The Yangtze River Economic Belt is becoming a national strategy and the Yangtze River Economic Belt will become the economic backbone of China. Nanjing metropolitan area is an important member of the Yangtze River Economic Belt. Nanjing metropolitan area is the fringe of the Yangtze River Delta city group and Wanjiang City Belt. The development of Wanjiang City Belt depends on Nanjing metropolitan area to be in line with the Yangtze River Delta city group actively, so the development of Nanjing metropolitan area is of great importance. Nanjing metropolitan area includes eight cities, and they are Nanjing, Yangzhou, Zhenjiang, Huaian, Maanshan, Wuhu, Chaohu and Chuzhou. Taking the Nanjing metropolitan area as an example and choosing four typical years of 1993, 1995, 2005 and 2011, the article uses the Spatial Analyst function of ArcGIS and gravitymodel to calculate the accessibility and economic linkage and the regional economic linkage gradation of Nanjing metropolitan area. Then the article studies the evolution of the regional economic linkage pattern and the maximum economic linkage direction of each city in Nanjing metropolitan area. Results are shown as follows.（1）The accessibility of Nanjing metropolitan area is improved evidently, and the average accessibility of Nanjing metropolitan area is improved obviously, too. But the increase amount of accessibility of each city is different.（2）The economic linkage of Nanjing metropolitan area is strengthening increasingly. The economic linkage pattern of Nanjing metropolitan area is changed from point axis pattern to network pattern and Nanjing is becoming the center city of the regional economic linkage of Nanjing metropolitan area.（3）Studying from the regional economic linkage gradation, Nanjing is the spatial linkage agglomeration center of Nanjing metropolitan area. The economic linkage pattern of Nanjing metropolitan area is around Nanjing. Nanjing is just like the moon and other cities are like the stars

Hightech industry represents a countrys scientific and technological strength and promotes the economic development, which has brought to the attention of the countries and regions. This paper introduces a measure of the development level of hightech industry and analyzes the changes of provincial hightech industry development level between 2000 and 2010. The results show as follows. (1)The gap of development level on temporal evolution analysis of Chinese hightech industry continuously extends during two periods of 2000-2005 and 2005-2010. Data shows that the provinces staying in a high level have the more rapid development speed than that in low level, and provinces which keep in the high level are the real driving force of development of high tech industry in China. Although the overall level of provincial hightech industrial development is constantly moving forward, the differences between regions continue to expand and the phenomenon of the strong being stronger and the weak being weaker namely “Matthew Effect” gradually emerges. (2)The provinces development index of which stay at the higher level and a high level mainly concentrate in the eastern coastal province. Low level provinces except the Shaanxi are increasing, of which the agglomeration trends to the central and western regions. The geographical scope is expanding, it has strong spatial correlation and exists “club convergence” phenomenon. (3)Basic factors, economic factors, policy factors and other traditional factors on the early period of hightech industry development play the apparent role in promoting the development level. With the industrial development to a higher level and the gradual improvement of the policy environment, the effect of traditional factors is gradually flattening. However, the influence of gathering, human capital and other new emerging factors on hightech industries continue to strengthen and the role of location factors has been evident, which coincides the development characteristics of hightech industry.

With the rapid development of economy, most watershed ecosystems have suffered serious human disturbance, leading to the severe degradation of ecosystem services and loss of species diversity. The Qingyi River, located in the south of Anhui Province, is the largest tributary of the lower Yangtze River. In order to fully understand the present status of macrozoobenthos community in the Qingyi River basin, a field investigation was conducted in different order streams in August 2013. The results showed that total species number was 60, belonging to 39 families and 58 genera. From first to fourth order streams, the species number decreased gradually, and was 46, 39, 36 and 16, respectively. The dominant group was aquatic insects in first to third order streams, and molluscs in fourth order stream. The density and biomass of macrozoobenthos in the Qingyi River basin was 382 ind./m2 and 3643 g/m2, respectively. The density was highest in second order stream, and lowest in fourth order stream. The biomass of second and fourth order streams was significantly higher than that of the first order stream. In terms of functional feeding groups, scrapers and collectorfilterers dominated the Qingyi River basin. Relative density and relative biomass of scrapers firstly increased and then decreased with the increase of stream order; shredders had high proportion in the first and second order streams, while the collectorgatherers and collectorfilters had high proportion in the first and fourth order streams

