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A structurally dynamic model was developed based on the software Pamolare II for the plant-dominated Baiyangdian Lake in North China. The model was applied to forecast the ecological health condition under different scenarios of removing submerged plants. The indicators for ecosystem health included phytoplankton biomass, ratio of zooplankton to phytoplankton biomass, eco-exergy and structural eco-exergy. The results showed that the lake''s health degraded following the decrease of removal of submerged plants. Meanwhile, the ecological health improved when the removal of submerged plants increased to 1.5 times the normal level. Finally, based on the model results, the biomass of submerged plants is recommended to be reduced to 140–180g/m2, which may provide reasonable reference for regulating and controlling submerged plants in Baiyangdian Lake. [Copyright &y& Elsevier]

Long-term water supplies are needed to address wetland degradation and the expansion of cones of depression, but this use of water is seldom considered in conventional reservoir operating models. In this paper, a new reservoir operating model is proposed to effectively direct water supply to wetlands, cones of depression, and humans. For ecological water provision to wetlands, the reservoir space is divided into two zones to maintain either the basic ecological water level in the wetland or the preferred ecological water level. The division provides reservoir operators with improved flexibility for balancing water supplies between wetlands and other users. The timing and rate of water release to alleviate cones of depression is triggered by the reservoir''s water level. The division of reservoir space for water supply to wetlands and the specified reservoir water level and release rates to cones of depression are optimized based on the overall water availability and the planned water supply to each user. The proposed model is applied to China''s Xidayang Reservoir to demonstrate its effectiveness for addressing the problems of water supplies for multiple ecological and socio-economic uses. The results demonstrate that this model effectively provides water supply to wetlands and cones of depression, while satisfying socio-economic water requirements. [Copyright &y& Elsevier]

Abstract: Analyzing the structure and functioning of the urban system revealed ways to optimize its structure by adjusting the relationships among compartments, thereby demonstrating how ecological network analysis can be used in urban system research. Based on the account of the extended exergy utilization in the sector of urban socio-economic system, which is considered as the composition of extraction (Ex), conversion (Co), agriculture (Ag), industry (In), transportation (Tr), tertiary (Te) and households (Do) sectors, an urban ecological network model is constructed to gain insights into the sustainable urban development process. Taking Beijing city as a model case, the network accounting and related ecological evaluation of a practical urban economy are carried out in this study in the light of flux, utility and structure analysis. The results showed Beijing had made some progress in moving manufacturing economy into service economy during the 10years. The increased output of the domestic sector (labor services) relieves the energy demand being placed on agricultural, industrial, transportation and tertiary sectors. The transportation sector was becoming a controlling factor to fluctuate the other sectors and the cross-regional trade is beginning to overshadow the crucial role of local manufacturing, which is due partly to the restructuring of the Beijing''s commodity markets since the 1990s. The major implication of our work is that the exergy-based network analysis can be refined to become an integrative tool for evaluation, policy-making and regulation for ecosystem management concerning structure and efficiency at urban levels. [Copyright &y& Elsevier]

Abstract: The alteration of natural water-level-fluctuation patterns is a key cause of ecological degradation in lake ecosystems. In this research a method is developed to measure the alteration degree of natural water-level-fluctuation patterns in lakes. Utilizing this method, a series of indicators are developed that can reflect the pattern of water level fluctuation. The dissimilarity between the pre- and post-impacted frequency histograms for each indicator is evaluated using a metric called the Earth Mover''s Distance. A case study of Baiyangdian Lake shows the water-level-fluctuation pattern alteration degree calculated by the new method is consistent with the ecological degradation degree, indicating the new method''s ability to reflect the ecological degradation degree based only on hydrological data [Copyright &y& Elsevier]

