The Yangtze River Economic Belt (YREB) is one of the important development axes of the regional development and economic spatial construction in China. To be the national strategy in recent years, it plays an increasingly important role in international competition, regional coordination, promotion of Two-direction Opening on east and west, construction of ecological civilization. With the new situation and requirement of international and domestic economic and social development, the development of the YREB is facing the opportunities and challenges. From the background which the development strategy of YREB was provided, the article reviewed its four periods of development. The progress and trend of the development in the YREB were analyzed from five aspects including economic status, industrial concentration, river port and shipping development, shoreline utilization and development, traffic construction along the River. The problems in the development of YREB were further discussed, including the excessive development of the heavy and chemical industrial, the destruction of the ecological environment, the excessive competition among the ports, and the imperfect urban system in the urban agglomeration. In the end, the paper proposed some countermeasures on the YREB development from reforming the assessment mechanism, breaking the administrative barriers, strengthening coordination agencies of river basin and establishing laws and regulations of river basin management, so as to provide reference for Yangtze River economic belt development and construction in the future.

The Pan-Yangtze River Economic Zone is derived from the Yangtze River Economic Zone and a conception of wide river basin. According to the layout of water system in the future, the Pan-Yangtze River Economic Zone includes not only the main stream of Yangtze River, but also the ecosystems comprised of headstream, main stream, branches and artificial rivers along the Yangtze River. The Yangtze River Economic Zone covers 9 provinces and 2 direct-controlled municipalities while the Pan-Yangtze River Economic Zone covers 16 provinces and 4 direct-controlled municipalities. The coverage area extends since Qinghai Province, Henan Province, Shaanxi Province, Guangxi Province, Shandong Province, Hebei Province, Tibet, Shanxi Province, Guangdong Province, Beijing and Tianjin are added to this new wide river basin. Formation of the Pan-Yangtze River Economic Zone is an objective reflection of increasing cooperation in economy and social aspects among provinces and cities. To guarantee the rapid development of each aspect in the Pan-Yangtze River Economic Zone, such as economy and legality, this article suggests that a new department, named the office for coordinated development of Yangtze River Economic Zone, which aims at coordination of regional projects, should be established. This new department will be conducive to the practical work in the Pan-Yangtze River Economic Zone.

Lying across three economic areas in east, middle and west China, the Yangtze River economic zone is one of the important engines to boost the social and economy progress in china, and also an essential part of the zonal development strategy in the sustainable development. Yangtze River Economic Belt has always been China's urban corridors, industrial corridors and commercial corridors, concentrate a large number of large water consumption, high energy consumption, large capacity, high-tech industries and large leading enterprises. By studying the current development status and issues of the industrial division and cooperation within the Yangtze river economic zone, the paper concludes that the Yangtze river economic zone has a complementary industrial features but it still exists some problems like the low degree of market development, poor elements flow, the height of central cities' industry is too low, lack of regional innovation capacity, the level of industrial chain is too low and so on. Spreading out in each of the planning, geographic reaches, central cities and leading enterprises aspects, this article not only points out the corresponding strategy in the division and cooperation, and transformation and upgrading of the industry, but also puts forward suggestions on how to build up the creativity and how to catalyze the endogenetic power for the industrial development. And expect it to be a foundation to inspire more future research, as well as to provide references and consultations for researchers and policy-makers in Yangtze River Economic Belt development.

Water is a vital resource. River basins are both the key bodies of water resources and the major cradles of human civilizations. It is particularly true for China, one of the ancient civilizations and the most populated country in the world. A long-term practice shows that the development of river basins has significant polarized characteristics of ecological effects: our human society began to set apart from the natural river basins as technology to be widely used to solve all the problems of life, that civilization made human successful, but great costs to the river basins, while a serious interference and damage to the phylogenetic diversity of natural ecosystems and watersheds. The higher the basin development, the more obvious polarized effects it has. Based on an empirical analysis, this paper argues that due to the lack of a fully understanding of the polarized ecological effects and the pursuit of human development, the carrying capacities of the Yellow River Basin and the Yangtze River Basin have been facing more and more serious challenges, such as rivers no longer flow into the sea, water is polluted, wetlands are draining out and aquatic animals are diminishing. For a sustainable development of the river basins in China, there is an urgently need to change the concept from the traditional one emphasized with "Human development first, natural protection second" to a new one addressed on "Natural protection first, human development second".

