Developing environmental indices using fuzzy numbers ordered weighted averaging (FN-OWA) operators

Environmental indices (EI) constitute a common communication tool that is often used to describe the overall status of environmental systems (air, water and soil). EI development entails the use of mathematical operators to aggregate various non-commensurate input parameters in a logical manner. The ordered weighted averaging (OWA) operator is a general mean type operator that provides flexibility in the aggregation process such that the aggregated value is bounded between minimum and maximum values of the input parameters. This flexibility of the OWA operator is realized through the concept of orness, which is a surrogate for decision maker’s attitude. The type of input parameters also affects the choice of aggregation operators. If the input parameters are linguistic or fuzzy, the aggregation through OWA operators is not possible, and the use of fuzzy arithmetic is warranted. The concept of fuzzy number OWA (FN-OWA) operators is explored to handle situations in which one or more input parameter has fuzzy (or linguistic) values. The proposed approach is demonstrated using data provided in an earlier study by Swamee and Tyagi (ASCE J Environ Eng 126(5):451–455, 2000) for establishing water quality indices. Multiple hypothetical scenarios are also generated to highlight the utility and sensitivity of the proposed approach.     

湖泊自生碳酸盐氧同位素环境记录研究：（一）环境解释模型

湖泊自生碳酸盐氧同位素组成(δ18OC)在区域气候与环境变化方面的应用研究近年来发展迅速,成果令人瞩目,保存在各类湖泊沉积物柱芯中的δ18OC记录揭示了湖泊水温乃至汇水区域气温,湖泊不同水深处的水温差异、湖泊水位、降水δ18O、冰川融水δ18O、湖水盐度等重要的气候和环境信息。对前人通过研究来自不同类型湖泊、具不同曲线形态的δ18OC记录提出的多种环境解释模型进行了归纳。     

Do river deltas in east India retreat? A case of the Krishna Delta

The construction of multiple dams and barrages in many Indian River basins over the last few decades significantly reduced river flow to the sea and affected the sediment regime. More reservoir construction is planned through the proposed National River Linking Project (NRLP), which will transfer massive amounts of water from the North to the South of India. The impacts of these developments on fertile and ecologically sensitive deltaic environments are poorly understood and quantified at present. In this paper an attempt is made to identify, locate and quantify coastal erosion and deposition processes in one of the major river basins in India—the Krishna—using a time series of Landsat images for 1977, 1990 and 2001 with a spatial resolution ranging from 57.0 m to 28.5 m. The dynamics of these processes are analyzed together with the time series of river flow, sediment discharge and sediment storage in the basin. Comparisons are made with similar processes identified and quantified earlier in the delta of a neighboring similarly large river basin—the Godavari. The results suggest that coastal erosion in the Krishna Delta progressed over the last 25 years at the average rate of 77.6 ha yr^− 1, dominating the entire delta coastline and exceeding the deposition rate threefold. The retreat of the Krishna Delta may be explained primarily by the reduced river inflow to the delta (which is three times less at present than 50 years ago) and the associated reduction of sediment load. Both are invariably related to upstream reservoir storage development.     

An integrated lake-catchment approach for determining sediment source changes at Aqualate Mere,Central England

This paper raises fundamental questions about the sole use of paleolimnological techniques to identify sediment sources and develop catchment management plans. The concept of an integrated lake: catchment framework was established 30 years ago, yet paleolimnologists occasionally fail to appreciate the dynamics of the contributing catchment. This is especially critical when the predominant source of sediment accumulating in a lake is allochthonous. In this paper we argue that a detailed appraisal of catchment sources and investigation of historical documentary evidence is needed to identify and evaluate the relative significance of sediment sources. We used such an approach at Aqualate Mere, Shropshire, UK. Mineral magnetic and radionculide signatures of potential catchment sources and accumulating lake sediments were compared in an attempt to match the sources to sediments deposited in the Mere. Dated lake sediments indicate there has been an increase in sedimentation rate and the relative amount of minerogenic material delivered to the Mere over the last 200 years. In contrast to a previous study at the same site, there is no evidence to attribute this increase to an overspill from a nearby canal. Other catchment disturbances include landscaping in parkland surrounding the Mere in the early nineteenth century and drainage systems installed to improve catchment agriculture over the last ca. 150 years. Both activities may explain the change in sedimentation rates and types, independent of the hypothesized canal origin. Although our results exclude the canal as a major sediment source, identifying the contribution of other potential catchment sources remains problematic. ¹³⁷Cs inventories for the lake are similar to those recorded at a local reference site, suggesting little influx of ¹³⁷Cs-bearing topsoil, yet ¹³⁷Cs activities remain high in the upper 20–30 cm of the lake sediment profile, indicating a topsoil origin. Combined radionuclide and mineral magnetic signatures proved to be relatively poor discriminators of potential sources, and the high atmospheric pollution load from the West Midland conurbation has probably altered recent lake sediment signatures. Although further research is required to identify the origins of recent (last ca. 200 years) minerogenic sediment inputs to the Mere, we suggest that the combined lake: catchment approach offers a more rigorous method for understanding the impact of catchment disturbance than analysis of the paleolimnological record alone.     

Environmental decision-making under uncertainty using intuitionistic fuzzy analytic hierarchy process (IF-AHP)

Analytic hierarchy process (AHP) is a utility theory based decision-making technique, which works on a premise that the decision-making of complex problems can be handled by structuring them into simple and comprehensible hierarchical structures. However, AHP involves human subjective evaluation, which introduces vagueness that necessitates the use of decision-making under uncertainty. The vagueness is commonly handled through fuzzy sets theory, by assigning degree of membership. But, the environmental decision-making problem becomes more involved if there is an uncertainty in assigning the membership function (or degree of belief) to fuzzy pairwise comparisons, which is referred to as ambiguity (non-specificity). In this paper, the concept of intuitionistic fuzzy set is applied to AHP, called IF-AHP to handle both vagueness and ambiguity related uncertainties in the environmental decision-making process. The proposed IF-AHP methodology is demonstrated with an illustrative example to select best drilling fluid (mud) for drilling operations under multiple environmental criteria.     

