Ecological footprint，as a measurement to estimate the status of sustainable development，reflects the degree of making use of the nature by humans. With the ecological footprint analysis theory advanced by William Rees, this article calculates the ecological footprint and ecological carrying capacity to research and analyze the sustainable development of Suzhou. According to the data of Suzhou Statistics Yearbook 1990-2010，the results show that the ecological footprint per capita of Suzhou was 648 hm2 in 2010，the ecological carrying capacity per capita was 027 hm2，the ecological deficit per capita was up to 621 hm2 in 2010 which is far beyond the current biocapacity. This means the urban ecological system is not sustainable now.There is contradiction between supply and demand of fossil fuel land, cultivated land, grassland and water, while construction land and woodland is slightly surplus. The deficit of fossil fuel land is up to 553 hm2 in 2010. The cultivated land and construction land provides more than 90% ecological supply for the city. The ratio reflects the large consumption of fossil fuel and it is in accordance with the economic development of Suzhou. Ecological footprint per capita of Suzhou is continued rising from 136 hm2 in 1990 to 648 hm2 in 2010. The average annual growth is 25.59% and increases most from 2000 to 2005. It turns slowly since 2005 because the city began to pay attention to the optimization of the industrial structure and improve the utilization rate of resources. The ecological footprint of Suzhou is much larger than the national and global average conditions. The ecological footprint of arable land is decreasing which is inconsistent with the increasing population and food consumption. It shows that Suzhou is increasingly dependent on imported food from the surroundings. The increase of construction land reflects the urbanization. The ecological capacity per capita steady decreases due to the reduction of cultivated land and the change of construction land. Thus, ecological deficit per capita is in accordance with the footprint. The city is in deficit condition since 1990, and sustainable development is the major problem that must be solved in the process of economic development in Suzhou. Analysis of energy resources consumption in Suzhou indicates that coal occupies the largest ecological footprint. The current energy structure has brought heavy pollution. Compared with relevant data in previous years, it is found that although the ecological footprint of Suzhou is increasing，the rate of growth is slowing and the ecological footprint of ten thousand yuan GDP is also declining. These means the utilization rate of resources is on the rise. Therefore, Suzhou should adjust the social and economic structure as soon as possible, control the growth of population, strictly protect the cultivated land, improve energy efficiency and cut down energy consumption, so as to reduce the ecological deficit and promote the social and economic sustainable development.

Countryside is an important geographical unit, and rural geography is always an important branch of human geography. Cities have always been the focus of human geography, but the rural study does not get enough attention.With the development of industrialization and urbanization, rural enclosed structure is broken, rural landscape and the form of community is undergoing changing, the country begins to transform into the city. Due to its own characteristics, different regions affected by urbanization influence degree differ, rurality shows a different state. Each zone can be seen as a unified urbanity and rurality, which has no breaking point. The evaluation of rural index should be able to fully reflect overall characteristics of county, the difference between village and city, namely, the basic properties of the rural characteristics. In this paper, we establish the evaluation index system including the proportion of primary industry employment, per capita GDP, population density, the proportion of primary industry output, the proportion of 20-49 yearold man and other indicators based on the connotation of rurality. We use land use change survey data, the Statistical Yearbook in Jiangsu province,the 5th and 6th national population census with the help of SPSS, ArcGIS, Geoda software to evaluate the rurality of 51 counties (countylevel cities) in 2000 and 2010, which have great meanings not only for analyzing the degree of development of the national rural change, but also for supplying public services and finance in future, targeted measures to determine the direction of regional development.The results showed that:The rurality of county unit in Jiangsu province weakened gradually from 2000 to 2010, showing the spatial distribution of ladderlike situation. The rurality index of each county does not show completely random state, but there was a significant positive spatial correlation. Hotspots of rurality index in Jiangsu province located in the junction of Siyang and Shuyang with the core of the circle structure, cold spots concentrate in SuzhouWuxiChangzhou region where the rural industry developed quickly. The influencing factors of rurality transformation included five aspects: social environment, traffic, capital, policies, industrialization and urbanization. We did not find the phenomenon of rurality strengthening in the paper. If the phenomenon does happen in future, the research of management system and spatial structure construction will get more attention. We also can discuss rurality through questionnaire survey and interview to investigate the changes in rural customs, culture, ideas and other aspects. Whats more, it will have more realistic guiding significance to research the rurality, using more available data, based on villages

In the Rapid Transit age, transportation accessibility has becoming one of the most significant factors of economic development. With the development of rapid transit, such as the highway and highspeed railway, accessibility of urban area is increasing sharply. Based on GIS and the methods of cost weighted raster analysis, this paper is conducted with regional accessibility indicators like average time, urban isochronous rings and daily accessibility to compare the accessibility spatial pattern changes of the central cities in Yangtze River delta with and without highway, with and without highspeed railways. Its purpose is to explore two types of rapid transit impact on central city accessibility. The result shows as follows. Firstly, highway network is perfectin Yangtze River delta, so the influence of the highway on city accessibility is relatively balanced, shortening the time between 30%-40%. Highway Bridges connecting both sides of the Yangtze River and Hangzhou Bay can significantly shorten the travel time of both sides, where the time variable ratio is high. Highspeed railway network is mainly along the megalopolis of the Yangtze River delta, so the changes of spatial distribution of the time variable ratio are unbalanced and accessibility improvement of the area along highspeed railway is apparent. The influence of the highspeed railway on the accessibility of cities which are along particularly the endpoint city like Nanjing and Ningbo, is more obvious than that of the cities like Nantong away from highspeed. Secondly, under the influence of highway, the expansion of isochronous rings is remarkable. Highspeed railway makes the isochronous rings stretched along the highspeed railway. Highspeed railway can better expand accessible area than railway within 1 hour. However, as a hub, the stops of highspeed railway are fewer. Only by upgrading other rapid transportation to enlarge the service range of stops, can it substantially expand communication circle of one day, reduce differences in external transportation between cities and areas around cities and promote the fairness of the social and economic development in Yangtze River delta. Thirdly, highway and highspeed railway can significantly optimize the daily accessibility between cities and speed up the formation of the regional division of the Yangtze River delta. The effect of the highspeed railway is significantly greater than the highway with 1 hour, but it tends to equilibrium within 3 hours, which is mainly due to the regional limitations of the Yangtze River delta. Highway can shorten total time of each city to other cities by more than 15 hours averagely, highspeed railway by more than 26 hours. Therefore, highspeed railway can better improve daily accessibility between central cities than highway. Lastly, although the benefits of Nantongs accessibility from the highspeed railway is small, in the future the electrification transformation of railway from Nanjing to Nantong will be completed, the time between two cities is shortened from 4 hours to less than 2 hours. When all the cities open the highspeed railway, the daily accessibility of all regional center cities in Yangtze River delta will be further optimized

