陕西省退耕还林植被覆盖度与湿润指数的变化关系  

Relationship between fractional vegetation cover and humidity index after returning farmland to forest in Shaanxi Province

作　　者：何慧娟[1] 卓静[1] 王娟[1] 董金芳[1] 权文婷[1] 

机构地区：[1]陕西省农业遥感信息中心,西安710014

出　　处：《生态学报》2016年第2期439-447,共9页Acta Ecologica Sinica

基　　金：陕西省气象局科技创新基金计划项目(2014M-14)

摘　　要：使用MODIS-NDVI数据和气象站点资料,通过GIS遥感技术和数理统计等方法,分析了陕西省退耕还林后(2000—2012年)植被覆盖度与湿润指数的时空变化规律及两者变化的关系。结果表明,陕西省植被覆盖度和湿润指数都呈现由南向北递减的分布规律并且有明显的季节变化特征。2000—2012年,陕西省植被覆盖度在波动中呈现大幅增加的趋势,陕北地区增加最为显著,生态环境得到明显改善,然而部分城市周边地区植被有退化的迹象。2000—2012年湿润指数年际变化波动较大,有上升的趋势,陕南地区增加显著。空间分布上随着植被覆盖度的增加湿润指数呈指数变化趋势,相关性与植被覆盖度面积取值范围有关,范围取值越大相关系数越高。植被覆盖度的年际变化受到气候和人为因素影响,陕南地区植被覆盖度与湿润指数的相关性较显著,而受到人为影响比较明显的陕北、关中地区相关性不显著。Vegetation is an important part of a terrestrial ecosystem, and climate condition determines the growth and development of plants. At the same time, vegetation also has a regulatory role on climate. Since 1999, a project to return farmland to forest has been ongoing in Shaanxi Province, leading to the mitigation of the deterioration in the local ecological environment. Therefore, an analysis of the vegetation and climate conditions in Shaanxi Province, as well as a study of the changed relations between the two, may provide an important theoretical basis for response to global climate changes, and should improve the further development of ecological environment construction in Shaanxi Province. In this study, MODIS- NDVI data were used to calculate the fractional vegetation cover, and the humidity index was taken as the climate indicator in order to reflect the degree of regional dryness and wetness, and the hydrothermal balance status. In addition, GIS and remote sensing technology and mathematical statistics were used to analyze the spatiotemporal variation laws and the changed relations between fractional vegetation cover and humidity index after returning farmland to forest in Shaanxi Province （2000--2012）. The following observations were made： 1 ） The fractional vegetation cover in Shaanxi declined from south to north, and the fractional vegetation cover in southern Shaanxi was the highest, followed by those in the Guanzhong region, Huanglong Mountain and Ziwu Mountain, whereas in the north, the Yan＇an region was the lowest. The fractional vegetation cover showed clear seasonal variations, reaching a peak in August. From 2000 to 2012, the fractional vegetation cover in Shaanxi Province showed an extremely significant increasing trend in volatility, and this was most significant in northern Shaanxi. Vegetation degradation occurred within the vicinity of some cities, especially on the border between Xi＇an and Xianyang. 2） The spatial distribution of the humidity index was similar to the fractiona

关 键 词：植被覆盖度 湿润指数 退耕还林 陕西省 

分 类 号：S718.5[农业科学—林学]