The spatial distribution and evolutional characteristics for rural settlements, which is an important form of human habitation in rural area, are driven by various factors, such as history, environment, society, economics, traditional culture, and so on.his paper, spatial analytical techniques in RS and GIS, utilized a series of digitalized vector data, including rural settlements, urban areas, road networks, rivers, and so on that were acquired from remote sensing data for the City of Dujiangyan in Sichuan Province for 2005 and 2012, quantitatively the spatio-temporal processes, patterns, and characteristics for the rural settlements in that studied area.Specifically, the spatial autocorrelation model was applied to deeply analyze the different influences by environmental factors to the form of spatial distribution for the rural settlements.The results indicated that: (1) In general there is a significant effect of spatial autocorrelation for the distribution density of rural settlements in the City of Dujiangyan, regions with higher/lower settlements density are neighboring with those with similar settlements density. the tendency of spatial heterogeneity becomes significant in some local areas.(2) The clusters with highest settlements density are mainly distributed at two regions, one is along Sha-Xi straight regions at Southeast of Dujiangyan, and the other is along Cheng-Qing rapid routeway at the South.Such high density regions are also found to be expanding along roads to inner area.However, the lower settlements density regions are majorly caused by the topographic factors since they are mainly distributed along the villages in Longmen Mountain area.Such lower density regions do not show an expanding tendency.(3) With 1% increasing in topographic index, the settlement density was decreasing by 0.505%.Similarly, with 1% increasing of distance to urban area, to river, and to road network, the settlement density would increase by 0.124%, 0.144% and 0.006%.(4) The rank for the influence by environmental factors to the rural settlements' spatial distribution follows: topography> urban > river > road network.Along with the time, such influences are all continuously increasing.This research is to provide some methodological reference to similar works in future.And it can also offer some theoretical and technical supports for dynamic monitoring for rural settlements, intensive use of rural land, and New Country planning.

From the view of the prefecture-level city and county, this paper analyzes the change and spatial mechanism of regional economic inequality in Jiangsu by Gini Coefficient and spatial autocorrelation method since 1978. The research reveals that since 1978 regional economic inequality is shown enlarge a trend before 2008, while after 2008 clearly narrow and the regional economy inequality of county is higher than that of the prefecture-level city. On the scale of county and prefecture-level city, regional economic inequality in Jiangsu has notable positive correlation, and constantly enhances. Spatial agglomeration is obvious in the smaller scale. A high-level agglomeration in the south of Jiangsu and a low-level agglomeration in the north of Jiangsu result in regional economic inequality and spatial autocorrelation on the scales. But in the scale of the prefecture-level city, the low-level agglomeration in the north of Jiangsu is the main reason to lead to regional economic inequality and spatial correlation, while in the scale of county, the high-level agglomeration in the south of Jiangsu is the key cause. Hence, we should pay more attention to regional inequality of county, focusing on improving the economic level in under-developed areas at the scale of prefecture-level city and promoting spatial diffusion in higher-developed areas at the scale of county.

Based on the coupling mechanism of three subsystem of tourism,urbanization and ecological environment,this paper builds evaluation index of the complex system,introduces the model of coordinated development degree,to make quantitative analysis for the coordinated development degree of Poyang Lake area from 1999 to 2013. According to the calculation result, then evaluating coordinated development of the whole Poyang Lake area,and compared the coordinated development degree of the six cities (Nanchang,Jingdezhen,Jiujiang,Yingtan,Fuzhou,Shangrao). the coordinated development degree of Poyang Lake area shows a rising trend on the whole from 1999 to 2013,however,the result also shows that average level of Poyang Lake area is still at primary coordination phases on account of hysteresis of tourism and urbanization,coordinated development level needs to be improved. There is a clear difference between the six cities and the features are absolutely different. The contradiction of the development of urbanization,tourism and ecological environment is the main constraint in Poyang Lake area.in the future,it should maintain improving and restoring ecological environment, prior to accelerating development of tourism and process of urbanization,so as torealize Comprehensive coordination and rapid promotion of tourism,urbanization and ecological environment in Poyang Lake area.

