Risk assessment and landslide prevention design using numerical modelling——A case study in Qingliu,China

Numerous Quaternary deposits are existed in the mountainous areas of Southwest China,especially in the transition zone between the QinghaiTibet Plateau and the Sichuan Basin, where strong tectonic movements and frequent climatic changes increase the potential landslides. The possible deformation and failure process of potential landslides and their impacts on the surrounding environment are important research topics. Field investigation and monitoring indicate that the Qingliu landslide in Xiame...     

Micromorphology of landslide soil——Case study on the Jibazi landslide in Yunyang in the Three Gorges Region, China

Introduction The studies on landslides in the Three Gorges Region were conducted, e.g., those on affecting factors and forming mechanism of landslide (YIN Kunlong et al. 1998, DENG Qinglu et al. 2000, CHEN Yongbo et al. 2003, XU Qiang et al. 2003), on ris…     

Analysis and modeling of slope stability in the Three-Gorges Dam reservoir (China) �� The case of Huangtupo landslide

The water level in the Three Gorges Dam reservoir is expected to change between the elevations of 145 m and 175 m, as a function of the flood control implementation and the intensity of the annual flood. As a matter of fact, the hydraulical and mechanical loadings, related to the water level modifications, will result in alterations in the slope stability conditions. The town of Badong (Hubei), of 20 000 inhabitants, is one of the towns which was submerged by the impoundment of the reservoir. As a consequence, the new town of Badong was constructed on a nearby site which appeared to be partly an unstable site. A part of this site corresponds to an old landslide, the Huangtupo landslide, the base of which had to be submerged by the water of the reservoir. The analysis of the Huangtupo landslide, taking into account various events scenarios, drainage and reinforcement measures and monitoring devices, allows to illustrate the general process implemented all along the reservoir in order to mitigate the landslide hazard.     

Analysing post-earthquake landslide susceptibility using multi-temporal landslide inventories——a case study in Miansi Town of China

The earthquake that occurred on May 12, 2008, in Wenchuan County aroused a great deal of research on co-seismic landslide susceptibility assessment, but there is still a lack of an evaluation method that considers the activity state of the landslide itself. Therefore, this paper establishes a new susceptibility evaluation model that superimposes the active landslide state based on previous susceptibility evaluation models. Based on a multi-phase landslide database, the probabilistic approach was used to evaluate landslide susceptibility in the Miansi town over many years. We chose the elevation, slope, aspect, and distance from the channel as trigger factors and then used the probability comprehensive discrimination method to calculate the probability of landslide occurrence. Then, the susceptibility results of each period were calculated by superposition with the activity rate. The results show that between 2008 and 2014, the proportion of areas with low landslide susceptibility in the study area was the largest, and the proportionof areas with the highest susceptibility was minimal. The landslide area with highest susceptibility gradually decreased from 2014 to 2017. However, in 2017, 15.06% of the area was still with high susceptibility, and relevant disaster prevention and reduction measures should be taken in these areas. The larger area under the receiver operating characteristic curve(AUC) indicates that the results of the landslide susceptibility assessment in this study are more objective and reliable than those of previous models. The difference in the AUC values over many years shows that the accuracy of the evaluation results of this model is not constant, and a greater number of landslides or higher landslide activity corresponds to a higher accuracy of the evaluation results.     

Marine hazards in coastal areas and human action against them—A case study of the Changjiang River estuaries and Qiantang River

China's eastern coastal area marine hazards (storm surge, erosion and deposition by tidal currents and seawater intrusion) and the history, present situation, experiences and problems of inhabitants in their fight against marine hazards are discussed in this paper, which also suggests counter-measures against, and scientific and rational management of, coastal area marine hazards in order to protect the coastal and estuarine ecosystems.     

Community tourism as practiced in the mountainous Qiang region of Sichuan Province, China — a case study in Zhenghe Village

In China, community tourism is still a relatively new phenomenon, but the villagers of a small Qiang village in the Qiang Autonomous County of Beichuan in Southwestern Sichuan have initiated tourism in a way which conforms to the basic theory of community tourism development. This demonstrates that community tourism possesses a strength and vitality that can promote the development of tourism in the rural and mountainous areas. In the district of Zhenghe Village, the tourism industry, based on the community tourism model, is the mainstay of its economy. The practice of community tourism in the village not only promotes the economic development of the village community, but also leads to the protection of the mountainous natural environment and of the culture of the Qiang people. This paper investigates the development process of community tourism in Zhenghe and shows how the local residents participate in this process. It also looks at how profits have been distributed within the community. It demonstrates that community tourism is a correct choice by the Zhenghe people as they have dearly been moving from poverty to prosperity, while the local ecology and environment have been simultaneously protected. The authors hope that other minority villages with similar local conditions and natural resources will be able to use this example to develop their own community tourism.     

