The Wenchuan earthquake in 2008 and geo-hazards triggered by the earthquake caused large injuries and deaths as well as destructive damage for infrastructures like construction, traffic and electricity. It is urgent t...The Wenchuan earthquake in 2008 and geo-hazards triggered by the earthquake caused large injuries and deaths as well as destructive damage for infrastructures like construction, traffic and electricity. It is urgent to select relatively secure areas for townships and cities constructed in high mountainous regions with high magnitude earthquakes. This paper presents the basic thoughts, evaluation indices and evaluation methods of geological security evaluation, water and land resources security demonstration and integrated assessments of geo-environmental suitability for reconstruction in alp and ravine with high magnitude earthquakes, which are applied in the worst-hit areas （12 counties）. The integrated assessment shows that： （1） located in the Longmenshan fault zone, the evaluated area is of poor regional crust stability, in which the unstable and second unstable areas account for 79% of the total; （2） the geo-hazards susceptibility is high in the evaluation area. The spots of geo-hazards triggered by earthquake are mainly distributed along the active fault zone with higher distribution in the moderate and high mountains area, in which the areas of high and moderate susceptibility zoning accounts for 40.1% of the total; （3） geological security is poor in the evaluated area, in which the area of the unsuitable construction occupies 73.1%, whereas in the suitable construction area, the areas of geological security, second security and insecurity zoning account for 8.3 %, 9.3% and 9.3 % of the evaluated area respectively; （4） geo-environmentai suitability is poor in the evaluated area, in which the areas of suitability and basic suitability zoning account for 3.5% and 7.3% of the whole evaluation area.展开更多
In this paper, a geo-environmental diagnostic was implemented to classify susceptibility to desertification in southern Mozambique (Chicualacuala) and deliver responses to revert occurring land degradation. The proces...In this paper, a geo-environmental diagnostic was implemented to classify susceptibility to desertification in southern Mozambique (Chicualacuala) and deliver responses to revert occurring land degradation. The process of environmental diagnostic is a useful approach to identify the very processes and phenomena belonging to the wide ranging concept of land degradation.展开更多
The area to the southeast of the Western Desert of Egypt has been subjected to considerable development activities over the last few years. The development includes the cultivation of about 2260 km2 of the desert lan...The area to the southeast of the Western Desert of Egypt has been subjected to considerable development activities over the last few years. The development includes the cultivation of about 2260 km2 of the desert lands “the well-known Toshka Project”. The hydrogeological conditions of the area are subjected to detailed investigation based upon the construction of the water table maps, hydrologeologic cross-sections, pumping tests, aquifer geometry, and recharge-discharge relationship. The study revealed that the Quaternary and the Nubia sediments are the main water bearing layers in the area. The Quaternary aquifer is of limited potential and made of mixed sand with clay deposit ranges in thickness between 5 to 10 m. The Nubia aquifer is the oldest sedimentary formation and the main groundwater resources in the area. It is represented by multilayered of sand and silt exists generally under artesian conditions. It is composed of three water bearing horizons partially separated by two confining horizons and extends in thickness ranges between 70 and 230 meters. The thickness increases away from the high dam lake. The analysis of pumping tests of the aquifer indicated that its potentiality is increasing north of the High Dam Lake (HDL) whereas it decreases in the other direction. This is due to high hydraulic conductivity and aquifer thickness in the area northeast of Khor Toshka and at west of Garf Hussein. The hydraulic conductivity of the aquifer ranges between 12.73 and 0.9 m/day. The review of the changes in groundwater levels in the area showed that there is a drop in ranges between 1 and 14 meters in the last few years indicating that the extraction from the groundwater is much more higher that the replacement rate. Also, the analysis of the fluctuation of water levels of the HDL and the groundwater level indicated that the influence of water on groundwater level in the area is observed only at a distance less than 10 km from the lake shore line. Seepage from the HDL is estimated as 238.13 × 106 m3/year.展开更多
Landslides are the most intense and serious manifestations of the degradation of slopes and they are the main causes of geological hazard when they,directly or indirectly,involving towns and infrastructures.They are a...Landslides are the most intense and serious manifestations of the degradation of slopes and they are the main causes of geological hazard when they,directly or indirectly,involving towns and infrastructures.They are a global environment problem;there are several examples that have produced untold damages and loss of human lives in many parts of the world.In 1920 the landslides mobilization,as a result of a strong earthquake in China,in the province of Kansu,killed 200,000 people;in 1938 fast debris flow,triggered by heavy rainfalls in Japan,caused the death of 600 people;in 1963 in Italy the Vajont disaster caused the death of 1,899 people,as a result of a landslide localized in the underlying artificial storage.During the last years there have been many tragedies linked to intense rainfall events which have sparked many shallow landslides:1996 in Garfagnana,1998 in Sarno,2009 in the Ionic side of Messina,2011 in Liguria.To throw light on this problem,over the past decades,the assessment and mitigation of landslides hazard and the danger related to it,have become goals of paramount importance in territorial planning and,more generally,in its management and with it the safeguard of the historical and cultural heritage within it.The occurrence of events which are considered exceptional thus implies a re-reading in terms of spatial planning to renovate the slopes and river-beds,as well as urban planning,infrastructural and socio-economic organization.The complex nature of these instability events that affect anthropized areas does not allow specific approaches for the defence of single good,but it finds a more effective solution based on the extensive knowledge of territory,perhaps at the scale of individual or several watersheds.展开更多
