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• B-MMI and three indices are built to assess benthic macroinvertebrate integrity. • The shared effects of hydromorphology and physico-chemistry are analyzed. • The main environmental factors contributed to B-MMI, D/A, S/T and FFGs for substrate types are recognized. Hydrology, water quality and biological pressures can influence structure and function of stream and river ecosystems. However, in practice, identifying the shared effects of factors on communities instead of isolated effects is a challenging task. Benthic macroinvertebrate community can reflect bottom conditions of streams and is less disturbed by river flows and human activities. Therefore, it is suitable to analyze the shared effects of hydromorphological and physico-chemical parameters. Benthic macroinvertebrate based Multi-Metric Index (B-MMI) was built to evaluate overall status and the effects on three biological traits were calculated, including diversity and abundance (D/A), sensitivity and tolerance to pollutions (S/T) and functional feeding groups (FFGs). Redundancy Analysis (RDA) was performed to evaluate the percentage of explained variance of 18 hydromorphological and physico-chemical parameters on invertebrate community. Our analysis showed that the two facets of the environment have high shared explained variances (28.2%–44.5%). Relatively, physico-chemical parameters have higher contributions on B-MMI than hydromorphological parameters. Seasonal analysis showed the shared effects are higher in dry season than wet season. S/T characteristics are most sensitive to seasonal shared effects, which in wet season can best show the isolated effects of the two facets of the environment. At the catchment-scale, middle stretches had higher B-MMI values since stony substrate and less disturbed land use types. And reach studies showed channel morphology contributed more in stony reaches while bottom conditions contributed more in silty and sandy reaches. Our findings consequently give rise to concern to the integrity index of benthic invertebrate community, which allows to show large shared effects of hydromorphological and physico-chemical factors. Besides catchment scale, reach scale also help add the perspective of substrate diversity and heterogeneity in habitat restoration and conservation. [ABSTRACT FROM AUTHOR]

As a systematic research at basin scale, this study explored the composition and concentration characteristics of 16 priority polycyclic aromatic hydrocarbons (PAHs) in sediments, water, and suspended particulate matter (SPM) in the water systems (rivers, lakes, and reservoirs) in the Hai River Basin through literature review. The sources and the ecosystem risks of PAHs in the sediments in the entire basin were specially discussed with diagnostic ration, PAHs composition, and an improved risk quotient method. Results showed that the total concentration of PAHs varied from 99.65 to 25,303 ng g dry weight in sediments, from 51.0 to 559.1 ng L in water, and from 4528 to 51,080 ng g dry weight in SPM, respectively. The dominant PAHs in the three examined phases were 2-3 rings in most waterbodies. PAHs in the rivers were from mixed sources (petrogenic and pyrolytic inputs), whereas those in lakes and reservoirs were mainly from biomass combustion and petroleum combustion. PAHs in the entire basin exhibited moderate to high ecological risk, and the rivers (especially Hai River, Jiyun River, Chaobai River, and Beiyun River) suffered higher ecological risk than reservoirs and lakes. Most of the rivers with higher PAHs risk flow through or around megacity Beijing and Tianjin. [ABSTRACT FROM AUTHOR]

The distribution, seasonal variations and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in water from three estuaries in Hai River Basin of China, which has been suffering from different anthropogenic pressures, were investigated. In three estuaries, the average concentration of ΣPAHs was the lowest in Luan River estuary, followed by Hai River estuary, and the highest in Zhangweixin River estuary. There were significant seasonal variations in ΣPAHs, the concentrations of ΣPAHs were higher in November than in May and August. The composition profiles of PAHs in different sites were significantly different, and illustrated seasonal variations. Generally, 2-ring (Nap) and 3-ring PAHs (Acp, Fl and Phe) were the most abundant components at most sampling sites in three estuaries. The PAHs in three estuaries were mainly originated from pyrogenic sources. A method based on toxic equivalency factors (TEFs) and risk quotient (RQ) was proposed to assess the ecological risk of ΣPAHs, with the ecological risk of individual PAHs being considered separately. The results showed that the ecological risks caused by ΣPAHs were high in Hai River estuary and Zhangweixin River estuary, and moderate in Luan River estuary. The mean values of ecological risk in August were lower than those in November. The contributions of individual PAHs to ecological risk were different in May, August and November. 3-ring and 4-ring PAHs accounted for much more ecological risk than 2-ring, 5-ring and 6-ring, although the contributions of 5-ring and 6-ring to ecological risk were higher than these to PAHs concentrations. [ABSTRACT FROM AUTHOR]