Controls on geomorphic characteristics of the Xiaohei River basin in the upper Lancang-Mekong,China

Understanding the evolution of the fluvial geomorphology in an orogenic belt provides valuable insight into the relationship between upper crustal deformation and surface processes.The upper Lancang-Mekong River is in an area experiencing both uplift and erosion.The related processes provide a steady sediment supply to the lower reaches of the river and play an important role in the regional environmental changes.The Xiaohei(Weiyuan)River Basin is an important sub-basin in this area,which is characterized by large-scale topographic fluctuations,active tectonics and erosion,and anthropogenic activities.These different factors introduce numerous complexities to the local surface processes.In this study,we investigate and quantify the controls of geomorphic evolution of the Xiaohei River Basin.We located and mapped the main knick-zones within the channels and examined the main genetic factors,such as faults and stratigraphic differences.The results show that the areas with the lowest uplift rates are characterized by a low steepness index and are located in the southeastern part of the basin.The stream power of the mainstream increases downstream,with an average value of^122 W/m.The erosional activity of the various stream channels is intense.Overall,the basin tends to expansion,with only local instances of inward contraction.Our analysis confirms that a number of the geomorphic evolutionary characteristics of the Xiaohei River Basin are transient.In addition,the future potential for the increasing the number of dams and the hydropower development in the basin may weaken the expansion trend of the basin over a long period of time.     

Urban three-dimensional expansion and its driving forces —A case study of Shanghai, China

Urban expansion is a phenomenon of urban space increase, and an important measuring index of the process of urbanization. Taking Shanghai as an example, the changes of urban average height and built-up area were studied to represent city’s vertical and horizontal increases respectively, and statistical methods were used to analyze the driving forces of urban expansion. The research drew following conclusions: 1) The urban expansion process of Shanghai from 1985 to 2006 had a clear periodic feature, and could be divided into three stages: vertical expansion in dominance, coordinated vertical and horizontal expansion, and horizontal expansion in dominance. 2) The average height and quantity of buildings in core city were significantly bigger than those in suburbs, but the changing speed of the latter was faster. And 3) urbanization process was the major driving force for the city’s horizontal expansion, while industrial structure improvement was the key driving factor for the vertical expansion. Those two driving forces were simultaneously affected by city’s political factors.     

Impact of climatic factors on vegetation dynamics in the upper Yangtze River basin in China

It is necessary to understand vegetation dynamics and their climatic controls for sustainable ecosystem management.This study examines the vegetation dynamics and the effect of climate change on vegetation growth in the pristine conditions of 58 woodland National Nature Reserves(NNRs)located in the upper Yangtze River basin(UYRB)in China which are little influenced by human activities.Changes in the normalized difference vegetation index(NDVI),precipitation,and temperature in the selected NNRs were observed and analyzed for the period between 1999 and 2015.The relationship between time-lag effect of climate and changes in the NDVI were assessed using Pearson correlations.The results showed three major trends.1)The NDVI increased during the study period;this indicates an increase in the amount of green vegetation,especially due to the warmer climate during the growing season.The NDVIs in March and September were significantly affected by the temperature of the previous months.Spring temperatures increased significantly(P<0.05)and there was a delay between climatic factors and their effect on vegetation,which depended on the previous season.In particular,the spring temperature had a delayed effect on the NDVI in summer.2)The way in which vegetation responds to climatic factors varied significantly across the seasons.Temperature had a greater effect on the NDVI in spring and summer and the effect was greater at higher altitudes.A similar trend was observed for precipitation,except for altitudes of 1000–2000 m.3)Temperature had a greater effect on the NDVI in spring and autumn at higher altitudes.The same trend was observed for precipitation in summer.These findings suggest that the vegetation found in NNRs in the upper reaches of the Yangtze River was in good condition between 1999 and 2015 and that the growth and development of vegetation in the region has not been adversely affected by climate change.This demonstrates the effectiveness of nature reserves in protecting regional ecology and minimizing anthropogenic effects.     

