摘要
以SPOT VEGETATION旬数据集为数据源,研究1999—2010年陕甘宁黄土高原区植被物候时空特征。采用时间序列谐波分析法对原数据进行预处理,通过傅里叶插值法将NDVI旬数据插值成日数据,再通过阈值法和最大比率法确定植被物候期。结果表明,陕甘宁黄土高原地区植被物候多年平均值呈纬度变化规律,纬度低的地区生长季始期(SOG)和生长季末期(EOG)提前,生长季长度(LOG)缩短。海拔高度每上升100 m,SOG提前约3d(P<0.01),EOG提前约2 d(P<0.01),LOG延长约1 d(P>0.05)。1999—2010年植被SOG、EOG和LOG的物候年际变化率分别为-0.02、0.003和0.02 d·a-1。陕甘宁大部分地区SOG呈提前趋势,EOG呈推迟趋势,LOG呈延长趋势。植物物候与降水和河流网相关,干旱低温高纬度地区植被生长停滞提前,生长周期缩短。
Based on a ten-year （1999-2010） SPOT VEGETATION dataset,spatio-temporal vegetation phenological features on the Shaan-Gan-Ning Loess Plateau were studied.The method of harmonic analysis of time series （HANTS） was adopted to pre-process the raw data,the fourier interpolation method to turn NDVI ten-day data into daily data,and the threshold value method and the maximum ratio method to specify vegetation phenological phases.Results show that the multi-year average of vegetation phenology space distribution in the Shaanxi-Gansu-Ningxia varied with the latitude,that is to say,the lower the latitude,the relatively earlier the growth season started （SOG） and ended （EOG） and the shorter the growth season （LOG）.Moreover,it started 3 days earlier （P＜0.01）,ended two days earlier （P＜0.01）,and lasted one day longer （P＞O.05） with the attitude rising every 100 m.During the ten-year period （1999-2010）,the annual rate of change in vegetation phenology,SOG,EOG and LOG in that region,was-0.02,0.003 and 0.02 d · a-1,respectively.The vegetation phenology in most part of the Loess Plateau tended to have SOG advanced,EOG postponed and LOG extended,which were supposed to be related to variation of precipitation and the river net system.In high latitude regions,arid and low in temperature,vegetation growth started stagnation earlier and shortened in life cycle.
出处
《生态与农村环境学报》
CAS
CSCD
北大核心
2014年第4期423-429,共7页
Journal of Ecology and Rural Environment
基金
国家自然科学基金(71361001)
