At 5: 39 AM on 24 June 2017, a huge landslide-debris avalanche occurred on Fugui Mountain at Xinmo village, Diexi town, Maoxian county, Sichuan province, China. The debris blocked the Songpinggou River for about 2 km,...At 5: 39 AM on 24 June 2017, a huge landslide-debris avalanche occurred on Fugui Mountain at Xinmo village, Diexi town, Maoxian county, Sichuan province, China. The debris blocked the Songpinggou River for about 2 km, resulting in a heavy loss of both human lives and properties(10 deaths, 3 injuries, 73 missing, and 103 houses completely destroyed). The objectives of this paper are to understand the overall process and triggering factors of this landslide and to explore the affecting factors for its long term evolution before failure. Post event surveys were carried out the day after the landslide occurrence. Information was gathered from literature and on-site investigation and measurement. Topography, landforms, lithology, geological setting, earthquake history, meteorological and hydrological data of the area were analysed. Aerial photographs and other remote sensing information were used for evaluation and discussion. Eye witnesses also provided a lot of helpful information for us to understand the process of initiation, development and deposition. The depositional characteristics of the moving material as well as the traces of the movement,the structural features of the main scarp and the seismic waves induced by the slide are presented and discussed in detail in this paper. The results show that the mechanism of the landslide is a sudden rupture of the main block caused by the instability of a secondary block at a higher position. After the initiation, the failed rock mass at higher position overloaded the main block at the lower elevation and collapsed in tandem. Fragmentation of the rock mass occurred later, thus forming a debris avalanche with high mobility. This landslide case indicates that such seismic events could influence geological hazards for over 80 years and this study provides reference to the long term susceptibility and risk assessment of secondary geological hazards from earthquake.展开更多
Physiography and soil in Mae Rim watershed, Chiang Mai Province, Thailand were investigated by using aerial photographs and satellite image in conjunction with field work, and soil infiltration rate and soil shear res...Physiography and soil in Mae Rim watershed, Chiang Mai Province, Thailand were investigated by using aerial photographs and satellite image in conjunction with field work, and soil infiltration rate and soil shear resistance were measured in field. Many factors affecting runoff were analyzed using the Integrated Land and Water Information System (ILWIS). As a result, a model determining flood hazard was set up. Three maps including runoff curve number map, runoff coefficient map, and flood inundation map were created. In addition, the time of concentration was predicted.展开更多
The urban environmental quality remains currently difficult to be assessed because of overlapping of several natural and anthropogenic factors having socio-economic and environmental outstanding impacts. The fast deve...The urban environmental quality remains currently difficult to be assessed because of overlapping of several natural and anthropogenic factors having socio-economic and environmental outstanding impacts. The fast developing and uncontrolled urbanization is behind the development of some negative side effects on the urban environment. Many studies demonstrate the ability of remote sensing and GIS （geographic information system） to monitor urban environment quality. Casablanca, Morocco＇s economical capital is facing a fast growing demographic development amplified by a massive rural depopulation and all this in an anarchic way. This growth of increased urban activity comes often with the proliferation of informal settlement and shantytown to the detriment of farming areas and green spaces. This study is made possible by using a SPOT-5 image of Casablanca city, taken March 16, 2004 merged with 2.5 m spatial resolution and census data. Indicators were defined and listed in social, economic and environmental categories. An index of environmental quality in Casablanca city for the 17 urban municipalities was calculated after the standardization and weighting of indicators used. The results may be useful to city managers and planners who are concerned with urban environment quality issues and sustainable development.展开更多
基金financially supported by the National Basic Reareach program of China (973 program, Grant No. 2013CB733201)Key Research Program of Frontier Sciences, CAS (Grant No. QYZDY-SSW-DQC006)the “Hundred Talents” program (SU Li-jun) of Chinese Academy of Sciences (CAS)
文摘At 5: 39 AM on 24 June 2017, a huge landslide-debris avalanche occurred on Fugui Mountain at Xinmo village, Diexi town, Maoxian county, Sichuan province, China. The debris blocked the Songpinggou River for about 2 km, resulting in a heavy loss of both human lives and properties(10 deaths, 3 injuries, 73 missing, and 103 houses completely destroyed). The objectives of this paper are to understand the overall process and triggering factors of this landslide and to explore the affecting factors for its long term evolution before failure. Post event surveys were carried out the day after the landslide occurrence. Information was gathered from literature and on-site investigation and measurement. Topography, landforms, lithology, geological setting, earthquake history, meteorological and hydrological data of the area were analysed. Aerial photographs and other remote sensing information were used for evaluation and discussion. Eye witnesses also provided a lot of helpful information for us to understand the process of initiation, development and deposition. The depositional characteristics of the moving material as well as the traces of the movement,the structural features of the main scarp and the seismic waves induced by the slide are presented and discussed in detail in this paper. The results show that the mechanism of the landslide is a sudden rupture of the main block caused by the instability of a secondary block at a higher position. After the initiation, the failed rock mass at higher position overloaded the main block at the lower elevation and collapsed in tandem. Fragmentation of the rock mass occurred later, thus forming a debris avalanche with high mobility. This landslide case indicates that such seismic events could influence geological hazards for over 80 years and this study provides reference to the long term susceptibility and risk assessment of secondary geological hazards from earthquake.
文摘Physiography and soil in Mae Rim watershed, Chiang Mai Province, Thailand were investigated by using aerial photographs and satellite image in conjunction with field work, and soil infiltration rate and soil shear resistance were measured in field. Many factors affecting runoff were analyzed using the Integrated Land and Water Information System (ILWIS). As a result, a model determining flood hazard was set up. Three maps including runoff curve number map, runoff coefficient map, and flood inundation map were created. In addition, the time of concentration was predicted.
文摘The urban environmental quality remains currently difficult to be assessed because of overlapping of several natural and anthropogenic factors having socio-economic and environmental outstanding impacts. The fast developing and uncontrolled urbanization is behind the development of some negative side effects on the urban environment. Many studies demonstrate the ability of remote sensing and GIS （geographic information system） to monitor urban environment quality. Casablanca, Morocco＇s economical capital is facing a fast growing demographic development amplified by a massive rural depopulation and all this in an anarchic way. This growth of increased urban activity comes often with the proliferation of informal settlement and shantytown to the detriment of farming areas and green spaces. This study is made possible by using a SPOT-5 image of Casablanca city, taken March 16, 2004 merged with 2.5 m spatial resolution and census data. Indicators were defined and listed in social, economic and environmental categories. An index of environmental quality in Casablanca city for the 17 urban municipalities was calculated after the standardization and weighting of indicators used. The results may be useful to city managers and planners who are concerned with urban environment quality issues and sustainable development.