It is important for the research of landscape as it is one of the most basic elements of the natural environment and its control over the differentiation of natural environment， There are still certain onesidedness and subjectivity for the traditional landscape classification due to the use of single or fixed terrain factor analysis. To overcome this problem， we carried out an autoclassification of landform test in the Three Gorges Reservoir Area. This region is lying on the lower section of the upper reaches of the Yangtze River. There are serious soil erosion and heavy landslide， collapse and debris flow here. Firstly， we took a statistics on the relief amplitude values in different analyzing grids (3×3，5×5 …… 39×39， 41×41) based on SRTM DEM using Arcgis93， then the method of mean of changepoint analysis was used to extract the optimum statistical unit of the relief amplitude. The calculated result is that the optimal analyzing grid is 17×17， about 234 km2 for the Three Gorges Reservoir Area, but this result may be lower than the true value. Through the comparison and analysis with former study, it proved that the optimal area of analyzing grid decreased with the increase of DEM resolution. Secondly， The method of correlation matrix and Sheffield entropy were used to get the optimal topography feature which contain the elevation， range， slope， accumulation curvature， slope of slope， height variation coefficient. Whether this optimal topography feature could be used elsewhere still need to be studied. Lastly， a multispectral remote sensing image was constructed with the red band of elevation， green band of range and blue band of slope. ISODATA unsupervised classification was applied to get the distribution of 8 kinds of geomorphic types in this region automatically. The western and the eastern region is given priority to with plains and low hills. The Dabashan mountain is under the intense river cut in northeast area with mainly mountain landscape， the Wushan and Daloushan are featured with middle mountain and low mountain effected by the development of karst landform and water erosion， the geomorphological process of middle part is relatively strong and characterized by the alternative distribution of middle hills and high hills. The landform classification is consistent with the actual landscape distribution. And there is a significant correlation between the distribution of city and morphology. This method of autoclassification of landforms could provide references for resource development， soil and water loss， land use research in the Three Gorges Reservoir Area

The Three Gorges Project is the largest construction project in China, with tremendous economic and social benefits in flood control, power generation, navigation and other aspects. However, the use of the Three Gorges Project will inevitably have some impacts on the original hydrological situation of rivers and lakes. This research quantitatively analyzed the water level impact of the use of the Three Gorges Project on the Poyang Lake by establishing water and sediment simulation models of the middle and down stream of the Yangtze River (Yichang to Datong segment). The results showed that, during the impoundment of the Three Gorges Reservoir (mid to late September to November), the discharge flow reduced 3 000-6 000 m3/s than before. The biggest drop of water level around the Poyang Lake was between 07 m and 19 m, and the average was between 04 m and 09 m. On this basis, the impacts of the impoundment of the Three Gorges Reservoir on farmland irrigation and urban water supply of the Poyang Lake area were analyzed through the typical investigation and analysis. For farmland irrigation impact, the loss around the Poyang Lake area by the impoundment of the Three Gorges Reservoir was estimated to 01 billion Yuan per year. For urban water supply, about 15 million urban populations were affected by the impoundment of the Three Gorges Reservoir, and about 270 million m3 water supplies was affected, affecting time was about 30 days. The countermeasures to eliminate or reduce the impacts were also proposed in this paper. The results can provide scientific basis and technical support for economic and social sustainable development of the middle and down stream regions of the Yangtze River and integrated management of the Poyang Lake

In order to better understand the significances of river corridors in urban landscape ecology, the spatial clustering characteristics of landscape type diversity and landscape pattern of Qionglai city were calculated. Results showed as follows. (1) The local spatial autocorrelation index GetisOrd Gi* displayed that high value clustering areas of the landscape type diversity scattered all over the study area, which accounted for 506% of the total area of Qionglai city. The distribution of the hot spot areas was similar to the spatial pattern of the rivers. (2) The buffer area of the river corridors were mainly farmland and forests, and the average patch area of forests was larger. While the buffer area of the road corridors were mainly the farmland and building land, and the overall landscape was more fragmentized. River corridors were more directly adjacent to farmland and forests, while the road corridors were more directly adjacent to farmland and building land. (3) The terrain factor impacted on the landscape pattern in mountainous areas of the west region of Qionglai, where the hot spot areas of landscape type diversity scattered mainly in river terraces. Thus, the city river corridors play a positive role in the landscape diversity of Qionglai. Protecting the landscape diversity of river corridors and strengthening the connectivity of the river and forest, are the main means to protect the ecological functions of river corridors in Qionglai

