Assessing land ecological security in Shanghai (China) based on catastrophe theory

Given the important role of land ecosystem in social-economic progress at regional, national, and international scale and concurrent degradation of land ecosystems under rapid urbanization, a systematic diagnosis of land ecological security (eco-security) for sustainable development is needed. A catastrophe model for land ecological security assessment was developed in order to overcome the disadvantages in subjectivity and complexity of the currently used assessment methods. The catastrophe assessment index system was divided into hierarchical sub-systems under the pressure-state-response framework. The catastrophe model integrated multiple assessment indices of land eco-security according to the inherent contradictions and relative importance of indices without calculating weights. Specifically, membership degree of higher level index was calculated based on the membership degrees of lower level indices that were subjective to suitable model, such as cusp, fold, swallowtail and butterfly model. This model was applied to evaluate the state of land eco-security in Shanghai. Mann–Kendall’s test was utilized to characterize its temporal trend between 1999 and 2008. Significant downward trend was identified for land eco-security, in terms of pressure sub-index, state sub-index, response sub-index and synthetic index. All these implied that land ecosystem conditions were not optimistic for Shanghai and such situation should draw the attention of policy makers. The calculation procedure presented in this paper does not require a high level of technical expertise to determine the membership degree, making it simple and operational. Being applicable to similar land ecosystems, the catastrophe model is thus believed to provide an alternative approach to land eco-security assessment.     

东太湖水生植物及其与环境的相互作用

通过PSR模型建立福建山仔水库生态安全评价的指标体系,应用熵权法确定各指标权重,引入密切值法对水库的生态安全进行评价．结果表明,2000—2003年福州市山仔水库生态安全状况从优到劣的排序依次为：2002年、2001年、2000年、2003年．该研究改进了水库生态安全评价指标体系和传统生态安全评价的数学模型,使指标体系更合理、更切合水库的生态环境保护目标,计算简便,能较客观、全面地反映出评价对象各样本状况．     

Efficacy of adapted estuarine fish-based multimetric indices as tools for evaluating ecological status of the marine environment

The assessment of ecological status of marine fish communities required by the marine strategy framework directive (MSFD) emphasises the need for fish-based ecological indices in marine waters. In this study we adapt five estuarine multimetric indices to the marine environment and apply them in three types of substrates, analysing the metrics responsible for the obtained patterns of ecological status. The results show inefficiency of the community degradation index (CDI) and the biological health index (BHI) in ecological status assessment and disagreement between the estuarine biotic integrity index (EBI), the estuarine fish community index (EFCI) and the transitional fish classification index (TFCI). Analysis of individual metrics suggests lack of representativeness and consideration for the particularities of each substrate’s typical fish communities. None of the tested indices were efficient on the marine environment, urging the need for new marine indices that account for differences between types of substrate and depth.     

地震灾害经济易损性评估研究——以甘肃省为例

从灾害学基本理论出发结合模糊综合评价模型,建立了相应的地震灾害经济易损性的评估模型,构造了易损性因素指标集及评语集,并对甘肃省13个地级市进行地震经济易损性风险评估,最终获取经济易损性等级划分.结果表明:易损性最高的地区为兰州市、金昌市、天水市、武威市、张掖市;易损性最低的地区为平凉市、酒泉市、定西市和甘南州;其他地区介于两者之间.由于评估指标对评估目标的影响具有模糊性的特点,因此采用模糊综合评判法进行评估是合适的.     