Based on super-efficiency DEA and ML index, we estimated the ML index of total factor energy efficiency and analyzed its temporal and spatial disparities in the Yangtze River Economic Belt from 1999 to 2013. According to the results, total factor energy efficiency of the Yangtze River economic belt declined 2.9% annually from 1999 to 2013, while the decline value regardless of environment is 0.4%. This demonstrates that environmental pollution is an important factor leading to the loss of energy efficiency. In the aspect of time, the overall level of total factor energy efficiency in the Yangtze River economic belt had a M-shaped locus with bimodal distribution, that is, it had two periods that include a "up-down" paths respectively. But the evolution features of inter-provincial are quite different from that in Yangtze River from upstream to downstream. Inter-provincial disparity of total factor energy efficiency is much larger than that among upstream, midstream and downstream of the Yangtze River. These disparities have a tendency to decrease in recent years with varying degrees. In the future,ecological civilization development strategy is needed to ensure sustainable development. Meanwhile, governments in the Yangtze River economic belt need to strengthen their cooperation in energy, environment protection and other fields to promote the development of total factor energy efficiency progress collaboratively.

With the development of Economic Geography, the effects of Internet for city networks are turning into a new and hot topic. In this study, the mid-Yangtze urban agglomeration was selected as an example and attention data of year 2011 and 2014 between cities were obtained based on "Degree of Consumer Attention" function provided by Baidu.com. The results showed that the structure of cities in this region stands in a shaping stage. The grade of cities becomes increasingly clearer and the differences are more obvious. The polarization effect and diffusion effect are in coexistence in three sub-urban-agglomerations. Internet has a tendency of adjusting and revamping the current structure, instead of overthrowing it totally, which is believed to be a good opportunity for some developing cities to change their positions. Combining the traditional industry and internet, with the direction of development of the division of labor, some developing cities are stepping into the way of changing their traditional structure of city network.

As the global warming problem is increasingly serious, it has caused widespread concern in the international community. As one of regional development "three strategies" in China, Yangtze River Economic Belt is facing severe pressure to reduce carbon emission. This paper used carbon dioxide emissions as a measure index to analyze the time and space character from 1998 to 2012 in Yangtze River Economic Belt, and applied spatial panel models on carbon emission to analyze the impact of industrial structure, total population, economic level, technical level and urbanization level on carbon emission in this area. The results showed that: ① The absolute difference in carbon emissions was increasing, while the relative difference was changing in a fluctuation; the correlation between carbon emissions and per capita GDP (1997 constant prices) was weak. ② The region of higher carbon emissions centered at Jiangsu, and gradually spread to the surrounding, and the spatial pattern of carbon emission is relatively stable. ③ The spatial panel model results showed that: total population is the determinant factor followed by economic level, technical level and urbanization level influencing the spatial evolution of carbon emission in this area.

The Yangtze River Economic Belt (YREB) is one of the most important economic development regions of China and becomes to national strategy in recent years. Since the idea of YREB development was put forward in the 1980's, scholars have carried out a lot of related researches. Analysis of the relevant research literature is helpful to academic research advance. Based on literature review, this article analyzed the source of literature, concept and scope of YREB first and then summarized and discussed the content of the literature from 8 aspects including strategy, industry, traffic, difference of regional economy, regional spatial structure, regional coordination and cooperation, relationship between the regions and YREB, and ecological environment. In the end, from aspects of cooperation reinforcement, classical theory application, transportation research attention, basin linkage mechanism and dynamic broad vision, the paper proposed some suggestions for the future research.

