摘要
根据安西极旱荒漠国家级自然保护区南部和北部2000年、2003年、2006年、2009年和2012年的MODIS影像数据和相关气象数据,对该保护区荒漠植被的归一化植被指数(NDVI)和比值植被指数(RVI)及水热因子(七月份均温、年均温和年均降水量)进行比较和相关性分析。结果表明:在2000年至2012年,该保护区南部植被的NDVI和RVI指数均随着时间推移持续升高;北部植被的NDVI指数在2003年达到最高值、2006年明显下降、之后持续升高但均低于2003年水平,而RVI指数则总体呈逐渐升高的趋势。该保护区南部和北部的七月份均温和年均温均在2003年最低、之后逐渐升高,其年均降水量变化趋势与北部NDVI指数的变化趋势一致。相关性分析结果表明:该保护区南部和北部植被的NDVI和RVI指数间存在极显著正相关;南部植被的NDVI和RVI指数均与年均温、七月份均温和年均降水量呈显著或极显著正相关;北部植被的NDVI指数仅与年均降水量呈显著正相关,其RVI指数与七月份均温和年均温呈极显著正相关。与该保护区南部相比,北部植被的NDVI和RVI指数均较低,年均温和年均降水量也较低,但七月份均温却较高。综合分析结果显示:与同期的水热因子变化相比,安西极旱荒漠国家级自然保护区南部和北部植被的NDVI指数虽然具有较明显的时滞效应,但仍然能够较好地反映植被的生长状况;而它们的植被RVI指数变化不明显,不适用于该保护区荒漠植被的影像研究。总体来看,该保护区的荒漠植被的生长缓慢但生长状况良好。
According to MODIS image data and related meteorological data in the south and north of Anxi Extra-Arid Desert National Nature Reserve in 2000, 2003, 2006, 2009 and 2012, comparison and correlation analysis on normalized difference vegetation index (NDVI) and ratio vegetation index (RVI) of desert vegetation and hydrothermic factors including mean temperature of July, annual mean temperature and annual mean precipitation of the reserve were done. The results show that from 2000 to 2012, NDVI and RVI indexes of vegetation in the south of the reserve increase gradually as time goes on. NDVI index of vegetation in the north reaches the highest value in 2003, decreases obviously in annual mean precipitation is consistent with that of NDVI index in the north. The result of correlation analysis shows that there are extremely significantly positive correlation between NDVI and RVI indexes of vegetation in the south and north of the reserve. Both of NDVI and RV! indexes of vegetation in the south have a significantly or extremely significantly positive correlation with annual mean temperature, mean temperature of July and annual mean precipitation. NDVI index of vegetation in the north only has a significantly positive correlation with annual mean precipitation, while RVI index has an extremely significantly positive correlation with mean temperature of July and annual mean temperature. Compared with the south of the reserve, NDVI and RVI indexes of vegetation in the north are lower, annual mean temperature and annual mean precipitation are also lower, but mean temperature of July is higher. The comprehensive analysis result indicates that compared with change of hydrothermic factors during the same period, although NDVI index of vegetation in the south and north of Anxi Extra-Arid Desert National Nature Reserve has an obviously time-lag effect, but it still can reflect well the vegetation growth status, while the change in their RVI index of vegetation is not obvious, so it is not suitable for image research of
出处
《植物资源与环境学报》
CAS
CSCD
北大核心
2015年第3期94-98,共5页
Journal of Plant Resources and Environment
基金
2013年甘肃省环境保护科技计划项目(GSEP-2013-12)