各组分的重金属含量,结果表明,垃圾中以厨余、橡塑类和纸类为主,共占到垃圾干基的78．08％,重金属含量大小次序为Zn〉Cu〉Pb〉Cr〉Ni〉Cd〉Hg;垃圾渗滤液中除Zn外,其他金属的含量都较低,一厂渗滤液中重金属Ni、Zn迁移量较大,分别达到24．46％和8．52％。二厂渗滤液中重金属的迁移有相同的趋势,但含量相对较高。垃圾焚烧后其重金属主要分布在飞灰和废渣中,烟气中的含量非常少,不同金属的含量均有差别,这与金属的性质有很大关系;通过浸出毒性分析,飞灰中重金属酸溶态含量多,容易浸出,属于危险废物。同时,不同烟气处理工艺产生的飞灰的重金属浸出量有很大差别。     

南漪湖沉积物磷的赋存形态及对上覆水的影响

以宣城市南漪湖为例,采用改进的无机磷分级提取方法对全湖共39个点位沉积物中磷(P)赋存形态进行系统研究,并分析其与上覆水体、间隙水等相互关系.结果表明,南漪湖水体磷污染水平已经处于高位,沉积物间隙水磷与上覆水体磷空间分布特征具有密切关系.南漪湖沉积物中总磷(TP)含量变化范围为463.3～1016.6mg/kg,其中各形态磷空间分布具有明显的差异性,与外源磷输入等密切相关.赋存形态含量大小、相对比例顺序依次为:钙结合态磷(Ca-P)>铁结合态磷(Fe-P)>铝结合态磷(Al-P)>还原剂可溶性磷(RS-P)>残渣态磷(Res-P)>弱吸附态磷(L-P).沉积物中TP含量与Fe-P、RS-P、Res-P极显著正相关,与L-P含量显著正相关.外源磷输入和水产养殖对南漪湖沉积物内源磷中Fe-P和RS-P贡献可能较大.南漪湖沉积物内源磷对上覆水体的潜在风险较高,其中生物有效性较高的L-P、Al-P、Fe-P和Rs-P的总和相对比例可达60%左右.沉积物中磷形态与间隙水磷浓度关系较密切,其中Al-P、Ca-P对间隙水中磷迁移转化具有重要影响.南漪湖主要出入湖河口沉积...     

Changes in bird‐migration patterns associated with human‐induced mortality

Many bird populations have recently changed their migratory behavior in response to alterations of the environment. We collected data over 16 years on male Great Bustards (Otis tarda), a species showing a partial migratory pattern (sedentary and migratory birds coexisting in the same breeding groups). We conducted population counts and radio tracked 180 individuals to examine differences in survival rates between migratory and sedentary individuals and evaluate possible effects of these differences on the migratory pattern of the population. Overall, 65% of individuals migrated and 35% did not. The average distance between breeding and postbreeding areas of migrant individuals was 89.9 km, and the longest average movement of sedentary males was 3.8 km. Breeding group and migration distance had no effect on survival. However, mortality of migrants was 2.4 to 3.5 times higher than mortality of sedentary birds. For marked males, collision with power lines was the main cause of death from unnatural causes (37.6% of all deaths), and migratory birds died in collisions with power lines more frequently than sedentary birds (21.3% vs 6.3%). The percentage of sedentary individuals increased from 17% in 1997 to 45% in 2012. These results were consistent with data collected from radio‐tracked individuals: The proportion of migratory individuals decreased from 86% in 1997–1999 to 44% in 2006–2010. The observed decrease in the migratory tendency was not related to climatic changes (temperatures did not change over the study period) or improvements in habitat quality (dry cereal farmland area decreased in the main study area). Our findings suggest that human‐induced mortality during migration may be an important factor shaping the migration patterns of species inhabiting humanized landscapes.     

The problem of estimating recent genetic connectivity in a changing world

Accurate understanding of population connectivity is important to conservation because dispersal can play an important role in population dynamics, microevolution, and assessments of extirpation risk and population rescue. Genetic methods are increasingly used to infer population connectivity because advances in technology have made them more advantageous (e.g., cost effective) relative to ecological methods. Given the reductions in wildlife population connectivity since the Industrial Revolution and more recent drastic reductions from habitat loss, it is important to know the accuracy of and biases in genetic connectivity estimators when connectivity has declined recently. Using simulated data, we investigated the accuracy and bias of 2 common estimators of migration (movement of individuals among populations) rate. We focused on the timing of the connectivity change and the magnitude of that change on the estimates of migration by using a coalescent‐based method (Migrate‐n) and a disequilibrium‐based method (BayesAss). Contrary to expectations, when historically high connectivity had declined recently: (i) both methods over‐estimated recent migration rates; (ii) the coalescent‐based method (Migrate‐n) provided better estimates of recent migration rate than the disequilibrium‐based method (BayesAss); (iii) the coalescent‐based method did not accurately reflect long‐term genetic connectivity. Overall, our results highlight the problems with comparing coalescent and disequilibrium estimates to make inferences about the effects of recent landscape change on genetic connectivity among populations. We found that contrasting these 2 estimates to make inferences about genetic‐connectivity changes over time could lead to inaccurate conclusions.