农业工程学报
農業工程學報
농업공정학보
2013年
24期
163-172
,共10页
遥感%决策树%分类%橡胶林地%中老缅交界地区
遙感%決策樹%分類%橡膠林地%中老緬交界地區
요감%결책수%분류%상효임지%중로면교계지구
remote sensing%decision trees%classification%rubber plantations%the border region of China%Laos and Myanmar
中老缅交界地区是橡胶林地的主要种植区,利用遥感手段快速动态监测橡胶林地的时空变化,对于橡胶合理种植、生态环境保护以及边境安全保障具有重要的科学价值和实践意义。研究基于 Landsat 数据和MODIS-NDVI数据,采用决策树分类的方法提取中老缅交界地区的橡胶林地。研究发现:1)1月上旬至3月下旬为提取橡胶林地的主要时间窗口;根据橡胶林不同树龄所表现的光谱差异,按照橡胶幼林(<10 a)和橡胶成林(≥10 a)提取橡胶林地;橡胶成林、高植被覆盖度的旱地、有林地容易发生误分,橡胶幼林、茶园、灌木林地和草地容易发生混淆。2)基于原始光谱特征、归一化指数、K-T变换指数以及纹理特征分别构建橡胶幼林和橡胶成林决策树分类模型;2010年橡胶成林分类总精度超过90%,橡胶幼林分类总精度超过75%;对同一地区1980、1990、2000年3个时相的决策树分类发现,橡胶幼林和橡胶成林决策树分类模型简单有效,结合晚期的橡胶成林来验证提取早期的橡胶幼林可以达到更高的分类精度。3)1980-2010年间,中老缅交界地区橡胶林地由7.05万hm2增至60.14万hm2,橡胶林地扩张趋势显著;橡胶幼林扩张速度明显快于橡胶成林,特别是近10 a来;西双版纳橡胶种植面积在中老缅交界地区占主导地位,橡胶林地不断向老挝、缅甸边境地区扩张。
中老緬交界地區是橡膠林地的主要種植區,利用遙感手段快速動態鑑測橡膠林地的時空變化,對于橡膠閤理種植、生態環境保護以及邊境安全保障具有重要的科學價值和實踐意義。研究基于 Landsat 數據和MODIS-NDVI數據,採用決策樹分類的方法提取中老緬交界地區的橡膠林地。研究髮現:1)1月上旬至3月下旬為提取橡膠林地的主要時間窗口;根據橡膠林不同樹齡所錶現的光譜差異,按照橡膠幼林(<10 a)和橡膠成林(≥10 a)提取橡膠林地;橡膠成林、高植被覆蓋度的旱地、有林地容易髮生誤分,橡膠幼林、茶園、灌木林地和草地容易髮生混淆。2)基于原始光譜特徵、歸一化指數、K-T變換指數以及紋理特徵分彆構建橡膠幼林和橡膠成林決策樹分類模型;2010年橡膠成林分類總精度超過90%,橡膠幼林分類總精度超過75%;對同一地區1980、1990、2000年3箇時相的決策樹分類髮現,橡膠幼林和橡膠成林決策樹分類模型簡單有效,結閤晚期的橡膠成林來驗證提取早期的橡膠幼林可以達到更高的分類精度。3)1980-2010年間,中老緬交界地區橡膠林地由7.05萬hm2增至60.14萬hm2,橡膠林地擴張趨勢顯著;橡膠幼林擴張速度明顯快于橡膠成林,特彆是近10 a來;西雙版納橡膠種植麵積在中老緬交界地區佔主導地位,橡膠林地不斷嚮老撾、緬甸邊境地區擴張。
중로면교계지구시상효임지적주요충식구,이용요감수단쾌속동태감측상효임지적시공변화,대우상효합리충식、생태배경보호이급변경안전보장구유중요적과학개치화실천의의。연구기우 Landsat 수거화MODIS-NDVI수거,채용결책수분류적방법제취중로면교계지구적상효임지。연구발현:1)1월상순지3월하순위제취상효임지적주요시간창구;근거상효림불동수령소표현적광보차이,안조상효유림(<10 a)화상효성림(≥10 a)제취상효임지;상효성림、고식피복개도적한지、유임지용역발생오분,상효유림、다완、관목임지화초지용역발생혼효。2)기우원시광보특정、귀일화지수、K-T변환지수이급문리특정분별구건상효유림화상효성림결책수분류모형;2010년상효성림분류총정도초과90%,상효유림분류총정도초과75%;대동일지구1980、1990、2000년3개시상적결책수분류발현,상효유림화상효성림결책수분류모형간단유효,결합만기적상효성림래험증제취조기적상효유림가이체도경고적분류정도。3)1980-2010년간,중로면교계지구상효임지유7.05만hm2증지60.14만hm2,상효임지확장추세현저;상효유림확장속도명현쾌우상효성림,특별시근10 a래;서쌍판납상효충식면적재중로면교계지구점주도지위,상효임지불단향로과、면전변경지구확장。
The border region of China, Laos and Myanmar (BRCLM) has attracted much international attention due to the special geo-economic and geo-political characteristics, as well as being the hinterland of the world’s famous “Golden Triangle,” and the optimal rubber planting areas for Chinese investment. Monitoring the spatial-temporal pattern of the rubber plantations is significant for regional land resource development, eco-environment protection, and maintaining border security. Based on Landsat remote sensing image data and MODIS-NDVI data, rubber plantations were extracted by the decision tree classification method in BRCLM using spectral features and texture characteristics. The results showed that: (1) On account of spectral differences between rubber forests at different growth stages, we were able to extract rubber plantations according to young rubber forest (<10 a) and mature rubber forest (≥10 a) respectively. The optimum temporal window to discriminate rubber plantations was from early January to late March, which is especially appropriate for mature rubber forest. Mature rubber forest, dry land with high vegetation cover, and forest land were prone to misclassification. Meanwhile, young rubber forest, tea plantation, shrubland and grassland were confused with each type in spectral characteristics according to the index of NDVI. (2) Based on the original spectral characteristics, normalized indices, K-T transform indices, and texture features, we established young rubber forest and mature rubber forest decision tree classification models respectively. The overall accuracy of the mature rubber forest went beyond 90%, and the young rubber forest beyond 75%, which meant that the decision tree method was better for mature rubber forest extraction. The rubber plantation distribution maps were obtained using the established decision tree models in 1980, 1990, and 2000 with high classification accuracy, which indicated that the models were simple and efficient for extracting rubber plantations in the tropical areas. This is an effective method for perennial vegetation extraction and classification accuracy verification. (3) From 1980 to 2010, the size of rubber plantations in BRCLM increased nearly nine times, from 705 km2 to 6 014 km2, and the expansion rate of the young rubber forest was faster than that of the mature rubber forest. National differences of rubber plantations in BRCLM were significant, and the cross-border planting developed quickly in the recent 10 years. Rubber plantations in BRCLM will definitely expand across the borders of China to the territories of Laos and Myanmar.