The study on the spatial distribution of population is a fundamental determinant of region development. To aaccurately obtain the global and local spatial information has important significance to formulate reasonable regional development policies. Based on the quantitative association between DMSP/OLS nighttime lights data and population- data, this study simulated grid scale population density of Jiangsu Province in 2012. With the use of population concentration index and spatial variogram analysis, population space structural features and spatial variation have been identified. The results can further explain the microscopic scales of population space differentiation characteristics. Studies have shown the results showed that: 1) At the Rregional level, there is a significant population spatial differentiation phenomenon in Jiangsu province. In northern Jiangsu, it acts as "low-density dot" distribution characteristics, while in south of Jiangsu it acts as "high-density surface-shaped " distribution. 2) At the Urrban level, The spatial distribution of population structure of Jiangsu Province has four types: H-H type has the strongest anisotropic difference, with the minimum random variation within the grid; H-L type has the smallest anisotropic difference, but the random variation within the grid is large; L-L type has obviously axial homogenization characteristics, and the random variation of grid unit is small; L-H type's space anisotropy is small, and it has the maximum grid cell random variation. The results showed that the non-radiance calibrated DMSP / OLS nighttime lights image has the potential to provide population density estimation at grids units, combined with the use of fitted variogram can quantitatively present inside spatial heterogeneity of urban population distribution.

With carbon-oxygen balance theory, ecological land demand with carbon-oxygen balance standards can be estimated by comparing the carbon release and oxygen consumption induced by human activities and carbon sequestration and oxygen release capacity of ecological land.This paper takes Wuhan as an example, land use comprehensive benefits optimal objective function is set up following the two-oriented society construction principles as "environmentally friendly, resource conservation," with 2013 as the base year and 2020 as the target year, the direction of land use structure optimization under carbon - oxygen balance constraints in Wuhan is explored.The results indicate that compared with 2013, the standard ecological land in 2020 will increase by 40908 hectares after optimization of land use structure, there will generate overall efficiency of 43.1 billion yuan carbon sequestration capacity and oxygen release capacity will reach 5.32 million tons and 14.18 million tons, accounting for 43.25% of carbon release and 30.29% of oxygen consumption respectivelycarbon sequestration task can be completed and there is a surplus, but oxygen balance can't be achieved within the region.It will be difficult to maintain carbon and oxygen balance only by increasing the ecological land, so development patterns must be transformed to hold the balance in the long term.

The research field of resource curse tend to focus on mineral resources and scarcely covered in other realms.On the basis of this research background,th research turn from traditional mineral resources to land resources, whose curse is in the empirical research by using curse coefficient based on the 10 years data of 18 cities in Jianghan Plain.The research results suggest that there resource curse phenomenon in 9 cities, Jianli city,Jiangling city,Tianmen city,Gongan city,Honghu city,Songzi city,Jingshan city,Shayang city,Zhongxiang city.In the resource curse cities,Jianli city and Jiangling city with slow growth in recent years are serious curse zone,seven cities are mild curse zone.Through calculation and analysis of the indicators, the research figure out the reasons lead to the phenomenon of land resource curse.Their agriculture has not developed at top speed,and the cities are by vari factors such as conception and investment, where the secondary industry and tertiary industry developed slowly in Jianghan Plain. This research selected typical factors affecting the industry development, main crop output efficiency of agricultural, agricultural mechanization level, electromechanical drainage-irrigation area, employments figures, fixed-asset investment of secondary and tertiary industries and urbanization level.Then they are analyzed in the model and the results show that, among these resource curse cities,the main crop output of Jianli city,Tianmen city,Gongan city,Songzi city is lower than the overall level of Jianghan Plainthe mechanization level of Jiangling city,Jianli city,Gongan city,Songzi city,Jingshan city,Shayang city is lower than the overall level of Jianghan Plainthe electromechanical drainage-irrigation level of Jiangling city,Tianmen city,Songzi city,Jingshan city,Shayang city,Zhongxiang city is lower than the overall level of Jianghan Plain the workforce level of Jiangling city,Jianli city,Tianmen city,Gongan city,Honghu city,Songzi city,Shayang city,Zhongxiang city is lower than the overall level of Jianghan Plain the fixed-asset investment of secondary and tertiary industries of Jiangling city,Jianli city,Tianmen city,Gongan city,Honghu city,Songzi city,Shayang city is lower than the overall level of Jianghan Plain,the urbanization level of Jiangling city.Jianli city,Gongan city,Songzi city,Shayang city is lower than the overall level of Jianghan Plain.Based on the detailed reasonshis research gives specific suggestions on resolving land resource curse based on different influence factors such as choos good quality and high yield crops,improv the mechanism of agricultural mechanization development,speed up the construction of small town to enhance the level of urbanization and so on,so as to indicate the direction of development in the cites which have the phenomenon of resource curse.

