地形発達効果および気候変動を考慮した斜面危険度の広域評価

随着我们的环境变暖，极端气候变得更加频繁。全球变暖直接或间接地影响坡面植被、地貌和稳定性，是坡面灾害发生的主导因素。边坡灾害评价的分析对象是滑坡，它是各种边坡灾害的根源。本研究旨在建立气候变化影响下的高分辨率斜坡灾害预测方法。在过去的两年中，我们成功地开发了一种新的基于力学的滑坡模型，用于识别陡峭和植被覆盖的山坡上不规则表土层的三维滑坡不稳定区。2014年7月在日本广岛和2011年7月在韩国首尔发生的两个历史事件被用于验证和案例研究。模拟结果与现场实际情况吻合较好。在三维地下水建模方面，成功地对水力地下水理论进行了解析研究，提出了一种新的正确建模方法，并采用松弛法对不规则三维土层的地下水位演化进行了数值模拟。将上述两种模型结合起来，实现了高分辨率的三维滑坡预测。然而，景观演变模拟部分仍在发展中，在不久的将来会出现长期气候变化影响下的山坡过程综合模拟。

As our environment becomes warmer, extreme climate becomes more frequent. Global warming directly or indirectly influences hillslope vegetation, landform and stability, which are the dominant factors for hazard occurrence on slopeland. To perform slopeland hazard assessment, the analysis target is landslide which is the origin of all kinds of slopeland hazards. This research aims to develop a methodology which can achieve high resolution prediction of slopeland hazards under climate change impact. In last two years, we have successfully finished the development of a novel mechanically based landslide model to identify three-dimensional unstable zones prone to landslide in irregular topsoil layers on steep and vegetated hillslopes by using Poroelasticity, Mohr-Coulomb failure theory and tree allometry. Two historical events occurred in Hiroshima, Japan in July 2014 and in Seoul, Korea in July 2011 are used for verification and case studies. The simulated results are in good agreements with real field conditions. For 3D groundwater modeling, we successfully analytically investigate hydraulic groundwater theory to propose a new way for correct modeling, and perform numerical modeling of groundwater table evolution in irregular 3D soil layer using relaxation approach. Both of the models above have been integrated to achieve 3D landslide prediction in the high resolution. However, the part for landscape evolution simulation is still under development, and to be appear in the near future for comprehensive modeling of hillslope process under long-term climate change influence.