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陈文阁 《内蒙古林业调查设计》1998,(Z1)
文章针对林区公路冰湖形成的特征及规律,分析其生成的原因,在设计时就预先考虑防治的措施,在形成冰湖后提出处理和解决的办法,同时对各种方案进行比较,分析其优缺点。 相似文献
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针对林区公路冰湖形成的特征及规律,重点介绍在分析其生成的原因,在设计时就预先考虑的防治的措施,在形成冰湖后处理和解决的办法,同时对各种方案进行比较,分析各种方案的优缺点。 相似文献
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针对林区公路冰湖形成的特征及规律,重点介绍在分析其生成的原因,在设计时就预先考虑防治的措施,在形成冰湖后处理和解决的办法,同时对各种方案进行比较,分析各种方案的优缺点。 相似文献
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本文为处理冰湖提供的一种简便易行的方法,即利用塑料薄膜的不透水和抗张拉的特点,有效地堵截和防治冰湖。 相似文献
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地表渗水形成的渗水冰湖;潜流溢出形成的潜流冰湖;沿流水上形成的沿流水湖,这些林区公路“冰湖”影响车辆正常通行,危害安全生产,给养路带来困难和负担,这里采用对症下药介绍了治理“冰湖”的三种办法:笫一,适用于渗水冰湖的办法:移冰上山;第二,适用于潜流冰湖的办法:引水入地;第三,适用渗水冰湖渗水量较大或潜流冰湖距桥涵较近的办法;截水入涵。 相似文献
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本文说明了冰湖的成因,对冰湖分为地表水冰湖和地下水冰湖两类。进而从我国北方林区实际情况出发,提出了预防这两类冰湖危害的几项措施,同时介绍几种林区养路工作人员采用的简单易行、费用低廉、行之有效的治理冰湖办法。 相似文献
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针对萍乡森林病虫害发生情况、特点及成因分析,提出有效控制防治对策。 相似文献
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对森林病害预防和治理作一简要的历史回顾和展望未来,并对预防为主,综合治理的基本特征和防治方针,森林生态治理,森林健康思想进行初步阐述和讨论。 相似文献
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我国丰富的林业资源为国民经济发展奠定了坚实的基础,但是我国林业资源还存在着分布不合理、不平衡、森林覆盖率低、人均占有量较小及人为破坏行为严重等情况,因此需要对林业资源加强保护的同时要加强森林防火管理.基于此,从林业资源现状入手,对林业资源保护以及森林防火管理措施进行深入分析,以期能够提升对森林的保护以及防火力度,确保林... 相似文献
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在阐述生态防治森林病害的依据、基本概念、理论基础的同时,对生态防治的森林培育技术措施、生物控制及经营管理3个主要内容进行了详细的介绍。 相似文献
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Effects of roads,topography, and land use on forest cover dynamics in the Brazilian Atlantic Forest 总被引:1,自引:0,他引:1
Roads and topography can determine patterns of land use and distribution of forest cover, particularly in tropical regions. We evaluated how road density, land use, and topography affected forest fragmentation, deforestation and forest regrowth in a Brazilian Atlantic Forest region near the city of São Paulo. We mapped roads and land use/land cover for three years (1962, 1981 and 2000) from historical aerial photographs, and summarized the distribution of roads, land use/land cover and topography within a grid of 94 non-overlapping 100 ha squares. We used generalized least squares regression models for data analysis. Our models showed that forest fragmentation and deforestation depended on topography, land use and road density, whereas forest regrowth depended primarily on land use. However, the relationships between these variables and forest dynamics changed in the two studied periods; land use and slope were the strongest predictors from 1962 to 1981, and past (1962) road density and land use were the strongest predictors for the following period (1981–2000). Roads had the strongest relationship with deforestation and forest fragmentation when the expansions of agriculture and buildings were limited to already deforested areas, and when there was a rapid expansion of development, under influence of São Paulo city. Furthermore, the past (1962) road network was more important than the recent road network (1981) when explaining forest dynamics between 1981 and 2000, suggesting a long-term effect of roads. Roads are permanent scars on the landscape and facilitate deforestation and forest fragmentation due to increased accessibility and land valorization, which control land-use and land-cover dynamics. Topography directly affected deforestation, agriculture and road expansion, mainly between 1962 and 1981. Forest are thus in peril where there are more roads, and long-term conservation strategies should consider ways to mitigate roads as permanent landscape features and drivers facilitators of deforestation and forest fragmentation. 相似文献
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