In this study, we took the middle and lower reaches of the Yangtze river typical grass type lake dragon lake as the research object, used biological index (surface layer sediment diatom), through the analysis of the diatoms, DCA analysis, clustering analysis and the lake nutrient characteristics analysis of diatom species, to explore the classification of dragon lake sediment surface diatom species, the potential environmental gradient of influencing diatom, the space distribution features of surface sediment diatom taxa, and analyzed the lake nutrient characteristics which surface sediment diatom taxa instruct. Research shows that dragon lake surface sediment diatom taxa had space differences in distribution. Surface of diatom taxa distribution was mainly explained by the first axis of environmental factors, reflecting the arrangement of the sample under the control of the first axis. The environmental significance reflected by the second axis was not significant. Rich nutrition of phytoplankton species was dominant species in dragon lake diatom combination. Dragon lake is close to eutrophic state. Half planktonic species Aulancoseira granulate is the biggest dominant species, and Aulancoseira granulate has absolute advantage in moderate nutrition lake. Floating and half floating kind of Cyclotella atoms and C. eneghiniana, Aulacoseita alpigea, Cyclostephanos dubius, Stephanodiscus parvus, S. hantzschii, which are eutrophication phytoplankton species that mainly occur in eutrophic lakes and can better indicate eutrophication appeared in Dragon lake. Phytoplankton species as the dominant species of east lake area than pick benthic species as the dominant species of west lake area in lake eutrophication is more serious. This study is looking forward to providing theoretical basis to the governance in the lakes wetlands.

Limnodrilus hoffmeisteri Claparède, a dominant species of zoobenthos, is widely distributed in shallow lakes of the middle and lower basin of the Yangtze River, and it plays an important role in the energy flow and biogeochemistry cycling of the lake ecosystem. To understand population dynamics, life history and production of L.hoffmesteri in the large shallow lake, field investigation were conducted in Lake Taihu during January to December, 2015. The annual average density and biomass of this worm were 3 273.75 ind./m² (0-13 800 ind./m²) and 4.70 g/m² (0-29.15 g/m²), respectively, all of which peaked in winter. The highest population density and biomass of L.hoffmeisteri were found in Meiliang Bay, Zhushan Bay and western river-mouth, while the other place of the lake had very lower worm density. According to the annual dynamics of the frequency distributions of body length, the species had three generations one year and reproduced in March,July and November. The annual P/B ratio was 14.17, which was due to high generations one year. The corresponding annual production of the animal calculated by size-frequency method was 480.21 g·m^-2·yr^-1 in wet weight, and was highest in studies reported, which is significant for potential fishery capacity in Lake Taihu.

Climate change characterized by global warming has become one of the most important universal attention issues to scientific circles,world's governments and social public.Impacts of climate change on water resources management is a new research direction has important academic valuehe key fields in the studies focuses on: integrated water resources management and integration study under climate change, mechanismofadaptive management under climate change,frequent occurrence of extreme and accidental event, the public participation understanding of mitigation measures and water resources sustainable development.The methods mainly consist of qualitative methods multi-scale adaptation analysis cost benefit analysis etc.The adaptive management is an effective strategy to deal with this uncertainty problem associated with addressing climate change.Future research should be based on the analysis of the uncertainty problems of water resources management in China's river basin, work on adaptation strategies preliminarily to the impact of climate change under climate change scenariosincluding mechanism and systems ofadaptive management.