Abstract: The method of ecosystem health assessment (EHA) based on an index system using thermodynamic indicators has been applied to assess the state of health of Baiyangdian Lake. Indicators consisting of eco-exergy, structural eco-exergy, ratio of zooplankton biomass to phytoplankton biomass, and phytoplankton biomass were selected for the ecosystem health characterization. The assessment principle has been modified based on the typical characteristics of current ecological conditions for water areas in Baiyangdian Lake. The results of the health assessment indicate that water areas in sites 4 and 14 are in relatively good health, while the states of health of other water areas are deteriorated to varying degrees. By comparing the values of the ratio of zooplankton biomass to phytoplankton biomass and structural eco-exergy, the order of relative states of health from good to bad has been determined as: water area in the northeast and southeast (A) > water area in the north (D) > water area in the central and south (C) > water area in the west (B). Furthermore, based on the distribution of human disturbances in the water areas, for proposed regulating measures to improve the health of the impaired water areas we focus mainly on decreasing the nutrient loadings in water areas B and C and the submerged plant management of water area D. [Copyright &y& Elsevier]

Abstract: Global climate change has tremendously altered the spatial and temporal distributions of precipitation. The Streamflow of the Yellow River decreased in the past decades, both because of human consumption and climate variations. This paper analyzed the trends of natural and observed streamflow of the Lijin hydrological station, as well as the precipitation and air temperature of the whole Yellow River Basin. There was an obvious change in the natural streamflow in 1991 when analyzed by the Mann-Kendall (M-K) method. Precipitation decreased in the whole Yellow River Basin. 22 Meteorological stations have slight increases, while the other 67 stations measured declines, in which 47 of the Meteorological stations’ decrements were over 5%. There was a descent of temperature for only 2 stations, while the temperature rose for the other 87 stations. The average temperature increment was 0.82°C and the highest was 1.91°C in Tsinghai Center station. The quantitative Streamflow-precipitation-temperature relations plot was drawn by Geostatistical Analyst module of ArcGIS 9.3. The streamflow have various responses to the different extents of precipitation and air temperature. In the past four decades, precipitation elasticity to streamflow was 1.95, and the elasticity index may give a general relationship between precipitation and streamflow. However, it varies with different scenarios. [Copyright &y& Elsevier]

Abstract: We calculated energy-related carbon emissions from Beijing''s production and household sectors in 1995, 2000, 2005, and 2009 based on the default carbon-emission coefficients provided by the Intergovernmental Panel on Climate Change (IPCC). Taking 1995-2000, 2000-2005, and 2005-2009 as the study periods, we decomposed the effects of changes in carbon emissions resulting from 8 causal factors using the method of the Logarithmic Mean Divisia Index (LMDI). These causal factors include: economic activity and population size which reflect the effect of activity change; energy intensity and energy consumption per capita which reflect the effect of intensity change; economic structure, urban and rural population distribution structure, and energy mix of production and household sectors which reflect the effect of structural change. Our results can reflect the reason of carbon emissions changes and provide a solid basis for policy makers to propose emission reduction measures and approaches. [Copyright &y& Elsevier]

Abstract: Water quality can be considered a key contributor to both health and disease for humans. This study involved the evaluation and interpretation of complex water quality data and the sources of pollution in Baiyangdian Lake (China). It also allowed us to obtain more advanced information about water quality, and to design a monitoring network for this study area. Multivariate statistical techniques, including principal component analysis (PCA) and hierarchical cluster analysis (CA) were applied to evaluate water quality of the lake. The 21 physicochemical parameters focused on in the study were analyzed in water samples collected monthly over a two-year period from 13 different sites located in and around the lake. Exploratory analysis of experimental data involved use of PCA and CA in an attempt to discriminate sources of variation measured in the samples. PCA was used to identify a reduced number of five principle components, demonstrating up to 92% of both temporal and spatial changes. CA classified similar water quality stations into 5 clusters based on the PCA scores. The results showed that cluster 5 (site 2) was characterized as the most heavily polluted site, a result that can be attributed to the pollution from the nearby Fuhe River (a upstream river that receiving almost all of the domestic sewage and some industrial wastewater from Baoding City). Cluster 1 (sites 3, 4, 5, 6 and 7) and cluster 4 (site 1) were identified as moderately polluted in association with the both domestic and agricultural sewage, as well as fishery-related pollution in the lake. Cluster 2 (sites 11, 12 and 13) and cluster 3 (sites 8, 9 and 10) were less polluted, which suggests that the water quality was better in the eastern and central portions of the lake. [Copyright &y& Elsevier]

