劉翀+張靖+鮑雅靜+李政海+徐媛+呂娜+鄭譚
摘 要:植被物候信號能夠反映溫度和降水等變化對植被生長的影響,對理解植物和環境間的相互作用關系、植物的適應機制和生存策略,應對全球變化具有重要的科學意義。研究區為遼寧朝陽、阜新,內蒙古赤峰、通遼,采用非對稱高斯函數對2000—2015年研究區MODIS MOD13Q1 NDVI數據重建,提取遼蒙交界地區植被的物候信息——返青期和枯黃期。結果表明,遼蒙農牧交錯帶植被返青期在16年間表現為明顯提前的趨勢,赤峰市和朝陽市植被返青期整體呈顯著提前,通遼市和阜新市植被返青期呈微弱提前;研究區內植被枯黃期發生變化區域較少,僅赤峰市和通遼市呈微弱延后趨勢。
關鍵詞:物候;遙感;NDVI;返青期;枯黃期
中圖分類號:S127 文獻標識碼:A DOI 編碼:10.3969/j.issn.1006-6500.2018.01.008
Abstract:Vegetation phenological signals could reflect the effects of temperature and precipitation on vegetation growth. It was of great scientific significance to understand the interaction between plants and environment, the adaptation mechanism and survival strategy of plants and the global change. In this study, the study area was reconstructed from MODIS MOD13Q1 NDVI in the study area of Chaoyang and Fuxin of Liaoning, Chifeng and Tongliao of Inner Mongolia, and the asymmetric Gaussian function was used to reconstruct the MODIS MOD13Q1 NDVI data from 2000 to 2015. The results showed that the vegetation turning greening period in the agriculture and animal husbandryin Liaoning and Inner Mongolia zone showed a tendency to advance in 16 years, and the vegetation return period in Chifeng City and Chaoyang City was significantly ahead of that. The vegetation in Tongliao and Fuxin area were weaker in advance. The area with vegetation change in the study area was less, only Chifeng and Tongliao area showed a slight delay trend.
Key words:phenology; remote sensing; NDVI; green period; yellow period
植被是聯系土壤、大氣和水分的自然“紐帶”,在全球變化的研究中起著“指示器”的作用[1]。隨著全球變化日益成為人們關注的焦點問題,植被的物候信號能夠反映出溫度和降水等變化[2],因此,研究植被物候特征對環境條件變化的響應,對理解植物和環境間的相互作用關系、植物的適應機制和生存策略,以及應對全球變化都具有重要的科學意義[3]。物候監測方法多通過定位監測,以人工方式逐日記錄某種或多種植物/植被的發芽、開花、展葉、紅葉、落葉等信息。但對于較大尺度的地理單元,如流域、省級區域,傳統方法存在著耗時、費力等諸多問題。所幸,隨著遙感技術的發展,特別是遙感物候學的出現,使監測大范圍的植被物候狀況及其動態變化變得快捷、方便。……