With more and more studies focusing on the agricultural nonpoint source pollution (ANSP) in the Three Gorges Reservoir area(TGRA), promotion the applicability of these relevant research results is of great significant for the regional ecological environment protection. However, the key in this process is to make a comprehensive survey for the various typical areas of the ANSP in TGRA and their spatial distribution patterns. This can not only make full use of the related research resources, such as research data or results about the ANSP in the TGRA, but also can guide the control managements and policy orientations about ANSP in the TGRA. To these ends, we first screened out the key factors, namely soil type, land use type, and the soil erosion intensity, that can mainly affect the ANSP and prepared their corresponding spatial data in the TGRA. After then, 24 different types of regions of ANSP in TGRA, were mapped by using the GIS spatial analysis (i.e., overlay analysis) of the prepared data in the TGRA. In order to find out the type region of ANSP in TRGA, 8 types of region were selected from these 24 types under the hypothesis that the typical region generally has large area. Each of these 8 mapped typical regions was further fully analyzed from the spatial distribution pattern point of view, and it was found that these patterns are more decided by the soil type than the other two factors. Based on this fact, the 8 typical regions were then can be grouped in 3 categories, namely “purple soildrylandforestpaddy field” typical region, “yellow soildrylandforest” typical region, and “limestone soilforest” typical region.Finally, the typicality of the numerous study areas which have been selected and studied in the previous researches about the ANSP in the TGRA, were used to evaluate the research status of the typical regions. It was found that the “purple soildrylandforestpaddy field” typical region has been heavily considered, and the spatial distribution of these study areas in this region is reasonable. Moreover, although the “yellow soildrylandforest” typical region has been certainly concerned, it is still unable to meet the application requirements on the entire reservoir scale. Nevertheless, as there was seldom studies focused on the ANSP in the “limestone soilforest” typical region, it is suggested that more works should be put forward on this type region. Meanwhile, the maps of different classes of typical regions of ANSP in the TGRA can provide a basis for decision making in the study area selection in the future. Although this study is mainly focused on the typical region of ANSP in the TGRA, the method used in this paper can be further applied to other regions

The backwater of the the Pengxi River was a typical region to study the effect of water hydrology on the chlorophylla (Chla) content. The computed area was 535 km of the Pengxi River reach range from the river estuary to Qukou section in Yunyang city and the Yangtze River reach of 68 km in Shuangjiang city. Currently there are three methods to study the effect of water hydrology on the Chla content: laboratory research, field monitoring study and ecological dynamics model simulation. In this paper, the verified ecological dynamics model was used to simulate CODMn, TN, TP concentrations and Chla content. The average permanganate index (CODMn), total nitrogen (TN), total phosphorus (TP) concentrations and Chla content along the Pengxi River were on two design conditions: 1) 175 m high water level with low flow and low pollutant load; 2) 145 m low level with high flow and high pollutant load. The low pollutant loads of CODMn, TN, TP were 1028 t/d, 206 t/d and 039 t/d, respectively, while the high pollutant loads of CODMn, TN, TP were 7795 t/d, 3096 t/d and 578 t/d respectively. The computed results showed that the ranges of CODMn, TN, TP concentrations and Chla content in the backwater of the Pengxi River were 137-160 mg/L, 055-080 mg/L, 0035-0050 mg/L and 032-096 μg/L on the design condition 1, and 567-680 mg/L, 302-408 mg/L, 0131-0240 mg/L and 1060-3213 μg/L on the design condition 2, respectively. CODMn, TN, TP concentrations from upstream to downstream tended to increase, and the water quality at the estuary trended toward the Yangtze water quality. In the period of 145 m low water level with large flow and high pollutant load, the Chla content was high. In the curve or wide surface sections such as Gaoyang or Shuangjiang Bridge, the flow rate was slow and Chla content was high. The correlation of flow rate (V) and Chla content (S) was fitted under the two design conditions. The equations were S=0186 0·V-0353 6(related coefficient r2=0838 0) and S=10844 9·V-0293 9(related coefficient r2=0838 0) respectively. The simulated results showed that the increase of flow rate tended to keep down the Chla content. Under the conditions of low flow with 175 m high water level, the pollutant load was low, average water temperature was 80℃, total solar radiation was 517 J/(cm2〖DK〗·d), and average sunshine hours were 20 h/d. The Chla content increased quickly when the flow rate was lower than 001 m/s, and the Chla content tended to be stable when the flow rate was higher than 010 m/s. Under the conditions of high flow with 145 m low water level, the pollutant load was high, average water temperature was 200℃, total solar radiation was 1 464 J/(cm2〖DK〗·d), and average sunshine hours were 58 h/d. Chla content increased quickly when the flow rate was lower than 005 m/s, and Chla content tended to be stable when the flow rate was higher than 040 m/s. This study suggested that 005 m/s was the critical flow rate of Chla content change in the Pengxi backwater under the appropriate environmental conditions. The simulated results showed that it was feasible to control Chla content through regulating hydrodynamic conditions