Abstract: This paper describes the development of a forecasting model, named the emergy-based urban dynamic model capable of accurately simulating the observed resource consumption, economic growth and environmental impact of Beijing. This model differs from previous urban emergy models by monitoring the negative effects to human well-being and ecosystem integrity in the developing urban system. A fresh perspective focuses on urban comprehensive performance linking such impacts to a supply-side environmental cost evaluation (including ecological service supply, ecological and economic losses and investment for treatment). In this introductory paper, we present the conceptual considerations of the most important components of the emergy-based urban dynamic model: the urban assets, lands, capitals, population, water resources, economic and environmental loss. Each subsystem in this model will enrich the feedback dynamics, policy levers and post-scenario analyses. Statistical Information and calibration are also considered in this dynamic emergy accounting. This study advances the temporal dynamic principles of emergy accounting through integrating upstream and downstream evaluation methods to quantify the environmental impact by addressing specific damages to human health and ecosystem''s integrity and by linking such impacts to a supply-side environmental cost evaluation. [Copyright &y& Elsevier]

Abstract: It is undoubted that low-carbon city has become a vital development trend for Chinese cities in the new century. Many Chinese cities have been devoted to the upsurge of low-carbon city construction in recent years. Focusing on these problems - What measures has been adopted to construct low-carbon city in China? How is the effect of low-carbon city construction? Are there some issues needing attention in the future - this paper summarizes the situation of low-carbon city development in China and clarifies a few viewpoints that need be paid attention to in the subsequent development. It is expected that the discussion in this paper can help promote the construction of low-carbon city in China. [Copyright &y& Elsevier]

Abstract: Evaluation of the ecosystem health of urban clusters will help to establish effective management that promotes sustainable regional development. The procedure for using emergy synthesis and set pair analysis models (EM-SPA) is established in this paper by combining the emergy synthesis''s ability to reflect health status from biophysical perspective and set pair analysis’ ability to describe extensive relationships among different variables. Based on the EM-SPA model, the relative health levels of different urban clusters and related health characteristics can be analyzed. The health states of three typical Chinese urban clusters, Jing-Jin-Tang, Yangtze River Delta, and Pearl River Delta, were investigated using the model. The results show that the health status of the Pearl River Delta was relatively good, while that of the Yangtze River Delta was poor. The specific health characteristics of three urban clusters were further compared. The management guidelines of the different urban clusters are also suggested. [Copyright &y& Elsevier]

Abstract: Water shortages and quality deterioration are serious dilemmas for lake managers as both problems sharply decrease the ecosystem services and functions provided by a lake. In this paper, using WASP as a tool, we have established and calibrated a water quality simulation model for Baiyangdian Lake and then analyzed water quality variations in scenarios with different pollution load reductions and different environmental flow releases into the lake and discovered the sustainable schemes for environmental flow management. From the results, in the scenarios of 30%, 50%, and 90% pollutant load reduction, the sustainable environmental flows are 3.52, 3.13, and 2.12 m3/s, and the corresponding lake levels could attain 7.45 m, 7.35 m, and 7.05 m from the initial 6.0 m. The obtained results indicated that water release could improve the lake volume and quality simultaneously. [Copyright &y& Elsevier]

Abstract: Landscape ecology planning of a scenery district is the typical application of landscape ecology principles and methods. It focuses on the spatial pattern, ecological process, and especially the relationship between human activities and landscape characteristics in a scenery district. In this paper, the spatial pattern of the Wuyishan Scenery District was studied at two scale levels:1) landscape elements and 2)the whole landscape. The change in spatial patterns for 10 types of landscapes from 2001 to 2006 was analyzed using diversity, dominance, evenness, and fragmentation. According to widely accepted landscape ecological classification principles, a new characteristic evaluation index system for landscape ecological suitability evaluation for a scenery district, including representativeness, stability, coordination, particularity, ornamental value, society, and gradient, was applied to assess its ecological suitability by the analytic hierarchy process and the composite evaluation index (CEI) was further calculated. By CEI, the ecological suitability of the scenery district was divided into three classes, including urgent landscape, normal landscape, and ideal landscape. [Copyright &y& Elsevier]

