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1.
对半干旱黄土丘陵沟壑区不同植被类型径流、侵蚀效应进行长期观测.研究结果表明:不同植被产流和侵蚀次数效应为:坡耕地＞牧草地＞乔木林地＞天然草地＞灌木林地;不同植被类型之间径流量和侵蚀量差异较大,其大小次序为:坡耕地＞牧草地＞乔木林地＞天然草地＞灌木林地;灌木林地的减流率和减沙率均在较高的水平,具有良好的水土保持效应;天然草地由于其独特的功能,水土保持效应较好;乔木林地和人工草地除了乔木林地减蚀效应较好外,减流效应较差;坡耕地的累积径流量及侵蚀量最大,而累积减沙率和减流率最低,水土保持效应最差. 相似文献
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Land use plays a much more important role than other factors, such as climate, soil properties, topographic features, vegetation
coverage, human activities and others, in affecting soil erosion and sediment discharge. In order to understand the effects
of changes in land use on sediment discharge and to provide a theoretical basis for land use planning, management and ecological
restoration, we used the controlled Qiaozidong watershed and the uncontrolled Qiaozixi watershed in the third sub-region of
the Loess Plateau as examples and analyzed the effects of land use and land cover on the discharge of sediments. The results
show that the impact of land use and land cover on the annual amount of sediment discharge is significant. Compared with the
uncontrolled watershed during similar periods, the amount of sediment discharged from the controlled watershed was reduced
by 44%, 75% and 86%, respectively, in wet, normal and dry years. In the controlled watershed, compared with the period from
1986 to 1994, the amount of sediments discharged was less during the period from 1995 to 2004. The impact of land use and
land cover on sediment discharge demonstrated characteristics of seasonal fluctuation. The effects of sediment reduction in
the controlled watershed were greater than those in the uncontrolled watershed in May and September. In the controlled watershed,
the reduction effect coincided with the distribution of rainfall. The amount of discharged flood sediments is closely correlated
with rainfall, rainfall intensity in a 60 min period and the volume of flood. The rainstorm-runoff process and the rainstorm-sediment
discharge process demonstrate that land cover has a strong regulatory and control function in the flood process and sediment
discharge in rainstorms. For the controlled watershed, given the same precipitation frequency distribution, the average amount
of sediment discharged during the land use period from 1995 to 2004 was less than that during the earlier land use period
from 1986 to 1994 under every recurrent period.
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Translated from Journal of Beijing Forestry University, 2007, 29(6): 115–122 [译自: 北京林业大学学报] 相似文献
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Effect of conversion of farmland to forest or grassland on soil erosion intensity changes in Yanhe River Basin, Loess Plateau of China 总被引：2，自引：0，他引：2
Dynamic changes of soil erosion affected by conversion of farmland to forest or grassland in the Yanhe River Basin were analyzed
based on the revised universal soil loss equation (RUSLE). The RUSLE variables were selected and calculated reasonably using
the GIS technique. Results show that: 1) After the conversion of farmland to forest or grassland, soil erosion decreased greatly.
Compared with soil erosion in period of 1986 to 1997, the soil erosion amount had been reduced on the average by 30.6% by
2000; 2) Of the different land uses, slope farmland, especially the steep slope land had the greatest impact on soil erosion.
The conversion of forest or grassland was the main driving force for the reduction of soil erosion; 3) In the short term,
soil erosion was mainly controlled by C-factor, implying that the adjustment of land use structure might be an effective approach to reduce soil erosion.