Owing to the regional differences in the nature, society and economy, there are diversities in space expansion in different cities which, accordingly, cause the diversities in social, economic and ecoenvironmental benefits. Therefore, it is beneficial to predict, guide and regulate the future development of the city, analyze and settle the problems in the citys social and economic development by clarifying the changes in urban expansion, revealing the growth process and evolution rule of the city. Since the 1980s, there has been a rapid development in the economy of Hefei City, an increase in its urbanization and obvious changes in the urban space expansion. Based on the geoinformatic map, the spatial expansion information of Hefei City was extracted by manmachine interactive method from multitemporal satellite images, and the temporal and spatial expansion characteristics of Hefei from 1987 to 2011 as well as their driving forces were analyzed with indices such as urban expansion intensity, compactness, fractal dimension, center coordinates, and elasticity coefficient with the help of ArcGIS software platform and some different research methods, such as spatial form analysis, fans analysis, fractal analysis. The result shows that after the expansion alongside the transportation axes, the dualcore group expansion and the filling in the transportation axes, the urban form of Hefei City has transformed from irregular block mass into starwedge complex and conjoined twin star shape. During 24 years, urban land area in Hefei City were increased by 22415 m2，the city size expanded 455 times. Before 2000, the city kept extending mainly at a medium and lower speed, while after entering 21st century, it began extending at a high speed, especially between 2000 to 2006. The urban expansion has showed an obvious spatial heterogeneity, and the urban space has expanded unevenly alongside the external traffic lines towards the southwest, the southeast, the east and the northeast. There are obvious differences among the expansion directions of the urban land in different period. The most obvious expanding area lied in the place which is about 8 km from the city center, and the focus of city shifted to the south. The compactness, fractal dimension and elasticity coefficient of the city were fluctuated just like types of “W”, “M” and “∧” respectively, and the urban spatial form developed towards the stability and rationalization finally. In the future, the focus of city will continue the expansion toward the south while its direction may move to the east a bit, the distance between the north and south will become longer, and the urban form will become more regular and develop into a round shape. Natural environmental conditions, economic development, population growth, traffic infrastructure development, and government behaviors are the main driving forces of the urban expansion in Hefei City. The unbalanced changes in the urban expansion are the results made by the influence of multiple driving forces.

With the development of the economy in the Poyang Lake Ecoeconomic Region, water resources have been intensively explored and utilized. In order to keep the economy and society developing sustainable, it is necessary to assess the water resource security (WRS) for the Poyang Lake watershed.Firstly, based on the representative principle, integrity principle,quantifiable principle and comparable principle, the index system to assess water resources security forPoyang Lake watershedwas established under the framework of statepressureresponse index system. Secondly, combining the data from the Statistical Yearbook and Water Resources Bulletin of Jiangxi Province, the composite index method wasapplied to calculate assessed values from 2000 to 2010. The variation coefficient method was also used to assign weights for each index objectively. Then, the assessed values of WRS were classified to five classes of the WRS status based on unequal interval method, and the WRS status included extreme safety (Class V), very safety (Class IV), safety (Class III), unsafety (Class II) and extreme unsafety (Class I).Results showed that among the indexes, population density, river network density and the application rate of chemical fertilizers and pesticides have a great influence on WRS in Poyang Lake watershed, because they had large weight calculated by the objective variation coefficient method. The status of WRS in Poyang Lake watershed had experienced the trend from the safety(Class III) to very safety (Class IV), to the safety (Class III), and finally developing to the unsafety (Class II) from 2000 to 2010. From the perspective of risk sources of WRS,thisvariation trendwas mainly caused by the increasing of the population, industry and agriculture production used water, domestic water used and the large utilizingof chemical fertilizers and pesticides. In addition, the overall trend of WRS status in Poyang Lake watershed from 2000 to 2010 show a trend of deterioration. Although the awareness of environmental protection has been gradually enhanced, and environmental investmentswere increasing, the rate of wastewater treatment has been improved and the management of industrial wastewater has been strengthened in recent years, it is difficult to suffer the pressure from the economic and social development, which made the water resources exposing the worsening trend.From the current status of WRS and their risk sources from 2000 to 2010, we can predict that the status of WRS will be in safety (Class III) or unsafe (Class II) status in Poyang Lake watershedin the near future. In the year with less precipitation, the status of WRS will be worse because of the economy increasing development. Only if the society and economy are developing with the growth of population controlled, environment protection awareness strengthened, the rate of wastewater treatment and environment investment increased, and water quality of rivers improved, the sustainable utility of water resource may be utilized and explored sustainably. Quantitative assessment of WRS and its variation trend analysis will provide a scientific basis for reasonable development and sustainable utilityof water resources in Poyang Lake watershed

