Urbanization affects the structure and function of ecosystem in a city. The “urban-to-rural” gradient is an effective technique to examine spatial pattern and processes of urbanization. Quantitative studies on interaction between landscape pattern and function of urban ecosystem have become the core issues of landscape ecosystem in city. In addition, terrestrial ecosystem carbon cycle research has been the hot issue of global ecosystem, while the urban ecosystem as a type of terrestrial ecosystem is an important source of carbon. It is therefore important for us to study ecosystem carbon cycle in urban area. Although urban green space is an important part in city, we know little of its function in carbon storage. This paper, based on remote sensing images, used geographic information system (ArcGIS 93), landscape pattern analysis (Fragstates 33) and statistics (SPSS 17) to calculate 6 commonly used indicators including physical variables and landscape metrics. Principal components analysis and multiple linear regression were used to assess the urbanization level of Shanghai in a direction. Using biomass regression equations and UTC area to estimate the carbon stocks of urban green space in an urban-to-rural gradient. The results showed as follows. (1)Urbanization indictors can be used to describe the level of urbanization. The gradient of “urban-to-rural” showed spatial differentiation. This kind of differentiation is consistent with the history of development in Shanghai and function of each region. (2)The total carbon storage and average carbon density of urban green space were 4,475, 4107 Mg C and 711 Mg C /hm2 in study area. (3)Distribution of carbon storage along the transect were as follows: the high carbon storage green space is more dispersed in Pudong and Center districts, which were dominated by small green space in residential areas, the high carbon storage green space is more concentrated in Fengxian and Minhang districts, which were dominated by largescale nursery; carbon density trends in different regions are urbanpublic park>residential green space >attached green space>street trees

According to the meaning of region, which can be regarded as a unity of urbanity and rurality, taking unban as criteria of reference, we constructed the evaluative indices system of rurality index and used entropy method to estimate the rurality on the county scale in Jiangsu Province from 2001 to 2012. Taking rurality index scores as variables, we also used coefficient of variation to quantitatively analyze the process and pattern of rurality on the county scale in Jiangsu Province. The results are as follows. Firstly, since the beginning of the new century, with the improvement of the level of urbanization, rurality index in Jiangsu Province has shown the trend of reduction. The evolution of rurality on the county scale showed the special pattern. From 2001 to 2007, the differences narrowed gradually. Then from 2007 to 2012, the differences expanded little by little. Secondly, the development of rurality subsystem was out of balance. The subsystem had significant difference in the land use. However, the population development, economic development and infrastructure had relatively little differences. Thirdly, the spatial polarization along Taihu and Ningzhen region became increasingly obvious. Southern Jiangsu counties gave priority to downward convergence. Northern Jiangsu counties gave priority to upward convergence. The central Jiangsu counties were dominated by upward divergence. Lastly, the spatial and temporal variation of rurality on the county scale was the result of many factors, including location conditions, economic base, infrastructure, social policy, etc. With the development of society and economy, the rurality in Southern Jiangsu area maintained a relatively low level. However, there was an increasing trend in recent years. In order to reduce the rurality in Southern Jiangsu area, it is important to formulate relevant policies to promote the level and quality of urbanization to realize the integration development of urban and rural area. At the same time, the rurality in Northern Jiangsu area was at a high level in a long period. In recent years it has further weakened. The government needed to further increase policy support to gradually weaken the rurality and constantly raise the level of urbanization. The rise of rurality in the central Jiangsu area was obvious. Its development foundation was inferior to Southern Jiangsu area. Economic development and the level of urbanization need to be further improved. On the whole, in order to reduce the spatial differentiation in the counties of Jiangsu province and realize the coordinated development of the counties, it is the need to provide the policies such as favorable industry and tax policy for the development of Northern and central Jiangsu area. We should not only focus on center city building but also speed up the construction of the counties and towns in Northern Jiangsu area. It is necessary to invest the transportation, water, power and information infrastructure in the central Jiangsu area. With those measures have been finished can we narrow the disparities in county development and promote the strategic transformation of rural development.

Road network is the material conditions and prerequisites for forming the metropolitan area network system, and also the main channel of material flow, energy flow and information flow, which plays an important role in the socioeconomic development of metropolitan area. Accessibility is an effectively comprehensive index which can be used for evaluating the developmental level and servo efficacy of road network. Therefore, accessibility study has attracted longterm and sustained enthusiastic participation by many scholars from urban planning and transportation geography, and those who are engaged in regional development. However, the current researches still has many defects in their research methods, perspective, and scale. For example, dividing effects of administrative boundaries and taking equal opportunity for all travel direction as the prerequisite are the two big problems of the current researches on accessibility. For the inadequacies of the traditional accessibility evaluation model based on the shortest path and the narrow research perspectives, this paper reconstructed the accessibility evaluation model and weighted field model based on the shortest transit time, seted up an evaluation index system of township accessibility based on city hinterland, from bottom to top reveals the spacetime patterns and the evolution characteristics of township accessibility with the help of urbanrural road network space database from 2000 to 2011 in Jingzhou: ①Township accessibility evaluation based on city hinterland behaves better in simulating the town’s willingness to travel, and is able to realize the unity of regional accessibility and interregional accessibility. From 2000 to 2011, the optimization of traffic network brings significant time-space compression effect to city hinterland. The spatial pattern of city hinterland based on township areas evolved from “a city (Jingzhou) dominating” to “two cities (Jingzhou and Yueyang) sharing”, and the spatial pattern of county hinterland also experienced a development process from “Jingzhou exclusive” to “peripheral sharing” in the last ten years; ②From 2000 to 2011, the spatial distribution of township accessibility was found to basically follow the distance attenuation law, showing a ring pattern distribution around Jingzhou city, and exhibiting microscopic dynamic and macroscopic stability characteristics in the time sequence: First, the spatial distribution of township accessibility presents a dynamic development trend from a low level of agglomeration to optimal equilibrium. Second, the spatial structure of township accessibility evolves from core periphery to layers. Third, the development of township accessibility has significantly rapid corridors directivity and temporalspatial inertia. ③From 2000 to 2011, the spatial evolution characteristics of township accessibility was found experience a process from “single coreuniaxialweak diffusion” to “single coremulti axisstrong diffusion” to “dual coremultiaxisfull proli”

