黄河中游多沙粗沙区(渭河段)土地利用对植被盖度的影响

Impacts of land use on vegetation coverage in the rich and coarse sediment area of Yellow River Basin

针对黄河中游多沙粗沙区植被变化及其影响因素研究薄弱环节,利用MSS、TM和环境星CCD等多源遥感数据,运用相邻图幅递进回归分析消除时相差异后反演植被盖度,人机交互式解译土地利用,研究黄河中游多沙粗沙区(渭河段)1978-2010年间3个时期土地利用对植被盖度的影响。结果表明:(1)研究区内植被盖度已显著恢复,植被变化有较强的波动性和异质性;(2)土地利用已发生明显变化,土地利用变化有较强的时空分异特征;(3)土地利用转型和渐变均有利于促进植被盖度恢复,但土地利用转型对植被恢复的贡献更突出;(4)土地利用对植被盖度的影响有一定的复杂性和差异性,区域植被持续恢复迫切需要有针对性的土地利用转型与生态系统优化策略。

As a main component of terrestrial ecosystem, vegetation has profound effects on the sharp decrease of water and sediment in the Yellow River Basin. In order to research the effects of land use on vegetation coverage in the typical rich and coarse sediment area （Weihe River）, this paper chose MSS, TM and HJ-CCD as data sources, applied adjacent images progressive regression analysis method to eliminate the radiometric difference and retrieved vegetation coverage based on NDVI, and used man-computer interactive method to interpret land use. Some conclusions can be drawn as follows. （1） Vegetation coverage in this area has been significantly restored from 1978 to 2010, but changes in vegetation have strong volatility and heterogeneity. （2） Significant changes can be found in land use, and present unique spatial and temporal characteristics. （3） Both of land use transition and land use gradient are conducive to vegetation restoration, but comparatively speaking, land use transition performs better than land use gradient. （4） Effects of land use on vegetation coverage are complex and diverse, and vegetation restoration in this region urgently needs targeted land use transition and land ecological optimization strategies.