摘要: |
【目的】作为陆地生态系统的重要组分,植被对流域水沙变化有深刻影响。黄土高原是世
界上水土流失最严重的区域之一,自1999 年退耕还林草工程实施以来,黄土高原植被覆盖呈明
显增加趋势,同期黄河水沙锐减现象也日益明显。然而,以往植被覆盖变化对地表产沙影响研
究多在小试验区或流域尺度上开展,以不同地貌分区为单元的研究还鲜有报道。【方法】文章基
于多源卫星遥感数据,采用像元二分模型估算了1980 年、2000 年、2010 年和2016 年黄河流域
植被覆盖度,通过分析黄土高原重点研究区植被覆盖的时空变化特征识别植被变化背景下不同
地貌分区侵蚀产沙风险变化,以期为将来黄河水沙治理工作提供参考。【结果】黄土高原重点研
究区全区植被盖度均值呈增加趋势,由1980 年的34.99% 提升至2016 年的63.64%,且2000
年退耕还林(草)工程实施后增加的速度更为显著,2010—2016 年间增速相对于2000—2010
年间较缓。研究期间产沙高风险区面积比例显著减小,产沙高风险和易产沙区均主要分布在
研究区的北部和西北部,不产沙区和产沙微弱区主要分布在研究区东南部。自1999 年实施退
耕还林(草)工程以来,不同地貌分区的植被状况均持续好转。【结论】沙丘、风蚀沙化丘陵、
平原、片沙黄土丘陵地貌区是未来水土保持工作需要关注的区域,植被改善工作仍需加强。 |
关键词: 退耕还林 植被盖度 侵蚀产沙 黄土高原 |
DOI:10.12105/j.issn.1672-0423.20190111 |
分类号: |
基金项目:国家重点研发计划(2016YFC0402403);国家自然科学基金委员会- 贵州省人民政府喀斯特科学研究中心
项目(U1812401);国家自然科学基金项目(U1603241) |
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The effect of Grain for Green Project on surfacesediment yield on the Loess Plateau |
Guan Yabing1,2, Zhao Changsen1, Yang Shengtian※1,3, Bai Juan1,2, Peng Ruiwen3
|
1.College of Water Sciences,Beijing Normal University,Beijing 100875,China;2.State Key Laboratory of Remote
Sensing Science,Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China;3.School of
Geography and Environmental Science,Guizhou Normal University,Guiyang 550001,China
|
Abstract: |
[Purpose]As an important component of terrestrial ecosystems,vegetation has
a profound impact on water and sediment changes in the basin. The Loess Plateau is one of
the most serious areas of soil erosion in the world.Since the implementation of Grain for Green
project in 1999, the vegetation cover of Loess Plateau has increased significantly, and the
phenomenon of sharp decline of water and sediment in the Yellow River has become increasingly
obvious.However,previous studies related to the effect of vegetation cover change on surface
sediment yield have been carried out on the experimental plot or basin scale, studies on different
geomorphological units have rarely been reported.[Method]Vegetation coverage of Yellow
River Basin in 1980, 2000, 2010 and 2016 were estimated by using dimidiate pixel model based
on multi-source satellite remote sensing datasets.Variations of erosion and sediment yield risk
under the background of vegetation change in different geomorphological units were identified by
analyzing the spatial-temporal variation characteristics of vegetation coverage in the key study area
of the Loess Plateau in order to provide reference for the future management of water and sediment
of the Yellow River.[Result]The results indicated that the average vegetation coverage in the
key study area of the Loess Plateau increased from 34.99% in 1980 to 63.64% in 2016, and the
growth rate after 2000 was more significant.The growth rate of 2010-2016 is relatively slower than
that of 2000-2010.During the study period, the proportion of high-risk area of sediment yield
was significantly reduced, and the high-risk-sediment-yield and easy-sediment-yield areas
were mainly distributed in the north and northwest of the study area.Non-sediment-yield and the
weak-sediment-yield areas were mainly distributed in the southeastern part of the study area.
Since the implementation of Grain for Green project in 1999, the vegetation conditions of different
geomorphological units have showed continuous improvement[. Conclusion]Sand dunes,winderosion
desertification hills, plains, and sheet-sand loess hills need to be considered for future soil
and water conservation work, and vegetation improvement work needs to be strengthened in these
geomorphological units. |
Key words: Grain for Green vegetation coverage sediment yield Loess Plateau |