Through field investigation and map analysis, this research studied the changes of landscape pattern and human drive of Wanzi Lake Wetland, a part of South Dongting Lake, as a fish habitat during 1983 to 2013.The results showed that the beach area increased from 1.410×10⁴ hm² to 2.135×10⁴ hm², water area decreased from 1.363×10⁴ hm² to 0.631×10⁴ hm², reed land decreased, while woodland increased from 0.056×10⁴ hm² to 0.728×10⁴ hm² and extended into the core protection area, and there is a large increase in the number of fishery facilities and channels.Human disturbance have a great influence on landscape.Plantation of Italian Poplar and reed changed the terrain and pattern of community and seized the original natural grassland, which reduces fish spawning and baiting' s suitable habitat.Mud enclosure, as one of the harmful fishing facilities, now remains in developing stage, just like the enclosure fishery facility.These fishing facilities occupied the good position on grassland and low beach, harmful to fish spawning and baiting.The construction of silt diverting canal caused the lake silt up rapidly, turn aquatic landscape to amphibious landscape and exposure to terrestrial landscape.As a result, fish habitat is compressed.However, in the meantime, the silt diverting canals keep diverting mud out of the core area of South Dongting Lake nature reserve.

Organochlorine pesticides (OCPs) were massively produced and extensively used in China.Although it has been banned in production and usage in agriculture, dicofol containing lindane and dichlorodiphenyltrichloroethanes (DDTs) are still produced and used illegally.In order to explore the residues of OCPs in the urban inner lake of Jiangxi Province, a famous agricultural province in China, Xianghu Lake was taken as a case study.Eight OCPs residues in the sediments of Xianghu Lake were determined by GC/ECD, and their characteristics and possible health risks were analyzed by principal components analysis (PCA).The results showed that all eight different kinds of OCPs could be detected, and concentraions of hexachlorocyclohexanes (ΣHCHs) and ΣDDTs were ranged from detected (nd) to 61.89 ng· g^-1 and nd to 81.47ng· g^-1, respectively.Concentrations of o,p'-DDT, β-HCH and δ-HCH were greater than OCPs.The spatial analysis showed that OCPs residues were unevenly distributed throughout Xianghu Lake, with relatively concentrations in the sediment surrounding the wetland floral park.Concentrations of HCHs and DDTs in the sediments of Xianghu Lake were than in other urban inner lakes or inner rivers in China, which could be attributed to the history that Xianghu area was an agriculatural development area.Source apportionment results showed that HCHs and DDTs residues in Xianghu Lake were mainly from historic use of pesticide, but there could have some new inputs of dicofol and lindane in recent years.ERL and ERM ecological risk assessments showed that the human health risk of DDTs pollutants in Xianghu Lake were relatively low, but a greater risk was found surrounding the wetland Floral Park, which might cause biological toxicities to the environment.The results could be useful for the pollution control and risk management of the urban inner lake.

Based on the data of 9 monitoring variables in 5 monitoring sections of Changsha section of Xiang River, with the use of synthetical index method, pollution share rate, and TLI method, analyzed the water environment parameter changing of Changsha section after the preliminary stage water retaining of multipurpose hydraulic project in Xiang River. The result shows that, the comprehensive pollution index level, pollution share rate and nutrient content level of the 9 monitoring variables, which are ammonia nitrogen, permanganate, total phosphorus(nutriment), volatile penol, petroleum(organic poison), mercury, arsenic, lead and cadmium(heavy metals), in 5 monitoring sections are in varying degrees of declining in both time and space scales, and the XMPI demonstrated a most obvious decline. The reasons of the improved water environment in Changsha section are: ①the optimization and adjustment of economic structure of Changsha city; ② the synchronous construction of Changsha multipurpose hydraulic project and the engineering of the pollution treatment; ③ the water retaining ability of Changsha hydraulic project. When the retaining water reaches the normal level, the lowest water level in Changsha section rises 1.5 m, and makes the average water level of sections of Changsha, Xiangtan, Zhuzhou rises 4-6 m, 2-4 m, and 1-2 m correspondingly, thus increased the volume of water of Changsha section, and can dilute, degradation and transport the pollutant in water.

Urbanization is one of the most intensive processes of human activities which have changed the earth's surface, and is also one of the most important influencing factors of hydrologic process, especially for flood. Base on the high resolution image and topographic map, the paper chose the middle and lower reaches of the Fenghua River Plain as the case area, the spatial and temporal change in land use change and the river system and topography characteristics were analyzed. The result showed that the proportion of urban area increased from 13.2% to 34.1% during 1990-2010, which was mainly gained from paddy fields. The increase of impervious surface tend to lend more surface runoff, and also increase the urban ground elevation changes and decrease the drainage density and water surface rates. The submerge model shows that the decreasing in water storage would cause higher stage giving the same submergence volume, which would cause higher risk in the low-lying land in the south of the study area.

