摘要
2007年日本群马县南牧村在"植被覆盖良好,且实施了泥石流工程防护"的情况下,依然发生泥石流灾害,究其原因,与南牧村大量培育的"浅根型杉木人工纯林"关系密切。研究表明,南牧村的高大浅根杉木纯林具有典型的抑灾、致灾双向影响作用,其中"致灾影响"使得持续强降雨过程中斜坡林地大量破坏,结果(1)出现多条新发育的泥石流沟,泥石流暴发规模超过防护设计标准;(2)产生的漂木堵塞透水型拦挡坝,实际防护效能下降;(3)有的泥石流沿公路输移并破坏沿线经济体,泥石流危害范围扩大。据此,探讨了浅根型人工乔木纯林斜坡林地的稳定性问题、漂木拦挡问题、良好植被覆盖区泥石流灾害防治对策问题,建议探索浅根型乔木林人工培育及良好植被覆盖区泥石流危险区辨识等工作的减灾途径,重视斜坡林地稳定性的动态评价、泥石流危害路径的探查及良好植被覆盖区低频泥石流灾害隐患的揭示。
A debris flow disaster happened in 2007 in Nanmoku Village,Gunma Prefecture,Japan,the place of which was well forested and under the protection of disaster control measures. The result of field investigation showed that this special disaster could owe to the artificial pure plantation of shallow root firs with highly coverage area in Nanmoku Village. Tall and shallow root firs in Nanmoku Village have typical disaster-suppressing and disaster-causing bidirectional effects on debris flow disaster formation,and the disaster-causing effect led to a situation that a large amount of well forested slopes failed and mixed with the flood during the strong rainfall period,with the produced drift logs plugging up the water passages of permeable dams,which resulted in the excess of debris flow scale over the designed standard of existing disaster control measures and the lower of practically effects of dams than expected. Besides,there were some failures of slope near mountain road happened without its potential risk being recognized before,and they made the mountain road acting as the passage of debris flow,which induced the economic body along roads dropping into the damage ranges of debris flows. Enlightened by the situations mentioned above,3 issues about debris flow disaster mitigation were proposed and discussed,which were the stability of forest slope covered with arbor of shallow root type,the blocking measure of drift logs,and the preventing countermeasures of debris flow disasters in well forested area. It is suggested that the mitigation measures in the field of artifact pure plants cultivation and risk zonation of debris flow in well forested area should be explored,the design idea of varying dimensions horn shape structure of drainage passage could be introduced to enhance the drain function of permeable dam,and more attention should be paid to the evaluation of dynamic stability of forest slope of different period,the identification of damage routs of debris flows,and the revelation of potential danger of low frequent debris flow in well forested area.
出处
《山地学报》
CSCD
北大核心
2010年第3期367-372,共6页
Mountain Research
基金
交通部西部交通建设科技项目"活动断裂区高速公路泥石流灾害防治技术与推广应用研究"(200831800087)
四川省交通厅科技项目"活动断裂区公路沿线泥石流启动机理与灾害防治对策研究"(2006A024-582)~~
关键词
泥石流
灾害调查
良好植被覆盖区
透水型拦挡坝
既有防护
杉木纯林
日本
debris flow
disaster investigation
well forested area
permeable dam
existing control measure
pure plantation of firs
Japan
