Potential volume for CO2 deep ocean sequestration: an assessment of the area located on western Pacific Ocean     

David Ching-Fang Shih  Yih-Min Wu  Jyr-Ching Hu 《Stochastic Environmental Research and Risk Assessment (SERRA)》2010,24(5):705-711

Captured CO₂ could be deliberately injected into the ocean at great depth, where most of it would remain isolated from the atmosphere for centuries. CO₂ can be transported via pipeline or ship for release in the ocean or on the sea floor. In Taiwan, CO₂ release is preliminarily projected from 2010 to 2030 in an average amount of 6.957 Gt within this duration. If deep sea sequestration for CO₂ can be the possible option in Taiwan, it seems to exists possible potential area delimited between 122.0°E to 122.5°E and 21.8°N to 22.3°N for CO₂ sequestration on account of its isolated and flat topography. Apparently, the area to the southeast of Taiwan is found to reach a depth deeper than −3,000 m and can be taken as a testing area for pilot studies. This study searches the area using the contours from the depth of −4,554 to −5,500 m with 1-m interval; the area, topographic volume, maximum mean height (volume/area), and ocean volume are reported. If the emission rate is kept constantly, for 20-year storage it needs 3 m of thickness reaching the sea ridge at the depth −4,554 m using top-down style; for 100 years of storage it needs 12 m. On the other hand, if it accounts for the bottom the sea floor is taken as the reference and the accumulated CO₂ is stored from the depth at −4,900 m using bottom-up style, it requires about 37 m for the 20-year storage and 61 m for one decade.  相似文献   

The formation and evolution of a coastal alluvial fan in eastern Taiwan caused by rainfall-induced landslides     

Hsien-Ter Chou  Ching-Fang Lee  Chia-Ming Lo 《Landslides》2017,14(1):109-122

The formation and evolution of a coastal fan in eastern Taiwan associated with a sequence of rainfall-induced landslides during the 2009–2013 period are explored in this study. The evolution of these landslides is mainly attributed to the head-cutting process initiated by Typhoon Parma in October 2009. During the attack of Typhoon Megi in October, 2010, a subaerial coastal fan with a surface slope of 8.9° was formed after the mobilization of the rainfall-induced landslides. The geomorphic features both in the steep gully and on the coastal fan were categorized as the sequence of granular debris flows and sheet floods. Severe fan toe erosion occurred thereafter due to the wind-wave forcing. Even if the variations of both the cumulative rainfalls and the drainage areas are one or two orders of magnitude among devastating fan-forming landslides worldwide, the mean annual precipitation and the basin ruggedness index (Melton ratio) are effective indicators to normalize the rainfall threshold and to characterize the fan surface slope, respectively. Severe catastrophic landslides generally occur when the normalized cumulative rainfalls with respect to mean annual precipitation are greater than 0.1. The fan slope generally increases with the increasing Melton ratio for the catchment. Uchiogi’s empirical model is applicable for predicting the rainfall-induced area ratio of newly generated landslides. In this case study, the relationship of the fan area to the total landslide area follows a linear regressive curve when the ratio of landslide area with respect to the drainage area exceeds 0.0056.  相似文献   

Application of sky view factor technique to the interpretation and reactivation assessment of landslide activity     

Chia-Ming Lo  Ching-Fang Lee  Jeff Keck 《Environmental Earth Sciences》2017,76(10):375

High-resolution digital elevation models are crucial to the investigation of natural disasters, and a variety of methods based on visualization and relief map compilations have been proposed. In this study, the sky view factor (SVF) is applied to slope maps and a digital elevation model (DEM) of the Oso landslide, a deadly landslide that occurred in Washington State on March 22, 2014, to demonstrate the effectiveness of SVF-enhanced relief maps in mapping and evaluating large-scale or deep-seated landslide hazards. A procedure for combining the SVF-enhanced DEM with slope and elevation maps is also presented. Then the maps are used to extract the landslide-prone areas and perform a reactivation analysis of the post-Oso landslide using an analytic hierarchy process (AHP). By using the SVF-enhanced DEM to perform the AHP assessment on multi-period images, we accurately evaluate hazard of the landslide for both pre and post-2014 conditions. Finally, different visualization maps, limitation and recommend parameters for generating SVF relief map are presented in the paper.  相似文献