黄河三角洲自然保护区1992～2010年土地覆被变化分析

Characteristics of Land Cover Change in the Yellow River Estuary Nature Reserve from 1992 to 2010

基于黄河三角洲自然保护区1992年、2000年和2010年三期遥感图像,分析近20年黄河三角洲自然保护区土地利用/覆被变化(LUCC)情况。结果表明,在1992~2010年间,黄河三角洲自然保护区内同种土地覆被类型的空间分布较一致,均以海域、滩涂和旱地为主,但同种土地覆盖类型的比重均发生不同程度的变化。总体上,旱地、河渠、水库、居民地和其他用地类型的变化程度不明显,但年际间有波动变化;草地面积虽持续减少,但总体变化不明显;灌木面积总体变化也不明显,但年际间波动较大;芦苇面积呈减少趋势,尤其是1992~2000年间,大量芦苇覆被地转化为旱地类型;养殖塘面积增加明显,近20年间增加约6.24×10~3 hm^2,主要由滩涂、柽柳、碱蓬等开发形成;海域面积变化剧烈,海域转化为滩涂是造成海域面积减少的主要原因。黄河三角洲自然保护区LUCC改变了自然保护区的生态系统结构,降低了自然保护区的生态服务功能。造成黄河三角洲LUCC的原因既有自然因素,也有人为因素,但在该区LUCC的驱动力主要为人类活动。

The characteristics of land cover and land cover change（LUCC） in nature reserve of Yellow River estuary were analyzed by using three phases landsat remote sensing images of 1992, 2000 and 2010. The results showed that the spatial distribution of land cover types in the natural reserve was sympathetic and the main land covers were the sea, tidal flats and dry land during the periods of 1992—2010. The proportion of the same land cover types in the nature reserve all had changed in different degrees. On the whole, the changes of dry land, reservoir, residential land and other land types were not obvious but there are interannual fluctuations. Although the grassland area decreased continuously, the overall change was not obvious. The changes of the shrub area were also not obvious which varied greatly in the interannual. The reed area was reduced especially in the 1992—2000 years, in which a large number of reeds were transformed into dry land types. The aquaculture area increased widely of 6.24×10^3 hm^2, the increased area mainly formed by development of the beach, Tamarix wetlands and Salsa wetlands in 20 years. The changes of sea area were violent, and the main reason for the reduce of the sea area was the conversion of the sea area to the tidal flat. The LUCC in the natural reserve had changed the structure and reduced the ecological service function of the nature reserve. The reasons for the change of LUCC in the Yellow River estuary were both natural factors and human factors, but the driving forces of LUCC in this area were mainly human activities.