Analyzing the structure and functioning of the urban system revealed ways to optimize its structure by adjusting the relationships among compartments, thereby demonstrating how ecological network analysis can be used in urban system research. Based on the account of the extended exergy utilization in the sector of urban socio-economic system, which is considered as the composition of extraction (Ex), conversion (Co), agriculture (Ag), industry (In), transportation (Tr), tertiary (Te) and households (Do) sectors, an urban ecological network model is constructed to gain insights into the economic processes oriented to sustainable urban development. Taking Beijing city as the case, the network accounting and related ecological evaluation of a practical urban economy are carried out in this study in the light of flux, efficiency, utility and structure analysis. The results showed that a large quantity of energy and resources have to be consumed to maintain the structure and function of a city. The thermodynamic efficiencies of individual sector in Beijing remain at a low level. The social system in Beijing is a highly competitive network, and there are 8 competitive relations and only two mutualistic ones. The Domestic and Agricultural sector are the major controlling factors of the system. Moreover, the assessment results of Beijing are compared with the other three socio-economic systems, Norway, UK and Italy, and the ecological network function and structure comparisons are correspondingly illuminated and discussed. The conclusions indicate that the exergy-based network analysis can be refined to become an integrative tool for evaluation, policy-making and regulation for urban socio-economic system management concerning structure and efficiency at urban levels. [Copyright &y& Elsevier]

In ecological network theory, network efficiency and resilience are two essential but complementary attributes of the network structure, and a balance between these factors is critical for an ecosystem's long-term sustainability. Our paper introduces this method and related concepts into water use systems to provide a new angle for sustainability quantification. In this paper, we investigate the meanings of network efficiency and resilience in the context of sustainable development of water use systems, and define sustainable systems based on the optimal balance between network efficiency and resilience. With the consideration of complex artificial characteristics of water use, we propose an optimal water use network and quantify its flows. By ascendency calculation, the balanced network structure can be determined. We then use the four sub-basins of China's Haihe River as a case study to illustrate how the optimal network can be constructed and how the optimal balance for each scenario can be calculated. The results show that the optimal balance for the sub-basins has ascendency values ranging from 0.5970 to 0.7161. By analyzing the contribution of each water use activity to network's balance structure, the location of the optimal balance in water use systems can be better understood. This research represents the first attempt to explore the balance between a network structure's efficiency and resilience as a way to quantify the sustainability of water use systems, and builds a foundation for future studies on the assessment, regulation, and management of water resources. [Copyright &y& Elsevier]

Maintaining a natural flow regime helps preserve the health of riverine ecosystems. Conventional studies on reservoir operations have focused mainly on identifying optimal operational schemes for satisfying human water demands. To systematically reflect the ecological effects of both natural and human-induced hydrologic alterations, water diversions downstream of the reservoirs should be considered as well. This research focused on a coupled reservoir operation and water diversion (CROWD) model, created through the integration of a reservoir operation model and a water diversion model. The proposed model considers both human and environmental flow requirements, and represents a compromise that balances ecological protection (preservation of the natural flow regime of a river) and human needs (reduced water shortages). In the reservoir operation model, the reservoir space is divided into three zones and different operating rules are developed for directing reservoir operation when water levels are in different zones; in the water diversion model, different water users are assigned different supply priorities with the instream flows no more than the minimum environmental flows having the highest priority; and the two models are coupled by the water mass balance between the two hydraulic facilities. The non-dominated-sorting genetic algorithm II (NSGA-II) was used to determine the parameters of the developed CROWD model and the model was applied to support the joint operational management of the Tanghe Reservoir and the Liaoyang Diversion in the Tang river basin, China. The resulting reservoir operation and water diversion schemes indicate that the CROWD model is useful for optimizing the operation of reservoirs and water diversion schemes. Moreover, it helps to analyze tradeoffs between human and environmental water needs, resulting in solutions that reduce the risk of water shortages and minimize ecological integrity disturbances. [Copyright &y& Elsevier]