The generalization of the Pan Yangtze River Delta has become inevitable because of economy development and problems facing in the Yangtze River Delta. Researching evolution of economy space structure the Pan Yangtze River Delta can help us appreciate and grasp its trends of space evolution, and to provide the basic data for regional integration of the Pan Yangtze River Delta. The author analyzed evolution process of the Pan Yangtze River Delta depending on Diffusion Theory and constructing Diffusion Effect Model of Field Logarithmic. The research showed that the primary urban effective regions are distributed along the Yangtze River Delta and Hangzhou Bay. They evolve from shapes of sparse pots, “S”, pipi shrimp, to that of bream. Areas of extremely strong field regions, stronger field regions and ordinary field regions were found to decrease, while areas of weaker field regions and the weakest field regions were found to increase. According to evolution laws and mechanism of spatial structure of economy, accessibility, urban field in the Pan Yangtze River Delta, especially spatial structure urban field, on the principle of establishing development axis in accordance with city nodes, establishing planes in accordance with axis, we conducted spatial integration for city nodes, industrial development axis and industrial development metropolitan in the Pan Yangtze River Delta and built first grade industrial development axis as a hairbrush compositing of the development axis along the Yangtze River, coastal zone, huninghe, huhangqu. Under first grade industrial development axis of hairbrush, we set Nanjing, Hangzhou, Hefei, Suzhou, Ningbo as diffusion sources and built the second grade development axis. And field strength in the Pan Yangtze River Delta was classed as core area, adjoining area, outer area and based on it urban economic region in the Pan Yangtze River Delta was classed as kernel metropolitan, adjoining metropolitan, outer metropolitan.

To clarify variation of Coilia nasus biomass and explore the conservational effects of the coastal waters on anchovy resources, investigations were carried out along the Jingjiang section of the Yangtze River 2 or 3 times per month from 2002 to 2013 using a stow net． The results showed that occurrence rate of C.nasus was 946% in 369 samples, accounting for 518 % (individual) and 546% (weight) of the total catch yield, respectively. The average abundance and biomass (CPUEN and CPUEW) of C.nasus was 167 ±199 ind. and 1066±1095 g. Being a dominant or subdominant species of the fish assemblage in 12 years, C.nasus was not stable in resource. The highest biomass in 2010 was 54 times higher than the lowest in 2002. The average body weight and body length was 75 g and 1236 mm, respectively. 1 315 specimens were determined as three age compositions: 789% of specimens as 0+ year age group, 207% as 1+ year age group and 05% as 2+ year age group. 2+ year age group only appeared in April and May, and accounted for 30% of the total individual. Thus, the larvae were major components of C.nasus population along the coast water. According to monthly length distribution of 0+ age group individual, larvae and juveniles began to appear in the coastal zone after hatching, coastal habitats supposedly play an important role in maintaining anchovy recruitment stock. Although the closed fishing season in the Yangtze River during April 1st to June 30th could protect the total 426% larvae and juveniles, properly longer fishing ban period in coastal region might acquire better protective effect. Maintaining habitat integrity of coastal waters is also an important measure to protect the resources of C.nasus larvae.

Urbanization and land use change are two processes with farreaching consequences at both global and local scale. Vegetation is an important characterization of terrestrial ecosystem function. Analysis of spatialtemporal change of vegetation greenness is an effective way to reveal the degree of vegetation degradation. Urbanization reduces the amount of vegetation by clearing natural and semi-natural vegetation for construction over large tracts of land. To study the impacts of land use on vegetation coverage is of significance to direct regional urban planning and land use planning. The Normalized Difference Vegetation Index (NDVI) can be used as a proxy for vegetation productivity and vegetation greenness. The Yangtze River Delta (YRD) is one of the most developed regions with highest urbanization speed in China. Rapid urbanization has occupied a large area of arable land and forest in this area, with a significant decrease in greenness and in vegetation productivity. Based on SPOT NDVI data from 2000 to 2010, land use data in 2000 and 2010, taking YRD as a study case, this paper studied the distribution of decrease in NDVI, and the relationships between land use change and vegetation degradation. Ordinary Least Squares was applied to analyze the negative trend of NDVI in 11 years. We analyzed the effect of land use change and construction land growth on NDVI by using 1-km area grid data. In 2000-2010, the highvalue region of NDVI was concentrated in mountain area of Southeast and West Zhejiang and the northern plain of Jiangsu. The low value area was mainly in and around big cities such as Shanghai, Hangzhou, Nanjing, Suzhou, Wuxi, Changzhou, Ningbo and so on. Spatial Differentiation of NDVI reflected the diversity of landscape. The vegetation cover in 14% of the study area decreased significantly. Vegetation degradation was mainly distributed in the south of the Yangtze River and in the north and east of Taihu Lake, around Hangzhou Gulf, or around big cities, such as Nanjing, Nantong, Taizhou (Zhejiang Province) and so on. Land use change was one of the main causes of vegetation degradation. About 35% of the region where vegetation cover significantly degraded was related to conversions of cultivated land and forest to construction land, and about 301% of areas of degraded vegetation are attributed to the transformation from paddy fields to fishponds. While the dominant land cover type in each grid still unchanged, the proportion of construction land increased at a different degree. We conclude that large areas are being continually and heavily impacted by the high levels of human use and unplanned urban development over the last decade. Our results indicate that varying patterns and processes can be detected using changes in NDVI values. UGBs (urban growth boundaries) should be used to contain future development, and protect farmlands and open space from development. We argue that metropolitan areas adopt compact-development policies. The local governments are urged to draw “red line” for farmland protection and ecological protection. There is an urgent need for the authorities to introduce laws and policies to manage the uncontrolled urban expansion and fragmented landscapes.