Spatially explicit assessment of land ecological security with spatial variables and logistic regression modeling in Shanghai,China

Ecological security is a fundamental component of regional security that has drawn increased attention worldwide over the past two decades. This paper presents a novel approach to assess the status of land ecological security (LES) in Shanghai, China from 1992 to 2011 using spatial variables and a logistic regression model. The LES status of 1745 points within the study area in 1992, 2001 and 2011 was sampled systematically using a 2 × 2 km grid sample frame and evaluated based on an expert method with ten experts from five fields. A five-point Likert scale was used to score the LES status as very insecure, insecure, neutral, secure or very secure. We identified several explanatory factors to the LES status, including distance-based variables describing the proximities to urban center, developed areas and sources of pollution, as well as variables regarding the density of built-up areas and the mean value of normalized difference vegetation index. A logistic regression model was used to quantify the relationship between LES scores and the spatial variables at each of the three time points, resulting in a series of maps illustrating the LES patterns of Shanghai in 1992, 2001 and 2011. The results show that LES is either very insecure or insecure at the center of Shanghai and at its district centers, and the LES of the entire Shanghai municipality has deteriorated significantly from 1992 to 2011. This research contributes to an enhanced understanding of LES changes resulting from rapid urbanization and industrialization of the Shanghai municipality and provides a methodological framework to study LES elsewhere.     

Projection Pursuit Evaluation Model: Optimizing Scheme of Crop Planning for Agricultural Sustainable Development and Soil Resources Utilization

Planting structure influences the economic, social, and ecological benefits of crop farming as well as the use efficiency of water and arable land resources, and so crop planning (CP) benefits for agricultural sustainable development and soil resources utilization. The projection pursuit evaluation (PPE) model is put forward to solve the problem of selecting an optimizing scheme for CP by considering the indices of water‐saving and economic, social, and ecological benefits. The real‐coding‐based accelerating genetic algorithm (RAGA) is introduced to accelerate the calculation process. The model can translate multi‐indices into a single index by transforming high‐dimensional data to low‐dimensional space, which helps evaluate CP optimizing schemes. For example, the model is used to evaluate and select an optimal scheme of CP in the middle reaches of the Heihe mainstream basin in the arid area of northwest China. According to four criteria (high efficiency of resources use, economic rationality, social equity, and ecological security) 19 indices were chosen to evaluate 12 optimizing schemes of four kinds (economic‐benefit, food‐security, ecological‐benefit, and water‐saving programs) in 2006, 2020, and 2030. The result shows that, in the 3 years, the water‐saving program is always the optimized scheme in an arid region with water deficiency and fragile ecology. The evaluated results match up to the developmental conditions of crop farming in recent years. Moreover, the direction of the optimal projection could reflect the weight and orientation of indices objectively and accurately.     

Comprehensive flood risk assessment based on set pair analysis-variable fuzzy sets model and fuzzy AHP

On the basis of the disaster system theory and comprehensive analysis of flood risk factors, including the hazard of the disaster-inducing factors and disaster-breeding environment, as well as the vulnerability of the hazards-bearing bodies, the primary risk assessment index system of flood diversion district as well as its assessment standards were established. Then, a new model for comprehensive flood risk assessment was put forward in this paper based on set pair analysis (SPA) and variable fuzzy sets (VFS) theory, named set pair analysis-variable fuzzy sets model (SPA-VFS), which determines the relative membership degree function of VFS by using SPA method and has the advantages of intuitionist course, simple calculation and good generality application. Moreover, the analytic hierarchy process (AHP) was combined with trapezoidal fuzzy numbers to calculate the weights of assessment indices, thus the weights for flood hazard and flood vulnerability were determined by the fuzzy AHP procedure, respectively. Then SPA-VFS were applied to calculate the flood hazard grades and flood vulnerability grades with rank feature value equation and the confidence criterion, respectively. Under the natural disasters risk expression recommended by the Humanitarian Affairs Department of United Nations, flood risk grades were achieved from the flood hazard grades and flood vulnerability grades with risk grade classification matrix, where flood hazard, flood vulnerability and flood risk were all classified into five grades as very low, low, medium, high and very high. Consequently, integrated flood risk maps could be carried out for flood risk management and decision-making. Finally, SPA-VFS and fuzzy AHP were employed for comprehensive flood risk assessment of Jingjiang flood diversion district in China, and the computational results demonstrate that SPA-VFS is reasonable, reliable and applicable, thus has bright prospects of application for comprehensive flood risk assessment, and moreover has potential to be applicable to comprehensive risk assessment of other natural disasters with no much modification.     