Pudong Dongtan, a vital stopover site for migratory waterbirds and wintering site for waterfowls, has experienced two largescale reclamations during last two decades, resulting in degradation of natural wetland and loss of biodiversity. Degradation wetlands were restored to compensate for the loss of natural wetlands. We carried out waterbird surveys in the ecological restored wetland and natural degraded wetland as a reference site in 2010 and 2012 to assess the effects of wetland restoration on waterbird communities. In our survey, a total number of 9,657 waterbirds corresponding to 49 species, 6 orders and 12 families were counted in the ecological restored wetland in 2010 and 2012. The dominant species are the Spotbilled Duck (Anas poecilorhyncha), Falcated Duck (Anas falcata) and Wigeon (Anas penelope). In the natural degraded wetland, 917 waterbirds were observed, which corresponded to 28 species, 6 orders and 9 families. The dominant species are the little grebe (Tachybaptus ruficollis), Common Moorhen (Gallinula chloropus) and Blackwinged Stilt (Himantopus himantopus). The waterbird diversity, the numbers of species and individuals in the ecological restored wetland are significantly higher than those in the natural degraded wetland, however, the significant difference was not observed in evenness. These results may be caused by the following reasons. Under the human management, diverse habitats were constructed to attract various waterbirds in the ecological restored wetland, whereas the less water surface area, mudflat area and the higher vegetation coverage were observed in the natural degraded wetland. The waterbird species number in the ecological restored wetland in 2012 was significantly lower than that in 2010, however, no significant difference in the waterbird diversity, evenness and the numbers of individuals were noted in 2010 and 2012. In the natural degraded wetland, the waterbird diversity, the numbers of species and individuals in 2012 were significantly lower than those in 2010, whereas no significant difference was noted in the evenness in 2010 and 2012. It is because that there are no obvious change in environment factors including water level, percentage of water area, the percentage of mudflat, vegetation coverage and human disturbance in the ecological restored wetland between 2010 and 2012 through vegetation management and water level control, whereas there are large changes appearing in the natural degraded wetland at the same time. In the addition, for without human management, the water level change in the natural degraded wetland was only decided by the amount of rainfall and the natural degraded wetland had been experiencing a rapid drought process, which was unable to meet the various needs of migratory waterbirds seasonally. In conclusion, the ecological restored wetland, as an alternative habitat to compensate for natural wetland loss, plays an active role in waterbird diversity conservation. We expected that our findings help protect the waterbird diversity effectively and provide waterbirds with important stop foraging and wintering sites in the coastal area of the Yangtze River

29 systematic investigations on the Xuliujing water quality monitoring intersect in the Yangtze River estuarine were carried out from 2005 to 2012. We analyzed a 8year dataset of water quality conditions in the Yangtze River estuarine and the pollutant fluxes into the East China Sea. The annual concentration of the water quality and the pollutant fluxes were studied. It showed 2005,2010 and 2012 were floodflow period, 2006 and 2011 were dryflow period, the other 3 years were normalflow period. The range of annual average concentration of chemical oxygen demand (CODCr) was 0044-0098 mg/L, ammonia nitrogen (NH4N) was 0051-0358 mg/L, total phosphorus (TP) was 0069-0255 mg/L, active phosphate(PO4P) was 0044-0098 mg/L, Oil was 2367-7939 μg/L, copper (Cu) was 171-277 μg/L, cadmium (Cd) was 0057-0116 μg/L, arsenium (As) was 234-294 μg/L. A calculation method on Spearman rank correlation coefficient (Rs) was introduced. Using relativity analysis between water fluxes and time sequence, through this method, the evaluation on mutative trend of environmental quality could be automatically gotten, and the marked meaning was examined．The results indicated that the concentration of TP, PO4P, NH4N, Oil, CODCr in Xuliujing monitoring intersect of the Yangtze River increased and the concentration of TP increased significantly. The concentration of Cu, As, Cd decreased, and the concentration of Cu decreased significantly. During the 8 years, water quality of the Yangtze River was degraded. The rank of water quality at all monitoring sites were fromⅡto Ⅳgrade. The main pollutants were TP, NH3N and organic contaminants such as CODCr. The pollutant fluxes flowing into the East China Sea was increased significantly, which were mainly affected by the Yangtze River runoff and sometime were affected by the economic development in the watershed, for the annual average concentration of CODCr being the critical factor affecting the pollutant fluxes. The export fluxes of N in the Yangtze River estuarine increased according to several studies in recent 15 years.

Poyang Lake is the largest freshwater lake in China, and has an internationally recognized wetland system. It receives inflows predominantly from five major rivers (i.e. the Ganjiang, Fuhe, Xinjiang, Raohe and Xiushui Rivers) within its drainage catchment. The Ganjiang, Fuhe and Xinjiang Rivers contribute approximately 89% of the lakes inflow from its drainage catchment area, and the remaining 11% is mainly made up of inflows from the Raohe and Xiushui Rivers. Poyang Lake is connected to the Yangtze River through a narrow channel at Hukou at its northern end, and the Yangtze River plays a complementary role in controlling outflows.Because the Poyang Lake has a nonlinear response to the river discharges from its drainage basin and the Yangtze River, the highly complexity and nonlinear characteristics determine that the threelayer back propagation neural network (BPNN) has the ability to simulate the lake water level responses. In this study, the water level timeseries of the Hukou, Xingzi, Duchang, Tangyin and Kangshan were used as the target variables for the BPNN construction under different model scenarios. Results indicate that both discharges from the catchment rivers and the Yangtze River are considered, thedetermination coefficients R2 and NashSutcliffe efficiency Ens for all gauging stations can reach 090 and the Root Mean Square Error RMSE is in range of 050-10 m during the BPNN training and testing phases, while the simulated results reveal that the Ens and R2 are lower than 050, and RMSE is significantly increased in range of 124-288 m under the condition of neglected the Yangtze River discharges. The BPNN can be used to combine the catchment hydrological models, which can provide an alternative tool for predicting the lake water levels in response to catchment river discharges under climate and landuse changes. The BPNN also can be used as an effective modeling tool to solve some hot issues in the Poyang Lake, such as how to quantitatively distinguish the individual contributions of catchment rivers and the Yangtze River to the flood and low water levels. At the same time, the model users should select long timeseries dataset with best data consistency to train and test the BPNN model