Relation between basin morphometric features and dynamic characteristics of debris flows——a case study in Siberia,Russia

Extreme and prolonged rainfall in the Tunka Ridge caused several debris flows in the vicinity of the Arshan village(Siberia, Russia) on June 28, 2014. These debris flows, in spite of similar geological conditions, had different velocity, peak discharge and alluvial fan volume values. The flow velocity was from 3.5 m/s to 19.6 m/s, the peak discharge ranged from 63 m3/s to 13566 m3/s, and the alluvial fan volume varied from 4.13×103 to 8.45×105 m3. Such a great range of values is due to the morphometric parameters of the debris flow basins. The article deals with the influence of morphometric parameters of debris flow basins, such as the basin area, the average slope, Melton ratio, relief ratio on the debris flow velocity, peak discharge and volume of alluvial fans. In this debris flow event the average values of slope angle and total basin relief of the debris flow basins did not affect the values of debris flow velocity, peak discharge and alluvial fan volume. The highest correlations were observed with the debris flow basin area that was connected with the water inflow volume into the debris flow basins during the rainfall. The unequal water distribution among debris flow basins also had an impact on the debris flow velocity, peak discharge and volume of alluvial fans.     

Spatio-temporal distribution of vegetation index and its influencing factors——a case study of the Jiaozhou Bay,China

The coastal zone is an area characterized by intense interaction between land and sea, high sensitivity to regional environmental changes, and concentrated human activities. Little research has investigated vegetation cover changes in coastal zones resulting from climate change and land-use change, with a lack of knowledge about the driving mechanism. Normalized diff erence vegetation index(NDVI) can be used as an indicator for change of the coastal environment. In this study, we analyzed the interannual changes and spatial distribution of NDVI in the coastal zone around Jiaozhou Bay in Qingdao, a coastal city undergoing rapid urbanization in northeast China. The underlying causes of NDVI variations were discussed in the context of climate change and land-use change. Results showed that the spatio-temporal distribution of NDVI displayed high spatial variability in the study area and showed a typical trend of gradually increasing from coastal to inland regions. The significant increase area of NDVI was mainly found in newly added construction land, extending along the coastline towards the inland. Land vegetation cover demonstrated a certain response relationship to sea-land climate change and land-based activities. The impact of land-based human activities was slightly greater than that of sea-land climate change for land vegetation cover. The results indicate that promoting ecological policies can build an ecological security framework of vegetation suitable for the resource characteristics of coastal cities. The framework will buf fer the negative ef fects of sea-land climate change and land-based human activities on vegetation cover and thereby achieve the balance of regional development and ecological benefits in the coastal zone.     

Regional structure and spatial morphology characteristics of oasis urban agglomeration in arid area —A case of urban agglomeration in northern slope of Tianshan Mountains, Northwest China

It is great important to the health development of urban agglomeration to correctly understand the formation and development law of regional structure of urban agglomeration. Employing the analysis methods like fractal theory and quantitative statistics, coupling with the use of remote sensing images and other spatial data, this article discusses the urban agglomeration of oasis on the northern slope of the Tianshan Mountains in an arid area, and conducts the researches on its city scale, spatial distribution and individual form from 1990 to 2005. The result shows that it has loose hierarchical scale structure and polarization trend of population distribution while its hierarchical scale structure tends to mature. Under the influence of natural conditions, the spatial layout of urban agglomeration of oasis has macro characteristics that suggest cities distributed along oasis edges (dense or sparse), spatially expand along rivers, and cluster around traffic branches. The connectivity among the cities is high and shows an internal organization form of a banding distribution. The whole spatial shape of the internal structure of cities presents a “dumbbell” form, with mononuclear phenomenon receding and multi-nuclear appearing gradually. Individual cities spatially expand along rivers, portraying a long strip appearance. It indicates that the urban agglomeration of oasis shows regular and close structure but with a tendency to be complicated form and the loose structure. In the development of urban agglomeration, the authors recommend that the development of the city with good economic development conditions should be strengthened, and more attention be put into regional planning.     