Thermodynamic indicators, including eco-exergy and structural eco-exergy, have been widely applied to lake ecosystem health assessment in recent decades. In this paper, the index system, including phytoplankton biomass, microzooplankton biomass, trophic state index (TSI), eco-exergy, structural eco-exergy and ecological buffer capacity to total phosphorus for phytoplankton, were applied to assess the health states of fourteen typical water areas in the plant-dominated Baiyangdian Lake. Different types of organisms, including zooplankton, benthonic animals and macrophytes with various denotative meanings, were differentiated to some extent and the latest weighting factors, were used in the eco-exergy and structural eco-exergy calculations for a better characterization of health state. The results showed that only the water area in site 4, with relatively high eco-exergy, structural eco-exergy, ecological buffer capacity and low phytoplankton biomass, microzooplankton biomass and TSI, is in healthy state. Health states of the other water areas were all deteriorated at various degrees due to the human disturbances. The health states of the northeast and southeast water areas were better than those of the northern, central and southern water areas with aquaculture and villages and western water areas close to the Fu River. For the plant-dominated Baiyangdian Lake, combining eco-exergy with structural eco-exergy could better characterize the health state of ecosystem with macrophytes hypermorphosis and meanwhile based on the distinguishing of various organism components, specifically benthonic animals, to some extent for eco-exergy and structural eco-exergy calculations, spatial variations of health state obtained better description, which indicated eco-exergy and structural eco-exergy were the robust indicators for ecosystem health assessment of the plant-dominated lake. [Copyright &y& Elsevier]

Abstract: Vegetation-disturbance-environment relationships in Xishuangbanna Nature Reserve (XNR) was examined using multivariate analysis to understand the impacts of environmental factors and human disturbance on vegetation along the highway corridor. The results show that native forests were the best habitat for protected/endangered species and native species. The exotic plants Eupatorium odoratum and Eupatorium adenophora were found primarily in secondary forests and their presence was positively associated with altitude and soil potassium concentrations. The distribution of two protected plants, Phoebe nanmu and Pometia tomentosa, was negatively associated with road disturbance. Understanding the complex effects of environmental factors and human disturbance is key for developing conservation and restoration strategies for roadside plant ecosystems. [ABSTRACT FROM AUTHOR]

Abstract: Carbon emissions from rural energy combustion have not been successfully addressed in the existing accounting system since incomplete data of rural energy consumption and exclusion of emissions from combustion of biofuels in the sectoral or national totals to avoid double counting. Presented in this paper were estimations of CO2 emissions from fuel combustions in rural areas of China from 1979 to 2007 and analysis of their contributions to national energy related CO2 emissions, to highlight the important role rural energy plays in regard to climate change and potential capacity for carbon abatement in rural areas. The temporal variations of CO2 emission in rural areas was also analyzed with regard to total emissions, intensity and source structure, which could provide a novel perspective to our GHGs reduction strategies and related policy making. The results showed that the CO2 emissions in rural China have constantly increased from 8.89×108 tons in 1979 to 28.74×108 tons in 2007. Commercial energy has become the dominant force of CO2 emissions in rural China, most of which is mainly derived from the consumption of coal and electricity. The proportion of carbon emissions from rural areas to nationwide underwent an inverted U-curve trend if biomass energy was ignored, with a peak at 47.40% in 2000. The situation becomes absolutely different when considering about biomass. For a long time (from 1979 to 2001), rural energy related carbon emissions has maintained a greatly high proportion in total carbon emissions with a fluctuations between 45.13% and 56.31%. The proportion of carbon emission in rural areas has declined since 2002, but still up 40.99% in 2007. [ABSTRACT FROM AUTHOR]

