长三角区域大气重污染应急减排效果评估

为评估长三角区域大气重污染应急减排方案的效果,依据上海市环境科学研究院编制的2015年长三角区域高分辨率大气污染源排放清单设计了3级减排方案,利用本地化的WRF-CMAQ模式对长三角区域一次重污染过程进行了模拟验证,并评估了各减排方案的效果.结果显示:①如各城市单独进行减排,在一级、二级和三级减排方案下ρ（PM_2.5）分别降低0~7.2、0~20.6和0.1~34.8 μg/m3,降幅分别为0~11.7%、0~19.5%和0.2%~28.0%,长三角区域空气质量优良率未见明显上升.②如进行区域协同减排,在一级、二级和三级减排方案下ρ（PM_2.5）分别降低0.5~10.0、2.7~30.2和4.3~51.8 μg/m3,降幅分别为1.8%~12.8%、9.3%~23.5%和14.7%~37.0%.对于多数城市,区域协同减排效果比单独减排效果显著,其中舟山市、连云港市和常州市的区域协同减排效果最突出.在三级减排方案下的区域协同减排会使空气质量优良率明显提升,空气质量优良的城市从6个升至10个,中度以上污染城市从12个降至2个.③工业源减排是应急减排的重点,其减排效果可占整体减排效果的50.0%~93.0%.研究显示,要在重污染期间达到较好的减排效果,需要进行区域协同减排,但针对不同城市需要协同进行污染控制的范围具有明显差异,因此,为实现精准管控,未来在开展重污染应急区域协同控制时,需根据实际情况进行协同控制关系的预测.      

Problems of environmental protection and ecology on Bangladesh

The paper deals with the characteristics of Bangladesh basin including river morphology, rain fall pattern, cyclonic storms, forests and coastal area environment and ecosystem. It deals with factors which contribute to floods both natural and man-induced. The paper does with pollution problems including land and water use and indicates briefly policy measures and strategy adopted by government to combat problems of environment and ecology in Bangladesh.     

‘Are you prepared?’ Representations and management of floods in Lomanikoro,Rewa (Fiji)

The islands of Fiji, in the Western Pacific, are exposed to a wide range of natural hazards. Tropical storms and associated floods are recurring natural phenomena, but it has been regularly alleged that Fijians lack preparation, over‐rely on state assistance in post‐disaster situations or engage in risky behaviours that aggravate the negative impact of floods. Risk reduction strategies, which are now implemented by government authorities and international organisations, heavily promote the principle of ‘community preparedness’. Both community awareness programmes and capacity‐building programmes are conducted throughout the country in the most vulnerable communities. This paper analyses how the inhabitants of Lomanikoro village, in the low areas of the Rewa Delta, perceive and manage existing flood risks. It examines social and cultural factors that contribute to shape risk response locally—in particular, why villagers may be reluctant to adopt some recommended preparedness measures and resettle in higher, safer zones.     

近49年中国北方典型强沙尘暴事件的分形特征与R/S分析

通过对1954-2002年我国北方的典型强沙尘暴事件的分形研究发现：该时间序列具有明显的分形特征。其饱和关联维数为3．34．说明要恰当描述其变化特征。进行动力系统建模，至少需要4个状态变量；该时间序列的Kolrnogorov熵近似为0．1142．说明该混沌动力系统的平均可预测时间尺度为8～9a。R／S分析表明。Huvst指数能够较好的表征我国北方典型强沙尘暴事件的发生规律，可以借此推断未来相应时间段中国北方强沙尘暴事件的变化趋势。     

STREAMFLOW TRENDS IN WISCONSIN'S DRIFTLESS AREA1

ABSTRACT: Trends in streamflow characteristics were analyzed for streams in southwestern Wisconsin's Driftless Area by using data at selected gaging stations. The analyses indicate that annual low flows have increased significantly, whereas annual flood peaks have decreased. The same trends were not observed for forested areas of northern Wisconsin. Streamflow trends for other streams in southeastern Wisconsin draining predominantly agricultural land were similar to trends for Driftless Area streams for annual low flows. The causes for the trends are not well understood nor are the effects. Trends in annual precipitation do not explain the observed trends in streamflow. Other studies have found that erosion rates decreased significantly in the Driftless Area, and have attributed this reduction to a change of agricultural practices, which increase infiltration, decrease flood peaks, and increase low flows.     