We investigate the influence of digital technology development on carbon emissions in the framework of spatial analysis. Using a sample of 283 prefecture-level cities in China, we find that digital technology development can positively influence carbon abatement through the "spillover effect", that is, it can not only reduce local carbon emissions, but also promote carbon abatement in the surrounding cities. The "siphon effect" which could negatively affect carbon abatement in the surrounding cities is outweighed by the "spillover effect". In addition, due to increasing information transmission costs and local protectionism, the "spillover effect" of digital technology development on carbon emissions has geographical boundaries. Although no economic boundary is found, there exists an optimal economic distance interval. Furthermore, the heterogeneous analysis shows that government intervention would reduce the carbon abatement effect of digital technology development. Compared with the eastern cities, this negative impact is more significant in the central and western cities of China. Our results suggest that governments could achieve the dual goals of digital technology development and carbon abatement by promoting regional cooperation, and reducing local protectionism and administrative divisions. [ABSTRACT FROM AUTHOR]

The pollution loads continuously increased in Haihe estuary, of Tianjin, China, due to intensive human activities, especially the construction of the Haihe Gate and Lingang Industrial Area. In 2011, hydrological variability in Haihe estuary was investigated and sediments were collected. Total organic carbon (TOC), particle size, total polycyclic aromatic hydrocarbons (ΣPAHs), heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn), and benthic diatom community were analyzed. The highest concentrations of ΣPAHs and heavy metals were found near the Haihe Gate. The Shannon diversity index and the relative abundance of Coscinodiscus perforatus (RC) indicated a decreasing trend seaward. Results of Pearson correlation analysis illustrated significant relations between water current velocity and ΣPAHs ( p < 0.01), Cr ( p < 0.05), and RC ( p < 0.05). Path analysis further indicated that water current played an important role in the distribution of PAH, Cr, and RC. [ABSTRACT FROM AUTHOR]

The variations and associations of abiotic and biotic variables in Baiyangdian Lake, China, were analyzed in situ. Abiotic variables included eleven water quality parameters, and were characterized by water quality index (WQI). Biotic variables included periphyton function and diversity metrics. WQI differed in different seasons at sampling sites and the highest value of WQI was observed in October 2009. Periphyton function metrics, expressed by extracellular enzyme activities of alkaline phosphatase, β-glucosidase and leucine aminopeptidase, gross primary productivity and daily respiration rate, and diversity indices, in terms of Shannon diversity index and Berger-Parker abundance index, showed significantly temporal and spatial variations. Regression linear analysis illustrated a fairly good correlation of WQI with periphyton function and diversity indices, Shannon diversity index was the best correlated with WQI (r = 0.904, P < 0.01), followed by leucine aminopeptidase (r = −0.847, P < 0.01) and Berger-Parker abundance index (r = −0.840, P < 0.01), alkaline phosphatase, β-glucosidase and gross primary productivity also showed a good inverse correlation with WQI. Redundancy analysis suggested that eleven environmental variables explained a significant amount of the variation in the periphyton community data. The study was helpful for us to understand chemical and ecological status of water quality, and give us messages for monitoring water quality accurately. [ABSTRACT FROM AUTHOR]

The Haihe River Basin is a semiarid water resources area of China. River ecosystem was degraded for high population density and intensive water resources development activities. To assist in the improvement of the ecological integrity of this river ecosystem, an environmental flow assessment model was developed that consider both spatial structure and dominant eco-function parameters. River ecosystem was divided into three sub-ecosystems which including river reach, wetland and estuary based on the spatial structure of river ecosystem. River reach was divided into three types which including habitat restoration type (HR), water quality restoration type (WQR) and vegetation restoration substitute water quantity restoration type (VRSWQR) according to their dominant eco-function. The spatio-temporal distribution of environmental flow (EF) for the river ecosystem in the Haihe River Basin was assessed based on the model. The results indicate that the EF for the river reach, wetland, and estuary are 2.267, 1.532, and 0.972 billion m, respectively. The EF for HR type of river reach, the WQR type of river reach and VRSWQR type of river reach are 1.140, 1.138, and 0.154 billion m, which are equal to 4.320, 4.312, and 0.584 % of the average annual flow of 26.39 billion m, respectively. EF for river ecosystem in wet period (June-September), normal period (October-January) and dry period (February-May) are 2.999, 0.951, and 0.821 billion m, respectively. Annual EF for river ecosystem of the Basin are 4.771 billion m, which accounts for 18 % of the average annual flows of 26.39 billion m. [ABSTRACT FROM AUTHOR]