The hydrological process of the Poyang Lake Basin is a local hot topic. Soil moisture is an important state variable of the hydrological process and plays a critical role in water balance at basin scale. However, the spatial and temporal variation of soil moisture is still lack of systematic research when compared with others hydrological factors, which leads to a strong uncertainty for the research of the hydrological process. The main objectives of this paper are to illustrate the soil moisture dynamics and its influencing factors at different spatial and temporal scales of the Poyang Lake Basin. For these objectives, this paper firstly obtained the AMSRE soil moisture data set from the National Snow & Ice Data Center (NSIDC, http://nsidc.org/data/amsre/index.html) from 2003 to 2009. Then the soil moisture was downscaled to resolution of 1 km and calibrated through the time series insitu soil moisture. After that, this paper investigated the annual and monthly variations of soil moisture at the spatial scales of basin, subbasin and land cover. Finally, it analyzed the relationships between soil moisture with precipitation, air temperature and land cover to capture the controlling factors. The results show that: i) at the scale of basin, the soil moisture presenteda spatial pattern of “Funnel” with the low soil moisture in center and high around at the basin scale, whereas the spatial difference at summer and fall season wasminor. Temporally, annual soil moisture decreased significantly at both basin and subbasin scale, and the rapidest decrease rate occurredin the Lake area (-035%/year). It implies that it is vulnerable to suffer from drought at the Lake area. Furthermore, there were significant differences among the monthly soil moisture, with the variability about 3~4%. The highest soil moisture mainly occurredin April, while the lowest occurred in September or October. ii) At the scale of land cover, forest obtainedthe highest soil moisture. Annual soil moisture decreased in all land cover types, with the lowest decrease rate occurred in forest area. It implies a strong ability to control drought at annual scale. Monthly soil moisture variedwith the land cover types, but the differences were minor in June, July and October. It demonstrates that the effect of land cover was weakened under the extreme climate condition (i.e., the extreme high precipitation and air temperature). iii) With regards to the controlling factors, soil moisture was positively correlated to precipitation and negatively to air temperature. However, soil moisture was positively correlated to air temperature in the Lake area, which is mainly attributed to the irrigation in summer. Furthermore, the correlation of precipitation was higher than that of air temperature. It means that precipitation plays more important role on the soil moisture. Results of this paper would help to understand the hydrological process, but also support the water resource and drought controlling for the basin

Drought as a major disaster has hit south and central China hard over the last decade. Seasonal hydrological droughts raise many concerns on the largest retention lakes in central Yangtze River, which has received wide attention due to the possible negative impact from the impoundment of Three Gorges Dam (TGD). The hydrological drought analysis at Dongting Lake is important for clarifying some of the most complex hydrological issues in relation to the intertwined interactions of a lakeriverreservoir system from the operation of Three Gorges Reservoir (TGR) located upstream of the central Yangtze River. The assessment metrics for a hydrological drought were established according to the exposing of wetlands at Dongting wetlands. These metrics were used to determine the characteristic water level in relation to the occurrence and duration (severity) of the hydrologic drought at varying lake areas during the dry seasons. The causal effects of a hydrological drought were analyzed based on the hydrological regimes and seasonality across lake areas. The drought impact on the lake water due to the water storage in the TGR was evaluated by using a neural network model. Such an analysis confirms that: （1) the frequency, severity and causes of hydrological droughts varied for different lake areas and seasons due to the specific basin morphology and the deviation of water regimes. The severity of a hydrological drought became more intensify after 2000, starting with the most severe impact at West Dongting Lake, followed by the East Dongting Lake, and then the South Dongting Lake; （2) the occurrence of a hydrological drought varied for different lake areas and seasons. The autumn drought at East Dongting Lake was caused by a runoff reduction from the Yangtze River whereas the autumn droughts at West and South Dongting Lake were caused by a runoff reduction from Yangtze River and Dongting Lake basin simultaneously. Yet the spring drought covering the entire lake was caused by a runoff reduction from Dongting Lake basin itself; （3) the water storage in the Three Gorges Reservoir has advanced the exposed time of wetlands, and has prolonged the autumn drought by approximately 30%. However, the modeling also reveals that the regular operation of the TGD did not change the natural drought trends at Dongting Lake, and it is not deemed as the primary cause of recent hydrological droughts. The river flows are less homogeneous over a large region, thus, flow regulation has the basis to balance low flow downstream. However, the TGDs operation has aggravated seasonal hydrological droughts by prolonging the exposed time of wetlands in autumn. Although the analysis reveals that the regular operation of the TGD did not change the general drought trends at Dongting Lake, and it is not deemed as the primary cause of recent hydrological droughts. There are still many challenges to accomplish a sustainable dam operation to enhance the resilience to hydrological extremes

The purpose of this study was to explore the relationship between the schistosomiasis epidemicity and the social, economic, environmental factors in a typical schistosomiasisepidemic area of the Poyang Lake region. We used simple correlation coefficient, partial correlation coefficient and multiple correlation coefficient, to study the correlations and the interrelationships among the number of infected persons and the five factors of 43 typical schistosomiasis epidemic administrative villages in Nanchang county, Jiangxi province. The five factors were divided into two portions, Infected Water Contact factors (including water contact index, lake border length and distance to the Poyang Lake) and Infected Water Distribution factors (including cattle stock, waters area). The previous studies of water contact index calculation were based on contact ways, contact frequency, the body area exposed and the lasting time without considering susceptible seasons, susceptible time and exposing spots. In the study,we tried to include these important elements into the computation of water contact index in forms of contact way, contact season, the number of contact days, contact time periods in a day, the number of the persons of different contact ways and contact spots. The lake border length and the waters area for each administrative village werederived from a TM image of the Poyang Lake region in June 2009; the distance to the Poyang Lake for each administrative village was measured by length of geometric center of village to the lake border; the cattle stock data was from a socialeconomic statistic of the Schistosomiasis Control Department of Nanchang county. The simple correlation coefficients between the number of infected persons and the selected 5 factors reached 005 significance level，among which the water contact factors (including lake boundary length and water contact index) hadhighest correlation coefficients (0747 and 0813 respectively); the partial correlation coefficients between either the number of infected persons and the water contact factors when fixing the Infected waters factors (including cattle stock, waters area and distance to the Poyang Lake), or the number of infected persons and the infected waters factors when fixing the water contact factors were lower than their simple correlation coefficients, implying there existed mutual interrelationship between the infected waters factors and the water contact factors; the multiple correlation coefficient between the number of infected persons and the whole 5 factors was 0948 (P<0005), accounting for 79% of the total variance of the Number of infected persons. Conclusions can be drawn that the selected 5 environmental factors were significantly correlated with the number of infected persons; the infected waters factors and the water contact factors were indispensable for epidemic occurrence and there are interrelationship between these 2 group factors; the 5 macro environmental factors can explain most variance of the number of infected persons.