Based on the daily precipitation data from 75 rainfall gauging stations covering 1960-2012 in the middle and lower reaches of the Yangtze River Basin, the trend variation and temporal and spatial distribution characteristics of drought-flood abrupt alternation was analyzed by using long-cycle drought-flood abrupt alternation index(LDFAI) and short-cycle drought-flood abrupt alternation index(SDFAI). The results are as follows: 1) Flood to drought abrupt alternation events are the main performance of the long-cycle drought-flood abrupt alternation (LDAF), as well as the short-cycle drought-flood abrupt alternation (SDFA); 2) The north shore of the middle and lower reaches of the Yangtze River tend to occur drought to flood events, while the south shore tend to occur flood to drought events; 3) Intensive short-cycle drought to flood abrupt alternation events during June to July in 1998 and 2011 occurred in the north shore of the Yangtze River, and flood to drought events occurred in the south shore. However, intensity distribution of drought-flood abrupt alternation events during periods of May to June and July to August was just the opposite to that during June to July; 4) In general, both the occurrence of long and short-cycle flood to drought abrupt alternation events shows decreasing trends, while the drought to flood abrupt alternation events are on the rise. It is worth noting that the trend during July to August is somewhat special. Drought to flood abrupt alternation events are increasing in the Xiangjiang River Basin, and increasing significantly in the Dongting Lake region, which may provide a preferable reference for the work of the Yangtze River flood and drought management.

Data of Particulate matter (PM_2.5) in Chongming Island area from January 2011 to February 2014 were used to study the distribution, seasonal variation, diurnal variation of PM_2.5 and their influencing factors. The effects of inversion, relative humidity, wind and other meteorological factors were included. The results showed that the average concentration of PM_2.5 during the last three years (2011-2013) were 24.7 μg/m³, 33.6 μg/m³ and 28.3 μg/m³, respectively, all lower than the limit annual averageof 35 μg/m³, indicating relative light pollution of fine particles. The PM_2.5 concentration varied little within one day, showing somewhat a unimodal distribution, and reaching the maximum at about 9:00 and the minimum at about 15:00. The seasonal variation of PM_2.5 concentration was significant, showing winter >spring >autumn >summer. The monthly average PM_2.5 concentration reached the maximum in May, and the minimum in August. 57.9% of the daily average concentration reached the first class of the national air quality standard, 93.4% reach the second class, and 6.6% exceed the limit of the national standard. Further analysis related to meteorological elements found that: it is easy to cause high concentrations of PM_2.5 pollution when static and stable weather with the stable inversion layer knot, low wind speed, high humidity, northwest to west wind near the ground happens with contaminant transport from the northwest in the high altitude.

Study on the interaction between urbanization and ambient air quality is an essential basis to guide urban sustainable development and formulate environmental policies. Firstly we evaluated the urbanization and ambient air quality of Wuhan Urban Agglomeration by combining Principal Component Analysis and integrated AQI. And then we explored relationship between urbanization and ambient air quality through curve fitting analysis make. The results revealed that: (1) The integrated level of urbanization in Wuhan Urban Agglomeration entered the stage of rapid development, with a hierarchical structure taking Wuhan as the core, Huangshi and Ezhou as the sub-core, and Xianning and Xiaogan as the margin. (2) The centers of the air pollution mainly concentrated in Wuhan, Huanggang, Ezhou and Huangshi, with PM₁₀ as the principle pollutant. (3) The air-urbanization curve was wavy, complex and changeable. Different cities have various effects of ambient air due to the differences in their natural geographical backgrounds, urban development type and economic industrial structure. There are mainly three types in Wuhan Urban Agglomeration: compound air pollution in Wuhan, soot-dominated air pollution in Huangshi and Ezhou, transformational air pollution mixed by soot and motor vehicle exhaust in Xianning and Tianmen. In the future, we need to strengthen the joint prevention on air pollution during the process of integrity. And we also need to take targeted measure to abate pollution according to the characteristics of the city.