Along with the increasing environmental pressure and ecological crisis due to forest overexploitation, studies on the quantitative relation between soil and water conservation function and forest ecological system, and on the water conservation mechanism of forest soil have been widely focused by ecologists, foresters, and expert of soil and water conservation all over the world. In order to evaluate the soil and water conservation function of different vegetation types, six widely distributed vegetation types in Lushan Nature Reserve of Jiangxi Province, including evergreen broadleaf forest, Yushan bamboo, evergreendeciduous broadleaved forest, deciduous forest, Huangshan pine, and Masson pine, were selected as study object. On the basis of the data of 15 indexes such as canopy density, richness, soil bulk density, capillary porosity, soil stable infiltration rate, litter reserves, litter decomposition intensity, elevation, and terrain slope obtained from field investigations and laboratory experiments, a multihierarchy and multiindex comprehensive evaluation system of soil and water conservations function was established, and the weights of various indexes were calculated and compared according to the total sorting of different index levels with the method of analytic hierarchy process (AHP). The results showed that the weights of vegetation factor, soil factor, ground litter factor, and terrain factors are 0200 5, 0401 1, 0248 0, and 0150 4, respectively. It indicated that the soil factor of forest ecological system has great influence on soil and water conservation of forest land. The integrated assessment values of six vegetation types were obtained by linear scoring function, and the order of soil and water conservation capacity of six vegetation types are: evergreen broadleaf forest (0701 3)>Yushan bamboo (0672 5)>evergreendeciduous broadleaved forest (0543 8)>deciduous forest (0494 7)>Huangshan pine (0418 1)>Masson pine (0316 4). The results indicated that the vegetation of evergreen broadleaf forest has the highest soil and water conservation capacity, while the Masson pine has the lowest capacity among the six vegetation types. The capacities of Yushan bamboo, evergreendeciduous broadleaved forest, deciduous forest, Huangshan pine are in between. The research results have certain reference significance to the Scholars of soil and water conservation.

Hydrologists have attempted to relate the hydrologic response of watersheds as runoff production from rainfall to watershed topographic structures for many years. Unit hydrograph explains many characteristics of the basin response to rainfall input. A number of approaches have been developed to derive a unit hydrograph from watershed geomorphology, but essentially they are all involved in using measurements of distance, velocity and time to derive physical characteristics of the watershed to parameterize a unit hydrograph in the absence of observed runoff and rainfall data. In order to solve the problem of being dependent on the rainfall and runoff data, taking the Yanduhe catchment of Three Gorges in Yangtze River as the study area, this paper proposed a new method to derive distributed unit hydrograph and a revised Muskingum method based on watershed geographic characteristics and hydrodynamic conditions. First, the basin is divided into a set of subbasins according to natural watershed line and topographic information is extracted based on DEM and GIS tools. Kriging interpolation method was used to estimate the precipitation depth at the centroid of each subbasin. Secondly, the areatime histograms derived by means of digital elevation model were translated to dischargetime histograms. And then the dischargetime histograms were routed through a linear reservoir and unit hydrographs were obtained. In addition, the Muskingum parameters K and x were estimated based on the physical characteristics of river reach, including slope, width and length. Finally, the HECHMS model is used to simulate and analyze the rainfallrunoff response processes coupling with proposed distributed unit hydrograph and Muskingum model. The seven evaluation indices are used to estimate and validate the simulation results involving water balance, goodnessoffit, peakflows and lowflows. The results showed that, 80% of the 25 floods has a relative error of peak flow of less than 20%, 96% has a relative error of runoff amount of less than 20%, and 84% has a NashSutcliffe coefficient of greater than 0.8 is. The simulated flow agrees well with the observed flow at the outlet of the Yanduhe catchment. The proposed distributed runoff modeling method can be used to simulate the rainfallrunoff processes in the mountain basins or these ungauged basins based on DEM data and GIS information.

n recent years, with the rapid growth of economy and population, a large amount of wastewater with high level of N and P has been discharged into the natural waters. It has been speeding up the process of eutrophication of lakes. The Dianchi Lake is in a status of heavy eutrophication, accompanied with frequent occurrence of cyanobacterial blooms. Many efforts have been proposed to improve water quality. Bioremediation with water hyacinths was one of the most efficient approaches to reduce the nutrient load and control cyanobacterial blooms. Partial death of water hyacinth (Eichhornia crassipes) in largescale confineplanted enclosures in Waihai of Dianchi Lake was however observed. Water physicochemical properties, cyanobacterial biomass and the phytopathology of water hyacinth were investigated in areas of normal growth, mild death, and severe death as well as the blank control (area without water hyacinth planted) in August, 2013, in order to find out the causes of death. The results showed that the cyanobacterial biomass in the plots of mild death and severe death ((421±049)×109 cells/L and (75700±1900)×109 cells/L, respectively) were significantly (P＜005) higher than those in the plots of control and normal growth ((014±009)×109 cells/L and (146±011)×109 cells/L, respectively). The same trend was observed for the concentration of NH+4N. The concentration of NH+4N in the plots of mild death and severe death (1144±002 mg/L and 36987±1537 mg/L) were significantly (P＜005) higher than those in the plots of control and normal growth (032±001 mg/L and 034±001 mg/L). The concentration of dissolved oxygen (DO) in the plots of mild death and severe death were only 140±013 mg/L and 030±004 mg/L, respectively, which were significantly (P<005) lower than those in the control and normal growth plots (770±083 mg/L and 680±097 mg/L); The redox potential of the severe death plots (Eh -27970±2970 mv) (Eh) was significantly (P<005) lower than those in the other three plots. In addition, no evidence of plant disease was found based on pathological detection. Hence, the death causes of water hyacinth might be a consequence of cyanobacteria accumulation, followed by algal biomass decomposition which resulted in hypoxia of water with excessively high concentration of NH+4N. These findings could provide references on theory and practice for aquatic ecosystem restoration with water hyacinth. The present research has brought up a topic of using water hyacinth as a cyanobacteria blocker, which will influence the migration of nutrients and the dynamics of nitrogen, phosphorus and carbon cycle in lakes. Further research in this field may provide new strategies of ecological restoration in practice.