Land Use and Cover Change (LUCC) have become the focus of global environmental changes research in 21st century. LUCC caused variations of geographical processes and surface landscape structures, greatly impacting on nutrient biogeochemical cycles and material transport, and produced a series of water environmental and ecological problems. Surface water and soil issues caused by LUCC in intensified agricultural area have attracted the attention of researchers from home and abroad. Agricultural land changes refer to changes of agricultural land use patterns, intensity and types, such as returning cropland to forest/grassland or lakes, abandoned cultivation, changing cultivated land to construction land, farming intensities variation, etc. Taihu region of Jiangsu Province is an important commodity grain base and one of the most intensified land use area in China. During the past 60 years, great changes have taken place in farming systems in the Taihu region under human pressure. Surface water and soil environment in this region deteriorated simultaneously. Based on the method of historical documents investigation, the authors analyzed the characteristics of farming systems and explored the impacts of farming systems changes on surface soil and water environment in Taihu region of Jiangsu Province over past 60 years. It shows that planting area of food crops, such as rice, wheat and corn, decreased annually, while that of economic crops changed relatively stably. Crops depleting soil fertility, such as vegetables, increased, while those improving soil fertility, such as green manure crops, decreased significantly. This led to excessive dependence on chemical fertilizer application. After a long period of screening, crop varieties experienced continuous selections and renewal. Fertilizer types and fertilization intensity changed a lot over past 60 years. The traditional method of manure collection and application was taken place by the application of chemical fertilizer gradually. The ratio of N, P and K in chemical fertilizer was imbalanced for a long time, and it gradually tended to be balanced in recent years. Excessive chemical fertilizer application increased the risks of soil N loss to surface water environment. While since 2000, the decrease of chemical N fertilizer application did not alleviate N pollution in rivers and Lake Tai at the Taihu region, which indicated that impacting factors of surface water environment has changed. Besides agricultural N loss, there are many other sources, such as urban and rural domestic wastewater discharge, rural human and animal waste, industrial wastewater discharge and feed input in aquaculture industry. To reveal quantitatively the contributions of different pollutant sources in lakes, great efforts must be done to monitoring and modeling different pollutant sources comprehensively

Regions along the Yangtze River in Shanghai are the main distribution area of tidal marshes in China. The ecosystem health has significant meaning for ecological safety in Shanghai and even the Yangtze River Delta. Ecosystem health assessment was accomplished through establishment of index system of PSR (PressureStateResponse) and entropy fuzzy comprehensive evaluation model, and the quality grading standards was worked out. It is divided into illness, general illness, subhealth, lesshealth and health. Results showed that Hangzhou bay beach, Nanhui beach, Pudong beach, Baoshan beach, Changxing beach, Hengsha beach, Chongming South beach and Chongming North beach were in the state of subhealth, Chongming West beach was in lesshealthy state, the comprehensive health index of Chongming Dongtan and Jiuduansha were in the state of health. Peripheral islands beaches were generally healthier than mainland beaches. Comprehensive health degree was a comprehensive reflection of three mutually causal relationships between pressure health index, state health index and response health index. Pressure health index of the mainland beaches was lower than that of the peripheral island, and state health index of Jiuduansha and Chongming Dongtan was higher, and response health index of Chongming Dongtan and Jiuduansha was also higher than the others. Investigation and analysis results showed that the environment of tidal marshes was under main stresses including highintensity enclosure, environmental pollution and biological invasion. Tidal marshes area was reduced, community structure was changed and ecological function was degraded under multiplestress for nearly 30 years. In order to maintain ecosystem health and ecological security, combination of dynamic protection and utilization should be used on tidal marshes conservation management. Controlling development intensity and pollutant emission, strengthening the protection of tidal marshes especially mainland beach should to be key focus. Given that reducing the beach area is not due to human factors as a baseline, the legal system building should be strengthened as well as the efforts to recover tidal marshes ecosystem. Beyond that, promoting the control and management of invasive species can relieve the stress to the maximum extent

