共查询到20条相似文献，搜索用时 828 毫秒
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乌拉盖水库建成于1980年,流域面积2.02万平方公里,1998年遭遇水毁后,经2002～2004年修复后蓄水。针对水毁后流域内的水土流失状况,水库管理局连续几年实施了小流域治理,使区域水土流失状况得到了有效遏制。一、小流域概况及水土流失原因1、流域概况乌拉盖水库位于锡林郭勒盟东北部、内蒙古最大的内陆河乌拉盖河中上游,是乌拉盖河上唯一一座水利枢纽工程,距霍林郭勒市40公里,是锡林郭勒盟乌拉盖 相似文献
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针对山区公路易遭水毁这一突出问题，从汛前检查、全面养护、工程防治等三方面提出具体的水毁防治措施及综合治理办法。总结本地区在防治公路水毁方面成功经验。 相似文献
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福建省林区公路技术标准低、抵御洪水冲刷能力差,每遇台风、暴雨、山洪暴发,往往发生不同程度水毁,如何采取有效措施对林区公路水毁进行防治,是公路养护面临的重要任务。文章分析了我省林区公路水毁的主要原因,并提出较有针对性的水毁防治措施,为我省林区公路的防护提供参考。 相似文献
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本文从设计、施工、养护和天然因素等方面分析了林区公路桥涵水毁产生的原因,提出了水毁桥涵的解决办法。 相似文献
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排水性沥青稳定碎石水稳定性的研究 总被引：9，自引：0，他引：9
在沥青路面结构层内设置多孔隙沥青稳定碎石排水层，可以迅速排出渗入结构层内部的自由水。但排水层本身可能较长时间处于水浸湿状态下，在水的浸泡及车辆荷载的作用下可能会发生水损坏。所以，排水性沥青稳定碎石应具有水稳定性。本文经对三种开级配的沥青稳定碎石进行了试验研究，得出ATPB的沥青用量应在2．5％以上，空隙率在18％以上的结论。 相似文献
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Isabel A. Munck Chandalin M. BennettKim S. Camilli Robert S. Nowak 《Forest Ecology and Management》2010
Lake Tahoe, on the boundary of California and Nevada, is world renown for its natural beauty and is also a popular location for winter-sporting activities. De-icing compounds, such as sodium chloride (NaCl), are used to maintain safe winter driving conditions. Sodium chloride, however, can damage roadside vegetation and affect surface and ground water quality. Our objectives were to: investigate the relationship among salt damage to trees and other damage (from insects, diseases, and other biotic and abiotic factors), examine the effects of vegetation characteristics and environmental factors on salt damage to trees, and to quantify the long-term impacts of de-icing salts on roadside conifers in the Tahoe Basin. From 2006 to 2008, 442 square plots (0.1 ha) were established and surveyed throughout the Lake Tahoe Basin, including 176 control plots > 300 m from roads, and 137 plots originally established in 1990 that were used for long-term trends. Both incidence and severity of salt damage, diseases, insect pests, and other abiotic damage were recorded on all trees within plots (more than 10,000 trees). Soil and vegetation samples were collected from a subset of plots and analyzed for salt content. At least 15% of roadside trees were damaged by salt every year. Very large year-to-year variation in the incidence of salt damage was observed, but the severity of salt damage has decreased since 1990. A clear roadside effect on roadside conifers existed because symptoms of salt damage were only observed on trees in roadside plots and never in control plots, and foliage from trees in roadside plots had more sodium and chloride content than those in control plots for both salt symptomatic and asymptomatic foliage. Incidence of salt damage decreased with increasing distance from roads, was more frequent on rocky soils, and increased with downhill slope steepness and tree density. Pines (Pinus spp.) were more frequently and severely damaged by salt than firs (Abies spp.). Trees were more likely to be damaged by something other than salt, and the relationship among salt damage and other damages was antagonistic rather than synergistic. The results from this study have important implications for the ecology and management of conifer forests in relation to salinity and road maintenance. 相似文献