Spatial Pattern of Rural Settlements in the Upper Reaches of the Minjiang River——a Case Study in Maoxian County, Sichuan

A quantitative analysis of the spatial pattern of rural settlements in the upper reaches of the Minjiang River was made with the major data sources being the relevant ETM image and the national geographical database of China (including contour line, river and road) at the scale of 1:250 000, and using image interpretation and field investigation to obtain spatial information on rural settlements. The results of the spatial analysis technique of GIS and correlation analysis showed that most settlements (78.2 %) were located in the mountain area at 1500 ~ 2700 m altitude, and almost half in the arid valley area. More than 80.0 % of settlements had their slopes above 15°. Most settlements had good access to water resources, roads and communications, and tended to cluster close to the road network rather than the river. About half of the rural settlements in the study area were relatively concentrated, while the others were decentralized. Those with higher altitude usually had land with steep slope, inconvenient water and road accesses, and were located far apart from each other. In view of such a situation, further research should be done to make reasonablecountermeasures on these settlements for better living conditions and ecosystem stability.     

Economic vulnerability of mining city —A case study of Fuxin City, Liaoning Province, China

The economic system of mining city is of typical vulnerability characteristics that can be manifested by its high economic sensitivity and lack of response capacity to the gradual depletion of regional mineral resources. Taking Fuxin City of Liaoning Province as a case, this paper established an economic vulnerability assessment method integrating BP neural network with vulnerability index, then carried out an economic vulnerability assessment of Fuxin during 1989–2006. The results indicate that: 1) Affected by the gradual depletion of regional mineral resources, the economic development of Fuxin had kept high economic sensitivity from 1995 to 2001, and the response capacity to cope with and adapt to the impacts of the perturbation of mineral resources was weak and relatively lag. The evolution of economic vulnerability can be divided into three stages: in 1989–1994, the economic vulnerability of Fuxin City decreased slowly; in 1995–2001, the beginning stage of economic transformation, the economic vulnerability of Fuxin City went up rapidly; in 2002–2006, the economic vulnerability of Fuxin City descended and showed a trend to be stable. 2) The influence of economic sensitivity on Fuxin’s economic vulnerability is more evident than that of response capacity. 3) The decreasing supply of mineral resources and the simple industrial structure are main factors leading to the economic sensitivity of Fuxin. 4) The improvement of economic response capacity of Fuxin has typical characteristics of input-driven growth, and external assistance is of great importance to the rapid improvement of economic response capacity of Fuxin. And 5) the change from the simple industrial structure to diversified one of Fuxin is still unaccomplished, and the contribution of non-coal-based industry to local economic development is relatively limited. Foundation item: Under the auspices of Key Program of National Natural Science Foundation of China (No. 40635030), Knowledge Innovation Programs of the Chinese Academy of Sciences (No. KZCX2-YW-342, No. KZCX2-YW-321)     

What is the relationship between ecosystem services and urbanization? A case study of the mountainous areas in Southwest China

China is undergoing a rapid urbanization process, and urbanization will have a direct impact on regional ecosystems and affect regional ecosystem services. Considering the mountainous counties in Southwestern China as the research object, this study reveals the spatial clustering characteristics of four typical ecosystem services(food production, soil conservation, water yield and carbon sequestration)as well as the trade-offs and synergies among ecosystem services in different urbanized areas. At the same time, piecewise linear regression is used to determine the threshold of the influence of urbanization on ecosystem services. The results indicate that: 1) There are spatial autocorrelations among the four typical ecosystem services; with strong clustering characteristics, the positive correlation types are "clustered" locally; and with significant spatial heterogeneity, the negative correlation types are scattered and mainly appear in the highly urbanized area. 2) There are also remarkable differences in the relationship among various ecosystem services in different urbanized areas, and in particular, there are marked trade-offs between food production and carbon sequestration in the moderately urbanized area and the highly urbanized area. However, there are synergies between them in the lowly urbanized area. 3) With an increase in the compounded night light index(CNLI), water yield, carbon sequestration, food production and overall ecosystem services values present an increasing-decreasing trend, the soil conservation function value shows a decreasing-increasing trend.The response of water yield, carbon sequestration,food production, and overall ecosystem services to the compounded night light index(CNLI) has a threshold of 1.2642, 1.4833, 1.3388, 1.5146 and 1.2237,respectively. Based on the detected relationships between urbanization and ecosystem services, this study provides a theoretical reference for the selection of urbanization development models in key ecological functional areas.     