Revisiting functional no-flow events in the Lower Yellow River

Functional no-flow is a topic of considerable interest in the research and management of the Yellow River. The operation of the Xiaolangdi Reservoir has been a source of concern regarding hydraulic characteristics and hydro-environmental responses. However, the impacts of the reservoir on functional no-flow events have not been reported to date. Using a complete set of daily hydrological data from four key hydrological stations for the past six decades and at three different temporal scales (year, wet season and dry season), the differences in incoming water and functional no-flow events have been compared before and after the Xiaolangdi Reservoir began operation, using two sets of critical runoff values that were summarized from previous studies. The results indicate that the frequency of functional no-flow events has decreased since the Xiaolangdi Reservoir began to operate, based on critical runoff or dis-charge values defined by long term hydrological records, and the frequency decreased more when the critical values defining the new situation were used. However, functional no-flow events still occurred in the Lower Yellow River, especially in the lower reach during the wet season. The degree of severity of the functional no-flow events and the magnitude and variation of daily discharge are strongly linearly related before and after the reservoir began operation, regardless of which set of critical values were used to identify the functional no-flow events.     

A habitat-specific fish-based approach to assess the ecological status of Mediterranean coastal lagoons

A habitat approach was promoted in the framework of ecological status assessment of transitional waters, assuming the importance of habitat heterogeneity to the overall system status. The approach was applied to the use of fish-based multimetric indices by adapting them to seagrass and marsh habitats in the Venice lagoon, Italy, through selection of appropriate metrics and reference conditions. While for marsh habitats, no clear patterns resulted, the index response for seagrass was consistent with the habitat degradation and loss recorded in the lagoon between 2002 and 2005 and with the higher habitat disturbance in southern and central lagoon sub-basins. The assessment of individual habitats is presented as a first step in the process of evaluating the overall condition of a Mediterranean lagoon environment, which should also take account of the diversity of habitats and their availability within the system to properly define an overall index of ecological status.     

河南小浪底水库库区地震剪切波分裂研究

采用河南小浪底水库数字地震台网2009—2016年的地震观测资料,结合双差重定位结果,利用剪切波分裂系统分析方法,获得了小浪底水库库区8个数字地震台站的剪切波分裂参数.研究表明,小浪底库区地震主要分布在库区中段的石井河断层附近,呈团状散布;该区域的剪切波快波平均偏振方向为100.4°±45.0°,慢波平均时间延迟为(2...     

Analysis of reservoir water quality using fuzzy synthetic evaluation

A general methodology for fuzzy synthetic evaluation is developed and illustrated with a case study of trophic status assessment for Fei-Tsui Reservoir in Taiwan. The historical data base was collected from the management agency of Fei-Tsui Reservoir from 1987 to 1996. In fuzzy synthetic evaluation, the classification is determined by a matrix operation of the weighted vector with the fuzzy evaluation matrix. After all individual membership functions of evaluated factors have been determined, the fuzzy evaluation matrix can be established. The weighted vector is determined by the analytic hierarchy process method (AHP). The results of this investigation show that the long-term change of water quality and the overturn phenomena cannot be observed with the Carlson index from 1987 to 1992 but is expressed by fuzzy synthetic evaluation. Fuzzy synthetic evaluation is better suited than the Carlson index to rating the trophic status of self-sustaining lakes. Interpretation of the results can provide valuable information to decision makers and aid reservoir management.     

Assessment of the ecological quality status of soft-bottoms in Reunion Island (tropical Southwest Indian Ocean) using AZTI marine biotic indices

The ability of the two synthetic marine biotic indices, AMBI and M-AMBI, to account for changes in the ecological quality of coastal soft bottoms of Reunion Island according to disturbances was assessed from macrobenthic samples collected in five sectors between 1994 and 2004. Samples were collected under non-perturbed conditions and at two sites subjected to heavy organic enrichment. Both indices are based on a classification of macrofauna into ecological groups (EG), and their transfer to tropical waters required some adaptations. These indices proved efficient in detecting a degradation of habitat quality. Their use resulted in the classification of all sites sampled between 1996 and 1998 as "good" or "high". M-AMBI nevertheless tended to result in the attribution of a slightly worse ecological quality status than AMBI. Together with an update of the EG species list for the Indian Ocean area, our results support the extension of both indices for the assessment of tropical soft bottoms.     