Highlights: [•] A conceptual model for the plain river ecosystem function in semiarid area and interfered by intensive human activities was developed. [•] The gray system model was improved. [•] Main functions of plain river ecosystem and the corresponding factors that determine the plain river ecosystem function were proposed. [Copyright &y& Elsevier]

Highlights: [•] The application of the AQUATOX model was based on the pelagic and benthic foodweb. [•] Calibration, sensitivity analysis and ecological risk assessment were carried out. [•] The model can determine ecological protection levels of “chemicals of concern”. [Copyright &y& Elsevier]

Natural biofilms were simultaneously grown on glass, plexi-glass, glass fiber and activated carbon fiber for 60 days in a shallow Lake in Haihe basin. Biofilm production and abundance of algae were influenced by the substratum. Magnitude of the substratum effect was glass < plexi-glass < glass fiber < activated carbon fiber. The bacteria communities in biofilms of nature substrata were similar with the biofilms on plexi-glass and glass fiber after 60-day growing, as well as the ones on activated carbon fiber after 14-day growing. On basis of algological and bacteriological investigations, as well as literature data, the activated carbon fiber substratum is recommended for biomonitoring the lake in Haihe basin. [ABSTRACT FROM AUTHOR]

Abstract: This paper compares water resource management policies between China and Denmark at the planning level. It takes two vulnerable freshwater bodies as a case study: Baiyangdian wetland in China and Mariager fjord in Denmark. It explores the commons and differences between the two ecosystems from the characteristics of the ecosystems, historical and cultural background of the society, the technologies affect the way the common is used, how the common is seen at different times, the existence of property rights through time and their development process. It also compares the environmental regulations and its impact on both water bodies. The analysis shows that both in Denmark and in China it can be expected that goals, once they are decided, will be implemented. But in reality it seems to be much easier to accomplish in Denmark than in China, probably due to the complicated administrative structure in China and clearer goals and better resources in Denmark. Denmark has also accomplished a large degree of environmental policy integration (EPI). But China has opened up the gate to the whole world and shows a positive attitude to participating in international affairs and environmental protection as well as sustainability. [ABSTRACT FROM AUTHOR]

The relative risk model (RRM) was applied in regional ecological risk assessments successfully. In this study, the RRM was developed through increasing the data of risk source and introducing the source-stressor-habitat exposure filter (SSH), the endpoint-habitat exposure filter (EH) and the stressor-endpoint effect filter (SE) to reflect the meaning of exposure and effect more explicit. Water environment which include water quality, water quantity and aquatic ecosystems was selected as the ecological risk assessment endpoints. The Luanhe River Basin located in the North China was selected as model case. The results showed that there were three low risk regions, one medium risk region and two high risk regions in the Luanhe River Basin. The results also indicated habitat destruction was the largest stressor with the risk scores as high as 11.87 for the Luanhe water environment, the second was oxygen consuming organic pollutants (9.28) and the third was nutrients (7.78). So these three stressors were the main influencing factors of the ecological pressure in the study area. Furthermore, animal husbandry was the biggest source with the risk scores as high as 20.38, the second was domestic sewage (14.00), and the third was polluting industry (9.96). For habitats, waters and farmland were enduring the bigger pressure and should be taken considerable attention. Water deterioration and ecological service values damaged were facing the biggest risk pressure, and secondly was biodiversity decreased and landscape fragmentation. [ABSTRACT FROM AUTHOR]

The distribution of polycyclic aromatic hydrocarbons (PAH) was studied by determining the levels of 16 PAH in the water and sediment samples of the Luan River; a very important drinking water source for Tianjin and Tangshan in Hebei province, China. A total of 11 water samples and 11 sediment samples were collected in April 2008. The total PAH concentrations in water varied from 9.8 to 310 ng L-1, and those in surficial sediments ranged from not detected (ND) to 478 ng g-1 dry weight. The results showed that the upstream and downstream areas were low-polluted and high-polluted sites concentrated in the middle reaches of the river, respectively. The concentrations of PAH in rural areas (5 sites), which could be considered as the “background” levels, were lower than those near city zones (6 sites), which could be regarded as the “maximum” values. The PAH were dominated by 3- (38.4%) and 4-ring (60.7%) components in water samples and by 3- (27.4%), 4- (38.5%), and 5-ring (15.8%) compounds in sediments. High molecular weight PAH were inclined to be absorbed into sediments. The 3- and 4-ring PAH were the most common components in the Luan River. The molecular indices and the distribution of different rings were used to infer the sources of PAH, and the results suggested that anthropogenic heavy fuel combustion was likely to be the main source. The petroleum PAH had a high contribution to the PAH pollution at Baohekou and Daheiting. [ABSTRACT FROM AUTHOR]