In this study, climatic features of fogs in Anhui Province were systematically analyzed, based on the data provided by surface observation stations from 1970 to 2009. The results showed that fogs in Anhui Province expressed a notable decadal variability. Foggy days peaked in 1980's, after which foggy days decreased continuously from 1980's to 2000's. Meanwhile, decadal variability of fog generation time was not evident, but delayed fog dissipation time was obvious. As a result, fog duration increased approximately one hour during the forty years. Besides, the seasonal variation was obvious and the spatial distribution was not uniform. The season of high-frequency fog was winter, with most foggy days, longest fog duration and lowest fog visibility. The effect of fog in winter was the largest in the whole year. In the opposite, the season of low-frequency fog was summer, with least foggy days shortest fog duration, lowest fog visibility. The effect of fog in summer was the weakest in the whole year. In terms of spatial variation, fogs mainly occurred in the north region and the south mountainous region.

Soil erosion has become a global ecological and environmental problem. Soil erosion not only lead to the destruction of land resources and reduced crop yields,but also cause water pollution and reservoir sedimentation,and increase flood risks. Therefore,the evaluation of regional soil erosion risk by analyzing the spatial and temporal variation of rainfall erosivity is of both scientific and practical significances. In order to study the spatial and temporal variations of annual rainfall erosivity and rainfall erosivity at each level in Yunnan province and its five sub-regions, this study used the data of daily rainfalls for nearly 43a from 120 observation stations in Yunnan province and made the systematic analysis through Man-Kendall trend test,Morlet continue wavelet transform and other approaches. The results indicated that: the annual mean rainfall erosivity is 4415.6 MJ·mm/(hm²·h·a), the annual mean precipitation is 1081.6 mm and the average precipitation day is 150.5 d. The erosivity of heavy rain played the leading role in regulating the annual rainfall erosivity,65.4-71.4% of the annual rainfall erosivity was generated from the rainfall erosivity of heavy rain or at a higher level that accounted for 5.3-8.5% of the annual precipitation days. 4.2-6.9% of erosive precipitation days was generated from the rainfall erosivity of heavy rain that accounted for 38-43.9% of the annual rainfall erosivity. The spatial distribution of average rainfall erosivity is basically consistent with that of average precipitation. The spatial distribution of average rainfall erosivity and precipitation is significantly different from that of average precipitation days. The diversity of spatial distribution of rainfall erosivity at different levels increased with the precipitation levels. The spatial distribution of rainfall erosivity at the same level is highly related with that of precipitation. Tn the Northwest Yunnan areas,the erosivity of heavy rain played the leading role for most of the months. In the remaining areas,the rainfall erosivity of moderate rain played the leading role in the dry season while the erosivity of heavy rain played the leading role in the rainy season. For the rainfall erosivity at each level, higher rainfall level is characterized by greater seasonal variation and concentration . In each region,the rainfall erosivity of moderate rain was relatively reduced while the rainfall erosivity at other levels was predominately reduced. The rainfall erosivity of rainstorm was relatively changed to a greatest extent while the rainfall erosivity of heavy rain and moderate rain was changed at a relatively slow rate. In each region,the annual rainfall erosivity and rainfall erosivity at each level generally has 3-4 fluctuation periods,the major oscillation period was measured by 9a in terms of the annual rainfall erosivity,the erosivity of heavy rain and the erosivity of moderate rain in the Northwest Yunnan areas. The major oscillation period was measured from 18a to 21a in the remaining areas. In terms of the rainfall erosivity of heavy rain,the major oscillation periods were largely distinguished in each region.

Through the 24 cases in 1981-2012 census on the big flood process in the upper reaches of the Yangtze River, it was found that the influencing heavy precipitation weather systems are mainly: the moving eastward trough in balkhash lake, the stable trough in Baikal Lake and the cold trough in northeast. By using the method of statistics, diagnosis and synthetic analysis, the large-scale circulation background, the main influencing system and the mechanism to flood-causing precipitation were analyzed for these three weather types and their characteristics and differences were also summarized. The results showed that the characteristics of three types of flood and precipitation in each were not identical and the large-scale circulation background and the weather systems are also different. The subtropical high and middle-high latitude circulation anomaly on 500 hPa are the direct factors of heavy precipitation. Southwest vortex, cold front shear line and warm front shear line and cold air in different types of rainfall flood effect each are not identical, anomaly cyclonic wind field, water vapor transport direction and the vapor flux divergence convergence zone is closely related to the position of the heavy rain.