Charting the emergence of ‘global water initiatives’ in world water governance

Over the last century, the aperture of water governance has widened beyond local and regional schemes to include a growing number of dynamic organizations and events with a “global” scope. Until recently, little had been written about the historical development of global water governance, institutional connectivity within the field, or key organizational successes and failures as perceived by water experts. This paper provides water scientists, managers, policymakers, and those with an interest in international water issues with an overview of global initiatives. It charts the emergence of a set of institutions and events, referred to as “global water initiatives,” or GWIs, using a survey of water experts and other research. Institutional diversity among GWIs is described by defining four distinct types of initiatives and specific differences in scope and programmatic orientation. This overview also entails the historical paradigms of water management, evaluation of the results of the growth and proliferation of numerous new GWIs in recent decades, and some recommendations for supporting and sustaining GWI efforts in order to foster and improve multilevel water management in the future.     

Deriving hillslope sediment budgets in wildfire-affected forests using fallout radionuclide tracers

Information on post-fire sediment and nutrient redistribution is required to underpin post-fire catchment management decisions. Fallout radionuclide budgets (²¹⁰Pb_xs, ¹³⁷Cs and ⁷Be) were derived to quantify soil redistribution and sediment yield in forested terrain following a moderately severe wildfire in a small (89 ha) water supply catchment in SE Australia. Application of these techniques in burnt terrain requires careful consideration of the partitioning of radionuclides between organic and mineral soil components. Beryllium-7 and ²¹⁰Pb_xs were shown to be closely associated with ash, litter and soil organic matter whereas ¹³⁷Cs was more closely associated with subsurface coarse mineral soil. Comparison of the three tracer budgets indicated that the dominant sediment source areas were ridgetops and steep valley sideslopes, from which burnt surface material was conveyed to the stream network via pre-existing gullies. Erosion was predominantly driven by sheetwash, enhanced by soil water repellency, and modified by bioturbation which both supplies subsurface sediment and provides sinks for erosive overland flow. Footslope and riparian zones were not important sediment source areas. The estimated event-based (wildfire and subsequent rainfall) sediment yield is 58 ± 25 t km^− 2, based on fallout ⁷Be measurements. The upper estimate of total particulate phosphorus yield (0.70 kg ha^− 1) is more than 10 times that at equivalent unburnt sites. This illustrates that, soon after fire, burnt eucalypt forest can produce nutrient loads similar to those of agricultural catchments. The tracer budgets indicate that wildfire is an important control on sediment and phosphorus inputs to the stream network over the decadal timeframe and the pulsed nature of this release is an important concern for water quality management.     

苏北王港近岸表层沉积物元素地球化学特征与环境意义

对王港河河道及河口附近潮滩典型地貌部位表层沉积物粒度、常量和微量元素进行分析,结果表明：潮滩和河道近岸沉积物为粘土质粉砂,粒度分布频率曲线在平均高潮线附近的沉积物为双峰态外,其余为单峰态。互花米草滩沉积物中常量和微量元素(Al2O3,TiO2,CaO,Fe2O3,K2O,MgO,MnO和Cu,Rb,Pb,As,Zn)均表现出相对富积的特征,盐蒿滩次之,反映海岸带互花米草在削浪促淤的过程中,对重金属污染有效吸附作用比盐蒿潮滩滩大。SiO2化学性质比较稳定,对沉积地貌动力的响应比较显著,近岸高潮线附近和河道中主洪道沉积物SiO2含量明显偏高。河闸上游河道沉积物中烧失量、磷(P2O5)、硫(稳定态SO3)的含量最高,反映流域营养盐在水闸以上河段沉积物中富积,重金属元素Rb,Pb,As,Ba在河道沉积物中与地壳风度相比表现为富集。王港附近潮滩表层沉积物物质组成不仅与王港河、黄河及长江的物质来源有关,而且与古潮滩沉积再搬运、再沉积以及人类围垦及排放污染活动有关。As,S是该区主要的污染元素。     

北京地区一次强对流大暴雨的环境条件及动力触发机制分析

通过对1998年6月29日北京地区发生在天气尺度脊中的强对流大暴雨过程分析, 得出该过程是由中层的高压脊和低层的辐合系统、近地面的冷空气之间的相互作用形成了具有聚能机制的中低空经向环流圈, 维持了暴雨区中低空的上升运动, 形成了近地面的动力锋生, 使中低层的潜在不稳定加剧.而对流层高层短波扰动的正涡度平流通过非地转平衡过程, 引发中高层产生的上升运动, 触发了潜在不稳定的释放.该短波扰动与风场的波动不相匹配, 其位相传播特征与重力波相似.     

Local government, local economic development and quality of life in Poland

The establishment of local self-government was a key part of the post-1989 transformation in East and Central Europe. Local government in both Western and East and Central Europe has increasingly been expected to play a role in local economic development (LED). Local government is one important agent in the complex processes of building 'institutional thickness' to ensure the development of local economies and the quality of life of inhabitants. This paper presents the results of a national postal questionnaire survey of the LED role of the lowest level of local self-government in Poland, the gmina or commune. The paper establishes a baseline of knowledge regarding: the local economic problems faced by communes; their attitudinal, strategic and organisational responses; and the main factors which are hindering the communes' LED role. This revised version was published online in July 2006 with corrections to the Cover Date.