Water resources in Yangtze River Basin is richer, but water of per capita is only 30 percent of the world average. How can we improve agricultural water use efficiency and overall agricultural production capacity in Yangtze River Basin? It is not only an urgent issue in the current water conservancy work, but of great significance to agricultural sustainable development and food security. Because green water resource of annual precipitation is of great importance to crop growth, the green water is included in total agricultural water consumption different from the one from current statistics. Ten provinces are taken into consideration except Tibet autonomous region (TAR) and Zhejiang province because TAR is taking as not agriculture but the livestock industry and most area of Zhejiang lies in Southeastern rivers. Thus the research objects include Shanghai, Jiangsu, Anhui, Jiangxi, Hubei, Hunan, Yunnan, Qinghai, Chongqing and Sichuan. Then some indicators, for example amounts of fertilizer, sown area of agricultural crops, agricultural machines, agriculture labor and agriculture water consumption, are selected so as to estimate agricultural water use efficiency of Yangtze River Basin. Based on the panel data of 10 provinces in Yangtze River Basin from 1998-2011, agricultural water use efficiency is estimated by the method of superefficiency DEA. On the basis of the efficiency estimation, the factors of agricultural use water efficiency are tested by Tobit model. Based on the water efficiency measurement method of Hu &Wang(2006), DEA model is used to measure agricultural water use efficiency from basin level. Moreover, according to features of water resources and agricultural water use, etc., dummy variables S1， S2， S3 are introduced in Tobit model. In order to know the deeper causes of the change of the agricultural water efficiency, some factors are observed including the water resource of per capita, annual precipitation, crop planting structure, watersaving irrigation technology, irrigation fees and opening up of agriculture. Some conclusions are as follows: ①During the research period, agricultural water use efficiency shows rise trend in waves; the efficiency of upper，middle and low reaches in Yangtze River Basin is on the decrease. ②Irrigation fees, watersaving irrigation technology and opening up of agriculture have significant positive effects on the efficiency. And annual precipitation has significant negative effects on the efficiency. In addition, water resource of per capita has negative effects on the efficiency, but not statistically significant. Results show that improving agricultural use efficiency in Yangtze River Basin, especially the middle and upper reaches, in which water resources is richer; in aspect of agricultural watersaving policies, adjusting agricultural irrigation water price, strengthening agriculture technology innovation and expanding opening up of agriculture can get remarkable watersaving effects.

Ranging extensively with a complex terrain and a great altitude difference, it shows an extremely great difference in climatic resources in the Northwest Sichuan plateau. In this area, the main feature of climate is plenty of sunshine and slightly low temperature and lesser precipitation, so the major industries are economically primarily supported by animal husbandry. The beginning date and the ending date of limited boundary temperature of livestock represent the effective period of pasture growth, and the climate resource from beginning date to ending date represent how much quantity of climate resources can be used effectively by animal husbandry. Therefore, the two parameters play a very important role in animal husbandry. The global climate changes, featured by temperature increases, will inexorably affect changes in the farming and animal husbandry environment. As shown by a great many research statistics, climate warming leads to increased frequency extreme climatic events, thereby constituting a severe threat to agriculture, animal husbandry and ecological safety. Employing the linear trend method, the MannKendall trend test and the Morlet wavelet analysis, this paper explicates in detail the change characteristics of climate resources elements for livestock such as beginning date of 0℃ and ending date of 5℃ and others, based on the observation data gathered by 31 weather stations from 1961 to 2012. The result shows that : (1) the start date of 0℃ and end date of 5℃ differs greatly from area to area, due primarily to the impact of elevation and altitude; (2) Interannual changes in livestock climatic resources shows increasing trend overall, but regional variations are uneven; (3) different parameters demonstrate different interannual changes, evidenced by that fact that accumulated temperature is on the increase year on year, while decadal changing trends of sunshine times are characterized by an increase (one  decade) and two decrease (two decades ) and an increase (one decade); but rainfall has an decadal change pattern contrary to that of sunshine times, which features a decrease (one decade) and two increase (two decades) and one decrease (one decade) pattern; (4) the various parameters pointed to a distinct mutation characteristics, with mutation time occurred primarily over the 1980s; different parameters feature different types of mutation; (5) the climatic resources for animal husbandry have a distinct periodic trend of change; different parameters vary in periodic length; in especial, rainfall is dominated by a short periodic oscillation (approx.4 a). In general, beginning date of 0℃ is advanced and ending date of 5℃ is postponed in the observed area. So this change feature implies that the average temperature and accumulated temperature from beginning date to ending date of livestock limited temperature increased. The increase in interval temperature and accumulated temperature helps extend the effective period of growth of pasture. Pasture species with a longer effective period of growth may be introduced appropriately to promote pasture yield. This plan is very beneficial to the development of animal husbandry. Although sunshine hours develop a minimal decreasing trend, the situation will not exert a substantial impact on the growth and yield of pasture.

In order to understand the reliability of total precipitable water vapor (TPW) derived from FY2E satellite data over the Southeast of Tibetan Plateau and its adjacent areas, FY2E TPWs are compared with the radiosonde (RS) TPWs during the period from 2010-2012. The results show that over the Tibetan Plateau the average monthly FY2E TPWs are larger than RS TPWs except in July. The relative errors are less than 25% in June and July and more than 50% in other months, especially in January as high as 78045%. The correlation coefficient between FY2E TPW and RS TPW is negative. Over the low altitudes the average monthly FY2E TPWs are larger than RS TPWs in June and July and smaller in other months. The relative errors are less than 4% in May to August, but in January as high as 105.84%. The correlation coefficient is greater than 0.5 during the period from April to October. The linear correction model of FY2E TPW with a standard error of 6.57 mm could be improved to count error in individual sites.

