共查询到19条相似文献，搜索用时 375 毫秒
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密云水库集水区水源保护林在北京地区饮用水源保护中起着非常重要的作用．本文给出了该区小流域对比实验的初步研究结果,有林小流域和无林小流域对１９９６年７月３０日降雨过程较为一致的径流响应表明,土壤前期含水量对流域产流有较大的影响,在降雨较多土壤含水量较大的情况下该区产流方式可以表现为饱和地表径流．尽管该区以霍顿超渗产流为主,但对于１９９７年７月３１日至８月１日降雨过程,森林流域产流总量为１３９３．８０ｍ３,无林流域为２２０２．４３ｍ３,森林流域减少洪水总量３６．７％,消减洪峰流量达３７３％．然而,１９９７年７月１９日降雨过程森林流域径流洪峰量与洪水泥沙含量均较无林流域高,这表明预处理措施对径流泥沙过程有极为显著的影响 相似文献
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微集水区是山区最基本的水文单元,其降雨产流特征研究可以为流域水文的规律研究提供重要的数据支持。针对迤者小流域的森林微集水区进行不间断观测,得出结论:降雨量直接影响微集水区的径流产生量,7月19日24h内降雨量为36.6mm,降雨性产流105.57m3;径流洪峰一般滞后于降雨量峰值,7月19日降雨—径流监测中,最大产流值滞后最大降雨量值2h50min。 相似文献
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林冠分配降雨过程模拟与模拟：Ⅰ.常雨强下穿透降雨,树干径流和林冠截… 总被引：8，自引：0，他引：8
应用系统方法，从连续方程出发推演出次降雨通过林冠的穿透降雨、树干径流和林冠截留三个过程模型均为ｎ＋１阶常系数微分方程。用ａ１ｄ２Ｑ／ｄｔ＾２＋ａ２ｄＱ／ｄｔ＋ａ３Ｑ＝Ｉ方程表达穿透降雨和树干径流过程，旨在揭示林冠分配降雨特征与动态规律。以穿透降雨为例，其模型模拟结果与实验比较，相对误差不超过２％，与野外观测比较，多次平均相对误差为６％。笔者发现次降雨通过林冠这一多孔介质的穿透降雨、树干径流过程与电 相似文献
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以女儿寨小流域为研究对象，着重研究了植被恢复与重建过程中小流域系统的降雨和水沙变化特征，并对植被恢复过程中的总体减沙水平做了分析。结果表明：①受大气环流的影响，小流域年际降雨量差异较大；小流域降雨年内时间分布极为不均，集中性很大，主要集中在汛期（4-8月），但年内降雨量的月间分布趋势基本一致。②小流域迳流年际变化很大，迳流年内分配不均。迳流集中是该小流域迳流变化的一个显著特征：小流域的植被恢复与重建对洪峰的出现和洪峰流量具有明显的延缓和削减作用。③径流（Qi）主要来源于降水（Pi），二者呈明显的一元线型关系：Pi=115．7678＋2．7386Qi。④小流域的年输沙模数与年迳流量的变化规律基本一致，小流域年内产沙也高度集中，且与降水、迳流关系密切，小流域的土壤侵蚀主要由汛期的强降水引起。⑤随着小流域大面积、高标准的生态环境建设，1990年至2004年间小流域的输沙模数呈锐减之势，植被恢复与重建起到了显著的减沙效应。 相似文献
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在考虑地表流边界条件情况下,森林对降雨径流和泥沙的影响是一个非常复杂的过程．本文给出了水源保护林在自然坡面尺度上对径流泥沙影响的初步试验研究结果,森林在自然坡面尺度上对１９９７年７月３１日至８月１日降雨过程的洪峰流量消减率达４５５９％,洪水总量的消减率为６．８％,森林坡面径流总量为９８０．７８ｍ３,荒草坡为１０５２２３ｍ３．森林对１９９６年７月３０日降雨过程的洪峰流量消减率为１７．９５％,森林坡面的径流总量为１５．０８ｍ３,荒草坡为１８．３８ｍ３．从１９９６年森林对降雨径流较低的消减率看,降雨量与降雨强度对径流泥沙有很大的影响． 相似文献
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应用系统论方法．从连续方程出发推演出次降雨通过林冠的穿透降雨、树干径流和林冠截留三个过程模型均为ｎ＋１阶常系数微分方程。用方程表述穿透降雨和树干径流过程，旨在揭示林冠分配降雨特征与动态规律。以穿透降雨为例，其模型模拟结果与实验比较，相对误差不超过２％，与野外观测比较，多次平均相对误差为６％。笔者发现次降雨通过林冠这一多孔介质的穿透降雨、树干径流过程与电学中Ｒ－Ｌ－Ｃ电路暂态过程的方程具有同一形式。 相似文献
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对乌江板桥河小流域防护林体系的水文效应进行 10年的定位监测 ,初步掌握了小流域的气候、水量分配情况 ,以及防护林体系建成对流域水文功能的影响。 10年来 ,小流域防护林体系对径流产生了明显的调节作用 ,洪峰径流量有所减少 ;林地的水量分配发生了一定的变化 ,林冠截留量和树干流有所增加 ,地表径流量减少 ;林地的地表径流系数仅为农地的5 3 3 % ;封山育林对改善次生植被的水文功能是非常有效的 相似文献
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WUSihong ZHANGXiaoming ZHUQinke KeyLaboratory of Soiland Water Conservation Combating Desertification Ministry of Education College of Soil WaterConservation Beijing Forestry University Beijing China 《中国林业科技(英文版)》2006,5(2):54-65
INTRODUCTION The vegetation construction on the Loess Plateau is of significant importance in ameliorating the serious situation of soil and water conservation. The Loess Plateau is characterized by lots of gullies, and its surface soil is fragile and easily eroded, the factors that influence soil and water loss are: rainfall, vegetation, slope and others. Rainfall is the motive, power of causing soil and water loss; besides, vegetation and slope also greatly affect soil and water loss. … 相似文献
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川中长江防护林紫色土侵蚀产沙研究 总被引：1，自引：0，他引：1
川中防护林林分类型不同，承受降雨过程产生的地表径流和土壤侵蚀产沙量也不同，钙质紫色土上其减少减沙贡献最大的落叶灌木林，其次是桤柏混交林，主要是枯林落叶层的作用，马尾松疏林土壤蚀量是马尾松柏木材的２．７倍。随着降雨量增大和雨强增强，冰碛黄土上松柏混交林减水减沙效果最大，是一种川中地区典型的水土保持林类型。针对叶林的削减水沙的作用是有限的。松柏混交林产沙率变化与该林分下洪峰流量变化相一致，马尾松疏林产 相似文献
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森林健康项目信丰示范区主要森林群落生物多样性研究 总被引：3，自引：0，他引：3