Beichuan Qiang Autonomous County was the very seriously destroyed area during the 2008's earthquake, with all kinds of urban and rural buildings greatly damaged because of the earthquake. The region's settlement space has been rapidly reconstructed during the post-disaster reconstruction of three years. However, the natural environment is not yet stable, coupled with the frequency of extreme weather events in recent years, a number of potential threats gradually were exposed, causing a number of catastrophic events in the settlement space of reconstruction after the earthquake. Particularly, the geological disasters broke out in Beichuan after the 7.9 flood disaster in 2013, causeing serious security threat to the settlement space of reconstruction. In this paper, the census data of disaster after the 7.9 flood disaster in 2013 and land use data of Beichuan were selected to analyze and evaluate the characteristics of geological hazard of the settlement space in Beichuan based on GIS technology, the nearest neighbor method and the principal component analysis method. Eventually, we calculated the disaster index of various settlement plaques, and divided them into four grades based on the size of the disaster index value as follows: mild, heavy, serious and very serious. The evaluation results showed that a total 1016 settlement patches are threatened by geological disasters points in the Territory of Beichuan County, accounting for 5.7 percent of the total settlement plaques. Among them, there are 45 settlements are very seriously destroyed by geological disasters and 64 settlements are seriously destroyed by geological disasters, 775 settlements are heavily destroyed by geological disasters, and 132 settlements are slightly destroyed by geological disasters. The evaluation results can provide a fundamental basis for local government to develop a scientific decision to disaster prevention and mitigation according to the disaster priorities of each affected settlements.

Babuli gully is located in JinChuan city,the upstream of Dadu river. Debris flows had occurred many times in this gully in history. Since 1980s, the government has taken countermeasures to manage the debris flow using the check dam and drainage canal and gained a great effect. After nearly 30 years of evolutions, the mitigation project together with the debris flow disaster are forming a unique silt resource and processing a preliminary development on the exploitation. This study carried out analyses on the characteristics of resources, the limitations to the general exploitation, the optimized configurations for the development and the protection, and the further development spaces. The results suggested that the development of sediment resources has extended the use period of check dam, the economical forest plant suppressed the debris flow disaster, the dam leveled up the gully bed to provide the water power for a electricity development and farmland irrigation, and economical and the mitigation forms a positive cycle, achieved a sustainable development. The project aims to advance the resources usage, to maximize the economic efficiency and social efficiency, to further the usage for current project to establish debris flow preventing and controlling science base, to build a restriction zone on both sides of gully front's accumulation fan debris flow drainage project, to build an ecological park and to optimized resources development.

In recent years, with the increase of extreme precipitation events in high-latitude Northern Hemisphere land, the average intensity and frequency of extreme precipitation and in China are also on the rise. Dadu River is the largest tributary of the Minjiang River. Because of their topography, lithology, structure, slope structure, avalanches, landslides and other disasters occur frequently. Variation in precipitation extremes in the Dadu River basin from 1960-2009 were analyzed based on daily precipitation data from 17 meteorological stations within and adjacent to the Basin. This paper used a recently developed interpolator, the greens line, based on the application of green's functions of the biharmonic operator.The interpolated surface is constructed by globally summing the weighted Green's functions centered at every data point. Moreover, the methods of linear regression, Mann-Kendall test and continuous wavelet transform were employed to delineate the rate of change, abrupt change points, statistical significance of the trends, and periodicity of extreme precipitation indices. The results showed inter-annual variations of the extreme precipitation index in Dadu River showed relatively stable volatility increases. The distribution of annual average showed an increased trend from the northwest to southeast, and there were significant regional differences in the trend of extreme precipitation index. Extreme precipitation indices showed a trend of reducing in upstream and increasing in downstream, with exception of the heavy precipitation days. The extreme precipitation indices were closely associated with annual total precipitation in the basin. The abrupt change point of each extreme precipitation index in the Dadu River basin was inconsistent. Abrupt change points of RX1 day, RX5 day were at 1974-1976, and 1978, and R25, R95 and R95 day were at 1984, 1979, 1977, and increased after abrupt changes. The cyclying characteristics of extreme precipitation indexes is more complex, we conclude that most extreme precipitation indices in the Dadu River basin existed two common oscillation cycles, 5-10 years and 20-25 years(major cycle).