Ecological status in the Ligurian Sea: the effect of coastline urbanisation and the importance of proper reference sites

The assessment of the ecological status, as required by the Water Framework Directive (WFD), plays an important role in coastal zone management, but only a small number of ecological indices are applicable on rocky bottoms. In this study, we apply a previously defined ecological quality index based on the cartography of littoral and upper-sublittoral rocky-shore communities (CARLIT), based on the sensitivity of algae dominated communities to anthropogenic impacts along a moderate urban gradient. We also apply this index in four Marine Protected Areas (MPAs), proposed as reference sites at a regional scale. After comparing the outputs with water variables and other quality indices, we can affirm that (1) the CARLIT index is suitable to detect different kinds of anthropogenic pressures, that (2) the choice of proper reference sites is a focal point in the fulfilment of the WFD (Water Framework Directive) and that (3) historical data are important to define reference conditions and the degradation of ecological status.     

Development of a River Macrophyte Index (RMI) for assessing river ecological status

We present the process of developing a macrophyte based index (River Macrophyte Index – RMI) for assessing river ecological status, that would be applicable for rivers with moderate to high water alkalinity, flowing over low slope terrain. A reference value and boundary values were determined for five ecological classes. The relation between the developed index and two existing indices, the Reference Index (RI) and the Trophic Index of Macrophytes (TIM), and selected environmental variables was established. The RMI is based on species composition and abundance from 208 sampling sites being in reference or good hydromorphological conditions and differing in the catchment land use. The percentage of natural areas in the sub-catchment was used for classifying macrophyte taxa into 5 ecological groups. 65 plant taxa, of which 47 were identified as indicator taxa, were included in the analysis. To assess the ecological status of a river site, the presence of at least 3 indicator taxa is necessary, otherwise the assessment is considered inconclusive. RMI is expected to indicate multiple pressures on the river, including trophic level. The developed index and RI and TIM indices differed in relation to slope, distance to source and catchment size.     

湖泊富营养化评价模糊集理论与模式

根据湖泊(水库)营养化具有模糊性的特点。建立了湖泊(水库)富营养化评价的模糊集理论与模式,并首次提出富营养化指标综合权重矩阵概念及其确定方法。应用该模式对我国12个湖泊(水库)的富营养化程度进行了评价,结论与实际情况相符。为湖泊(水库)富营养化治理和保护提供了科学依据。上述理论与模型原则上亦可在其他环境评价领域中应用。     

Modeling the effect of artificial flow and sediment flux on the environment and plankton of an estuary

Estuarine environments are influenced by both river flows and oceanic tidal movement of water, sediment, and nutrients, often forming ecosystems that are rich in resources and biodiversity. The Yellow River once carried the world’s largest sediment load, but artificial structures have transformed its hydrodynamic processes. An annual Water-Sediment Regulation Scheme(WSRS) was introduced to flush accumulated sediment from the Xiaolangdi Reservoir, which provides flood control and water storage.Ho...     

