基于CRNBR物候算法的西双版纳橡胶成林提取及时空变化研究

基于西双版纳2014年和2018年旱季Landsat-8 OLI遥感影像,利用橡胶林落叶-新叶萌生期内归一化焚烧指数变化率（CR_NBR）算法,运用当年新叶萌生期植被分布（NDVI）与海拔数据（ASTER GDEM）进行掩膜提取,分别获取了2014年和2018年西双版纳橡胶成林种植面积,基于ArcGIS 10.5平台分析了橡胶成林时空格局和种植面积增减变化。结果表明： ① 西双版纳橡胶林主要分布于南部水热条件较好、中低海拔的橡胶种植适宜区。景洪市的橡胶林面积最大,其次是勐腊县,勐海县最小。集中分布于景洪市的勐龙镇、允景洪街道和嘎洒镇;勐腊县的关累镇、勐棒镇和勐满镇;② 西双版纳及其下辖一市两县2014-2018年橡胶林种植面积总体呈现下降趋势,减幅为17.27%。其中,勐腊县的减幅最大为19.10%,勐海县减幅最小,仅2.70%。③ 橡胶林持续种植区主要在景洪市勐龙镇、嘎洒镇和景哈镇等,勐腊县的关累镇、勐棒镇和勐腊镇等;橡胶林种植增加区主要集中在景洪市勐龙镇、嘎洒镇和允景洪街道,勐腊县关累镇、勐腊镇和勐伴镇,勐海县打洛镇;橡胶林种植减少区主要在景洪市勐养镇、嘎洒镇和勐龙镇,勐腊县勐棒镇、勐腊镇和勐伴镇,本研究可为西双版纳橡胶林种植现状特征提供了新的认识。

Extraction of Mature Rubber Plantations based on the CRNBR Algorithm and Spatio-temporal Variations in Xishuangbanna

With the Landsat-8 Operational Land Imager (OLI) images over Xishuangbanna acquired during the dry seasons of 2014 and 2018 , the Change Rate of Normalized Burn Ratio (CR_NBR) algorithm (reported in our previous study), along with two masks of Landsat-derived natural forest and Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM), were used to detect and obtain the geographical information of the mature rubber plantations during this period. The spatial and temporal change pattern of mature rubber plantations were detected and analyzed by means of spatial and statistical analyses using the ArcGIS 10.5 platform. Results showed that: (1) Mature rubber plantations were mainly distributed in areas with well hydrothermal conditions and moderate to low elevations in the south of Xishuangbanna. Jinghong City had the largest area of mature rubber plantations, followed by Mengla County and Menghai County accordingly. These plantations were typically concentrated within the towns of Menglong, Yunjinghong, and Gasa of Jinghong City, and Guanlei, Mengbang, and Mengman of Mengla County. (2) The declining area of mature rubber plantations were initially reported in Xishuangbanna from 2014 to 2018 (at a reduction of approximately 17.27%). In particular, Mengla County had the largest reduction in mature rubber plantations (19.10%), while Menghai County had the least (2.70%). (3) The stable plantation areas of mature rubber were predominantly located in the towns of Menglong, Gasa and Jingha of Jinghong City, and Guanlei, Mengbang and Mengla of Mengla County. The increase in mature rubber plantation areas were mainly concentrated in the towns of Menglong, Gasa and Yunjinghong in Jinghong City, Guanlei, Mengla and Mengban in Mengla County, and the town of Daluo in Menghai County. The reduction area was mainly evident in the towns of Mengyang, Gasa and Menglong of Jinghong City, and Mengbang of Mengla County and Mengban in Mengla County. This study can provide a new understanding of the current status of rubber plantation in Xishuangbanna.