Recently, the Yangtze River Economic Belt (YREB) has risen to a national strategy. It however is facing high pressure of ecological environment protection. Ecological environment protection is in relation to orderly and sustainable development of YREB. With China's National Environment Policy Act being revised and carried out, ecological environmental protection work of YREB development possesses strong institutional guarantee. This article firstly analyzed the tendency of China's ecological environment problems from 7 aspects including ecological environment degradation, species reduction, and high incidence of environmental accident and so on. Secondly, we interpreted China's National Environment Policy Act from 5 aspects including making clear government environmental responsibility, solving the problem of low illegal cost and so on. Thirdly, we analyzed environmental legal system of YREB development from 9 aspects including comprehensive planning, rational layout, strict environmental protection, technology level improvement, local government legislation, strict law enforcement, reducing risk of environmental accident, information being publicized and public participation, so as to provide reference for YREB development in new period.

The paper defined the significance of recognizing port generations in Yangtze River Economic Zone and illustrates the criterion of recognizing port generations under the framework of UNCTAD. Then, the article studied the port generations in Yangtze River Economic Zone (YREZ) based on the method of fuzzy pattern recognition. The results showed as follows. ①The generational grade are low on the whole, and most ports in YREZ belong to the first or second generation port. ②Both of the generation grade and the distribution density of ports present a trend of decreasing from east to west. ③From the perspective of local space, different types of ports show provincial character in the geographical distribution. That is, port cluster consisting of 1 or 2 high-grade ports and several low-grade ports as lateral ports or feeder ports are appearing within the scope of province. According to the research conclusion, we propound the new strategic transformation on port development under the construction of YREZ: fully realizing the important function of ports in the Yangtze River comprehensive transportation system, orderly prompting the upgrade of port generation, propelling the advancement of port cluster and impelling the construction of free trade area in due time.

Using data of the economic growth and resources and environmental protection in Nanjing city from 1995 to 2012, the influence index of industrial structure on nature eco-environment (ISE), resource and environmental performance index (REPI) and decoupling analysis tools were analyzed to evaluate the coordination in Nanjing city since 1995, with typical industrial growth and resource and environmental index. The results showed that, coordination between economic growth and resource and environment was in an increasing tendency. The ISE was moderate and the REPI was decreasing gradually. Industrial wastewater performance was improving the fastest, and industrial exhaust gas performance was improving slowly from 1995 to 2012. Decoupling condition was weak expansive decoupling and positive strong decoupling in general, but parts of decoupling condition temporarily became worse during 1995-2012. Countermeasure and suggestion were put forward to improve the coordination of economic growth and resource and environment.

This paper analyzed the urban efficiency of urban agglomeration in the Middle Reaches of the Yangtze River in 2013 with the DEA model. The result showed that: Changsha,Tianmen,Changde, Huanggang, Nanchang,Jingdezhen,Wuhan,Loudi, Xinyu,Hengyang,Xiantao,Ezhou,Qianjiang, and Jiujiang had a higher urban efficiency; Fuzhou,Xiangtan, Yingtan, Shangrao, Yueyang, Huangshi,Jingzhou, and Zhuzhou had a moderate urban efficiency; Pingxiang, Yichun, Yiyang, Ji'an, Xianning, Xiaogan,Xiangyang, Yichang and Jingmen are located in the low efficiency level zone. Based on these, analyses on the space features of urban agglomeration found there existed moderately heterogeneous spatial pattern in the efficiency of urban agglomeration in the middle reach of Yangtze river city development level of similar area.

Based on measurement index system of urban influence and entropy method, the urban influence index for 110 prefecture-level cities in the Economic Belt of the Yangtze River in 1988, 2001 and 2012 has been calculated in this study. According to field model and diffusion effect model, further analysis on the urban influence index which comprehensively measure accessibility, spatial field and diffusion effect has been conducted with spatial analysis method and the aid of ArcGis. The result showed that: the urban influence index differed a lot but tent to be narrowing, the city accessibility moved mainly towards pattern of "East > Middle > West", and the urban differences had gradually narrowed due to the rapid development of expressway and high-speed railway. The Economic Belt of the Yangtze River has basically formed regional spatial structure with one main axis, three core cycle and multipleaxis supported, building an development pattern of "1+3+X. The Economic Belt of the Yangtze River has gone through five phases, i.e. urban gestation, core development, pole-axis diffusion, networking, and local integrated development, mainly forming a beaded core-periphery structure and presenting multi-phrase in those regions at one time. In order to accelerate the optimization of spatial structure in The Economic Belt of the Yangtze River, structural elements will be optimized with the precondition of insistence in ecology and efficiency, the strengthen in reform and innovation of spatial management and the idea of "extending axis based on the point". The optimization of spatial diffusion axis will be performed under the rational urban level system, local growth pole and scientific transportation networking plan. Then, the goal of optimization of the Economic Belt of the Yangtze River will be fulfilled with the rational region distribution and cooperation and multi-level urban agglomeration construction.

