Impacts of quarrying activities on the environment and livelihood of people in Border II sub-location,Nyando sub-county,Kisumu County,Kenya

The aim of the study was to assess the impacts of quarrying activities on the environment and livelihood of people in the Border II sub-location. Primary data was collected through questionnaires, Key Informant Interviews, Focus Group Discussion, laboratory analysis and observations. Whereas, secondary data was obtained from Landsat satellite images, journals, articles, books and reports. The acquired data were analyzed using excel and Arc GIS; and presented into tables and figures. The Land use/cover change analysis from the satellite images of the area showed that quarry lands have increased by 5.2 Ha (0.26%). Quarrying activities in the area were perceived to have both positive and negative impacts on the livelihood of people and the environment. Some of the most serious environmental problems were; dust pollution (82%), noise (76%), land degradation (74%), vegetation loss (60%) and vibration (52%). Whereas, negative socioeconomic impacts were; building cracks (54%), injuries (36%), school dropouts (35%), roads damages (33%), child labor (31%) and crop effects (30%). Moreover, 45% of the area residents and 44% of the quarry workers have experienced health problems related to quarrying activities. Nevertheless, there was a significant relationship between quarrying activities and the environmental as well as human health problems in the area (p<0.05). The positive impacts identified are; employment, roads improvement, security, CSR, building materials, business opportunities, among others. To mitigate the negative impacts, the quarry operators should develop and implement an Environmental and Social management Plan, including fair compensation of the project which affect a person, relocation of near homes, environmental pollution control, public participation, scaling down blasting activities, and strict policies compliance and enforcement.     

Principle of the worst scenario in the modelling past and future of biosphere dynamics

The “biosphere–climate” system is subjected to different influences (influx of anthropogenic CO₂ and pollutants, deforestation, harmful land management, biological species depopulation, etc.). Therefore, the vital question arises: “Can these influences lead to irreversible negative changes in the climate–biosphere system or a global ecological catastrophe?” The possibility of irreversible changes may be not very high, but one cannot ignore it. So the main aim of our investigation is to evaluate possible consequences of human impact on the biosphere focusing on irreversible changes of it.     

土地利用/覆被变化对土地生态系统有机碳库的影响——以吉林省通榆县为例

土地利用/覆被变化对陆地碳循环影响显著.文章基于实地采集的土壤、植物样品的测试数据和1989、2004两年8月陆地卫星TM遥感影像数据,采用生态系统类型法分析吉林省通榆县1989-2004年耕地、林地、草地、盐碱地、沙地等11 种地类之间土地利用变化对土地生态系统有机碳库的影响.计算结果表明1989-2004年通榆县土地生态系统有机碳库共损失了3.18 TgC(1Tg=106t),年均损失约为0.265 Tgc.其中,湿地、草地有机碳库分别损失5.54 TgC和3.71 TgC,盐碱地面积的增加导致有机碳库损失4.75 TgC.林地面积增加和沙地面积减少分别使有机碳库增加了4.58 TgC和3.75 TgC.研究区总体上为一个碳失汇,草地退化、湿地萎缩、土地沙化和盐碱化造成了有机碳库的碳损失,而植树造林、草地植被的恢复和重建等活动则可以显著增加土壤有机碳储量.该研究对于评估自然环境与人为活动影响下,特别是大规模土地整治与生态修复对土壤有机碳的增汇潜力和固碳效应的影响具有重要的理论意义和应用价值.     