建立永久样地,采用群落调查与测度方法,对江西信丰森林健康项目示范区主要森林类型进行了生物多样性分析.结果表明:毛竹林、次生常绿阅叶林、灌木林等阔叶林物种多样性较高,而杉木、马尾松、湿地松、火炬松等针叶林物种多样性较低,但从乔木层来看,只有次生常绿阔叶林和灌木林物种组成较复杂,其他类型都比较简单或为纯林,而且各类型间灌木组成相似性系数都比较小.这些结果说明天然阔叶林转变成其他林型后,不但乔木树种发生变化,而且灌木层组成也发生较大的差异.本研究为森林健康评价提供基础数据,为长期监测提供本底资料. 相似文献
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上海大金山岛的自然植物群落多样性 总被引：11，自引：0，他引：11
<正>大金山岛位于上海西南角的杭州湾中(E121°24′-25′,N30°41′-42′),面积0.3km2,最高点的海拔高度为105.03m,是上海市地面最高点。该岛地处中亚热带北缘,受东亚季风以及太平洋暖湿气团的影响,四周被水域包围,属海洋性气候,温和湿润,四季分明。年平均温度16℃,最冷月(1月)平均温度为3.3℃,年平均降雨量大于1000mm。Kira的温暖指数(WI)为130.2℃·月,寒冷指数(CI)为-2.1℃·月。土壤为地带性的褐色山地黄壤,厚约1m,pH值4.5~4.7。 相似文献
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Xiaoming Zhang Xinxiao Yu Sihong Wu Tianxing Wei Xuepei Zhang 《Frontiers of Forestry in China》2006,1(3):336-342
According to fixed-position data for 1985–2003 from nine runoff plots of Caijiachuan watershed which lies in Jixian County
of Shanxi Province in Loess area, this paper studied the relationship between vegetation and runoff and sediment production
in sloping lands in detail, which helps to provide scientific basis for vegetation re-construction and studies on environmental
transformation of water and sediment in watersheds of Loess area. Although, many study results testify that forest vegetation
has an important function in soil and water conservation and cutting runoff, the effect of vegetation on runoff and sediment
transmission is complicated, and this needs to be studied in depth. The results of the paper showed the following. Firstly,
the natural secondary forest performs better function of soil and water conservation than artificial Robinia pseudoacacia forest, and runoff and sediment produced in the former in individual rainfall were 65%–82% and 23%–92% of those produced
in the latter. At the same time, better correlative relationship between runoff and sediment production and rainfall and rainfall
intensity were testified by multiple regression, but the correlation decreased gradually with the increase of canopy density
of forest. Secondly, the difference of runoff and sediment production in several land use types was very distinct, and the
amount of runoff and sediment produced from Ostryopsis davidiana forest and natural secondary forest were the least, and runoff and sediment produced from in artificial Robinia pseudoacacia forest and Pinus tabulaeformis forest were 5-fold as much as those from O. davidiana forest. Besides, runoff and sediment produced in mixed planting of apple trees and crops were 16.14-fold and 2.96-fold than
those of O. davidiana forest, respectively, but the amount decreased obviously after high-standard soil preparation in the case of the former.
Thirdly, based on gray cognate analyses of factors affecting runoff and sediment production in sloping land, the factors of
stand canopy density and herb and litter biomass were the most significant ones, whose gray incidence degree exceeded 0.6.
Therefore, mixed forest with multi-layer stand structure and shrub forest should be developed in vegetation re-construction
of Loess area, which will help to increase coverage and litter thickness in order to cut down the runoff and sediment dramatically
in sloping land.
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Translated from Chinese Journal of Applied Ecology, 2005, 16(9): 1,613–1,617 [译自: 应用生态学报, 2005, 16(9): 1,613–1,617] 相似文献