Regarding various energy and materials flowing in the urban ecosystem and the merit of emergy as an embodied energetic equivalent for integrated ecological economic evaluation, an evaluation framework of emergy-based urban ecosystem health indicators (UEHIem) was established in view of five aspects including vigor, structure, resilience, ecosystem service function maintenance and environmental impact to depict the urban ecosystem health states. Further, set pair analysis (SPA) was employed to assess the urban ecosystem health level based on the UEHIem, by which the approximate degree of real index set to the optimal one was defined and evaluated to describe the relative health state of the concerned urban ecosystems. Choosing twenty typical Chinese cities in 2005 as cases, we evaluated and compared their urban ecosystem health levels based on UEHIem and SPA. The results showed that health levels of Xiamen, Qingdao, Shenzhen and Shanghai are pretty well, while those of Wuhan, Harbin, Yinchuan, Beijing and Urumchi are relatively weak. Moreover, the relative health levels were analyzed by SPA to discern the influences of the mentioned five aspects on the UEHIem. It is concluded that emergy synthesis combined with SPA can serve as an effective relative-measure to compare different ecosystem health levels of urban ecosystems. [Copyright &y& Elsevier]

The objective of this study is to measure and evaluate the ecosystem health levels of 31 Chinese capital cities in 2004 through an emergy synthesis framework. A system of indicators was developed corresponding to the four factors of urban ecosystem health including efficiency, structure, impact and flux. Furthermore, combined with individual indices, an emergy-based urban ecosystem health index (EUEHI) was proposed to measure and evaluate the health levels among various typical cities in China, which offers an integrated evaluation tool in view of urban production, trade and consumption. The results showed that there are intrinsic differences among six clusters associated with driving mechanisms distinguishing the rankings of urban health levels. After lining the cities of similar health levels with cluster map, the spatial distribution of the urban health is found to be arch-shaped, increasing initially and then decreasing from coast to inner land. This kind of spatial hierarchy is per se compatible and consistent with the hierarchical theory of emergy synthesis. The results also revealed double restrictions of urban health between economy and environment. Moreover, the interaction analysis was used for mirroring the driving mechanism of urban ecosystem health. Three conclusions were arrived at. Firstly, environmental health is inversely related to the economic health in China, indicating that cities cannot achieve win–win between environment and economy in the current urban development mode. Secondly, based on economy-driven mode, four quadrants were divided in the city division map, wherein 43.33% of the concerned cities developed in high economy-restriction mode, which means low economic level is still an important limiting factor for the major cities of China. Finally, based on environment-driven mode, two sections were divided, of which weak environmental dominance mode expounds the special characteristics of urban environment with obvious fragility. 23.33% of the 30 cities were in the intermediate state, which means a few correspondingly unhealthy cities should develop concrete polices for the urban ecosystem restoration. [Copyright &y& Elsevier]

Abstract: In Chinese history, Tuoshan Weir, located in Ning County of Ningbo, Zhejiang Province, Eastern China, is ranked as one of the four most outstanding hydrological projects ever undertaken. Since the weir was originally constructed during the Tang Dynasty in 833 a.d., it has succeeded for 1171 years in playing a distinctive role in preventing saline water of the East Sea from backing up, conserving freshwater, ensuring safety of people from flooding hazards and irrigating farmlands in the Ningxi Plain. From eight highlights in planning, design and construction of the hydrological project, this paper reveals the ancient knowledge involved in using hydraulic principles, such as distributed flows and mechanics, such as engineering infrastructures. [Copyright &y& Elsevier]

Efficient urban environmental management methods are of importance, even essential to urban sustainable development. Economic methods have increasingly had advantages over other methods of environmental management during the course of the economic system's transition in China. Therefore, the establishment of an effective urban environment-economic management system is necessary and valuable. This paper primarily studies urban environment-economic management and establishes a framework for an urban environment-economic management system. As an example, we created the environment-economic management system of Xiamen, giving priority to economic methods combined with other management methods. We also investigated some problems probably arising in the application of this management system. Finally, a preliminary benefit analysis of the environment-economic management system of Xiamen was conducted. This new comprehensive framework for an environment-economic management system may be used in other cities in China and other developing countries around the world. [ABSTRACT FROM AUTHOR]