基于不同卫星降雨产品的澴水花园流域径流模拟比较研究

卫星降雨产品作为缺资料或无资料地区估算流域降雨径流的一种途径,适用性尚需大量实验研究。以澴水花园流域为研究区,综合评估了TRMM(3B42V7)、TRMM_RT(3B42V7)、PERSIANN CDR和CMORPH 4个卫星降雨产品在流域平均雨量计算与径流模拟中的精度,设置多方案与多种水文模拟情景全面检验各降雨产品的可靠性与适用性。研究表明：(1)在研究期2002~2013年,没有一个卫星降雨产品对所有精度评价指标均表现最优,PERSIANN始终表现为最差;(2)各卫星降雨产品对于不同年代和不同统计时段的精度差异明显,且一般汛期精度高于全年精度。各年代精度最高的卫星降雨产品在年与汛期尺度上与实测雨量相关系数均超过0.9;(3)各卫星降雨产品对有雨日降雨探测能力较强,但空报率较高,所有卫星降雨产品对于年最大1 d、3 d和7 d降雨估算误差较大,无法达到可利用精度;(4)采用卫星降雨产品进行径流模拟时,以相应的卫星降雨进行水文模型参数率定可获得更高的模拟精度。TRMM_RT与CMORPH日径流模拟精度较好,CMORPH月径流模拟精度较好。总体而言,CMORPH更适用于径流模拟。对于典型的3场大洪水模拟结果表明,TRMM_RT和CMORPH对洪峰与洪量（径流深）的模拟精度相对较高。     

新型城镇化背景下失地农民福利变化研究

基于森的可行能力理论,从经济状况、居住条件、居住环境、社会保障及社会机会等方面构建失地农民福利评价指标体系。并进一步基于农地价值理论视角,将失地农民可获得的福利划分为经济福利、社会福利和生态福利3个部分。在此基础上利用江苏省苏州市、南通市及宿迁市540户农户调查数据对征地前后农民福利水平进行测度,以探索不同城镇化发展阶段土地征收对失地农民福利变化的影响。结果表明:(1)由于实行了"土地换社保"征地补偿方式,苏州市和南通市目前处于城镇化发展改革阶段,且前者在"人的城镇化"方面更为成熟;宿迁市采取一次性货币补偿方式,仍处于传统城镇化发展阶段。(2)苏州市和南通市失地农民福利水平呈上升趋势,总模糊指数分别从0.444、0.369上升到0.529、0.385;宿迁市样本农户福利水平则有所下降。(3)除苏州市外,南通市和宿迁市样本农户的经济福利均出现下降,下降幅度分别为36.1%、34.5%;三个地区失地农民社会福利均有所提升,且苏州市和南通市农户福利改善程度明显优于宿迁市;生态福利方面,除南通市外,苏州市和宿迁市均出现下降。(4)传统城镇化发展模式下,失地农民的福利水平明显受损,城镇化改革一定程度上缓解了农民福利受损,尤其是社会福利得到较大提升。加快新型城镇化建设,真正实现"土地城镇化"与"人口城镇化"同步发展,在提高征地补偿标准的同时,政府还需通过完善失地农民社会保障体系、加强就业指导培训、提供一定就业安置等途径实现征地补偿方式多元化,并加大对农村基础设施、配套设施、环境保护等的投入。     

中国新能源汽车产业的政策变迁与政策工具选择

伴随着新能源汽车产业的发展,中国政府有关新能源汽车产业政策也在不断地跟进。梳理相关产业政策变迁之中的内在逻辑,分析政策工具的选择是一项极为重要的任务。本文基于政策框架理论及其分析方法,对有关新能源汽车研究文献进行了分析,将关注重点从政策的评价转到从历史的角度关注新能源政策变迁的推动力上。政策变迁是与其动力因素密切相关的,这些动力因素又总是体现为政策变迁的主导力量。在中国新能源汽车产业的政策变迁历程中,其主导力量或政策制定的主要影响因素不断变化,中国新能源汽车的发展政策也可以分为政府主导、汽车厂商主导和消费者主导的三个阶段。政策变迁体现了政策本身的社会价值。基于中国新能源汽车发展的各种不同政策要素及其相关性,本文发现,在中国新能源汽车产业的组织性政策工具、管制性政策工具、经济诱因性政策工具、信息性政策工具和资源性政策工具这五个方面,经济诱因性工具和信息性工具应该是推动新能源汽车产业的关键工具,组织性和管制性工具只适用于产业化初期,后期应逐渐减少,而自愿性工具在新能源汽车产业市场完善前不提倡使用,在该产业市场得到完善后可以成为政府的选择之一。经过研究发现,在新能源汽车产业发展过程中,政府应注意自身的作用范围,适当处理市场与政府规制的便捷,降低交易成本,提高规制效率,是未来产业化政策工具选择应重点关注的环节。同时,政府必须在政策上致力于技术创新,把通过技术创新推动新能源汽车产业发展作为重要的政策目标。     