Over the past two decades, metropolises in China witnessed unprecedented growth rates in urban areas. The rapid growth of urban space could lead to a series of problems. The fact that China has the largest population manifests the negative consequences of urban expansion. A rigorous and quantitative comparison of urban growth among metropolitan areas will lend basic support to policy making on regional urban development and will help city planners, economists, environmentalists, etc. This study analyzed the spatiotemporal patterns of urban expansion at different distance from city center in 27 metropolises in China using multi-temporal remotely sensed data. We use three satellite images obtained from the Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) sensor system circa 1990, 2000 and 2010 for each city to develop maps of urban areas. A concentric partitioning method was employed to define urban core area and urban fringe on the basis of built-up density calculated in a series of 1km concentric rings. Urbanization Concentricity Index was proposed to measure the degree to which residential or non-residential development is close to urban core area. Then we calculated and analyzed Urbanization Intensive Index across a series of 1km buffer zones for each city to identify the location-based spatiotemporal patterns of urbanization. UII offers a measure of speed and intensity of urban expansion. The results showed that the spatial structure of these cities was closely related to national policies for regional development, demonstrating obvious regional characteristics. In general, the UCI value of the cities in western and northeastern China is higher in central and eastern China. Most cities exhibited lower UCI value in 2010 compared with 1990, showing a tendency toward dispersion. The highest UII for each city usually occurs around the urban core area and move outward over time. The UII value for second- and third-tier cities became quite small in rings more than 20 km away from city center. The area close to city center witnessed higher UII value in the first decade as compared with the second one. On the contrary, the UII value for the buffer zones away from the city center was much larger in the second decade. Urban form also correlated to the level of economic development to some extent. In the first decade, first-tier cities expanded more intensely and broadly than other cities. Some Second-and third-tier cities experienced significant urban expansion in the second decade, demonstrating a tendency towards decentralization in their development pattern. In 1990, almost all metropolises in China exhibited a trend of comprising one single large central area for the entire landscape. With the expansion of urban land and rapid new nuclei development, some developed cities exhibited a transition of urban space from being mono-centric to multi-nucleated in form, with the emergence of some sub-centers. However, some relatively less developed cities still retained their mono-centric urban space. It can be inferred that urban structure tends to transform from being monocentric to polycentric with the continuous development of economy.

Global warming has resulted in devastating hazards for human society, such as floods, droughts and heat waves. The Dongting Lake Basin is a region characterized by frequent heat waves and high temperatures in summer. Severe heat waves had brought enormous influences on human health and agriculture in this area. Take the 2013 heat wave as an example, it caused water shortage of more than 3 million people and 1.2 million animals, and resulted in loss of about $ 0.18 billion. In recent years, many researchers have focused on the warming characteristics. However, most of this studies focused on the trends of several single indices, while few studies have studied the probability, especially the joint probability of heat waves. On the other hand, duration and temperature are the two inherent characteristics of a heat events, hence, analysis of the joint probability of the two indices could improve our knowledge of severe heat events and for helpful hazards prevention in this region.Therefore, based on the ground surface observed daily temperature dataset (1960-2013), this study investigated the spatial-temporal characteristics and the risks of extreme heat events (EHE) in the Dongting Lake Catchment, by using MK test, probability distribution and copulas. Four indices, i.e. length of heatwaves (HWL), mean max temperature in heatwaves (HWT), hot days (HDL) and mean max temperature in hot days (HDT) were employed to reflect the extreme heat events. The results showed that, the four indices decreased first and then increased obviously after 1987. The amplitudes of EHE were relatively high in eastern and southeastern parts of the catchment, and were relatively lower in western and southwestern parts. Furthermore, though there existed heterogeneous patterns, the amplitude and risk of EHE after 1987 in this area overall increased compared to that in 1960-1987. In particular, the regional mean of 5-year return levels for HWL, HWT, HDL and HDT (HWL₅, HWT₅, HDL₅ and HDT₅) increased by 0.5 day, 0.2^oC, 2.0 day, and 0.2^oC, respectively. Moreover, the copula results indicated that the risks of serious heatwaves had increased in the major part of the basin, and decreased in southwestern and southern parts.