Telecentres in mountain regions — A Peruvian case study of the impact of information and communication technologies on remoteness and exclusion

Communities in developing country mountain areas, in part due to their remoteness, find themselves excluded from social, political and economic systems; and excluded from access to resources. This paper aims to study the impact of information and communication technologies （ICTs） on remoteness and exclusion. It utilises two models - the resource movement framework, and the ＂information chain＂ - to analyse a telecentre in one district of mountainous Huancavelica, Peru＇s poorest region, set in the high Andes. It finds ICTs enabling new and positive resource flows for the two key user groups： teenaged school students and young farmers. These help to maintain social networks. They also support information searches that have improved agricultural practice where other information chain resources have been available. But non-use and ineffective use of the telecentre are found where information chain resources are lacking. ICTs have some impacts on intangible elements of remoteness. In this particular example, they also offer access to some previously-excluded resources. But they have not really addressed the systematic exclusions faced by mountain communities. And they so far appear to be a technology of inequality; favouring those residents who begin with better resource endowments. The paper concludes by offering some recommendations for mountain ICT project practice.     

Cassini growth of population between two metropolitan cities—A case study of Beijing-Tianjin region, China

The existing models of population distribution often focus on the region with a single city or even multiple centers, and lack the detailed explorations of the common and special type of urbanization areas with two centers. Taking Beijing-Tianjin region of China, which is a distinct dual-nuclei metropolitan area in the world, as an example and choosing Landsat-5 TM image in 2005, population, etc. as the data, this paper devotes to comprehending and illustrating a model of Cassini growth of population between the two metropolitan cities through the research of spatial population distribution pattern, aided with RS and GIS techniques. Main technical processes include Kriging interpolation of the population data and character simulation of the Cassini ovals. According to the calculation of a/b, a key characteristic index of Cassini growth model, the spatial structures of population distribution were given. When a/b<1, it is a curve with two separated loops with a population density more than 3000 persons/km². When a/b=1, it is a lemniscate curve with a population density about 3000 persons/km². When 1<a/b√2, it is a dog-bone shaped concave curve with a population density between 500–3000 persons/km². When a/b=√2, it is an oblate curve with a population density about 500 persons/km². When a/b>√2, there is an oval-shaped convex curve with a population density less than 500 persons/km². The results show that owing to the combined action and influence of the regional dual-nuclei, the population distribution of Beijing-Tianjin region is in accord with Cassini model significantly. There-fore, there is Cassini growth of population between the two metropolitan cities in Beijing-Tianjin region. In addition, the process of Cassini growth has extraordinarily instructive significance for judging the development stages of the dual-nuclei metropolitan areas. Foundation item: Under the auspices of National High-Tech Research and Development Program of China (863 Program) (No. 2007AA12Z235), National Natural Science Foundation of China (No. 40471058)     

Residents’ satisfaction with public services in mountainous areas: An empirical study of southwestern Sichuan Province,China

Enhancing the efficiency of public services is essential to residents in mountainous areas. It is also important to promote sustainable development of these regions. Analysing residents’ satisfaction with public services in mountainous areas can help in evaluating outcomes of fiscal investment and identifying potential coping approaches for improving public service efficiencies. The residents’ satisfaction with public services and the factors that influence such satisfaction were examined in this study. A study of 12 towns located in the southwestern Sichuan Province was performed using an entropy-weighted analytic hierarchy process (EWAHP), the technique for order preference by similarity to ideal solution (TOPSIS) and Tobit regression methods. The results indicate that: 1) the spatial distribution of satisfaction with public services is non-uniform, and the spatial distribution structure varies for different types of public services. 2) Residents’ satisfaction with public services is influenced by both objective and subjective factors. Population density, economic distance, social and cultural divisions and elevation are the major objective factors, whereas bounded rationality, the hierarchy of needs and service expectations are the main subjective factors. The most effective strategies for enhancing residents’ satisfaction with public services are likely to be clustering the population, choosing supply centres with different public services, regulating the cultural division in ethnic minority towns, selecting supply priorities in accordance with residents’ needs, implementing targeted intervention policies and establishing ‘bottom-up’ and ‘top-down’ integrated decision-making mechanisms.