In order to understand the pollution characteristics of heavy metals in sediments of the Lake Dishui，eighteen sediment samples were collected in December 2012 at the Dishui Lake and its surrounding areas. The concentrations of Hg, As, Cu, Cd, Pb, Zn, Cr in the sediments were analyzed and the pollution statue of heavy metals in the sediments was evaluated using geoaccumulation index and potential ecological risk index. Principal component analysis was applied to identify their sources. The results showed that the concentrations of Hg, As, Cu, Cd, Pb, Zn, Cr in sediments of the Dishui Lake were 005-028，037-593，808-2638，013-025，1136-1766，5692-9743，6730-10718 mg/kg，respectively. The As and Pb concentrations were inferior to their background values in intertidal sediments of Shanghai，but the Hg, Cd, Zn and Cr concentrations were exceeded the background values，the Cu concentrations of 50% sediment samples were exceeded the background values. Compared with domestic and international lakes，the level of heavy metals in sediments at the Dishui Lake was under Macquarie and the Dongting Lake，but corresponding to the Nansi Lake. The spatial distribution of heavy metals in sediments had certain regularity. The heavy metal concentrations in sediments from the lake were less than those from the river and estuary，which indicated the heavy metals did not have an obvious precipitating in the lake land. Pearson correlation analysis showed that TOC was the main factors influencing the spatial distribution of heavy metals in sediments，and particle size influenced the spatial distribution of Cu and Cd in sediments. The results of geoaccumulation index showed that the Dishui lake was mainly polluted by Hg, Cd, zinc and Cr，the pollution extent of Cr was partial moderate pollution，Hg, Cd and Zn were light pollution，As, Cu and Pb were unpolluted. Based on the potential ecological risk assessment results，the mean RI value can be ordered from high to low as Shanghai Maritim University > Intertidal sediments > Lake outlet > Estuary > Dishui Lake. The heavy metals in sediments of the Dishui Lake belonged to the moderate ecological risk. Hg and Cd was the main contribution of the potential ecological risk elements，accounting for 58.73% and 30.89%，respectively, while As, Cu, Pb, Zn and Cr accounted for 10.38%. The principal component analysis revealed that Hg, Cu, Cd, Pb, Zn and Cr mainly came from the anthropogenic sources，Cr was also affected by the chemical composition of the earth，but As mainly came from the initial tidal flat sediment

The reconstruction of heavy metals record in coastal sediment core can improve the acknowledgement on the history of their usage/emissions in the coastal areas and the related river basins. In recent years,more and more reports have indicated the gradually increased emissions of various heavy metals into the shelf seas in China. However, the emission and accumulation history of multiple heavy metals have been less referred. In the present work, the contents of heavy metals (such as V, Cr, Zn, Ni, Cu, Co, As, Pb, Hg and Cd) from two sedimentary cores of DH33 and KP04 in the inner shelf of the East China Sea have been measured for studying their history records and then evaluating their ecological risks in the past. The Pearson correlations between these heavy metals have been used for evaluating their accumulation process and the influencing factors. Also the ecological risks have been performed by using potential ecological risk index during the last 100 years. Our results showed that the contents of V, Cr, Zn, Ni, Cu, Co, As, Pb, Hg and Cd in DH33 were 6669±582, 4872±369, 5688±372, 2682±134, 780±076, 1265±063, 399±025, 1277±091, 0042±0008 and 0069±0005 mg/kg respectively, while they were 6658±160, 4937±345, 8562±636, 2990±160, 1171±076, 1345±103, 767±102, 1904±110, 0044±0004 and 0007±0004 mg/kg respectively in KP04. By comparing with the interannual runoff variation of the Yangtze River, it was found that the accumulative process was strongly correlated with the annual runoff of the Yangtze River. The contents of these heavy metals except Cd in core KP04, which is farther away from the Yangtze Delta and the coastline, were higher than those in DH33. The results were in conflict with the geological locations and the “granularity law”. This could be attributed to the different accumulation process or controlling factors in the two sea regions. The contents of heavy metals in core DH33 were mainly controlled by the Yangtze River runoff, with higher accumulations in larger runoff years. In core KP04, their accumulations of these heavy metals were controlled by the provenance supply and the sedimentation rate, with Taiwan Warm Current as another important provenance source. Significant correlations between V, Cr and Ni have been observed, suggested their possible origin and accumulation mechanism. The poor correlations of As, Hg and Cd with other metals suggested their different origins and accumulation process in marine settings. The evaluation on the ecological risk showed that there was only “moderately polluted” by Hg, Cd and As in KP04 and it happened in 1990s and 1930s. Comparing with the deltas and coastal areas, the overall ecological risks of heavy metals were at lower levels in the inner shelf. The potential risks of Hg, Cd and As still needed to be concerned because of their bioaccumulations along the food chain