Abstract: Sustainability is receiving increasing amounts of attention in higher education in terms of how it can best be integrated with university curricula. Sustainability is closely related to complexity, innovation, and interdisciplinarity; therefore, it requires alternative approaches rather than traditional, lecture-based pedagogy. This paper reports an educational initiative and research project based on collaboration between Beijing Normal University, China and Aalborg University, Denmark: developing a sustainability curriculum using the methodology of Problem and Project Based Learning (PBL) in a Chinese context. A theoretical framework is established to understand and analyze the culture's change toward a sustainability curriculum that employs PBL methodology. Empirical work is drawn upon first year results from the implementation of this methodology in an engineering and science curriculum. Data generation is based on multiple collection methods, such as survey of students' feedbacks, interviews with students, and analysis of students' project reports and reflection essays. This paper summarizes that a sustainability curriculum as proposed in this research can attract students' interests in not only mastering relevant knowledge, but also in developing necessary skills and competencies. PBL as a teaching and learning method can successfully facilitate participative learning, critical reflection, systemic thinking, creativity, and cultural awareness, which are the core values of sustainability. However, implementing a new curriculum with new teaching and learning methods can be more complex than expected. Many issues impact the implementation process and are therefore remain challenges to further development; for example, how to change the existing grading system, how to provide both teaching staff and students' with prior knowledge about the new PBL methods, how to gain institutional support, and how to change the broader societal and cultural values. [Copyright &y& Elsevier]

Climate change profoundly influences the geospatial distribution of secondary metabolites and causes the geographical migration of plants. We planted seedlings of the same species in eighteen ecological regions along a latitudinal gradient in eastern and western China, in order to explore the regulation of multi-climatic factors on active ingredient accumulation in Salvia miltiorrhiza Bunge. The correlations between six active ingredient contents and ten climatic factors were investigated to clarify their relationships. We found that climatic factors not only regulated active ingredient contents but also markedly influenced their composition and led to a specific geospatial distribution of these active ingredients in China. The main climatic factors include the air temperature, precipitation, atmospheric vapour pressure and sunshine duration. Future warming in high-latitude regions could cause continued northward expansion of planting areas suitable for S. miltiorrhiza. The effect of extreme climatic conditions on active ingredients should not be overlooked. The findings of this study can help farmers scientifically choose suitable cultivation regions in the future. Furthermore, this study provides an innovative idea for the exploration of secondary metabolic responses to changing ecological factors in medicinal plants.

Phthalate esters (PAEs) are widely used in the manufacturing of plastics, and the demand for PAEs has grown rapidly, especially in China. This trend will lead to much more environmental PAE contamination. PAEs are listed as priority substances in the European Union and are therefore subject to ecological risk assessments. This paper reviews the literature concerning the pollution status of PAEs and their ecological risk to aquatic environments. Risk quotients (RQs) based on the predicted no effect concentration and PAE concentrations in aquatic environments demonstrated significant (10 ≤ RQ < 100) or expected (RQ ≥ 100) potential adverse effects for algae, Daphnia, and fish in aquatic environments near PAE-based industrial and urban areas. Thus, the ecological risk of PAEs in Chinese aquatic environments should be considered, especially in areas where commercial plastics are produced.

Heavy metals may adversely affect the structure and function of the periphyton community in lake ecosystems. We carried out samplings of three habitats at eight sites located in the Lake Baiyangdian that is strongly influenced by wastewater discharge (Sites 1 and 2), aquaculture and densely populated villages (Sites 3, 6, and 8), and the least disturbed (Sites 4, 5, and 7). Cu, Ni, Pb, Zn, Hg, Cd, and Cr were determined in these samples, and the periphyton community was simultaneously studied. The contamination factor (C f (i) ) was estimated for every metal as the ratio between pre-industrial records from sediments (C n (i) ) and present concentration values (C (i) ), and the individual potential risk (E r (i) ) was calculated by multiply the toxic response factor (Tr (i) ) and C f (i) for a given substance were based on Hakanson's methodology. The RI was obtained for each sampling site by summing the values of E r (i) first and the average was calculated across the sampling sites. The results showed that the RI for all three habitats was lower than 94, and they are in decreasing order: wastewater discharge, aquaculture and densely populated villages, and the least anthropogenic impacted. When the three sampling seasons were compared, August appeared to show the highest risk, followed by April and November. The RI values showed negative correlations (r = -0.444 to -0.851, p < 0.05) with the structural and functional metrics. The best correlation was detected between chlorophyll c/chlorophyll a (Chl c/a) ratio and E r (i) Hg (r = -0.851, p < 0.01). Our results suggest the periphyton community can be used in bio-monitoring.