〗Lake and its drainage catchment are viewed as a community existed in nature, which constitutes essential component of the regional and global water cycles. Integrated simulation of hydrological and hydrodynamic processes is very important for lake catchment water resource planning and management. The review of integrated simulation provides useful information for understanding the model development and model mechanism. It also provides critical insights into the international modeling approaches. Conventional simulation approach mainly combines the catchment hydrological model and lake water balance model, which was used to calculate the catchment hydrological processes and lake water budgets. However, the lake water balance method only can give the general description and this method may not reflect the lake system with significant water gradients and complex hydrodynamic behaviors in space. The integrated model based on the catchment hydrological models and lake hydrodynamic models overcomes the difficulties in complete simulation for the largescale area. In this paper, we described the advances in integrated hydrological and hydrodynamic simulation for lakecatchment systems in various scales, thus summarized the advantages and deficiencies of the external coupling technique, internal coupling technique and full coupling technique using in the integrated models. In theory, the internal and full coupling techniques are the most reliable methodologies for the integrated simulations, but they usually have many numerical problems. The external coupling technique is the most effective and easiest approach to link different model components, but it is not adequate to represent the feedbacks between models. Overall, the coupling techniques are useful to improve our understanding of integrated hydrological and hydrodynamic models around many counties

The West Works in SouthtoNorth Water Diversion Project is an important transbasin water diversion project to divert water from the upstream main stream and tributaries of the Yangze River (referred as source area) to upstream of the Yellow River (referred as target area). In the West Route Works, dams shall be constructed on the Jinsha River, which is the main stream of the Yangze River, the Yalong River and the Dadu River which are the tributaries of the Yangze River, with the dam sites at El. 3 000-4 000 m, and water is diverted to the upstream of the Yellow River by diversion tunnels through the Bayankala Mountain which is the divide between the Yangze River and the Yellow River, with the diverted water amount of 8 billion m3, 645 billion m3, and 255 billion m3 respectively, annual totaling 17 billion m3. This can compensate for the insufficiency of the Yellow River water resources and resolve the water resources shortage problems. Because of large water diversion amount, long diversion route, many water source points, difficult construction, remarkable benefit, etc., the West Route Works in SouthtoNorth Water Diversion Project is regarded as the greatest transbasin water diversion works in the world.The source area is located in the southeast of QinghaiXizang Plateau at north latitude 31°30′-35 ° 30′ and east longitude 90°30′-103°30′, including the areas upstream of Zhimenda on the Tongtian River (Jinsha River), area upstream of Ganzi and Daofu on the Yalong River, and area upstream of Zumuzu and Zhuosijia on the Dadu River, with a total area of 220 000 km2. This area is at El. 3 000-4 500 m, with the daily mean air temperature below 0°for a period of 5-8 months in a year.Based on the runoff, precipitation, temperature and sunshine duration series of 5 hydrological stations and corresponding meteorological stations in West route of SouthtoNorth water Diversion Project over the past 50 years, significant autocorrelations at a 5% level in series were identified and removed by the PreWhiten method. The MannKendall test was used to detect trends and abrupt change, which were validated by the Spearman test and Double Mass Curve technique. Moreover, the 〖JP2〗Pearson method was applied to analyze the correlations between runoff and various climatic factors. The results indicated that in the recent 50 years, the runoff does not change obviously，but in the past decade, it has a further decreased trend except Zhimenda. Precipitation and sunshine have no obviously trend, in contrast, the temperature increases significantly. On the whole, runoff is mainly affected by climate change and the changes of runoff in future need a comprehensive study on spatial and temporal distribution of temperature, precipitation, runoff, glaciers, etc

The Three Gorges Dam,the largest hydroelectric dam in world currently, is located at Sandouping of Yichang City, Hubei Province. While it has brought farreaching economic and other benefits in flood control, hydroelectric power, and greater navigation access to the Yangtze River in central China, it also has many negative impacts on ecology and environment. Since the initial filling of Three Gorges Reservoir (TGR), eutrophication and algal bloom have been observed in some tributaries, which arouse the attention from the scholars both home and abroad, and have been carried out a large number of researches. Since the initial filling of TGR, the hydrodynamics of the Xiangxi Bay(XXB) has also been changed. Regulation of water level in reservoir and the physical and chemical difference of water in XXB and steam stream, cause the frequent water exchange between steam stream and tributaries in the TGR.The hydrodynamics of the XXB could be generalized as a densitystratified flow, and could not be simply simulated by onedimension model. The upstream water mainly flowed out of the bay in a process of downslopebottom density current, meanwhile, the TGR mainstream water flowed into the XXB in a flowed reverse density current. SO42,Cl,Na+,Ca2+,Mg2+,K+,F are constant ion in water. The content of some ions in the water is relatively stable, which have chemical conserved. In this paper, XXB was as the study location. On September 26th, 2012，hydrodynamics and inorganic ion were measured in XXB, the largest tributary bay in the TGR, to study hydrodynamic characteristics of XXB at TGR. Based on the tracer principle of inorganic ion, spatial distribution of inorganic ion in XXB suggest that inorganic ions in XXB exist gradient trend. The concentration of Mg2+ is low in downstream and high in upstream in space,
the concentration of Na+ is contrary，and they form wedgeshape while diffused to upstream. The wedgeshape is the same with that of the velocity distribution profile diagram. The water is from the steam stream, and it back flows into XXB. It verified the stratified density currents in XXB. Velocity distribution profile diagram in XXB suggests that the water back flows into XXB in the middle of the estuary, which is the middle density currents; while the water in the upstream flow into XXB at the bottom, which is the upstream slope density current. Stratification movement of the water in XXB is obvious. Finding out the hydrodynamics in XXB is a basic work to solve eutrophication