In order to promoting the building of ecoisland and low carbon development for Chongming Island, the LEAP Model was used for the prediction of Chongming Island's medium and longterm carbon emissions, on the basis of a complete assessment of Chongming Island's energy consumption and GHG emissions in recent years, with application of the bottomup sectorbased GHG inventory methodology. Besides, the LMDI method is applied for quantitative analysis of the contribution ratio of major driving factors influencing future carbon emissions in Chongming Island. The results showed that under baseline scenario, total energy consumption in Chongming island will grow from 101 million tce in 2010 to 533 million tce in 2050, and the growth rate of energy demand for business and service industry is most obvious, followed by household. The total net GHG emission, equals to the sum of emission from energy combustion, agricultural activities and waste disposal, minus carbon sink, also has an increasing trend, and it will grow from 238 million tCO2e to 539 million tCO2e in 2050, among which, the emission from energy combustion contributes most in total GHG emission, and carbon sink due to wetland and woodland can offset only 57% of the total GHG emissions in 2050, compared with 12.8% in 2010. However, with a series of optimized actions under mitigation scenario, including energy structure optimizing, industry structure adjustment, energy efficiency improvement and carbon sink capacity enhancement, the total energy consumption will reach a peak around the year of 2039. The ratio of GHG emission from energy combustion will decrease significantly, while emission from agricultural activities will play the most important role in total GHG emissions. By 2050, the carbon sink will have the potential to offset the total GHG emissions. The analysis of the contribution ratio of influencing factors to GHG emission demonstrates that, compared with the level of 2010, economy development contribute more in the growth of GHG emission than population growth and the improvement in living standards, however, energy structure optimizing and energy efficiency improvement will have a great contribution for the realization of ‘zerocarbon emission island’ longterm target, with a contribution ratio of 49% and 23%, respectively. Finally, the medium and longterm low carbon development target and priority areas are put forward.

Light is one of the main environmental factors influencing plant growth and distribution. In natural conditions, high plant usually shades the adjacent species, which inhibit the growth of some ambient species. The light intensity partially affects the condition of habitat, such as surface evaporation and salinity. Consequently, available light will probably structure plant community in some regions. In order to understand how does light affect the distribution of Spartina alterniflora and Scirpus mariqueter in Yangtze River estuarine salt marsh, we explored the response of plant distribution to photon flux density (PFD) in different vegetation zones at the salt marsh of the Chongming Dongtan. The results showed as follows. 〖JP2〗The photon flux density was 1 570 μmol/（m2·s） in the Spartina zone, and 1 556 μmol/〖JP〗（m2·s） in Scirpus zone. In the core zones of Spartina and Scirpus, the effect of light on plant growth and reproduction depended on the capacity and efficiency of using light. However, in the mixed zone of Spartina and Scirpus, the photon flux density on the top of Spartina was significantly greater than that on the top of Scirpus, with the value of 1 398 μmol/（m2·s） and 601 μmol/(m2·s), respectively. Spartina shaded 63% of lights of reaching the top of Scirpus in the mixed zone. With the increase of biomass and height of Spartina, relative shading effect of Spartina on Scirpus was significantly increased(P<0.05). The deficiency of light significantly affected the colonization and distribution of Scirpus in the mixed zone, such as low relative growth rate, and decreased biomass and density. As a result, the shading effect of Spartina constrains the distribution of the upper Scirpus, which further resulted in the loss of habitat of Scirpus adjacent to the exotic Spartina.

Remote sensing inversion is one of the effective ways to monitor the distribution of suspended sediment concentration (SSC) in water surface. Nevertheless，the present empirical regression models are based on assumption of large samples, while the samples number are actually small in most cases, so it is necessary to introduce new retrieval models which could be based on small sample number. Support Vector Machine (SVM) is established on the theories of Structural Risk Minimization Principle and VC Dimension, it has better generalization ability and is suitable for small-sample regression model. In this paper, one SVM remote sensing retrieval model for SSC has been established with HJ1B CCD2 satellite images and synchronous in situ SSC data in the middle reaches of Yangtze River, and its parameters was optimized by using Fruitfly Optimization Algorithm (FOA). The results showed that, SVM model has higher prediction accuracy and stability than the traditional empirical regression models, and in the parameter optimization of SVM model, FOA algorithm has satisfactory results and much smaller calculation amount than Grid Search Algorithm. Finally, the already trained SVM model was used to retrieve SSC in the water of Yangtze River and Dongting Lake around Chenglingji, and the spatial distribution features of SSC was analyzed. The results showed that, SSC is significantly smaller in the mainstream of Yangtze River than in Dongting Lake. This is mainly caused by significant decrease in sediment discharge because of Three Gorges Project. As a result, one blending zone can be distinguished in the Yangtze River between Chenglingji and Honghu city when the muddy waters of Dongting Lake flows into the river. In addition, the SSC is significantly higher in the outlet channel than in the other area in Dongting Lake, which may be caused by the strong disturbance of the sand mining activity in the region.

Recently, reverse density flow was found in many tributary bays of Three Gorges Reservoir (TGR), such as Xiangxi River and Daning River. Nutrients of high concentration carried by intruding water from TGR are likely to be the main nutrient source of these tributary bays. Due to the multifaceted importance of water quality in the Shennong Bay (SNB), the eutrophication in SNB increasingly draws extensive attention of local government. In addition, the water ecenvironment change of SNB are strongly affected by the regulation of TGR. Therefore, continuous monitoring has been carried out in SNB to study the hydrodynamics and their impacts on nutrient distribution during preflood water supply period. Results of the hydrology, water quality and aquatic ecology of SNB were presented in this paper. According to the water regime information of TGR during the period of monitoring, on the basis of the daily change extent and variation trend of water level, the preflood water supply period of TGR in 2013 can be divided into three stages. The first was February 3 to April 5, which lasted 62 days, the water level changed slowly from 170.07 m to 161.33 m with a total decrease of 8.74 m and by an average daily decline of 0.14 m. The second stage was April 6 to May 10, water level changed from 161.36 m to 160.21 m with an overall decline of 1.15 m. The third stage was May 11 to June 21, water level changed rapidly from 160.15 m to 145.06 m, creating a total decline of 15.09 m with an average daily decline of 0.36 m. It can be seen from the spatial and temporal distribution of flow rate in SNB that flow velocity ranged from -0.249 m/s to 0.246 m/s in the bay, and bidirectional flow phenomena persisted during the period of monitoring as the mainstream water of TGR was intruding into SNB in a form of reverse density flow from varied depths. It again provided a piece of evidence for the universal presence of reverse density flow in tributary bays of TGR. This special flow pattern in SNB provided a hydrodynamic basis for nutrient transport, and nutrient distribution of tributary bays was obviously affected by the mainstream of TGR. Affected by the intrusions from mainstream of TGR, nutrients decreased as the distance from estuary of SNB increased until the end of the bay, the mainstream water of Yangtze River supplied a large number of nutrients to SNB. Form and range of intrusions can be affected by water level management which was proven to have interplays between the algal blooms. At the same time, sustained and steady change of the water level can make a specific type of intrusion so that stable water stratification can form which was proved to be related to algal blooms in tributary bays of TGR. Therefore, algal blooms and eutrophication in tributary bays of TGR can be resolved through reservoir operation.