The temporal and spatial environmental flow requirements (EFRs) for the river ecosystem of the Haihe River Basin were analyzed based mainly on the eco-functional regionalization of available water resources. The annual EFRs for the river ecosystem of the Haihe River Basin were 47.71 × 10(8) m(3), which accounted for 18% of the average annual flow (263.9 × 10(8) m(3)). The EFRs for river reaches, wetlands, and estuaries were 22.67, 15.32 and 9.72 × 10(8) m(3), respectively. Moreover, the EFRs for the river ecosystem during the wet (June to October), normal (April, May, November), and dry (December to March) periods were 29.99, 9.51 and 8.21 × 10(8) m(3), respectively. Thus, toward a more integrated water resource allocation in the Haihe River Basin, the primary effort should focus on meeting the EFRs for river systems located in protected areas during the dry period.

Ecological risk assessment for water environment is significant to water resource management of basin. Effective environmental management and systems restoration such as the Haihe River Basin require holistic understanding of the relative importance of various stressor-related impacts throughout the basin. As an effective technical tool for evaluating the ecological risk, relative risk model (RRM) was applied in regional scale successfully. In this study, the risk transfer from upstream of basin was considered and the RRM was developed through introducing the source-stressor-habitat exposure filter (SSH), the endpoint-habitat exposure filter (EH) and the stressor-endpoint effect filter (SE) to reflect the meaning of exposure and effect more explicit. Water environment which includes water quality, water quantity and aquatic ecosystems was selected as the assessment endpoints. We created a conceptual model which depicting potential and effect pathways from source to stressor to habitat to endpoint. The Haihe River Basin estuary (HRBE) was selected as the model case. The results showed that there were two low risk regions, one medium risk region and two high risk regions in the HRBE. The results also indicated that urbanization was the biggest source, the second was shipping and the third was industry, their risk scores are 5.65, 4.71 and 3.68 respectively. Furthermore, habitat destruction was the largest stressor with the risk scores (2.66), the second was oxygen consuming organic pollutants (1.75) and the third was pathogens (1.75). So these three stressors were the main influencing factors of the ecological pressure in the study area. For habitats, open waters (9.59) and intertidal mudflat were enduring the bigger pressure and should be taken considerable attention. Ecological service values damaged (30.54) and biodiversity decreased were facing the biggest risk pressure., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Although there are many studies of heavy metal contaminations of sediments, attention has seldom been paid to the problem in developing countries. The purpose of this article is to find the distribution and ecological risk of As, Hg, Cr, Cd, Pb, Cu, and Zn in surface sediment of Baiyangdian which is the biggest wetland in Northeast China. We apply three methodologies. The first is literature analysis comparing total concentrations of heavy metals with other water bodies around world. The second is Chinese Environmental Quality Standard for Soils (EQSS), National Environmental Protection Agency of China 1995, and the third is Soil and Aquatic Sediment Guidelines and Standards issued by New York Department of Environmental Conservation (NYSDEC). The results show that compared to other water bodies around the world, the seven heavy metals are low. However, Cd was found in the most polluting level of EQSS near a village and was second grade some distance from it. The village was also the most polluted site of Zn, which was in the second grade. When assessed by NYSDEC, Cu, Cr, and As contaminated the sediment and with moderate impacts on benthic life while Pb, Hg, and Zn were found at tolerable levels throughout Baiyangdian. The centre of Cu and Cr contamination was also near the village. As is the most polluting heavy metals with a major occurrence in the middle of the wetland. There were no heavy metals creating severe disturbance to the benthic communities. Based on the assessment, this article proposes different options for more sustainable management.