The relationship between land use/land cover(LULC) and water quality is one of the important components of land use environmental effects research. The type, size and distance of different land use types to water bodies are usually studied in a manner relating them to water quality. With Landsat Thematic Mapper(TM) images and the water qualities in 11 monitoring sections, this paper analyzed the relationship between land use and water quality parameters(DO, CODMn, NH3N) in Chishui River basin on the buffers and subwatershed scale，and made multiple regression model of water quality parameters. Based on Geographic Information System (GIS) spatial analysis, round types of contributing zones were developed around these monitoring sections. And based on GIS hydrology analysis, the subwatersheds were segmented. Then, six types of land use types were extracted from TM images in 2009. On the basis of water quality parameters, the correlation relationship between water quality and land use pattern over different contributing zones was examined. Correlation analysis showed that, from round types of buffers to subwatersheds scale, the correlation of construction land and NH3N increased form significant positive correlation to highpositive correlation, and the correlation coefficient reached 0.836. The correlation of construction land and CODMn increased form positive correlation to significant positive correlation, and the correlation coefficient reached 0776. The correlation of cultivated land and CODMn increased form significant positive correlation to highpositive correlation, the correlation coefficient reached 0913.The correlation coefficient of cultivated land and NH3N increased to 0782. The correlation of cultivated land and DO increased form negative correlation to significant negative correlation, and the correlation coefficient was 0.609. On the buffer scale, the forestland exhibited negatively correlated with CODMn and NH3N，and the degree of correlation increased with the increase of buffer radius. While on the subwatersheds scale, the forestland exhibited significant negative correlation with NH3N and highly negative correlation with CODMn, the correlation coefficient reached 0.673 and 0.822, respectively. All of these showed that the land use patterns in Chishui River basin had great impacts on surface water quality, and construction land and cultivated land gravely influenced the water quality in Chishui River basin. City domestic sewage, industrial sewage and agricultural nonpoint source pollution hosted on these land use types are the important sources of water pollution. Nevertheless, the shrubgrass and forestland showed positive effects to some extent. Generally, the correlativity between land use and water quality parameters was consistently on both buffers and subwatershed scale in Chishui River basin, while it was exhibited more significant on subwatershed scale .On buffers scale, we cloud analyze the effect of the distance between land use types and the river on water quality. However, the natural attributions of subwatershed cloud be taken into account on subwatershed scale. The research could provide both critical information in sustainable land use practice for water resource conservation for Chishui River basin, and a methodological reference for analogous study

Leakage water from the bottom layer of a reservoir, which is low in dissolved oxygen (DO) and water temperature (WT), would cause ecological problems if flowing into the downstream channel without any recovery methods. The recovery of DO and WT in leakage water from a reservoir along the stream remains poorly understood, although studies of stratification of WT and DO in such a reservoir have been more numerous in recent years. In this study, field investigation and field experiment were carried out on the 2.25kilometerlong test section of Wenxia River, downstream of the Wenxia Reservoir. DO and WT values were measured along the test reach as well as their diurnal variation. Effects of steppool on channel reaeration abilities and influence of sandbar on the transverse distribution of DO downstream were preliminarily analyzed based on the data collected in the field experiment. Besides, macro invertebrates were sampled to evaluate aquatic ecology. Results show that flow velocity almost has no effect on the diurnal variation of DO and WT for a single spot in the test reach. Both WT and DO increased along the downstream reach of the reservoir and almost got completely recovered at the end of the test reach.WT experienced an 18.7 °C rise and was close to the air temperature at the end of the test reach; DO reached saturated state from 16.1% in saturation through a 1.7kilometerlong reach. Channel width is well correlated with the recovery of both DO and WT, however, WT is more susceptible to channel width than DO.WT experienced a growth spurt but DO did not at where the channel is broadened to a large extent. Reaeration rate had a limited variation along the test reach except at the experiment site, uncorrelated with channel width. For a steppool, the reaeration ability was weaker in the morning than in the afternoon under large discharge, which was opposite to the situations under small discharge or in plane bed. The phenomenon could be explained by different submergence of steppool under different discharges. Submergence affected turbulence intensity and thus had impact on air entrainment. DO is sectional in the downstream area of a sandbar, high at the tail but low in the two branches flowing by. Besides, the difference of DO concentration between the branches and bar tail grew with larger flow velocity difference, indicating a remarkable influence of flow velocity on DO distribution for this river pattern. Biodiversity increased with the reaeration process and a species succession, from species with high tolerance against low DO to species without the capacity, occured with higher DO concentration, implying a controlling effect of DO on the downstream aquatic ecology of the reservoir