The spatial reconstruction of the rural settlements is an important topic in the current. This topic was studied in this paper taking Wuhu city in Anhui Province as an example, based on the function oriented zone. With the supports of GIS, the units of villages and towns were defined as the basic administrative areas, and 1 km² areas as the basic assessment geographical one. An ecological footprint method of assimilated dynamic clustering was adopted, with a mutex-similar matrix classification with eco-environmental restriction system and support system with economy-development condition. Finally, the preferential reconstruction area, the hortative reconstruction area, the moderate reconstruction area, the leading exploiting reconstruction area and the restricted exploiting reconstruction area of the rural settlement are classified, and the different reconstruction modes are put forward.

Schistosomiasis is a kind of many parasitic diseases which jeopardizes humankind's health and the economic development of the Oncomelania Snails distribution regions. After the foundation of China, a large-scale epidemiological investigation have been launched in the country, which proved that Hubei Province was one of the schistosomiasis prevalence areas and its hazard was very serious. Schistosomiasis japonica is the only schistosomiasis epidemic in our country, and Hubei oncomelania is the only intermediate host of Schistosoma japonicum. So we can block the spread of schistosomiasis by wiping out the snails, in order to achieve the purpose of reducing the number of patients with Schistosomiasis japonica. In the studies on the distribution and succession of Oncomelania snails at present, the overall trend of the growth and decline of the quantity of snails in one region can be shown by numbers or graphs. It needs a more sophisticated method to present temporal and spatial distribution of snail and its growth and circumstances in each administrative village, to replace the description with simple graphs and words which may be not enough to minutely show the long-term changes of snail distribution of growth and decline in the Oncomelania Snails distribution regions. Geographic Information Systems (GIS) is a computer information system with the capabilities of geospatial-related data management, analysis and description. GIS can clearly show the complex analysis results through map. In the field of public health, GIS can be used to analyze the spatial distribution, the spatial and temporal trends of the diseases. Therefore, using GIS to analyze the growth and decline of snail is appropriate. To get the specific information of distribution and succession of Oncomelania snails in the Oncomelania Snails distribution regions of Hubei Province in the past three decades, the statistical yearbook data of Oncomelania snails in Hubei and Hubei administrative division map are combined and analyzed by the logical operation function and statistical function of ArcGIS software to get the detailed map which can clearly reflect the distribution and change of Oncomelania snails acreage in the Oncomelania Snails distribution regions every other five years from 1980 to 2009. We can get the detailed information of Oncomelania snail succession of all the division, then we can draft sophisticated map to find the place where the Oncomelania snails recur or be hard to be wiped out. For example, most places of Oncomelania snails area in Honghu City was decreasing in these years, however, the Oncomelania snail areas of Mashi Village and Shangsheng Village in Gong'an County were increasing. Then, we combined with the type of snails dynamics, the natural geography, human governance approach, etc. to do related analysis to sum up the reasons of the Oncomelania Snails succession in the Oncomelania Snails distribution regions of Hubei Province from 1980 to 2009. Geographic Information System can be used to analyze the distribution and succession of Oncomelania snails in the Oncomelania Snails distribution regions, which is beneficial to review the effect of schistosomiasis control work in the past thirty years and guide the schistosomiasis prevention work in the future.