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Translated from Science of Soil and Water Conversation, 2007, 5(4): 27–33 [译自: 中国水土保持科学] 相似文献
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全球荒漠化防治现状及发展趋势 总被引：8，自引：2，他引：8
文章在讨论了荒漠化定义的基础上,介绍了全球荒漠的分布状况和因荒漠化引起的经济损失情况,论述了荒漠化的主要危害,并针对干旱地区的不同地类,如旱作农地、灌溉农地、草地、林地分别提出了相应的荒漠化防治对策。 相似文献
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选择林地、未翻耕地、耕地、半流动沙地4种土地利用类型,通过定位实验观测与定量分析,研究阳高县沙地不同土地利用类型的风蚀规律。结果认为：1）不同类型近地层2 m内风速随高度近似地服从对数分布规律,林地的斜率最大为1.663 1,未翻耕地的斜率最小为0.895 4,说明林地上林分对风速梯度影响最大,风速降低比率最大,其他下垫面类型斜率大小次序是耕地〉半流动沙地〉未翻耕地。2）不同下垫面对应的粗糙度大小不同,林地粗糙度为3.267 9 cm,属于最大;其次为半流动沙地、耕地、未翻耕地。增大下垫面的粗糙度,可以控制风速和风沙流的产生及运动。3）林地、耕地、未翻耕地和半流动沙地土壤输沙量的大小依次为半流动沙地〉未翻耕地〉耕地〉林地。 相似文献
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以珠江上游的流域地区为研究区域,选择6个树种进行树种对比试验,并对水土流失进行监测.结果表明:参试树种表现出较好的适应性,旱冬瓜生长最为迅速,其它树种生长情况依次为圆柏>藏柏>柳杉>川滇桤木>云南松.生物多样性在不同地类上有一定差异,其表现依次为退耕地阴坡>荒草地>退化林地>阳坡耕地.经过5年的造林恢复植被,土壤养分得到改良,土壤的结构得到了改善.试验区的土壤侵蚀减少了38.48%,水土流失面积减少44.32%. 相似文献
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ZHANG Xiaoming WEI Tianxing ZHANG XuepeiKey Laboratory of Soil Water Conservation Desertification Combating of Ministry EducationBeijing Forestry University. Beijing . PR Chinaxivulama @ sina. com 《中国林业科技(英文版)》2003,(4)
This paper analyzes the function of preventing soil erosion of the different woodlands according to a long-term fixed-position observation, and points out that the steep slope plantation of uncontrolled measures for soil and water conservation is apt to produce sediment Forestland has very strong effect in soil and water conservation when the biomass of arbor in the hillslope is over 1 4.51t/ha. Through analyzing the function of soil and water conservation about forestland (arbor, bush and the mixed wood of arbor and bush), it can be known that if the high forest coverage reaches 40%, forests will provide better protective function. To vegetation under forest, litter layer, herb and sparse forest land which do not suffer destruction from human beings, they all have good function in preventing erosion, and the amount of soil loss is far less than the tolerance of soil erosion. At the same time, when vegetation coverage and biomass are in an appropriate state, they will have powerful protective function. 相似文献
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本文研究了浑善达克沙地流动沙地上黄柳活沙障的防风固沙效益,通过对设置3年后的不同类型的活沙障进行测定和分析,得出如下结论：沙障设置3年后,沙地趋于固定,障内植物种类明显增多;设置黄柳活沙障的区域内下垫面粗糙度显著增大,风速明显减弱,其顺序为：4 m×4 m黄柳网格沙障〉6 m×6 m黄柳网格沙障〉间距4 m的黄柳带状沙障〉间距6 m的黄柳带状沙障〉流沙,而且黄柳网格沙障降低风速的能力较带状沙障强;当旷野平均风速为7.86 m/s时,只有流沙和间距6 m的黄柳带状沙障起沙,其他几类活沙障内均不起沙。 相似文献
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阐述永胜县水冲河小流域土壤侵蚀的类型、影响及现状,提出了相应的治理措施:调整土地利用结构措施;生物措施(封山育林、植树造林);工程措施(农地坡改梯,修建谷坊、拦沙坝、拦洪墙等);土壤改良措施。 相似文献
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选取农田、撂荒草地、人工乔木林、人工灌木林和次生林5种不同土地利用类型土壤颗粒为研究对象,采用Microtrac S3500激光粒度仪测定土壤样品粒径,利用土壤分形学理论和方法,分析不同土地利用类型对土壤颗粒组成及其分形特征的影响。结果表明,土壤粒径在不同土地利用方式下存在显著差异,其中撂荒草地以砂粒为主,农田、人工乔木林、人工灌木林和次生林以粉粒为主;次生林、人工乔木林黏粒体积分数最大,且显著大于其他土地利用类型,撂荒草地最小;次生林、人工乔木林、人工灌木林粉粒体积分数最大,且显著大于农田与撂荒草地;砂粒体积分数则与粉粒相反。土壤分形维数的大小依次为撂荒草地＜农田＜人工灌木林＜次生林＜人工乔木林;土壤分形维数与土壤黏粒含量、粉粒含量均呈显著正相关,与土壤砂粒含量呈显著负相关。 相似文献