The water conservation area in the Three Gorges Reservoir plays a key role in water and soil conservation, biodiversity protection, and even in the health of Yangtze River and ecological safety of the state. With the rapid development of urbanization, industrialization and a huge increase in water resources and energy consumption in this area, the structure and function of the original ecosystems, to some extent, have been destroyed in recent years, resulting in a series of ecological and environment problems. All of these changes have attracted great attention from ecologists, environmentalists and geologists over the past decade, but the most of studies focused on the geological disasters, water and soil loss and the environmental problems of drawdown area. The knowledge to elaborate the precise impact that the impoundment of the Three Gorges has effect on the structure and function of the ecosystems is extremely sparse. The goal is to provide us with theoretical support for water resource management and collaborative development of nature and society. This paper, using remote sensing classification data of three periods (in Aug. 2000, Aug. 2005 and Aug. 2010) as data sources, combined with field verification and ecological spatial methods to analysis the spatialtemporal changes of ecosystem pattern in the Three Gorges Reservoir Water Conservation Area during 2000-2010. To establish the evaluation index systems of ecosystem pattern change in the study area, we used the method of ecological space analysis that is to solve the problem from the perspective of ecological system structure, the characteristics of the landscape pattern and the transformations of ecosystem. Results showed as follows. The spatial distribution of various ecosystems is different obviously. Forest and farmland ecosystems are the main types located in this region. Forest ecosystems are mainly distributed in the higher altitudes and high mountains areas of east and Midwest of Three Gorges Reservoir, while farmland ecosystems are mainly distributed in the west flat areas. The Three Gorges Reservoir flooded a lot of farmland and woodland, and eventually led transformation of forest and agricultural lands to wetlands, with 179.99 km2 and 191.27 km2 respectively. These newborn wetlands are mainly distributed in the main stream and tributaries areas of the Yangtze river. The main reason for these changes is that the areas below 175 m elevations on both sides of the Yangtze River were directly converted to wetland after the impoundment of the Three Gorges Reservoir. Urban construction occupied part of farmland and woodland，then causing other ecosystem (mainly is the artificial surface) areas increased 506.63 km2. Total area of the forest ecosystems didn’t decrease sharply due to the project of returning grain plots to forestry and others related ecological projects. Comprehensive ecosystem dynamic in the Three Gorges Reservoir water conservation area was 1.40% during 2005-2010, but this data had been increased to 2.39% during 2005-2010, which means that the strength of ecosystem conversion was gradually enhanced. Conversion intensity of dynamic ecosystem types in this area was 188% from 2000 to 2005, but this data had been sharply declined to 0.44% during next five years. That is to say, the overall ecosystem conversion has deteriorated in the later period.

It has been 〖HT5〗worldwidely trying to increase soil carbon sequestration to mitigate carbon emission pressures. The spatial distribution of soil organic carbon (SOC) pools, and the dynamics in storage and loss of SOC are internationally frontier research fields. Soil organic carbon pool is an important component of terrestrial ecosystem, and soil organic carbon plays a key role in the carbon cycle dynamics. Because of the varied study scales and methods, there exists a huge difference in various results for the current estimates of our country’s soil organic carbon pool. Research on soil organic carbon storage and its spatial pattern characteristics under typical county scale could provide a reference for regional carbon sequestration, and provide a basic data supporting for the study of regional soil organic carbon storage in China. Based on the latest data in 2012, combined with GIS and GPS techniques, the soil organic carbon density and soil organic carbon stock were estimated and its spatial distribution pattern was analyzed, in the typical hilly area of the central Sichuan Basin. The results showed that the soil organic carbon densities of these major soil types ranged from 1.11 kg m2 to 4.26 kg m2 and the average soil organic carbon density in hilly areas of central Sichuan Basin was 266 kg m2. The soil organic carbon density of paddy soil and dry land were 3.45 kg m2 and 2.34 kg m2, respectively, which were both lower than that of national level. The total soil organic carbon stock of the Yanting was 2.50×109kg C in the depth of 20 cm. The maximum SOC stock was in purple soil group with 1.53 ×109kg C, followed by paddy soil with 0.93×109kg C, accounting for about 98% of the total SOC stock in Yanting County altogether. The soil carbon storage richness index (RI) of each soil type was low, indicating that the SOC storage capacity of each soil type was in the lower level. Soil erosion is prone to happen in the purple soil area due to its natural property and the shallow topsoil as well as the steep slope gradient of upland. Furthermore, the soil erosion is seriously affected by the rain in summer. Therefore, contour plough, crossslope planting, straw and residues returned to cropland will effectively prevent the loss of soil organic carbon. There was a large spatial difference of cropland SOC between north and south in Yanting County, and with increase of slope gradient, soil erosion exacerbated and soil organic carbon density showed a decreasing trend. In the county scale, the climate difference and the types of vegetation have little effects on the spatial pattern of cropland SOC, the spatial difference of soil type and topography are the main reason for the formation of the SOC spatial pattern.

