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现代草地沙漠化中自然因素贡献率的确定方法 被引量:15
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作者 李振山 贺丽敏 王涛 《中国沙漠》 CSCD 北大核心 2006年第5期687-692,共6页
基于草地沙漠化发展过程中流沙面积变化模型和植被盖度变化模型,结合沙漠化监测资料,提出了。种定量确定自然因素在沙漠化中贡献率的方法,从而也可以间接地推算人为因素在沙漠化中的贡献率。以内蒙古奈曼旗现代草地沙漠化为例对模型... 基于草地沙漠化发展过程中流沙面积变化模型和植被盖度变化模型,结合沙漠化监测资料,提出了。种定量确定自然因素在沙漠化中贡献率的方法,从而也可以间接地推算人为因素在沙漠化中的贡献率。以内蒙古奈曼旗现代草地沙漠化为例对模型进行了应用,效果良好,并发现人类活动停止后,如果随后不出现持续的干旱年份,沙漠化所造成的流沙一般经过4~5a的时间就会自然消失,说明在计算时段内草地沙漠化中自然因素的贡献率为零。 展开更多
关键词 草地沙漠化 自然因素 贡献率 流沙盖度 植被 模型
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Influence of vegetation cover and other sources of variability on sediment and runoff response in a burned forest in South Korea 被引量:1
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作者 EWANE Basil Ewane LEE Heon-Ho 《Journal of Mountain Science》 SCIE CSCD 2017年第2期296-315,共20页
Post-fire field measurements of sediment and run off yield were undertaken in natural rainfall event-basis during five rainy months in Korea on a total of 15 small plots: four replica burned unseeded plots, six replic... Post-fire field measurements of sediment and run off yield were undertaken in natural rainfall event-basis during five rainy months in Korea on a total of 15 small plots: four replica burned unseeded plots, six replica burned seeded plots, and five replica unburned plots. The main aim was to evaluate the effects of vegetation recovery and spatial distribution patterns on sediment and runoff response between and within the treatment replica erosion plots. Sixyears after the wildfire, total sediment and runoff yield in the burned unseeded plots with 20%-30%vegetation cover was still 120.8 and 20.6 times higher than in the unburned treatment plots with 100%ground cover, 8.3 and 6.7 times higher than in the burned seeded plots with 70%-80% vegetation cover,while only 1.6 and 2.0 times higher than in the burned seeded plots with 50%-60% vegetation cover,respectively. The differences in sediment and runoff yield between the treatment plots was proportional to total vegetation cover, distance of bare soil to vegetation cover, magnitude of rainfall characteristics and changes in soil properties, but not slope gradient.Three out of the six within-treatment pairs of two replica plots showed large differences in sediment and runoff yield of up to 6.0 and 4.2 times and mean CV of up to 99.1% and 62.2%, respectively. This was due to differences in the spatial distribution patterns of surface cover features, including aggregation of vegetation and litter covers, the distance of bare soil exposed to vegetation cover closer to the plot sediment collector and micro topographic mounds and sinks between pairs of replica plots. Small differences in sediment and runoff of only 0.9-1.4folds and mean CV of 8.6%-25% were observed where the within-treatment pairs of replica plots had similar slope, total surface cover components and comparable spatial distribution pattern of vegetation and bare soil exposed surface covers. The results indicated that post-fire hillslopes undergoing effective vegetation recovery have the potential to reduce sediment and runoff production nearer to unburned levels within 6-years after burning while wildfire impacts could last more than 6-years on burned unseeded ridge slopes undergoing slow vegetation recovery. 展开更多
关键词 Bare soil exposed Vegetation cover Post-fire Soil erosion Spatial distribution patterns Replica erosion plots
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