The Poyang Lake is the largest freshwater lake in China, and also one of the globally important ecological area delimited by World-Wide Fund for Nature. It plays an important function on the flood regulation and the conservation of biological diversity in the Yangtze River Basin. However, due to influences of climate change and human interferences, increased frequency of lower water levels in the dry season, decreased lake area, frequent drought-flood abrupt alternation and the destruction of the ecological system in the Poyang Lake Basin have emerged, and caused extensive attentions of the whole society. Hence, By using Mann-Kendall trend test and regression method, changes of annual runoff from 1950 to 2012 and annual sediment loads from 1956 to 2012 at five hydrological gauging stations (Waizhou, Lijiadu, Meigang, Hushan and Wanjiabu) in the five tributaries (Ganjiang River, Fuhe River, Xinjiang River, Raohe River and Xiushui River) of the Poyang Lake Basin were analyzed, and the causes underlying runoff and sediment changes were discussed. The results showed that (1) characteristics of the changes in runoff and sediment loads were different among the five tributaries of the Poyang Lake Basin. No significant trend of annual runoff was found at the Lijiadu station, while the other gauging stations showed an increasing trend. The sediment loads showed a decreasing trend at the Waizhou station in the Ganjiang River, the Meigang station in the Xinjiang River, and the Lijiadu station in the Fuhe River (the decreasing trend at the Waizhou station and the Meigang station are significant at > 95% confidence level after the year 1985), but increasing trend at the Hushan station in the Raohe River and the Wanjiabu station in the Xiushui River during the period of 1965-1999, and then began to decrease. (2) Total runoff into the Poyang Lake showed no significant increasing trend, and its abrupt alteration year is 1992. Total sediment transportation into the lake showed a significant decreasing trend, and its abrupt alteration year is 1996. (3) The annual runoff changes were mainly affected by precipitation, the annual sediment loads changes were mainly affected by water and soil conservation and the water reservoir construction. Sediment capture by water reservoir was found to be the major cause underlying the decrease of sediment loads in the Poyang Lake Basin. These results are of great significance for better understanding on the spatial and temporal changes of runoff and sediment loads in the Poyang Lake Basin and influences of climate change and human interferences on the hydrological processes.

In accordance with the strength of water environment constraint, we divided the Poyang Lake area into core, marginal and peripheral zone. In this paper, we tried to predict urbanization and make simulation pattern of cities around the Poyang Lake in the three buffer zones in 2015. After interpreting the Landsat images of the study area, we built up multiple data fusion database, and then statistically described the present situation of land utilization in the study area. Based on Logistic regression we got land suitability atlas. The use of Markov model generated the state transition probability matrix of land use during 2005 to 2010. Under both the restrictions, let Cellular Automata processed research area natural developmental scene simulation. Based on the 2005-2010 land use pattern, the paper combined the CA, Markov, Logistic model and use this model to achieve the future land use simulation scenarios of Poyang Lake area, then use Landscape Indexes to analyze the change trends of landscape pattern of Poyang Lake area which under the constraints of water environment. The results showed that: (1) The cultivated land and woodland covering almost 82% area of district around Poyang Lake will degrade substantially, while the proportion of urban land will rise sharply on Poyang Lake area, along with its gradually accelerating economic development. (2) The probability of land type distribution has a certain relationship with population urbanization rate, life urbanization rate and economic urbanization rate. (3) From the simulation results, the cultivated land of the core area in Poyang Lake area will be smaller and it will expand the scope of water bodies, in marginal zone the construction land and rural residential area increased, the water bodies range in the peripheral area will be substantially reduced, which is reflected in the pattern of land use change on the landscape manifested as the land landscape fragmentation degree decline according with the order: the marginal area-the peripheral area-the core area, suggesting that the protective effect in Poyang Lake is on the emerging, the entire land use pattern orientation is more reasonable.