重污染河道中浮游植物初级生产力特征

通过对苏州城市河道的调查研究发现,城市河道的浮游植物初级生产力与其它水体有明显不同。从2004年6月至2005年5月通过取样分析苏州苗家河水体浮游植物种类、数量和叶绿素a含量变化及采用黑白瓶法测定浮游植物产氧能力,结果表明：该河道氮、磷含量较高,浮游植物群落为绿藻一硅藻型,种类少,季节变化明显,水体中表层叶绿素a的含量低于底层。分析表层水体和底层水体叶绿素a的产氧能力发现,河道中浮游植物的光合产氧能力普遍较低。本文揭示了重污染河道中大量悬浮颗粒附着在浮游植物的体表,影响了浮游植物的光合产氧能力,是整个水体和底泥中的溶氧普遍较低的重要原因之一。探讨了重污染河道溶氧偏低产生黑臭的原因,为重污染河道的综合治理提供了参考。     

Stimulating flood damage mitigation through insurance: an assessment of the French CatNat system

Flood risk has increased in France in the last 20 years and is projected to increase further in the future due to climate change and increase in exposure. Since 1982, France has had a natural disasters insurance system (‘CatNat’) in place that covers flood damage. This insurance system has been combined with what are called ‘Risk Prevention Plans’ (PPRs) in order to stimulate the undertaking of flood risk mitigation measures by communities and households. However, these schemes do not provide optimal incentives for flood damage reduction. This is confirmed by the results from a survey about flood preparedness of 885 households who live in flood-prone areas in France, which are presented in this paper. Moreover, this study provides suggestions for improvement, which are assessed on their potential economic, social and political implications. Among these suggestions are increasing the effectiveness of PPRs and increasing the incentives to apply and implement PPRs; improving the monitoring of the implementation of damage mitigation measures; and the possibility to differentiate premiums and deductibles according to flood risk.     

Simulated interior floods and the flood experience in urban communities

The Hydrologic Engineering Center (HEC-1) model was used to construct synthetic hydrographs for isolated interior urban floods. Flood peak and lag time were very well preserved in simulated flows. Total volume was not adequately expressed. Lag time varied inversely with both urban development and storm intensity. Peak discharge varied with storm intensity, but this variability was well defined only at very high urbanization levels. An 175% increase in storm intensity produced a change of about 15% in peak discharge. Claims for flood damage correlated well with estimates of peak flow and lag time combined. Other measures of flood experience also correlated with the two features. Within the range of storms utilized, urban development factors consistently outranked storm intensity as a determining factor in flood damage.     

HYDROLOGICAL APPLICATIONS OF LANDSAT IMAGERY USED IN THE STUDY OF THE 1973 INDUS RIVER FLOOD,PAKISTAN1

ABSTRACT: During August and September 1973, the Indus River Valley of Pakistan experienced one of the largest floods on record, resulting in damages to homes, businesses, public works, and crops amounting to millions of rupees. Tremendous areas of lowlands were inundated along the Indus River and major tributaries. Landsat data made it possible to easily measure the extent of flooding, totaling about 20,000 km² within an area of about 400,000 km² south from the Punjab to the Arabian Sea. The Indus River data were used to continue experimentation in the development of rapid, accurate, and inexpensive optical techniques of flood mapping by satellite begun in 1973 for the Mississipi River floods. The research work on the Indus River not resulted in the development of more effective procedures for optical processing of flood data and synoptically depicting flooding, but also provided potentially valuable ancillary information concerning the hydrology of much of the Indus River Basin.     

APPLICATION OF RORB MODEL TO A CATCHMENT IN SINGAPORE1

ABSTRACT: Runoff Routing model (RORB) is a general model applicable to both rural and urban catchments. The performance of the model is illustrated through its simulation of flood runoff hydrographs in an urban catchment in Singapore. The essential feature of the model is the routing of rainfall excesses on subareas through some arrangement of concentrated storage elements, which represent the distribution of temporary storage of flood runoff on the watershed. This nonlinear routing procedure of the storage elements has two common parameters, k_c and m. With the limited data available, these two parameter values were determined through calibration runs. The same set of values of k_c and m were then used in the model to determine the runoff hydrographs of five other storms selected from the rainfall events between 1979 and 1981. It was found that the simulated runoff hydrographs matched reasonably well with the recorded hydrographs.