珠三角地区大气中HCFC-22的浓度观测和变化趋势初步研究

通过罐采样和预浓缩-色谱/质谱方法,对珠三角地区广州城区和鼎湖山大气中HCFC-22进行了初步的观测和分析.结果表明,2005年广州城区HCFC-22年平均体积分数达到(479.5±241.4)×10-12,鼎湖山仅为(244.4±51.3)×10-12.广州城区大气HCFC-22日变化幅度夏秋季节相对较大,而鼎湖山日变化不明显;广州城区大气HCFC-22的体积分数夏秋季节高于冬春季节,鼎湖山则相反.与城区HCFC-22排放的季节性有关,夏秋季节广州城区与鼎湖山HCFC-22体积分数差别很大,冬春季节则比较接近.初步研究结果表明,广州城区和鼎湖山大气HCFC-22的体积分数呈现快速增长趋势,年增长率分别达到6.57%和7.28%,约为一些全球基准观测站(NOAA/CMDL)的1.9～2.8倍.     

三峡水库上游河流入库面源污染负荷研究

借鉴水文分割法的原理,在基流分割的基础上,建立了面源污染负荷估算公式. 基于相关性分析、回归分析,提出了污染类型判定和数据补插原则. 以2004和2005年的水文水质数据为基础,将该方法应用于三峡库区上游河流入库面源污染负荷研究, 并采用相关系数法作为对比,对该方法在应用中可能导致的结构性偏差予以探讨. 结果表明,2004年嘉陵江、长江干流、乌江三江入库COD_Mn,总氮和总磷的污染负荷(以包含溶解态和颗粒态成分的总物质通量表示)分别为168.96×104,70.30×104和10.95×104 t;2005年分别为228.24×104,66.64×104和14.24×104 t;在总量组成中,面源是三江入库污染物的主要来源,占总入库负荷的60%～80%;在空间分布上,长江干流对入库面源污染负荷的贡献占绝对优势,嘉陵江、乌江的面源污染总贡献率仅占13.4%～39.4%;在营养物负荷组成方面,氮对水体的影响以溶解态氮作用为主,磷对水体的影响以颗粒态磷作用为主. 水文分割法的改进值得进一步关注,但在尚未出现十分科学、合理的改进算法时,该方法仍不失为面源负荷研究的有效方法.      

Impact of climate changes on pollution levels in Denmark

The impact of climate changes on the pollution levels in Denmark is the major topic of this paper. Variations of the Danish air pollution levels that are caused by climatic changes are studied together with variations caused by other factors (emissions, inter-annual variability of meteorological conditions, etc.). The Unified Danish Eulerian Model (UNI-DEM) was run on a fine, 10 km × 10 km, grid over a space domain covering all of Europe to minimize the influence of the boundary conditions on the Danish pollution levels. This study is based on four categories of scenarios: (i) traditional scenarios, (ii) climatic scenarios, (iii) scenarios with variations of the human-made (anthropogenic) emissions and (iv) scenarios in which the biogenic emissions were varied. The total number of applied scenarios was 14, and a time-period of 16 years was used. The results show clearly that although the concentrations of the major pollutants do not depend too much on the climatic changes, some quantities, in particular quantities related to high ozone levels, might be increased significantly as a result of the warming trends in the future climate. The reason for this phenomenon is explained.     

Seasonal differences in mercury accumulation in Trichiurus lepturus (Cutlassfish) in relation to length and weight in a Northeast Brazilian estuary