This paper aims to investigate the climatic and anthropogenic impacts on the Yangtze River water discharge over the last six decades. We analyzed the time series of annual temperature, precipitation, evaporation and water discharge, employing the means of MannKendall and regression methods, in combination with data of reservoir construction, water consuming, and water and soil conservation. The results are as follows. (1) From 1956 to 2011, the catchmentaveraged annual temperature significantly increased, at a rate greater than the level of global average. (2) No significant trend was found for the catchmentaveraged annual precipitation, and therefore the annual precipitation was not well related to the annual temperature. (3) No significant trend was found for the catchmentwide actual evaporation (i.e. the difference between precipitation and runoff), although a significant decreasing trend was found for the catchmentwide annual pan evaporation. (4) Interannual changes in annual precipitation and water discharge were frequent and significant. For the whole Yangtze River Basin, the maximum annual precipitation was 1.4 times greater than the minimum annual precipitation, and the maximum annual discharge was 1.9 times greater than the minimum annual discharge. The correlation between annual precipitation and water discharge was very significant (R2 = 0.78). (5) No statistically significant trend was found for the annual water discharge of the Yangtze River, although the water discharge decreased by 3% from the initial decade (1956-1965) to the recent decade (2002-2011). (6) Spatial changes in climatic and anthropogenic impacts on water discharge were found within the Yangtze River Basin. A significant decreasing trend in annual water discharge was found for the North Area (Minjiang, Jialingjiang and Hanjiang tributaries), and a significant increasing trend in annual water discharge was found for the Centre Area (the “ungauged area” along the main river below the Jinshajiang), whereas no significance was found for the other subareas. Compared with the initial decade, the water discharge of the recent decade decreased by 14% in the North Area and decreased by 4% in the West Area, whereas it increased by 7% in the Central Area. The significant decreasing trend in water discharge in the North Area was attributable mainly to human activities (e.g. watersoil conservation projects and reservoir construction). On the other hand, the significant increasing trend in water discharge in the Centre Area was most probably due to the decrease in evaporation which was presumed attributed to decreases in net solar radiation and wind speed. These two aspects of influencing factors, anthropogenic and climatic, have opposite effect on actual evaporation, and therefore offset each other in affecting the whole Yangtze River water discharge. This study suggests that anthropogenic and climatic impacts on water discharge, even though they could be separately significant, could cancel each other in some rivers and during some periods. We predict that human activities will be the dominant factor influencing the water discharge in the Yangtze River in the coming decades. Under the influences of the South to North Water Diversion, construction of new reservoirs, increasing water consuming and watersoil conservation, the decadal water discharge will probably decrease by 10% by the end of this century, compared with the present level

The distribution of polycyclic aromatic hydrocarbons (PAHs) was studied by determining the levels of 16 PAHs in water samples of the Jiulong River, a very important drinking water source for Fujian and Longyan, China. Samples of surface water were collected from the Jiulong River in November 2011, January 2012, and March 2012, and polycyclic aromatic hydrocarbons (PAHs) were analyzed with constantenergy synchronous fluorimetric method in the present study. The results showed that the total concentrations of PAHs in water ranged from 9.9 to 178.8 ng/L. The PAHs were dominated by 3-ring (56.7%), 5-ring (24.6%) and 4-ring (15.1%) components in water samples.The 3-ring, 4-ring and 5-ring PAHs were the most common components in the provincial control section of the Jiulong River. The toxic quivalency factors (TEFs) were used to calculate benzo\[a\]pyrene equivalents (EBaP) for water samples. The values in four sampling point of benzene\[a\] pyrene (BaP) toxicity equivalent value (EBaP) were beyond the Chinese Environmental Protection Agency (CEPA) guidelines for drinking water (2.8 ng/L). Overall, the surface water resources showed some carcinogenic potential. The result of ecological risk assessment indicated that high potential ecological risk of PAHs was not found in water of the provincial control section of the Jiulong River, Longyan

Horizontal visibility and extinction coefficients could reflect the aerosol changes in the atmosphere. By using the data of visibility, relative humidity, precipitation and other weather phenomena observed at 147 sites in Sichuan Province during 1961-2010, the dry visibility (DV) and dry extinction coefficient (DEC) were calculated through the correction of relative humidity, the temporal and spatial DVvariations were characterized and the trends in the DEC and annual number of days with haze were analyzed over recent 50years in Sichuan Province. Climatologically, the poor DV of 12-20 km distributed in the Sichuan Basin and its rim region, and the good DV of 40-50 km was concentrated in the high altitude region in western Sichuan Plateau, especially in the border region to the Tibetan Plateau with the best DV (>50 km). From the 1970s to the end of last century, the Sichuan Basin and western Sichuan Plateau respectively experienced the significant decreasing and increasing trends in DV. The decreasing DVtrends in Sichuan have ceased in this century. In the Sichuan Province, there were 544% sites with the decreasing DVtrends centering in the Sichuan Basin and Panzhihua area, and 456% sites mostly in the western Sichuan Plateau with the increasing DVtrends over the 50years. The variation patterns of DEC and haze day were similar with rapid increases before 1996 and slight increases after 1996. The trend rates over the 50years were 003/10 a for DEC and 104 d/10 a for haze occurrences. The deteriorating DV, increasing DEC and frequent haze were closely related with the energy consumption and anthropogenic pollutant emissions