The structural and functional attributes of biofilms from Lake Baiyangdian, China, were tested to evaluate the utility of biofilms as indicators of macrophyte-dominated lake health. Biofilms on artificial substrata were sampled at 8 sites in the lake during different seasons. The responses of biofilms to land use and water quality changes were analyzed. The biofilm structural and functional attributes fluctuated seasonally. All attributes we tested differed significantly with different land use. Generally, biomass and enzyme activities increased, whereas chl c/a decreased with human disturbance. Attributes were strongly correlated to environmental variables, especially the trophic status of the lake. Overall, biofilms were good indicators of macrophyte-dominated lake health. The proportions of Bacillariophyta and Cyanophyta, Chlorophyll-a, b, chlorophyll-b/a, chlorophyll-c/a, algal density, β-glucosidase, aminopeptidase and ash-free dry weight of biofilms are recommended as tools for assessing responses to land use changes, and for monitoring the effectiveness of ecosystem rehabilitation.

The objectives of this study were to investigate the contamination levels and dispersion patterns of heavy metals and polycyclic aromatic hydrocarbons (PAHs) and to estimate the risk to health effects within the Luanhe river basin of northern Hebei Province, China. Samples of water were collected from upstream to downstream locations, and also from the main tributaries of Luanhe river. After appropriate preparation, all samples were analyzed for eight metals (As, Hg, Cd, Cr, Pb, Cu, Zn, and Fe) and 16 PAHs. Mean concentrations of As, Cd, Cu, and Zn were within the permissible levels, but Hg, Pb, and Fe concentrations were exceeded at some sites. The results indicated that the metal levels of upriver sites were higher than lower river sites; the metal levels of the main river were higher than ones of the tributaries except for Goutaizi at Xiaoluanhe. Only seven out 16 PAH components, which were mostly three- to four-ring compounds, were detected. Predominance of three- to four-ring PAHs suggests relatively recent local sources of PAHs in the study area. The combined hazard index for all metals and PAHs was from 2.26E - 02 to 1.18E - 01, which was lower than 1, suggesting minimal risk to humans. Only Arsenic (As) was evaluated with potential carcinogenic risks of 7.27E - 06 to 2.50E - 05. The study represents the preliminary implementation of a well-defined methodology into the environmental management process and provides a scientific basis for the pollutant controlment order.

Evaluating six main rivers and six lakes in Beihuan water system (BWS) and diagnosing the limiting factors of eco-health were conducted for the ecohealth assessment and ecological restoration division of urban water system (UWS) for Beijing. The results indicated that Jingmi River and Nanchang River were in a healthy state, the degree of membership to unhealthy were 0.358, 0.392, respectively; while Yongding River, Beihucheng River, Liangma River, Tongzi River and six lakes were in an unhealthy state, their degree of membership to unhealthy were between 0.459 and 0.927. The order of that was Liangma > Beihucheng > Tongzi > Yongding > six lakes > Jingmi > Nanchang, in which Liangma Rivers of that was over 0.8. The problems of Rivers and lakes in BWS are different. Jingmi River and Nanchang River were ecotype limiting; Yongding River, Tongzi River and six lakes were water quality and ecotype limiting. Beihucheng River and Liangma River were water quantity, water quality and ecotype limiting. BWS could be divided into 3 restoration divisions, pollution control division including Yongding River, Tongzi River and six lakes; Jingmi River and Nanchang River were ecological restoration zone, while Beihucheng River and Liangma River were in comprehensive improvement zone. Restoration potentiality of Jingmi River and Nanchang River were higher, and Liangma River was hardest to restore. The results suggest a new idea to evaluate the impact of human and environmental factors on UWS.

Distribution and characteristics of heavy metals enrichment in sediment were surveyed including the bio-available form analyzed for assessment of the Luan River source water quality. The approaches of sediment quality guidelines (SQG), risk assessment code and Hakanson potential ecological risk index were used for the ecological risk assessment. According to SQG, The results show that in animal bodies, Hg at the sampling site of Wuliehexia was 1.39 mg/kg, Cr at Sandaohezi was 152.37 mg/kg and Cu at Hanjiaying was 178.61 mg/kg exceeding the severe effect screening level. There were 90% of sampling sites of Cr and Pb and 50% sites of Cu exceeded the lowest effect screening level. At Boluonuo and Wuliehexia, the exchangeable and carbonate fractions for above 50% of sites were at high risk levels and that for above 30% of sites at Xiahenan and Wulieheshang were also at high risk levels. Other sites were at medium risk level. Compared to soil background values of China, Hg and Cd showed very strong ecological risk, and the seven heavy metals of Hg, Cd, Cu, As, Pb, Cr, Zn at ecological risk levels were in the descending order. The results could give insight into risk assessment of environmental pollution and decision-making for water source security.