Background, aim, and scope  At tropical latitudes, and especially on the semi-arid coasts of the Brazilian Northeast, the rainfall regime governs the water quality of estuaries due to the pronounced difference between the rainy and dry seasons. These changes may be responsible for seasonal changes in bioavailability of mercury (Hg) and other pollutants to the estuarine and coastal biota. Mercury bioaccumulates along estuarine–marine food chains usually result in higher concentrations in tissues of top predators and posing a risk to both marine mammals and humans alike. The Goiana River Estuary (7.5° S) is a typical estuary of the semi-arid tropical regions and supports traditional communities with fisheries (mollusks, fish, and crustacean). It is also responsible for an important part of the biological production of the adjacent coastal waters. Materials and methods   Trichiurus lepturus (Actinopterygii: Perciformes) is a pscivorous marine straggler. Fish from this species (n = 104) were captured in a trapping barrier used by the local traditional population and using an otter trawl net along the main channel of the low estuary during two dry seasons (D1 = November, December 2005, January 2006; D2 = November, December 2006, January 2007) and the end of a rainy season (R = August, September, October 2006). Fish muscle samples were preserved cold and then freeze-dried prior to analysis of its total mercury (Hg-T) contents. Total mercury was determined by cold vapor atomic absorption spectrometry (CV-AAS) with sodium borohydride as a reducing agent. Results  The studied individuals (n = 104) were sub-adult (30–70 cm, 71 ind.) and adult fish (>70 cm, 33 ind.). Weight (W) (204.1 ± 97.9 g, total biomass = 21,229.7 g) and total length (TL) (63.1 ± 10.1 cm, range 29.5–89.0 cm) presented a significant (p < 0.05) correlation. Two-way ANOVA (n = 81) showed that TL and W had significant differences (p < 0.05) among seasons, being higher in D1 than in D2 and R, respectively. Moreover, season vs. month interaction were detected for the variables length and weight. For the variable weight was detected significant difference for the factor month (p < 0.05). It suggests that the fish enter the estuary at the end of the rainy season and increase in length and weight during the time they spend in the estuary. Fish from this estuary are shown to be fit for human consumption (125.3 ± 61.9 μgHg-T kg^–1 w.wt.; n = 104). Fish mercury contents increased with size and weight. Correlations between TL and Hg-T (r = 0.37286) and between W and Hg-T (r = 0.38212) were significant (p < 0.05). Dryer months showed higher mercury concentrations in fish (D1 773.4 ± 207.5 μgHg-T kg^–1 d.wt., n = 27; D2 370.1 ± 78.8 μgHg-T kg^–1 d.wt., n = 27; R 331.2 ± 138.5 μgHg-T kg^–1 d.wt., n = 27). The variable mercury concentration showed differences in relation to the factor season (p < 0.05), where fish captured during the first dry season showed the highest concentration of mercury. The correlation between Hg-T and rainfall (Rf) showed a negative correlation (r = –0.56; p < 0.05). Discussion  The main likely source of mercury to this estuary is diffuse continental run off, including urban and industrial effluents. Since concentration of mercury in fish tissue is negatively correlated to rainfall, but positively correlated with fish length and weight, it suggests that fish growth in this estuary results in mercury uptake and concentration on the fish tissue. In the dry season of 2005–2006, when rainfall remained below the historic average, fish bioaccumulated significantly more mercury than in the dry season 2006–2007, when rainfall was within the predictable historic average. It is suggested that less rainfall, and consequently less particulate matter and less primary production in the estuary, make mercury more available to the higher levels of the estuarine food chain. In the case of higher rainfall, when river flow increases and water quality in the estuary is reduced, mercury probably is quickly exported associated to the particulate matter to the adjacent coastal waters where it then disperses. This species is a potential routine bioindicator for mercury contamination of the biota, but so far was used only with a limited number of individuals and contexts. Conclusions  Fish from the Goiana River estuary can still be safely consumed by the local population. However, any further contamination of this resource might lead to total mercury levels above the recommended limits for pregnant women and small children. The proposed heavy dependency of total mercury levels in fish on water quality indicates that land use and water quality standards must be more closely watched in order to guarantee that best possible practices are in place to prevent bioaccumulation of mercury and its transfer along the food chain. Human interventions and climatic events which affect river water flow are also playing a role in the mercury cycle at tropical semi-arid estuaries. Recommendations and perspectives   T. lepturus is largely consumed by coastal populations of tropical and sub-tropical countries all over the world. It is also consumed by a number of marine mammals over which we have a strong conservation interest. This species is also a link among different ecosystems along the estuarine ecocline. Therefore, knowledge of its degree of contamination might contribute to public health issues as well as marine conservation actions. Studies on mercury and other contaminants using this species as bioindicator (cosmopolitan, readily available) could help elucidating mechanisms through which pollutants are being transferred not only through the food chain, but also from estuarine–coastal–open waters. In addition, using the same species in marine pollution studies, especially as part of a mosaic of species, allows for wide range comparisons of marine food chain contamination.