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随着城市化的不断推进以及全球气候变化的加剧,高温、干旱等极端气候频发,对城市园林绿化造成重大影响。城市道路绿化作为城市绿地一种典型的带状绿地,其对高温干旱气候的响应机制尚不明确。以2022年南昌市所遭受的极端高温干旱气候为契机,对南昌市经开区十五条主次干道绿化树种进行受害特征调查分析,结果表明：(1)受高温旱害影响的植株分布呈现出一定的空间聚集性和规律性,南北向道路植物受灾较为严重,东西向道路植物受灾情况相对较轻;(2)随着树下铺装面积的增加,乔木、灌木受损情况呈上升趋势;随着铺装透水率的增加,乔木、灌木受损情况呈下降趋势;(3)乔木个体越大、长势越好,其抗干旱能力越强;(4)对耐旱性较差、小胸径及低矮的树种及时养护。适当增加南北朝向道路的人工浇灌及管护频次。选择透水性较好的铺装,并适当减少树下铺装的面积,以此来缓解高温干旱对城市道路绿化的影响。 相似文献
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Our presentation focuses on some important issues associated with ecotourism in nature reserves in mainland China. Conducting ecotourism in certain areas in nature reserves is important for its protection. However, some problems do exist because of special conditions in our society and in the current projects of nature reserves themselves, such as water and air pollution, unplanned construction of roads and facilities, damage of core zones and buffer zones, and confused ownership of nature reserves. These problems are discussed and solutions are proposed in detail, and we emphasize the participation of local communities in order to help residents fight against poverty. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):427-435
In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads. 相似文献
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殷墟为晚商时期的都城遗址,已考古发掘出大量的宫殿、陵墓、手工业作坊、路网及水网等遗迹,很多学者也展开了相关研究.对我国近20年来有关晚商殷墟池苑研究的文献资料进行梳理,发现晚商时期殷墟地区气候温和湿润,具备营造园林的社会、经济和技术条件,再结合建筑、水体等池苑构成要素及池苑功能方面的文献资料得出以下推论:晚商殷墟池苑是... 相似文献
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Grizzly bears and forestry: I: Road vegetation and placement as an attractant to grizzly bears 总被引：1，自引：1，他引：0
Today's growing demand for timber is increasing road development in once roadless forest ecosystems. Roads create both local changes in plant communities and landscape-level changes in forest connectivity. Roads also increase human access, which can be detrimental to species such as grizzly bears. Because most grizzly bear mortalities occur near roads, we examined grizzly bear attractants near roads, which could increase bear use of roadsides and consequently increase human/grizzly bear interactions. We measured the prevalence of 16 grizzly bear foods near roads and examined patterns in road placement to better understand use of roaded habitats by grizzly bears in west-central Alberta. We found that roadsides had a higher frequency of ants, Equisetum spp., Taraxicum officinale, Trifolium spp., graminoids, and sedges; whereas, interior forest stands had a higher frequency of Shepherdia canadensis, Vaccinium myrtilloides, V. vitis-idaea, and ungulate pellets, an indicator of ungulate presence. In addition, roads near water had a greater occurrence of Arctostaphylos uva-ursi and Equisetum spp. than roads not near water, indicating that road placement influenced bear food diversity. Patterns in road placement varied between the upper and lower foothills, although models for the lower foothills predicted road placement in both regions. In the lower foothills, roads were constructed at low elevation, low soil moisture, high sun exposure, and intermediate terrain ruggedness, possibly similar to sites selected by bears. Reducing grizzly bear foods near roads should involve decreasing the width of roadside ditches, banning the planting of clover (Trifolium spp.), and reevaluating road placement in areas with high grizzly bear density. 相似文献
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针对常宁市域范围,利用GIS和Fragstat软件,通过建立缓冲区并进行情景分析,分析了不同等级道路对景观格局的影响。结果表明:常宁市内一级道路所影响面积最大,二级道路最小,而影响的斑块数目则为三级路一级路二级路高速路,受影响生态面积为水田灌木林地茶园旱地其他建筑用地有林地水体住宅用地其他林地疏林地裸地果园其他园地,受影响斑块数目最高为灌木林地,其次为水田。情景分析表明,随着道路的建设,斑块分维数升高,但总体上,高等级道路对景观形状指数和斑块形状因子升高的贡献率最小。 相似文献