论文部分内容阅读
【目的】探索塔里木河流域树木年轮与植被遥感间的关系。【方法】借助树木年轮学的方法和技术手段,利用塔里木河下游10个采样点的胡杨样芯数据和长时间序列中国植被指数(GIMMS NDVI)数据及水热因子数据,在分析该区胡杨年轮指数和植被指数变化特征基础上,重点探讨水热因子、胡杨年轮指数及归一化植被指数(NDVI)三者间的相关性。【结果】胡杨年轮指数和年际NDVI变化在1980—2001年间均呈下降趋势,区内植被在该时间段内退化较为严重。年内NDVI变化呈单峰状,5—8月为植被生长季,1—4月和9—12月为植被非生长季。【结论】该区胡杨年轮生长受5月(P<0.01,显著负相关)地下水埋深和6月(P<0.01,显著负相关)温度影响显著,而NDVI主要与5—7月(P<0.01,显著负相关)和10月(P<0.01,显著负相关)的地下水埋深及7月(P<0.01,显著负相关)温度有关,且影响NDVI和胡杨年轮指数的主要因子是水热因子中的地下水埋深因子。胡杨年轮指数与NDVI间的相关性差,未能通过0.05水平检验。
【Objective】 To explore the relationship between tree rings and vegetation remote sensing in the Tarim River Basin. 【Method】 Based on the tree ring method and techniques, Populus cristata sampled at 10 sampling points in the lower reaches of the Tarim River and long time series of China Vegetation Index (GIMMS NDVI) data and hydrothermal factor data, The annual growth index, the annual growth index and the vegetation index. On the basis of this, the relationships among hydrothermal factors, annual rings index of Populus euphratica, and normalized vegetation index (NDVI) were discussed emphatically. 【Result】 The results showed that the annual growth index and interannual NDVI of Populus euphratica decreased from 1980 to 2001, and the vegetation degradation in this area was more serious. NDVI changes during the year were unimodal, May-August for the vegetation growth season, January-April and September-December for the vegetation non-growing season. 【Conclusion】 The annual growth of Populus euphratica in this area is significantly affected by the groundwater depth in May (P <0.01, significant negative correlation) and June (P <0.01, significant negative correlation), while the NDVI is mainly related to the temperature in May-July <0.01, significant negative correlation) and groundwater depth in October (P <0.01, significant negative correlation) and July (P <0.01, significant negative correlation), and the main factors affecting the annual index of NDVI and Populus were Groundwater depth factor in hydrothermal factors. The correlation between Populus euphratica index and NDVI was poor and failed to pass the 0.05 level test.