In this research, an inexact two-stage chance-constrained programming model (ITSCCP) was developed for supporting the planning of coupled coal and power management systems in China based on the integration of multiple programming methods and China’s special coal-pricing mechanism. Multiple uncertainties that were expressed as interval numbers and probability density functions could be effectively tackled. Recourse decisions for power generation with a certain level of economic penalties could be identified to evaluate economic penalties associated with violation of original coal-pricing contracts between coal suppliers and power plants. Also, risks associated with the violation of coal transportation capacities were quantified and analyzed. The developed ITSCCP was applied to a case of long-term management of coal and power in north China. Interval solutions associated with different risk levels of transportation-supply constraint violations under varying power-generation demands were obtained. The solutions indicated that they could be used for generating decision alternatives and helping decision makers identify desired strategies under multiple social-economic, environmental and system-reliability constraints. Moreover, ITSCCP could not only provide in-depth analysis of various policy scenarios associated with different levels of economic penalties when the promised targets were violated, but also identify optimal solutions under the existing government-guided coal-pricing mechanism. [ABSTRACT FROM AUTHOR]

Emergy and economic methods were used to evaluate and compare three fish production models, i.e., cage fish farming system, pond intensive fish rearing system and semi-natural extensive pond fish rearing system, in Nansi Lake area in China in the year 2007. The goal of this study was to understand the benefits and driving forces of selected fish production models from ecological and economic points of view. The study considered input structure, production efficiency, environmental impacts, economic viability and sustainability. Results show that the main difference among the three production systems was the emergy cost for fish feed associated with their feeding system, i.e., feeding on natural biomass such as plankton and grass or on commercial feedstock. As indicated by EYR, ELR and ESI, it can be clearly shown that the intensive production model with commercial feed is not a sustainable pattern. However, the point is that more environmentally sound patterns do not seem able to provide a competitive net profit in the short run. The intensive pond fish farming system had a net profit of 2.57E+03 $/ha, much higher than 1.27E+03 $/ha for cage fish farming system and slightly higher than 2.37E+03 $/ha for semi-natural fish farming system. With regard to the drivers of local farmer’s decisions, the accessibility of land for the required use and investment ability determine the farmer’s choice of the production model and the scale of operation, while other factors seem to have little effect. Theoretically, the development of environmentally sustainable production patterns, namely water and land conservation measures, greener feed as well as low waste systems is urgently needed, to keep production activities within the carrying capacity of ecosystems. Coupled emergy and economic analyses can provide better insight into the environmental and economic benefits of fish production systems and help solve the problems encountered during policy making. [Copyright &y& Elsevier]

Ecological network analysis (ENA) is introduced in this paper as a promising approach to study water use systems. Information indices from ENA involving total system throughput (TST), ascendency and overhead are calculated here. Two related aspects including organization inherent in system structures and synthesized water use intensity related with sustainable development of water use systems are analyzed. The indices of ascendency and overhead are applied for analyzing and characterizing water use network organization. For comparison of sustainability of water use systems from integrated aspects of environment, society and economy and based on TST, a new indicator termed as total system throughput intensity (TSTI) is constructed incorporating parameters of land, precipitation, population, GDP and environmental flow, which can be used as a measure of sustainability in terms of synthesized water use intensity. The Yellow River Basin in China during 1998–2006 is chosen as the case study and divided into subsystems according to the six river sections as from source to Lanzhou (S1-L1), Lanzhou to Toudaoguai (L1-T), Toudaoguai to Longmen (T-L2), Longmen to Sanmenxia (L2-S2), Sanmenxia to Huayuankou (S2-H) and Huayuankou to the mouth of Bo Sea (H-B). The results show that (i) the organization levels of L1-T and H-B are better than those of S1-L1 and T-L2, with those of L2-S2 and S2-H the worst; (ii) the synthesized water use intensity has been improving, of which T-L2, L2-S2 and S2-H are at the highest levels while H-B the lowest. In addition, the comparison between TSTI and other metrics and the relationship between ascendency and TSTI are discussed, from which the importance of TSTI is reflected and the optimization criterions for sustainable development of six subsystems are derived. It can be concluded that the application of ENA in water use systems can provide new angles for water resource management to address the challenges of assessing and optimizing options to obtain more sustainable water use. [Copyright &y& Elsevier]

