The present research aims to investigate the geomorphological changes of the city lands due to the physical development of Shiraz during the years 1967-2018.Therefore,to find out the type and amount of changes in this...The present research aims to investigate the geomorphological changes of the city lands due to the physical development of Shiraz during the years 1967-2018.Therefore,to find out the type and amount of changes in this area,images of Landsat sensor+MSS,TM,ETM,for years(1976,1986,1996,2006,and 2018),and aerial photographs of Shiraz at a scale of 1:20,000 in 1967,as well as the map and statistics of the demographic changes of the city during the above years have been analyzed.Envi4.8 and ArcGis10.3 software have been used to process and interpret satellite imagery and to provide intended maps.First,the land cover and land use for Shiraz metropolis and its surroundings were derived and the changes of agricultural and barren lands to urban use were identified using the changes detection by post-classification comparison images technique.The results of this research show that during the 50 years of study,the area of this metropolis and its population was increased around 12 and 6 times respectively.These changes were mainly due to human activities,including the effects of urban development on the landforms and lands around the Shiraz,such as changes in the steep slopes of the mountains and the canals(from the north),expansion of the city on loose formations with low strength(from northwest and west),development of the city in the areas where groundwater levels are high and also the flood plain(from south and east).展开更多
针对地形复杂、植被覆盖度高的隐蔽性地质灾害的识别,激光雷达技术(light detection and ranging,LiDAR)较传统手段具有非接触、高效率、精准判识等优点。本文采用机载LiDAR、有人机航拍等手段对福建省平溪镇—下党乡潜在高位隐蔽性地...针对地形复杂、植被覆盖度高的隐蔽性地质灾害的识别,激光雷达技术(light detection and ranging,LiDAR)较传统手段具有非接触、高效率、精准判识等优点。本文采用机载LiDAR、有人机航拍等手段对福建省平溪镇—下党乡潜在高位隐蔽性地质灾害隐患区进行数据采集及地质灾害隐患早期识别工作。首先,采用整体滤波为主,人工精细化分类为辅的方法进行点云去噪滤波处理;其次,利用随机算法抽稀高密度点云数据;最后,分析不同植被覆盖度下,不同点云密度对微地貌识别效果。展开更多
Structural characteristic of surface soil ground has great effect on the ground motion amplitude when earthquake happens. Recent studies in Japan on seismic zonings use a database that covers entire Japan with 1 km me...Structural characteristic of surface soil ground has great effect on the ground motion amplitude when earthquake happens. Recent studies in Japan on seismic zonings use a database that covers entire Japan with 1 km mesh size, which is useful for prefecture scale researches. However, it is hard, even with 500 m or 250 m mesh sizes to consider a city, a county or award as scale studies. Kanagawa Prefecture is highly urbanized and vulnerable to seismic disaster. The prefecture suffered a wide spread damage during the 1923 Kanto earthquake. In this paper, we deploy a very fine mesh 50 × 50 m mesh to develop a general seismic intensity map useful for micro scale disaster management for local governments and educational information for earthquake preparedness promotion. In this paper, first we prepared two detailed databases for 50 × 50 m mesh size over entire Kanagawa Prefecture. One was for geologic formations and the other the geomorphologic condition. Then these databases were used for preparation of high-resolution digital soil classification maps for 15 categories of micro landforms of prefecture. The later database was used for mapping the site amplification factors for 50 × 50 m mesh by applying the empirical relations for AVS30. We could create a GIS platform with sufficient accuracy to consider potential risk analysis.展开更多
文摘The present research aims to investigate the geomorphological changes of the city lands due to the physical development of Shiraz during the years 1967-2018.Therefore,to find out the type and amount of changes in this area,images of Landsat sensor+MSS,TM,ETM,for years(1976,1986,1996,2006,and 2018),and aerial photographs of Shiraz at a scale of 1:20,000 in 1967,as well as the map and statistics of the demographic changes of the city during the above years have been analyzed.Envi4.8 and ArcGis10.3 software have been used to process and interpret satellite imagery and to provide intended maps.First,the land cover and land use for Shiraz metropolis and its surroundings were derived and the changes of agricultural and barren lands to urban use were identified using the changes detection by post-classification comparison images technique.The results of this research show that during the 50 years of study,the area of this metropolis and its population was increased around 12 and 6 times respectively.These changes were mainly due to human activities,including the effects of urban development on the landforms and lands around the Shiraz,such as changes in the steep slopes of the mountains and the canals(from the north),expansion of the city on loose formations with low strength(from northwest and west),development of the city in the areas where groundwater levels are high and also the flood plain(from south and east).
文摘针对地形复杂、植被覆盖度高的隐蔽性地质灾害的识别,激光雷达技术(light detection and ranging,LiDAR)较传统手段具有非接触、高效率、精准判识等优点。本文采用机载LiDAR、有人机航拍等手段对福建省平溪镇—下党乡潜在高位隐蔽性地质灾害隐患区进行数据采集及地质灾害隐患早期识别工作。首先,采用整体滤波为主,人工精细化分类为辅的方法进行点云去噪滤波处理;其次,利用随机算法抽稀高密度点云数据;最后,分析不同植被覆盖度下,不同点云密度对微地貌识别效果。
文摘Structural characteristic of surface soil ground has great effect on the ground motion amplitude when earthquake happens. Recent studies in Japan on seismic zonings use a database that covers entire Japan with 1 km mesh size, which is useful for prefecture scale researches. However, it is hard, even with 500 m or 250 m mesh sizes to consider a city, a county or award as scale studies. Kanagawa Prefecture is highly urbanized and vulnerable to seismic disaster. The prefecture suffered a wide spread damage during the 1923 Kanto earthquake. In this paper, we deploy a very fine mesh 50 × 50 m mesh to develop a general seismic intensity map useful for micro scale disaster management for local governments and educational information for earthquake preparedness promotion. In this paper, first we prepared two detailed databases for 50 × 50 m mesh size over entire Kanagawa Prefecture. One was for geologic formations and the other the geomorphologic condition. Then these databases were used for preparation of high-resolution digital soil classification maps for 15 categories of micro landforms of prefecture. The later database was used for mapping the site amplification factors for 50 × 50 m mesh by applying the empirical relations for AVS30. We could create a GIS platform with sufficient accuracy to consider potential risk analysis.