文摘The Wenchuan earthquake in 2008 and geo-hazards triggered by the earthquake caused large injuries and deaths as well as destructive damage for infrastructures like construction, traffic and electricity. It is urgent to select relatively secure areas for townships and cities constructed in high mountainous regions with high magnitude earthquakes. This paper presents the basic thoughts, evaluation indices and evaluation methods of geological security evaluation, water and land resources security demonstration and integrated assessments of geo-environmental suitability for reconstruction in alp and ravine with high magnitude earthquakes, which are applied in the worst-hit areas （12 counties）. The integrated assessment shows that： （1） located in the Longmenshan fault zone, the evaluated area is of poor regional crust stability, in which the unstable and second unstable areas account for 79% of the total; （2） the geo-hazards susceptibility is high in the evaluation area. The spots of geo-hazards triggered by earthquake are mainly distributed along the active fault zone with higher distribution in the moderate and high mountains area, in which the areas of high and moderate susceptibility zoning accounts for 40.1% of the total; （3） geological security is poor in the evaluated area, in which the area of the unsuitable construction occupies 73.1%, whereas in the suitable construction area, the areas of geological security, second security and insecurity zoning account for 8.3 %, 9.3% and 9.3 % of the evaluated area respectively; （4） geo-environmentai suitability is poor in the evaluated area, in which the areas of suitability and basic suitability zoning account for 3.5% and 7.3% of the whole evaluation area.
文摘In this paper, a geo-environmental diagnostic was implemented to classify susceptibility to desertification in southern Mozambique (Chicualacuala) and deliver responses to revert occurring land degradation. The process of environmental diagnostic is a useful approach to identify the very processes and phenomena belonging to the wide ranging concept of land degradation.
文摘The area to the southeast of the Western Desert of Egypt has been subjected to considerable development activities over the last few years. The development includes the cultivation of about 2260 km2 of the desert lands “the well-known Toshka Project”. The hydrogeological conditions of the area are subjected to detailed investigation based upon the construction of the water table maps, hydrologeologic cross-sections, pumping tests, aquifer geometry, and recharge-discharge relationship. The study revealed that the Quaternary and the Nubia sediments are the main water bearing layers in the area. The Quaternary aquifer is of limited potential and made of mixed sand with clay deposit ranges in thickness between 5 to 10 m. The Nubia aquifer is the oldest sedimentary formation and the main groundwater resources in the area. It is represented by multilayered of sand and silt exists generally under artesian conditions. It is composed of three water bearing horizons partially separated by two confining horizons and extends in thickness ranges between 70 and 230 meters. The thickness increases away from the high dam lake. The analysis of pumping tests of the aquifer indicated that its potentiality is increasing north of the High Dam Lake (HDL) whereas it decreases in the other direction. This is due to high hydraulic conductivity and aquifer thickness in the area northeast of Khor Toshka and at west of Garf Hussein. The hydraulic conductivity of the aquifer ranges between 12.73 and 0.9 m/day. The review of the changes in groundwater levels in the area showed that there is a drop in ranges between 1 and 14 meters in the last few years indicating that the extraction from the groundwater is much more higher that the replacement rate. Also, the analysis of the fluctuation of water levels of the HDL and the groundwater level indicated that the influence of water on groundwater level in the area is observed only at a distance less than 10 km from the lake shore line. Seepage from the HDL is estimated as 238.13 × 106 m3/year.
文摘Landslides are the most intense and serious manifestations of the degradation of slopes and they are the main causes of geological hazard when they,directly or indirectly,involving towns and infrastructures.They are a global environment problem;there are several examples that have produced untold damages and loss of human lives in many parts of the world.In 1920 the landslides mobilization,as a result of a strong earthquake in China,in the province of Kansu,killed 200,000 people;in 1938 fast debris flow,triggered by heavy rainfalls in Japan,caused the death of 600 people;in 1963 in Italy the Vajont disaster caused the death of 1,899 people,as a result of a landslide localized in the underlying artificial storage.During the last years there have been many tragedies linked to intense rainfall events which have sparked many shallow landslides:1996 in Garfagnana,1998 in Sarno,2009 in the Ionic side of Messina,2011 in Liguria.To throw light on this problem,over the past decades,the assessment and mitigation of landslides hazard and the danger related to it,have become goals of paramount importance in territorial planning and,more generally,in its management and with it the safeguard of the historical and cultural heritage within it.The occurrence of events which are considered exceptional thus implies a re-reading in terms of spatial planning to renovate the slopes and river-beds,as well as urban planning,infrastructural and socio-economic organization.The complex nature of these instability events that affect anthropized areas does not allow specific approaches for the defence of single good,but it finds a more effective solution based on the extensive knowledge of territory,perhaps at the scale of individual or several watersheds.