Abstract: Sustainable development is of great significance in rural areas of China, which are under coupled pressures of poverty reduction, environmental protection and economic development. In these areas, agriculture is the primary sector in supporting their economies, where a number of the relevant production and processing practices cause many adverse impacts on environment and ecosystem. This poses many challenges for decision makers in formulating sustainable development strategies without invoking potential controversies or objections from the public. In this study, a two-level expert system (TES) for facilitating the investigation of public’s perception towards sustainable development in rural areas was developed. Interactive relationships among objectives of socio-economic development and environmental protection, as well as the related policy implications and public responses, were comprehensively examined and incorporated within TES. A two-level system was particularly adopted for facilitating participation of various stakeholders, including decision makers and farmers. The Yongxin County of the Shanjianghu Region in Jiangxi Province, China was selected to demonstrate the applicability of the developed TES. A series of questionnaire surveys were conducted both for acquiring knowledge about the interrelationships among sustainable development, agricultural production, poverty reduction and environmental protection. Public’s perception towards various system components of rural sustainable development were efficiently acquired and analyzed. The results indicated that sustainable development would be very significant on rural areas in China. Also, public awareness to the concept and profile of rural sustainable development was still at a low level, especially for farmers. The developed TES can be not only used for acquiring knowledge of sustainable development, but also providing basic information for the formulation of relevant policies and strategies in rural areas of China. [Copyright &y& Elsevier]

Abstract: Water footprint is an indicator showing the consumption impact on environment with water equivalent, which allows a detailed quantification of water use directly and indirectly in sectors for the domestic and abroad final consumption. This paper presents a framework of calculating national water footprint (NWF) with input–output method on China 2002. The results indicated that the NWF of China was 381m3/capyr in 2002. A new indicator termed as national water footprint intensity (NWFI) is also derived from NWF to evaluate the water consumption intensities of different sectors. Then the evaluation of virtual water trade in sectors is followed, the results of which give a detailed quantification of net virtual water import of sectors, verifying that China is a net virtual water exporter concerning the whole national sectors, which is different from the previous studies. Finally, it is suggested that the sectors with high NWFI and volume of net virtual water export should be regarded as the priority of Chinese water-saving strategy. [Copyright &y& Elsevier]

Abstract: In this paper, the methods of GIS buffer, spatial comparison, and scenario analysis were used to elucidate the influence of roads on landscape within Lancang River Valley. The results showed that forest and shrub land decreased while farmland and constructed land increased in the past 20 years in the study area. Also, the ecosystem''s change rate near roads increased while the diversity evenness, patch density and human disturbance indices all decreased. Different aspects of road development had different negative consequences for the environment. In Lancang River Valley, forests were most affected by road network development, although there were also negative affects for grassland, farmland or shrub land and these differences varied by type of road. The greatest effects for forests were observed near high-level roads, while the greatest effects for farmland occurred near the low-level roads, Scenario analysis showed that the fractal dimension index, patch numbers, and average patch area of ecosystems decreased with development of road network density. The ecological risk analysis showed that various type roads cause different risk levels and that road density has a positive relationship with regional ecological risk level at county scale. Also, different ecological risk level exists in different level roads. Full road network data (density, level) should be considered to avoid the underestimate of the ecological effects. [Copyright &y& Elsevier]

Abstract: This study presents an ecological analysis of Chinese agriculture for the period from 1980 to 2000, on the basis of Odum''s well-known concept of emergy in ecological economy. Emergy analysis methods are explained, illustrated and used to diagram the agro-ecosystem, to evaluate environmental and economic inputs and harvested yield, and to assess the sustainability of the Chinese agriculture as a whole. Detailed structure of the input/output and system indicators are examined from a historical perspective for the contemporary Chinese agriculture in the latest two decades after China''s Reform and Open in the late 1980s. Temporal variation of indices such as increasing environmental load ratio (ELR), decreasing emergy self-support ratio (ESR) and decreasing emergy yield ratio (EYR) illustrate a weakening sustainability of the Chinese agro-ecosystem characteristic of profound transition from a self-supporting tradition to a modern industry based on non-renewable resource consumption. [Copyright &y& Elsevier]