In order to study the effects of acid deposition on the soil acidification, this paper analyzed the conditions of acid deposition of Chongqing area and the soil acidification trend of four kinds of typical forest (shrubwood, evergreen broadleaf forest, mixed coniferous broad leaved forest and Phyllostachys pubescens forest) by the method of soil sampling and laboratory analysis from 2010 to 2012 in August of each year. This study divided the soil of the four kinds of typical forests into four layers according to the soilforming process and analyzed the physical and chemical properties, respectively. The results showed as follows. (1) Although the sulfur dioxide levels in the atmosphere was going down with each passing year and the nitrogen dioxide levels was in a very steady state, the acid rain condition was very serious in Chongqing area and indicated that the type of acid rain was turning to mixed acid rain from typical sulfate acid rain. (2) Because of the effects of acid deposition for decades, the soil acidification phenomenon was very serious in the four kinds of typical forest. The surface soil pH was various from 387 to 447 and with the increase of soil depth, soil pH value decreased. All stands surface soil pH values reduced year by year, but the subsurface soil layers pH values of evergreen broadleaf forest and mixed coniferous broad leaved forest increased. (3) The organic matter content existed significant difference between the four forests, indicating that the stand type had a very important effect on soil organic matter. Because the litter is the main source of organic matter, the surface soil had the highest content and decreased with the soil depth. The content of surface soil of four typical forests were ranked as follows: 〖JP2〗shrubwood （8845 g/kg）> mixed coniferous broad leaved forest (5565 g/kg) > evergreen broadleaf forest (4087 g/kg) > Phyllostachys pubescens forest (2469 g/kg). (4) Under the influence of the leaching of acid rain for a long time, cation exchange capacity (CEC) was very low. For the same kind of stand, the change trend of cation exchange capacity was the surface soil had the highest content and decreased with the depth of soil. The content of CEC of surface soil of four typical forests were ranked as follows: evergreen broadleaf forest (2765 g/kg) > shrubwood （2319 g/kg）> mixed coniferous broad leaved forest (1971 g/kg) > Phyllostachys pubescens forest (1519 g/kg). (5) The content of exchangeable Al3+ of the four typical forests was very high under the effect of acid rain for a long time, and ranked as follows：evergreen broadleaf forest（4097 mmol/kg）> shrubwood（3132 mmol/kg）> mixed coniferous broad leaved forest（3006 mmol/kg）> phyllostachys pubescen（2615 mmol/kg）.In this study, there was a negative correlation between exchangeable Al3+ and soil pH

Investigations of macrozoobenthos in the Jinggu River were carried out both in high flow period (July 2011) and low flow period (April 2012) for researching the impacts of small hydropower plants(SHPs) on macrozoobenthos.Cobble substrate samples were collected with a surber net (0.09 m2); reservoir sediment samples were collected with a weighted Petersen grab (1/16 m2) and cleaned with a 250 μm sieve. Large animals were manually sorted in a white porcelain dish and small ones were sorted under a dissecting microscope. Specimens were all preserved in 10% formalin.Altogether 61 species belonging to 54 genera, 34 families were recorded,among which, there were 7 species of Oligochaetes, 7 species of Molluscans, 44 species of aquatic insects and 3 other species.The measured density of macrozoobenthos was 1135.3ind./m2, and biomass was 7.93 g/m2during high flow period; 1231.6 ind./m2 in density and 6.92 g/m2 in biomass during low flow period. Taxon number of low flow period was much higher compared to high flow period, density also higher in low flow period, while biomass was lower in low flow period.The dominant species in these two seasons were Corbicula fluminea, Hydropsyche sp. and Polypedilum sp..On the basis of individuals, the composition of the functional feeding groups in the Jinggu River was classified as about 50 percent collectors and 50 percentothers.We did hierarchical agglomerative clustering with macrozoobenthic data of the Xiaoheijiang River and the Jinggu River, the analyzed results showed SHPs have caused some impacts on macrozoobenthic resources.Due to the constructions of SHPs, habitat in the Jinggu River can be classified into three types, i.e. reservoir section, waterreducing section and mixing section.Obviously, taxon number of reservoir section was much less compared to waterreducing section and mixing section, and standing crop was highest in mixing section, lower in waterreducing section, and lowest in reservoir section.Results showed that SHPs had the greatest impact on reservoir section, less impact on waterreducing section, and minimal impact on mixing section.Biodiversity and standing crop were higher in the Jinggu River than the main stem of the Lancangjiang River. The reasons of the status of macrozoobenthos were discussed, and we thought the basic reason was SHPs blocked the river longitudinal continuity. Meanwhile, two types of habitat restoration measures were discussed.Ecological flow was the most effective way to restore rivers hydrological regimes, and artificial step pool system was one of the most effective ways to restore physical habitat

The water and energy balance transmission mechanism and process simulation of Yangtze River Headwater region (YRHR), are widely related to land surface process, ecological environment protection, frozen soil engineering,and regional hydrological processes. Due to the great sensitivity to climate change in source area, YRHR is regarded as a hot climate change research area. GEOtop model is a distributed hydrological model with coupled water and energy budget. The model domain consists of a soil profile of specified depth to the ground surface, the heat and subsurface water flow equations are then solved with finite differences schemes. The heat equation is solved as a onedimensional form, while the equation describing the water flow in the soil is solved with a fully threedimensional way. GEOtop model allows a complete coupled description of vertical and lateral flow. The determination of heat flux exchanged from the atmosphere to the ground surface is very important, which constitutes the upper boundary condition of the heat equation. Therefore, GEOtop model is used to model the water and heat transfer processes under bare land, 30%, 65% and 92% vegetation coverage. The model was calibrated using data in situ observations at local scale for: soil temperature profiles, soil moisture profiles, and evapotranspiration under different vegetation coverage. The results show that, the simulation of soil temperature under different vegetation coverage at different depth was ideal, especially for ground surface soil temperature of bare land. The NashSutcliffe (NSE) coefficients of soil temperature were all larger than 09. Compared with soil completely melted periods, the modeling deviation of soil temperature in soil completely frozen periods was larger. Longterm field monitoring found that snow cover in the study area was thinner and melt in fast time, therefore snow module was not contained in our modeling. However, the snow melt and cover for a short time will cause soil temperature fluctuation. In addition, the NSE coefficients of soil moisture were around 0.8, indicating that model can preferably simulate water transfer processes in the active layer soil. The simulation deviation of soil moisture at soil completely melted periods was big. This is because of model not including plant growth module and assuming that the vegetation parameters fixed. Moreover, the modelling of actual evapotranspiration under different vegetation coverage also got desired result. The actual evapotranspiration was overestimated from March to June and from August to September. They were due to freezethaw cyle of daily temperature flucuation and vegetation growing, respectively. All of them will change the albedo and roughness of groundsurface, thus affecting the water and heat transfer processes. In a word, the model is able to predict soil freezing/thawing process, soil temperature, unfrozen soil moisture and actual evapotranspiraion under different vegetation coverage well. Because of fewer parameters needing to rate, thus it reduced the uncertainty of model simulation and improved the simulation accuracy. The GEOtop model shows promising performance in simulating hydrological processes in cold regions. This model can be applied to improve our understanding of the water and heat transfer processes in cold regions