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黑龙江省沙质荒漠化土地治理的生态效益研究 总被引：3，自引：0，他引：3
通过多年的观测与实验结果 ,黑龙江省沙质荒漠化土地治理开发综合试验区的改造利用取得了良好的生态效益 ,具体表现为 :①降低风速 ,抑制风沙活动 ,延缓荒漠化进程 ;②减轻土壤风蚀量 ,减少空中含沙量 ;③恢复和提高风沙化土地生产力 ;④改善沙区小气候 ,实现沙区生态环境的好转。 相似文献
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鄂托克旗土地利用动态变化及其影响要素分析 总被引：1，自引：0，他引：1
在RS与GIS技术的支持下,利用1991、2000和2007年三期TM影像,对鄂托克旗1991-2007年的土地利用动态变化特征及其影响要素进行分析。结果表明,土地利用最重要的转化方向有：1991-2000年耕地向草地、未利用地和城乡、工矿用地的转化;草地、水域向未利用地的转化;2000-2007年未利用地向草地、水域和耕地的转化;耕地向林地和草地的转化;城乡、工矿居民点用地向草地和林地的转化。反映鄂托克旗既有退耕还林还草、积极治理沙漠的事实,又有毁草开垦荒地的现实。随着耕地和未利用土地的减少,林地和草地面积增加,说明当地环境的改善已取得了成效。 相似文献
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【目的】为了更好地利用半干旱黄土丘陵区的土地资源,促进该区域植被恢复,提高生物多样性,使区域生态环境有所改善。【方法】以半干旱黄土丘陵区龙滩流域的植被为研究对象,对该流域11种典型的土地利用类型(2种农地、自然荒草地、人工牧草地、撂荒草地、灌木林地、5种乔木林地)的植被物种组成和多样性进行了调查研究。【结果】流域内共调查到种子植物56科166属254种,其中裸子植物门3科7属13种,占流域总科、总属、总种的5.36%、4.22%、5.12%;被子植物门53科159属241种,占流域总科、总属、总种的94.64%、98.78%、94.88%。在被子植物门中,双子叶植物纲有50科134属205种,单子叶植物纲有3科25属36种,两纲物种分别占流域总种数的80.71%和14.17%,占该门物种总种数的85.06%和14.94%。不同土地利用类型植被多样性分析结果表明,物种丰富度表现为农地物种丰富度低,人工牧草地、撂荒草地和灌木柠条林地居中,乔木林地(山杏、山毛桃、油松、侧柏、青杨)和天然荒草地高;物种多样性表现为马铃薯农地的物种多样性低,覆膜农地、人工牧草地、撂荒草地及灌木柠条林地居中,自然荒草地和乔木林地比较高;物种均匀度表现为农地、撂荒草地、人工牧草地及灌木柠条林地的均匀度高,自然荒草地居中,乔木林地低。【结论】不同土地利用方式和植被演替恢复时间差异是产生植被多样性差异的基础,也是该区域植被恢复和物种多样性保护需要考虑的重要要素。 相似文献
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以河南省第三次荒漠化沙化土地监测为依据，以生态恢复理论为指导，探讨河南省沙化土地治理中存在的问题，提出生物治理措施中要遵循自然法则和社会经济技术原则，以乡土植被恢复为主，乔灌草合理配置，建设多层次、多类型的防风固沙林与农林复合生态防护体系；并针对不同沙地类型提出相应的治理模型。 相似文献
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中国荒漠化评价指标体系 总被引：9，自引：0，他引：9
根据《联合国防治荒漠化公约》对于荒漠化所作的定义 ,该文首先介绍了中国荒漠化现状 ;其次介绍了中国荒漠化评价指标体系 ,其中包括 :(1)荒漠化气候区划 ;(2 )中国土地利用类型划分 ;(3)中国荒漠化成因类型 ;(4)荒漠化程度分级指标 ,其中包括风蚀、水蚀、土壤次生盐渍化以及草原退化 ;最后 ,从理论及经济可行性观点出发 ,详细讨论并列出了可用于荒漠化评价的相关指标 相似文献
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针叶树幼树移栽与容器大苗造林试验 总被引：2，自引：0，他引：2
为了提高半干旱地区针叶树造林的成活率,在内蒙古奈曼旗兴隆沼林场开展了针叶树幼树带土坨移植试验与塑料容器大苗造林试验。结果表明,８年生境子松幼树移植成活率达８８％￣９８％;４年生不同树种容器苗造林成话率达７６％￣８７％。樟子松容器苗成活率比裸根苗高５３％;流动风沙土造林地比生草风沙土造林地高４５％。 相似文献
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Economic policies that boost profits from agroforesty, thereby creating financial incentives for land managers to favor these
systems over less environmentally friendly land uses, could, in theory, have ancillary environmental benefits. This paper
analyses primary and secondary data to determine whether a voluntary price support program for Mexican coffee—mostly grown
in shaded systems that supply important ecosystem services—has had such “win-win” benefits by stemming land-use change in
the coffee sector. We find that although the program attracted the types of growers associated with land-use change, it attracted
only a relatively small number of them, did not target growing areas hardest hit by conversion to other land uses, and provided
subsidies that were probably too small to affect land-use decisions. These results raise serious questions about the ability
of an agroforestry price support program with a modest price floor to have a significant conservation impact. 相似文献