With the daily meteorological data and air quality data of Wuhan city in 2013, the comprehensive research on the characteristics and influencing factors of haze weather is conducted, and the main meteorological influence factors for haze weather are gained. Support Vector Machine is proposed for haze days visibility forecasts based on multifactor. Research shows that, in the visibility forecast for short term, the accuracy of visibility prediction, based on support vector machine model, reached 733%, 867% and 967% within the error range of ± 1 km, ± 2 km and ±3 km, respectively. 〖JP2〗Owing to the MAE within 1km, it achieved highprecision visibility forecast for haze days, and is superior to some other models. Besides, the accuracy of visibility forecasting during the first two and three days has reached 90% within the error range of ± 3 km, showing a strong capability and stable performance for longterm forecasting

By using daily visibility and relative humidity data in 78 meteorological stations of Anhui Province during 1971-2010,this paper analyzed the temporal and spatial distribution characteristics of haze days.It also analyzed the climate variation of haze days in recent 40 years in Anhui province by using EOF decomposition method. The results show as follows.There was a significant increasing trend of haze days in Anhui Province. The most concentrated period of time for haze was in winter, the daily variation of haze days mainly showed twopeak structure,one peak was in January, and the second peak was in May to June.The heavest haze offen occured in June. The diurnal variation showed haze more happened in day time than night,peaking at 08〖DK〗∶00 BT. The spatial distribution characteristics of haze days was were very inhomogeneous,haze more happened in plains and around major cities than in mountains. The heavest haze days most happened in Huaibei. The annual haze days was highest at 2007 in 40 years.The contribution of the first four modal cumulative variance of EOF decomposition of haze days up to 793%. The spatial distribution of haze days was increasing with years in most areas in Anhui province.The time coefficient showed the haze days had significant annual variation of 3-4 years oscillatory growth

Based on the data collected from 69 surface observation stations during 1961- 2012 in Jiangsu province，using proper measures to define the concept of haze hours，the temporal and spatial distribution features of severe，moderate，mild and slight haze hours are discussed in the research．According to the characteristics of haze disasters, the administrative regions (districts and counties) are taken as the basic evaluation unit, considering four factors such as the hazard risk, disaster pregnant environment sensitivity, vulnerability and disaster prevention and reduction capacity. This study selects eight factors including the moderate haze hours, severe haze hours, water area, vegetation area, population density, road mileage, public finance expenditure, the number of doctors per million people possessing as the evaluation indexes, uses the analytic hierarchy process to establish a risk assessment model, and with the help of GIS analysis tool, the haze disaster risk regionalization is given. The research shows that the slight haze is the most haze weather in Jiangsu province, with proportion of 77% in all haze weather. The frequency of severe and moderate haze weather is lower, with proportion of 2% and 4% respectively. The trend of annual haze hours of every grade is identical, rising slightly during 1980-2010, and obviously during 2011-2012. The rising trend of slight haze is most obvious, followed by the mild haze. There are common spatial distribution characteristics of all grade haze. West area along the Yangtze River , local area in the north and the southeast of Jiangsu province are the high value area, Nantong is the low value area, and the area facing to the sea and its altitude is low. The natural intensity of haze (the hours of severe and moderate haze) and the risk assessment results of haze disasters are correspondent in the geographical distribution. West area along the Yangtze River and local area in north of Huaibei are the high value areas, showing the correctness and the rationality of the assessment methods. But the haze disaster risk also considered three factors such as disaster pregnant environment sensitivity, vulnerability and disaster prevention and reduction capacity. Thus, the distribution of the result of risk assessment and the natural strength of haze are different. Haze risk level is medium in the area such as the south of the Huaihe, part of Suzhou, Yangzhou, and Zhenjiang because of densely population and developed traffic, although moderate and severe haze hours are less in these area. In northern of Huaibei, some area such as Xinyi, Suqian and other places, the haze risk level is higher, because water and vegetation area is relatively less, disaster prevention and mitigation ability is relatively lower