基于湖库水质目标的流域氮、磷减排与分区管理——以天目湖沙河水库为例

湖库水环境保护在保障生产与生活用水、维系生态平衡、发展旅游等方面发挥着重要的作用.水质目标管理是保护湖库水质的最佳管理办法.本文以天目湖地区沙河水库及其流域为研究区域,建立模型模拟沙河水库流域的水文与水质,评估入库污染通量和主要来源;依据水质目标测算氮、磷污染的容量和减排量,结合土地的生态保护与开发适宜性评估,提出氮、磷污染分区减排和土地管控的对策和措施.研究结果表明,沙河水库氮、磷污染物入库通量分别为206.01和3.29 t/a,面源总氮和总磷分别占总入库量的85.7%和67.5%.不同土地利用类型氮、磷输出强度有显著差异,总氮输出强度依次为茶园 >耕地 >建筑用地 >裸地 >草地 >退耕地 >林地 >河湖漫滩,总磷输出强度与地表覆盖度有关,依次为裸地 >建筑用地 >茶园 >耕地 >草地 >退耕地 >林地和河湖漫滩.从氮、磷输移过程来看,沙河水库流域总氮排放量为321.64 t/a,进入河流的为255.53 t/a,在河道输送过程中损失19.4%,最终有206.01 t/a进入水库;沙河水库流域总磷排放量为13.42 t/a,进入河流的为7.90 t/a,在河道输送过程中损失58.3%,最终有3.29 t/a进入水库.不同分区河流氮、磷滞留降解率有很大的差异,中田河总氮、总磷滞留降解能力最强,分别为34.71%和84.31%.2009年的通量计算结果显示,沙河水库总氮达到Ⅳ类水质目标需要的入湖减少量为32.01 t/a,入湖削减比例为15.50%,总氮达到Ⅲ类水质目标需要的入湖减少量为59.66 t/a,入湖削减比例为29.00%;总磷达到Ⅲ类水需要的入湖减少量为0.682 t/a,入湖削减比例为20.70%,总磷达到Ⅱ类水需要的入湖减少量为1.479 t/a,入湖削减比例为44.90%.为了实现基于土地利用的面源污染减排管控,选定植被覆盖度、水源涵养能力、地形坡度、土地利用、氮磷分区贡献量、与道路和村落距离等指标综合评估生态保护价值和开发适宜性,并划定禁止开发区、限制开发区和保护性开发区3个管理分区,最终确定各分区的开发强度限制和管控方式.     

Seasonal variability of benthic indices: an approach to test the applicability of different indices for ecosystem quality assessment

In recent studies, several benthic biological indices were developed or used to assess the ecological quality status of marine environments. In the present study the seasonal variability of several univariate and multimetric indices was studied on a monthly scale (September 2000 until May 2002) in different areas of the North Sea such as the German Bight, the Oyster Ground and the Dogger Bank. The stations were chosen to reflect a gradient in the hydrographic regime, temperature and organic matter supply. The seasonal variability was highest for the univariate indices such as the Shannon–Wiener Index and the Hurlbert Index. Thus, due to sensitivity to recruitment the corresponding ecological status ranged from ‘good’ to ‘poor’ depending on the season. For the multimetric indices such as the AMBI or the BQI the seasonal variability and the corresponding ecological status were low. The results are discussed concerning possible consequences for ecological quality assessment especially related to the Water Framework Directive (WFD).     

Influence of macrofauna long-term natural variability on benthic indices used in ecological quality assessment

An essential prerequisite for the assessment of the ecological quality of marine ecosystems is the understanding of the natural variability and its effect on the performance of quality indices. This study is focused on the long-term natural variability of diversity, biotic and multimetric indices by using long-term macrofauna data of a coastal area in the southern North Sea (1978-2005). The univariate and most biotic and multimetric indices respond significantly on specific natural disturbance events such as cold winters, but the strength of response varied between indices as well as between events. As a result, the ecological quality status can decrease over a range of 3 (out of 5) classification units. The overall ecological quality was good to high, but an increase of indices occurred from the mid 1980s onwards due to changes in the climate regime. This long-term variability has to be considered within ecological quality assessment schemes.     

Reservoir operation by staging due to climate variability

The changing environment enhances the hydrological cycle and increases the frequency of extreme floods. In this paper, the impacts of climate variability on flood season segmentation are determined and the scientific basis for determining corresponding flood limiting water levels (FLWLs) is provided. Climate variation was determined and then the flood season was divided into several sub-seasons using the results of the set pair analysis method (SPAM) and four indices; peak floods crossing the transitional periods were sampled to obtain a design flood hydrograph; and, finally, seasonal FLWLs were determined for reservoir operation. The performance of this reservoir staging operation was evaluated for a case study in the Chengbihe Reservoir, China.