The traditional methods of indicator normalization such as maximum difference normalization were used in the research of spatial variation of intensive land use. These methods seldom considered the effect of location differences and assumed the same critical point of intensive level at different locations, leading to higher land use intensive levels at better locations. This paper pointed out the shortcomings of the traditional normalization methods and built a theoretical model of spatial variation of land use intensive level based on the theory of differential rent I and differential rent II, and tested the model by assessing the spatial variation of the intensive level of the cultivated land Chongqing. This study considered the difference of the ideal value (critical value) of a single indicator caused by endowment variation of different regions. Therefore, it may overcome the shortcomings of the traditional indicator normalization methods and improve the research on the spatial variation of intensive land use. The results showed that: the land use intensive level is a relative concept, the reference frame of which is the critical point of regional land use intensive level and the theory basis is differential rent II. The location differences cause the differences of regional land use intensity, which is a type of differential rent I and can be called "endowment variation". The normalized value Y of a moderate indicator of one location has relationship with the actual value and the critical point of intensive level of this location, which has no relationship with the actual values of other locations. The traditional normalization methods set actual value or actual average value as the critical point of intensive level, leading to the consistence of the result with the spatial variation of land reward. The spatial variation assessment of the cultivated land intensive level of Chongqing showed that the theoretical model is better than traditional methods in the investigation of spatial variation, intensive level of land use and the comparison between counties. The theoretical model more conforms to the real cultivated land use of different counties than traditional methods.

Hucho bleekeri is one of the species in the genera Hucho in China, and the only large salmon fish in the Tibetan Plateau area. During the past several decades, Hucho bleekeri lost its habitat severely as a result of anthropogenic changes. In this paper, a quantitative analysis on habitat ranges and characters of Hucho bleekeri in the Dadu River basin was made, and the suitable habitat areas for this fish species were evaluated and determined based on field investigation and history data collection. The results showed: 1) from 1950 to 2012, the habitat loss in the Dadu River basin was extremely high in the past 60 years and now the loss rate was 91.4%. Intensive human activities such as hydropower development were the main reasons for this tendency of habitat loss; 2) the habitat requirements for Hucho bleekeri was relatively high and the suitable water temperature was in a narrow range (ranged from 4℃ to 14℃). Meanwhile, there were differences in habitat requirments during its different life stages; 3) the upper Dadu River with its tributaries were very important for Hucho bleekeri habitat protection. The rivers which can be protected as suitable habitats for Hucho bleekeri mainly distributed in the upper reaches of the Dadu River, with a total length of 2 222.9 km. Based on our results, some helpful suggestions on Hucho bleekeri habitat protection can be given: 1)in order to protect the habitat effectively, it is vital that different types of habitats should be considered comprehensively. Not only the present distribution areas, but also the historical and potential distribution areas which can be recovered as suitable habitat for Hucho bleekeri should be included. 2) planning and research works on habitat protection for Hucho bleekeri should be carried out in the headwaters of Dadu River as early as possible; 3) for the coordination of watershed protection and development, mechanism of ecological compensation should be constructed and improved.

Global warming caused by greenhouse gas emission may cause severe environmental and social problems. As climate problem is becoming increasingly serious, the preparation of greenhouse gas emissions inventory has become important basic work of research on greenhouse gas. Some researches hve been undertaken on greenhouse gas accounting and some progresses have been made. However, there are many shortcomings in this research field. The main problem is that current research is mainly focused on carbon emission, particularly carbon emission from fossil fuel combustion, and is less involved in carbon fixation and ways of assessing regional carbon emission levels. Although much research were related to carbon emission, the results are difficult to compare owing to inconsistent research methods and standards. Based on the IPCC Guidelines for National Greenhouse Gas Inventories and the Provincial Greenhouse Gas Inventory Preparation Guide of China, this paper analyzed the dynamic of greenhouse gas emission in Hunan Province during 1995-2011. The results showed that, the component of greenhouse gas emissions wass predominant with CO₂, with a proportion of 79.25% to the total emissions, and the second part is CH₄ and the third part is N₂O with a proportion of 16.95% and 3.79%, respectively. Energy consumption is the main reason for the increase in greenhouse gas emissions in Hunan Province, and forestry carbon sequestration ability needs to improve. Greenhouse gas emissions by energy consumption, agricultural production, waste treatment and cement production was 421.5、641.6、592.2、498.8Mt CO₂e, of which accounted for 70.87%, 10.79%, 9.96% and 8.39%, respectively. Forestry performance for carbon sequestration effect with a 18.2Mt CO₂e, of which fixed 3.06% of the total greenhouse gas emissions. From 1995 to 2011, the greenhouse gas emissions increased from 241.7 to 594.7Mt CO₂e in Hunan Province, ant its fluctuations can be divided into the slowly decrease stage(1995-1999), the slow rise stage (1999-2003) and the rapid growth stage (2003-2011). The greenhouse gas emission per 10000 Yuan GDP reduced from 10.64 to 2.93, indicating that carbon reduction technology has made great progress and energy efficiency has been greatly improved in Hunan Province. However, the greenhouse gas emission per capita had increased very quickly from 3.65 to 8.07 t CO₂e. The greenhouse gas emission increasing trend cannot be ignored. So it is urgent to reduce greenhouse gas emissions. Countermeasures for greenhouse gas emission reduction in Hunan province were put forward at the paper. First, actively explore new energy and to enhance the energy utilization efficient. Secondly, increase the vegetation cover rate to increase the carbon sequestered ability in vegetation. Thirdly, advocate low carbon life. Fourthly, accelerate the development of low carbon economy and green economy.