Aerosol Optical Depth (AOD) is a basic parameter in total aerosol content, which can be used to represent the degree of atmospheric pollution. The AOD data from ground observation is difficult to reflect the spatial and temporal distribution. Some studies have demonstrated that the AOD retrieved using satellite remote sensing data can make up for this shortage. As the one of the most developed economic province of China, Jiangsu province has a high proportion of total GDP and total industrial output in China. Meanwhile, due to large amounts of toxic substances by industrial production and exhausts emissions, air pollution has become increasingly hazardous in Jiangsu province. The haze weather frequently occurred in recent years. These environmental issues have threatened seriously people’s health and environment quality. Aerosol is a key factor which contributes to haze weather. It will be useful to obtain the overall information of aerosol spatial and temporal distribution for atmospheric monitoring and air pollution controlling. Therefore, taking Jiangsu province as the study area, this paper obtained AOD distribution of spring and summer in 2010 using Dark Dense Vegetation (DDV) and V52 method based on EOSTERRA MODIS data. Then the two results of AOD distribution were validated using AOD measured data from CE318 instrument on the ground and the MODIS NDVI product as well. Finally, the spatial and temporal distribution of AOD and the possible affecting factors in the study area have been discussed based on AOD map from V52 method. The results showed that there was a significant negative correlation between AOD and NDVI. The AOD from V52 was more accurate than that from DDV in the study area. The absolute error and relative error of AOD from V52 was 016 and 33% respectively. In the study area, there was difference of AOD distribution in both spatial and seasonal. In detail, AOD gradually decreased from southern area of Jiangsu province to the northern area. The mean AOD of southern Jiangsu, center Jiangsu and northern Jiangsu was 077, 065and 058 respectively It can be found that the distribution of AOD was affected by the geographical environment, population density and industrial distribution. For seasonal changes, AOD mean value changed in a small range in spring and summer in 2010. But variation tendency was distinct in different regions. In the south of Jiangsu, AOD in spring was significantly lower than that in summer.The mean value was reduced from 0.81 to 0.70. In the north of Jiangsu, AOD was increased with the mean value rising from 056 to 062. In the center Jiangsu, seasonal change was not obvious with AOD mean value being 066 and 063. The changes of AOD value was mainly affected by natural and human activities. In the natural factors, rainfall erosion can greatly reduce aerosol life cycle to reduce its value. According to the 2010 climate impact assessment of Jiangsu province issued by the Jiangsu meteorological bureau, the precipitation of southern Jiangsu was greater than northern in spring of 2010, but little different, both around 200 mm. However, the precipitation was mainly concentrated in the areas along the Yangtze River in summer of 2010, southern region rainfall reached 500 mm, while the northern and center hovered at 300 mm and thus made AOD value in south of Jiangsu was significantly lower than that in the northern. Besides, the effect of human activities was also an important factor in affecting AOD value. A large number of construction projects in the areas along the Yangtze River in spring of 2010 were contributed to produce local dust weather which can result in high value of AOD. This was an objective factors lead to higher AOD value in the areas along the Yangtze River in spring of 2010 than that in summer during the study period

The characteristics of the surface situation and the boundary layer climate with consecutive haze and the heavy haze over south Jiangsu were analyzed based on surface observations obtained from Wuxi Meteorological Station and temperature profile obtained from Nanjing, Shanghai and Hangzhou sounding stations during 1981-2011. The main surface situations in haze days were isobaric pressure, back of the high pressure, cold front, inverted trough with low pressure and saddle field. According to the variation of the surface situation, the nine consecutive haze days could be divided into four types which had different boundary layer structures. The high pressure went across the south of Jiangsu which would be controled by isobaric pressure with typeⅠ. In this type, the bottom of the temperature inversion layer was lower and there appeared inverse humidity areas in the middle level. Accompany by the high pressure motion, the south of Jiangsu was controled by the bottom of the high and then the cold front and the isobaric pressure in type Ⅱ. At the same time, the main situation was isothermal layer and the high humility areas was main on the ground. 〖JP2〗In type Ⅲ, there was inverted trough growing in the middle and lower reaches of the Yangtze River, accompaned by the high going to the sea, the south of Jiangsu located in the top of the inverted trough. Then by the cold air flowing to the south, isobaric pressure and the bottom of the high pressure took over the south of Jiangsu area one by one. The intensity and the thickness of the temperature inversion was weaker and thiner, at the same time the high humility on the low layer went through the whole days in type Ⅲ. In type Ⅳ, it was affected by the warm high on the west of the pacific, the cold vortex at the north east of China and the cold air from the Siberia in the south of Jiangsu which was controlled by the cold front and then the isobaric pressure. The intensity of the temperature inversion was stronger with this type meanwhile there was inverted humility at the top of the temperature inversion. The lower and the stronger of the height and the intensity of the temperature inversion layer, the lower ground visibility appeared. The main surface situations when the heavy haze occurred also were isobaric pressure, cold front and inverted trough with low pressure. In most of the heavy haze days, the bottom of the temperature inversion was near the ground. When the temperature inversion or isothermal existed and the high moisture appearred on the ground, the pollutant could not spreaded and the particulate matter expanded by taking in the water vapour. And then the ground visibility was lower and the heavy haze occurred