| 摘要: |
| 【目的】研究了小流域土地覆被物的主要类型、空间分布特征及其影响因素，为黄土丘陵区复杂地形条件下的流域水土流失防治及评估提供参考。【方法】在陕北黄土丘陵区安塞县的大南沟、纸坊沟、县南沟3个小流域，选取172个样地调查了植被、枯落物及生物结皮等土地覆被物的盖度、厚度及所处的地形条件等数据，并运用SPSS 13.0进行了分析。【结果】黄土丘陵区小流域土地覆被物以草本盖度最大，枯落物和生物结皮盖度次之，乔木和灌木盖度较小；植被盖度在沟坡大于梁峁坡，阴坡和半阳坡大于阳坡，不同坡度之间无显著规律，不同地形条件下枯落物盖度的变化与植被的变化趋势一致，生物结皮盖度的空间分布与植被盖度和枯落物盖度呈相反趋势；小流域9个土地覆被物指标可以归为3类土地覆被物因子，即地表覆被物、近地覆被物和地上覆被物。土地覆被物空间分布受地形因子及土地覆被物之间的影响，乔木盖度受地形影响较大；灌木盖度受坡度影响较大；草本盖度主要受乔木盖度的影响；枯落物受乔灌草盖度影响较大，受地形类因子影响较小；苔藓、藻类盖度及生物结皮盖度主要受枯落物、草本盖度等近地因子的影响。【结论】流域土地覆被物空间分布特征与水土流失状况密切相关，在黄土丘陵区小流域水土流失防治过程中，要针对不同的地形条件进行合理的植被配置，进而形成优化的土地覆被物配置，促进黄土丘陵区的生态环境建设和保护。 |
| 关键词: 黄土丘陵区 小流域 土地覆被物 空间分布特征 影响因素 |
| DOI： |
| 分类号: |
| 基金项目:中国科学院知识创新工程重要方向项目（KZCX2-YW-421,KZCX2-YW-443）；国家重点基础研究发展规划项目(2007CB407205)；国家自然科学基金项目（40971174） |
|
| Spatial distribution characteristics of land cover of small watershed and its influencing factors in Hilly-gullied region of Loess Plateau in China |
|
|
| Abstract: |
| 【Objective】The types of land coverage,its spatial distribution characteristics and influencing factors were studied according to the topography conditions,soil and water conservation and prevention in the hilly of Loess Plateau.【Method】Based on 172 plots in 3 small watersheds of the Loess Plateau,the coverage and thickness of land cover and its topography condition were investigated,then analyzed by SPSS 13.0.【Result】The Loess Hilly-gully region is mostly covered by herbage,secondly by litter and crust.The coverage of arbor and shrub is the least.The coverage of vegetation in gully slope is greater than the ridge slope,the ubac-greater than the tailo.However,the effect of the slope gradient on the coverage of vegetation was not significant.The change of the litter coverage was coincident with the vegetation coverage.On the contrary,there was a negative correlation between the biological crust and the vegetation，litter coverage.All land cover indicators in Loess Hilly-gully region were divided into surface cover,nearly surface cove and up-surface cover.The spatial distribution of land cover was affected by topography factor and land cover.The arbor coverage was affected by topography.The shrub coverage was affected by slope gradient.The herbage coverage was affected by arbor coverage.The litter was more affected by arbor,shrub and herbage coverage,but less affected by topography factor.The moss coverage,algae coverage and biological crust coverage were more affected by litter and herbage coverage.【Conclusion】The spatial distribution characteristics of land cover was closely related to the condition of soil and water erosion in small watersheds.In the progress of controlling water and soil erosion in small watersheds of Loess Hilly region,the suitable vegetation arrangements to different terrains would form the optimized arrangement of land cover and promote the construction and conservation of ecological environment in this area. |
| Key words: Hilly-gullied region of Loess Plateau small watershed land cover the spatial distribution characteristic influencing factor |