Litter decomposition, as one of the important processes in the forest ecosystem, is mainly controlled by climate, forest type, litter quality, and soil organisms. In order to investigate the mass loss rates in for the different mesh sizes of litterbags and analyze the contributions of soil fauna and soil microbe to the litter decomposition, a field experiment using litterbags was conducted in Picea aspoerata pure and mixed plantations of western Sichuan. First, our results showed that the total amount of soil fauna was decreasing during the whole litter decomposition stages, which suggested that soil fauna was the dominant factor of the litter decomposition at the early stage. We also found that the phytophagous soil macrofaunal species during the whole litter decomposition stages appeared earliest, followed by the predatory and saprozoic species. Correlation analysis showed that the correlation coefficient of nematode amount and litter decomposition rate was the highest, followed by that of macrofauna amount. Secondly, quantity of soil microbe was increasing during the whole litter decomposition stages, which meant that the microbe prevailed as the regulator of the litter decomposition at the later stage. Correlation analysis showed that the correlation coefficient of litter decomposition rate with fungus quantity and was higher than those with bacteria and actinomycete. Thirdly, we found that the rates of litter mass loss in P. asperata pure plantation were lower than that of the mixed plantation. The decomposition rates of small mesh litterbags in pure plantation were 65.51%, 95.73%, 98.91%, 94.8% of that in the mixed plantation and the decomposition rates of big mesh litterbags in pure plantation were 89.83%, 92.95%, 98.13%, 97.13% of that in the mixed plantation at 3,15,21,24 months respectively. The difference of the rate of litter mass loss between two forest types was more significant at the early stage than at the later stage and more significant in small mesh litterbags than in big mesh litterbags. Our results inferred that the rates of litter mass loss were influenced not only by the quality of litter, but also by the soil organisms which involved in the litter decomposition, especially nematode, macrofauna and fungus.

The emerged plant Nasturtium officinale R. Br. is a wild vegetable widely distributed in Europe, Asia and North America, and can grow rapidly in nutritious water. In a preliminary study, the cadmium content in shoot of N.of〖KG-*7〗ficinale reached 133.52 mg/kg when the dose of cadmium was 60 mg/kg in soil, exceeding the critical value of a Cdhyperaccumulator (100 mg/kg), indicating that this plant might be a Cdhyperaccumulator. To further the understanding on the cadmium accumulation characteristics of N.of〖KG-*7〗ficinale under various concentrations of cadmium and identify whether this plant is a Cdhyperaccumulator, a pot experiment with cadmium concentration gradient (0, 25, 50, 75, 100 mg/kg) in soil was conducted to study the growth characteristics, the cadmium tolerance and the cadmium accumulation characteristics of N.of〖KG-*7〗ficinale. The results were showed as follows. The cadmium contents in root and shoot of N.of〖KG-*7〗ficinale increased with the increase of cadmium concentration in soil, while the number of branches, the root biomass, the shoot biomass, the chlorophyll SPAD value and the resistance coefficient decreased. The leaves of N.of〖KG-*7〗ficinale appeared yellow when the concentration of cadmium in the soil was greater than 50 mg/kg, and the area of yellow leaf increased with the increasing cadmium concentration in soil, indicating that N.of〖KG-*7〗ficinale had been seriously poisoned by cadmium at these high doses. When the cadmium concentrations in soil were greater than 0 mg/kg, the root/shoot ratio of N.of〖KG-*2/5〗ficinale showed an increasing trend with the increasing concentration of cadmium in soil, indicating that N.of〖KG-*7〗ficinale could increase the proportion of root biomass to enhance the tolerance to cadmium stress. The cadmium content in shoot of N.of〖KG-*7〗ficinale exceeded 100 mg/kg when the dose of cadmium was more than 50 mg/kg in soil, up to the maximum of 214.84 mg/kg (100 mg/kg cadmium in soil). The shoot bioconcentration factor (BCF) of N.of〖KG-*7〗ficinale was greater than 1 and increased with the increase of cadmium concentration in soil. The translocation factor (TF) of N.of〖KG-*7〗ficinale was less than 1 and decreased with the increase of cadmium concentration in soil. The cadmium extraction in root of N.of〖KG-*7〗ficinale was increased with the increase of cadmium concentration in soil. The cadmium extraction in shoot of N.of〖KG-*7〗ficinale was increased when the dose of cadmium was no more than 50 mg/kg in soil, and decreased when the dose of cadmium was more than 50 mg/kg in soil. The amount cadmium extraction of N.of〖KG-*7〗ficinale got the maximum at the dose of 50 mg/kg cadmium in soil, reached 192.23 μg/plant. In field investigation, we found that N.of〖KG-*7〗ficinale had strong tillering ability, easily survived by cutting, and suitable for mowing. Therefore, N.of〖KG-*7〗ficinale is a Cdaccumulator, and could be used to remediate Cdcontaminated less than 50 mg/kg paddy field soil. In addition, N.of〖KG-*7〗ficinale could not be as wild vegetable to eat in cadmium contaminated areas.