Hydrological investigations were carried out in the upper reaches of the Hanjiang River. The Huangping profile in the Hanjiang River Valley was found and observed in detail in the field which contains a layer of palaeoflood slackwater deposits. The geomorphology and the parameters of the Huangping reach of Hanjiang River were measured in the field. The grainsize distribution was analyzed in laboratory. The result shows that the gray palaeoflood slackwater deposits inserted in the paleosoil were different from the loess and the paleosol. The palaeoflood slackwater deposits recorded a catastrophic floods events that might occur during the Eastern Han Dynasty (1 900-1 700 a B.P). According to the theory of Sedimentology and Hydrology, using the palaeoflood SWD pinch out and SWD thicksand content method,the palaeoflood water level elevation was found respectively for 154.95 m and 156.85 m;Its peak flow wasrestored by slope method, and the ancient flood peak flow was calculated respectively for 65 320 m3/s and 74 442 m3/s. These results were checked with various methods, which indicate the reconstructed peak discharge is reliable. These results are of great significance to exploit water resources and mitigate flood disasters of the upper reaches of Hanjiang River, at the same time, these results are of great significance to understand hydrological response to global climatic change

In this paper, the three years observational data for fog of 39 fog signal stations laid in the Chongqing section of the Yangtze River mountainous waterway are used to investigate the temporal and spatial distribution of fog over the Yangtze River mountainous waterway. Meantime, a neural network is used to simulate the regional fine distribution of fog composite index over the Yangtze River mountainous waterway according to the whole fog and six kinds of geographic information fators such as longitude, latitude, channel width, river bend, river change intensity, river tributaries fork over the whole Yangtze River mountainous waterway (from Yibin to Yichang). The results show that fog of the Yangtze River mountainous waterway increased in winter and decreased in summer overall. Most fog formed from 0 to 8 am and ended from 8 to 12 am, while heavy fog exhibited forming early, ending late and keeping longer time. There were much difference in spatial distribution of fog over the Chongqing section. About 30-50 heavy fogs were occurred in Lanshi to Fengdu section of Peiling and Huanghua section of Wanzhou every year, while less than 5 from Anping to Kuixia section. The simulation results show that we can simulate the distribution of fog over the Chongqing section on the whole by making use of geographic information factors and the neural network. Besides, we can obtain the fine distribution of fog over the whole Yangtze River mountainous waterway when using the neural network further, and the simulation results keep close to the observational results and the field survey in distribution trend. But the simulation results can not represent the actual distribution of fog over the Yangtze River mountainous waterway completely because of local error convergence and limitations of factor selection, thus the simulation test needs more data and impact factors.〖JP〗〖HJ1〗〖HJ〗〖HQ〗

The worldfamous“Three Gorges Reservoir”is situated on the middle reaches of the Yangtze River. The fina1 water leve1 reaches 175meter and the reservoir covers 10000 km of region. It has more foggy days on the river because of the water bodies and special terrain, seriously affecting waterway. And the foggy days is becoming more and more dangerous in the Yangtze River waterway. With the support of the government of Three Gorges Project construction and China Meteorological Administration, 15 meteorological stations and 12 visibility instruments have been installed in 2009, in order to analyze the influence on the regional climate environment. In this paper, based on the meteorological data of 12 meteorological stations along the Yangtze River in the Three Gorges Reservoir Area, visibility of the Yangtze River waterway have been analyzed, in order to analyze the characteristics of visibility along the different regions of Three Gorges waterway, compare the influence of the different vertical sections and the distance from the river.The spatialtemporal distribution characteristics of visibility of Fuling, Wanzhou, and Yichang region have been discussed．It is found that the frequency distribution of visibility of Fuling has the greatest impact on the shipping safety, followed by Wanzhou and Yichang. The monthly variation trend of foggy days in Fuling and Wanzhou district is consistent. The variation within the year is 6 month period. The frequency of fog was more higher in May, June, November and December of the year. The monthly variation of fog is larger in Yichang district. The fog occurs at night and in the morning time, and the frequency peak generally appears in the morning. By verifying the relationship model of visibility and local factors, it showed that the visibility differences of the Three Gorges waterway were due largely to the altitude and water and topography of the monitoring points. The visibility is lower and foggy frequency is relatively higher if the altitude of monitoring points is higher or near the water, and vice versa.

The mountainous channel of the Yangtze River from Yibin city to Yichang city, has complex and diverse climate.The terrain navigation is seriously influenced by the heavy fog. There are very sparse 36 artificial observation platforms along the river,with the distance from 3 to 10 km or more. How to get the unknown point reliable fog information, change the limitation of the subjective judgment alone and provide the scientific basis for waterway traffic control on the basis of the limited observation pointsis very necessary and urgent. In this study,fisher discriminant analysis method is adopted, the unknown point of meteorological elements and the fog around for the center with its rank as the dependent variable, in order to realize the target fog levels of interpolation. According to the data characteristics and interpolation requires of fog along the Yangtze River Waterway, discriminant analysis method is used for five adjacent stations. The fog situation grade and the quarter points of corresponding meteorological elements are divided into different scenarios to establish interpolation equations.Most of the actual grade of fog can be accurately reported. When two neighboring stations and observed fog over the situation, most of the actual target station fog level can accurately calculate;when three or more stations fog are graded 0,meteorological judgment is depended.Vapor pressure and the diurnal range also have a significant positive correlation to the formation of the fog. Breeze promote the formation of fog, the wind tends to increase naturally dissipate. Spring and winter fog situations are highly correlated with meteorological factors,and the compliance rates is high. The probability of reported empty is higher in summer and autumn. Many factors affect the space of fog, including meteorological stations topography, river width, camber back inlets, a tributary of River Inlet and the others alike. Because there is only one year of the fog situation observations, the season of the sample after three cases are limited segments, we need to extend the time scale, increase the number of samples to obtain a better result of discrimination.However, this method has some limitations，the visibility grade interpolation can only provide a reference to the shipping,and visibility values spatial interpolation remains to be further studied