地理研究 ›› 2020, Vol. 39 ›› Issue (3): 749-760.doi: 10.11821/dlyj020190029

• 研究论文 • 上一篇    

老挝VIIRS活跃火的主要自然地理要素特征

刘怡媛1, 李鹏2,3(), 肖池伟2,3, 刘影1, 饶滴滴2,3   

  1. 1. 江西师范大学地理与环境学院,南昌 330022
    2. 中国科学院地理科学与资源研究所,北京 100101
    3. 中国科学院大学资源与环境学院,北京 100049
  • 收稿日期:2019-01-11 修回日期:2019-07-11 出版日期:2020-03-20 发布日期:2020-05-20
  • 通讯作者: 李鹏
  • 作者简介:刘怡媛(1994-),女,江西瑞金人,硕士,从事资源遥感研究。E-mail: liuyiy163@163.com
  • 基金资助:
    中国科学院地理科学与资源研究所“秉维”优秀青年人才计划(2018RC201);国家自然科学基金面上项目(41971242);中国博士后科学基金(2019M660777)

Characteristics analyses of major physical geographic elements of Visible Infrared Imaging Radiometer (VIIRS) active fire in Laos

LIU Yiyuan1, LI Peng2,3(), XIAO Chiwei2,3, LIU Ying1, RAO Didi2,3   

  1. 1. College of Geography and Environment, Jiangxi Normal University, Nanchang 330022, China
    2. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    3. College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-01-11 Revised:2019-07-11 Online:2020-03-20 Published:2020-05-20
  • Contact: LI Peng

摘要:

利用美国国家航空航天局火灾信息资源管理系统(FIRMS)VIIRS V1活跃火、先进星载热发射和反射辐射仪全球数字高程模型(ASTER GDEM)、MODIS NDVI/LSWI与土地覆被数据产品(FROM-GLC),基于GIS定量分析老挝2012—2017年从分省到国家不同空间尺度活跃火频次的动态变化,并重点分析2015厄尔尼诺年活跃火频次及其与海拔、坡度、植被-水分(NDVI *、LSWI)指数、土地覆被等主要自然地理要素的相关特征。结果表明:① 老挝活跃火频次呈先增后减的趋势,峰值在2015厄尔尼诺年,主要集中在上、中寮,其中琅勃拉邦、沙耶武里与沙湾拿吉三省居前三位,而万象市、塞公和赛宋本则居后三位。② 老挝2012—2017年活跃火发生频次与地形因素(海拔、坡度)的关系基本相同,活跃火集中在海拔1000 m以下、坡度小于30°的低山-丘陵区。其中,上寮活跃火集中分布在500~1000 m、10~30°的斜陡坡山地,中、下寮集中在500 m以下、2~20°的缓斜坡丘陵。③ 活跃火高度集中在旱季,以3月、4月最多,并集中分布在NDVI为0.4~0.8和LSWI为0.2~0.6的中高覆盖度植被区。④ 老挝活跃火主要发生在森林这一土地覆被类型中,且以上寮最为集中,而中寮多以农田、草地和灌丛活跃火为主。综上,基于自然地理要素的活跃火特征分析可以有效识别其发生类型,即老挝活跃火主要由刀耕火种农业所引起。

关键词: 活跃火, 地形, 植被-水分指数, 土地覆被, 成因-类型, 刀耕火种农业

Abstract:

Using US NASA's Fire Information for Resource Management System (FIRMS) VIIRS V1 (or Visible Infrared Imaging Radiometer Version 1) active fire location vector data, ASTER GDEM (30 m, or Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model), Moderate Resolution Imaging Spectroradiometer (MODIS, 1 km) Normalized Difference Vegetation Index (NDVI) and Land Surface Water Index (LSWI), and Global Land Cover products (30 m), based on GIS, the dynamic changes in active fire events were quantitatively analyzed from provincial to national scales in Laos in 2012-2017. In addition, characteristics analyses of major physical geographic elements of VIIRS V1 active fires, including topography (elevation and slope), MODIS vegetation-moisture indices (NDVI and LSWI) and land cover types, were conducted in detail in the 2015 El Niño. The results showed that: (1) the number of active fire events in Laos increased first and then decreased in 2012-2017, with the peak in 2015. Active fires in Laos were mainly concentrated in the northern and central regions. Luang Prabang, Sayaburi and Savannakhet had the top number of active fires at the provincial level, while Vientiane City, Sekong and Xaisomboun in sequence ranked the last. (2) The relationship between the frequency of active fires in Laos and topographic factors (elevation and slope) in 2012-2017 was basically the same. Active fires primarily occurred in the hilly and low mountainous areas with elevations of less than 1000 m (86.10%) and slopes of less than 30° (92.45%). Among them, active fires in the northern region were concentrated in the mountainous areas with elevations of 500-1000 m and slopes of 10-30°, while others in the central and southern regions were concentrated in the hilly areas below 500 m and gentle slopes of 2°-20°. (3) Seasonally, the active fires in Laos mainly happened during the dry season (94.75%), with the most number in March and April (82.24%) and in the medium-high coverage vegetation area with NDVI of 0.4-0.8 (92.05%) and LSWI of 0.2-0.6 (75.70%). (4) Active fires were mostly distributed in the forests of Laos, especially in the northern part, while the counterparts in the central and southern parts mainly occurred in farmland, grassland and shrubland. (5) In summary, characteristics analyses of major physical geographic elements of VIIRS active fires can be used to determine its fire type, that is, active fires in Laos were mainly caused by swidden agriculture.

Key words: active fire, topography, vegetation-moisture indices, land cover, ignition source-types, swidden agriculture