According to the newly revised “Law of the People’s Republic of China on Soil and Water Conservation”, the delimitation of Soil and Water Lossprone Areas is significant and the new Soil and Water Conservation Program is quite necessary. It’s different between assessment on “Sensitivity to Soil and Water Loss” and “Soil and Water Lossprone Areas”. In rapid urbanization areas, the artificially pressure should be emphasized in the research of Soil and Water Lossprone Areas. The plain area of Jiangsu Province is determined to be the studied area which is around 8.21 km2. Based on the “PressureStateResponse” conceptual model, an index system of twelve indices is established to delimiting Soil and Water Lossprone Areas. The pressure index, which describes the pressure that human activities or nature factors exerting on the soil and water environment, consists of landuse intensity of human disturbance, population density, fixedasset investment, distance to the city, distance to major transportation routes, average annual precipitation, relief of topography, soil erodibility Kfactor, vegetation coverage, and river density. The state index, which relates to the situation of the soil and water loss, is composed of the ratio of soil and water loss areas. The response index, which reflects the reaction of human beings to protecting environment, is defined as the areas protected by the Ecological Red Line. The indices weight is obtained with the improved classical analytical hierarchy processes. Through digitizing, the spatial database including the indices’ maps and their attributes data is built in ArcGIS software. Each index map is converted into grid format with size 250 m×250 m. Then each index is classified into several classes with regard to their changing in Jiangsu, and each class is valued with 1/3/5/7/9 according to their impacting degree on soil and water loss. Subsequently, the values of the indices classes are multiplied by derived weights for each index and then are summed together. Furthermore, the evaluation and analysis is made separately from the three sublevel indices of pressure, state, response and the general index. The results showed that the distribution of the pressure which would cause soil and water loss is common in the plain area of Jiangsu Province. The area of Ⅲ degree and above pressure accounts for 40.75%, and artificially pressure is greater than the natural pressure both in grade and area. The areas ofⅠ to IV degree Soil and Water Lossprone Areas accounts for 10.12%, 42.90%, 25.73% and 1.24%, respectively. There is no V degree Soil and Water Lossprone Areas. Finally, the regions confirmed as the Soil and Water Lossprone Areas of Jiangsu Province accounts for 26.97% of the total area, mainly distributed in the regions such as the urban district and suburb of the city and the county, urban area of the town, and development zones, as well as the Coastal Plain Sandy Area, the Highcontent Sands in Tongnan Area, and the Disused Sandy Districts of the Yellow River. The evaluation results of the units which have soil and water loss data are consistent with the actual situation, indicating that the results can basically reflect the characteristics and statue of soil and water loss in Jiangsu Province. The result can be used as an important basis for Soil and Water Conservation Planning in Jiangsu Province.

The research of historical flood is playing a more and more important role in the risk assessment and prediction in recent years. The research on interactions between flood disasters and flood factors in history could provide analogies for better understanding of the underlying mechanism and impacts of the current and future floods. To investigate the decisive role of different floodfactors interactions on flood hazards, the five types of floodfactors in the Yangtze River Delta during 1644-1949 including continuous rainfall, typhoon, tidal disaster, upstream flood and heavy rainfall were yearly identified and evaluated based on historic documents. And the yearly total floodfactors values sequence was accordingly obtained. The results showed that: (1) The average value of the five floodfactors is 1.66. Among them, 88.56% of the years were shown as a singlefloodfactor years and twofloodfactors years, and only 11.44% of the years were three and fourfloodfactors years. There are no fivefloodfactors year and only 1 zerofloodfactor year occurred. Based on the total sequence of yearly floodfactors, the studied period was divided into three stages. Stage 1 (1644-1718) contained most of the threefloodfactors years and fourfloodfactors years, and the average of the floodfactors in this stage was higher than the mean average of the whole sequence as well as the other two stages; Stage 2 (1719-1864) showed relatively large fluctuation. In this stage, singlefloodfactor years and twofloodfactors years showed higher frequency of flood occurrence. The average of the floodfactors in this stage was the lowest. Heavy rainfall factor was the dominating factor in singlefloodfactors years; Stage 3 (1865-1949) consisted of mostly singlefloodfactor years and twofloodfactors years showed a stable sequence with small fluctuation. (2) The singlefloodfactor years, mostly showing heavy rainfall factor and then continuous rainfall factor, occurred most frequently in the whole period. The frequency of twofloodfactors years was secondly highest, and most of the years exhibited continuous rainfall factor and heavy rainfall factor, followed by continuous rainfall factor and typhoon factor. The combination of continuous rainfall typhoonheavy rainfall factors was most common in threefloodfactors years, followed by continuous rainfalltidal disasterheavy rainfall factor and then continuous rainfalltyphoontidal disaster factor. And the combination of continuous rainfalltyphoonupstream floodheavy rainfall factors interactions mostly appeared in fourfloodfactors years. There was no fivefloodfactors year. (3) Six extreme flood disaster and seven extreme typhoon disaster years in the Yangtze River Delta during 1644-1949 were identified by the disaster influence. Extreme flood disaster years, including 2 fourfloodfactors years, 3 threefloodfactors years and 1 twofloodfactors years, were mostly found in middle of Stage 1 and second half of Stage 2, all associated with continuous rainfall and heavy rainfall. On the other hand, most extreme typhoon disaster years occurred in the first half of Stage 2. Most of them were the results of concurring typhoon and tidal disasters. If occurrence time and intensity vary among the five flood factors, a higher number of flood factors does not necessarily mean that the year is an extreme flood disaster year or an extreme typhoon disaster year.

Using the rainfall data provided by the Nanchang Weather Bureau and Statistical Yearbook Data by Nanchang city, Jiangxi Province, this paper analyzed the changes in rainfall time series and suburban rainfall characteristics in Nanchang city. In order to analyze rainfall data from 1951 to 2007, various methods have been used, including trend analysis, moving average and correlation analysis. It studied the multiple time scale features, periodic variation, different rainfall intensity and rainfall mutation characteristics about the rainfall in Nanchang city. There is another process which is made a prediction for the change of annual rainfall and the rainfall of the four seasons in the same time. The urbanization process is studied on the influence of rainfall characteristics through the outskirts of contrast analysis method. This paper also discussed the existence of “rain island effect” in Nanchang city. The results showed that, precipitation in flood season did not increase along with the urbanization. However, the seasonality of rainfall become more obvious. In spring and summer, the rainfall presents the downward trend in general. In contrary, rainfall in autumn and winter, tends to increase. Furthermore, the changes in seasonality of rainfall were found to be affected at both large and small scales. The results also showed that the overall trend in the seasonality of rainfall in the next few years will be consistent with the annual rainfall. The overall rainfall trends to slightly reduce, suggesting that there is no obvious “rain island effect” in Nanchang city. At the same time, urbanization was found to contribute 2.8% to the increased rainfall, indicating slight effect urbanization of rainfall. Further analysis suggested that rainfall has the tendency of centralization. The uneven rainfall distribution has become more obvious. Because of the influence of urbanization, rainfall frequency will increase Nanchang city’s urban. At the same time, the urban heavy rainfall frequency will increase as well and the probability will also become higher. 〖JP2〗Among them the biggest influence of torrential rain occurred frequency and probability, which will directly affect the urban drainage engineering standards existing and proposed but also will affect the safety of rain flood drainage design.