Based on the related impact factors of the precipitation anomaly in summer in the Middle and Lower Reaches of the Yangtze River, 15 atmospheric circulation indicators as the independent variables and the hazard dangerousness level of drought-flood abrupt alternation index as the dependent variable were selected to construct the nonlinear and non-parametric classification and regression tree (CART) model for the hazard evaluation. The time series of data is from 1954 to 2010. Results showed that Arctic Oscillation Indices in summer (AOI_SU) and spring (AOI_SP), Asia Meridional Circulation Index in spring (AMCI_SP), and Asia Polar Vortex Area Index in spring (APVAI_SP) were the four main impact factors, which were proved to be suitable for the hazard evaluation of disaster about drought-flood abrupt alternation through the CART model. The type of the disaster (flood to drought or drought to flood) and the predicted dangerousness level under different diagnosis conditions can also be obtained from the model. The diagnosis thresholds and dangerousness level as follows: 1) When AOI_SU more than 1.11, the disaster of the quick turn from flood to drought is more apt to happen (dangerousness level is 1). 2) When the AOI_SU is less than 1.11 and the AOI_SP is more than -1.11, the disaster of the abrupt alternation from drought to flood will occur (dangerousness level is 6). 3) When the AOI_SU is less than 1.11, the AOI_SP less than -1.11, and the AMCI_SP more than 61, the same situation will happen as the one before this, and the predicted level is 5.5. 4) When the AOI_SU is less than 1.11, the AOI_SP less than -1.11, and the AMCI_SP less than 57, the abrupt alternation from flood to drought will happen, and the predicted level is 1.29. 5) When the AOI_SU less than 1.11, the AOI_SP less than -1.11, the AMCI_SP between 57 and 61, and the APVAI_SP less than 172, the abrupt alternation from flood to drought will happen, and the predicted level is 2.1. The corresponding indicators from 2011 to 2013 were selected to verify the final model through the comparison between the predicted values and actual levels, and the model was proved to be reliable for the close values. The CART proposed in this study provides a new method that can predict the hazard dangerousness level from the disaster of drought-flood abrupt alternation in the middle and lower reaches of the Yangtze River.

In this paper, the influences on fog (visibility) of the Yangtze River Three Gorges Reservoir from meteorological and geographical factors were studied. We provided a scientific basis for monitoring and forecasting visibility through the quantitative analysis. This article selected 9 artificial fog observation stations and 12 visibility observation instrument data from Yichang to Yibin in 2011-2012. First, the discriminant analysis method is used to find the key meteorological influencing factors in different months. The path analysis method is further used for the direct and indirect influence on the fog. The results showed that the fog compliance rate is more than 50% judged by conventional meteorological elements. Wind speed, temperature and humidity were found to affect the fog level in late fall and winter. Humidity at 1000 hPa directly affected the maximum visibility value with a path coefficient of -0.5182. Geographic features of the mountain and the river drop-on played an indirect role in the breeding of fog.