2010年春季西南地区干旱遥感监测及其影响评估

Drought Monitoring and Its Impacts Assessment in Southwest China Using Remote Sensing in the Spring of 2010

利用国产环境减灾星多光谱、热红外数据以及美国中分辨率MODIS数据建立了2010年春季我国西南地区的干旱及其影响的遥感监测与评估方法。主要包括:1)旱情遥感监测,利用环境减灾星多光谱数据和热红外数据构建旱情遥感综合指数监测西南地区的旱情;2)地表可用水资源遥感监测,主要利用2010年3月中旬及去年同期的多光谱数据,对位于云南、贵州、广西境内的三个典型水体的水面面积进行了动态监测,以评估地表水面面积及水位的变化;3)干旱对农作物的影响,主要通过农作物生长过程曲线分析各省(市)区的作物受旱情的影响过程,并利用耕地面积与遥感监测作物种植成数、分类成数,以及耕地受旱比例计算作物受旱面积,通过田间实验对不同生育期冬小麦受到水分胁迫条件下的减产结果,确定不同旱情等级对应的粮食减产比例,计算各省(市)的冬小麦减产数量。结果表明旱情最严重区域在广西西北部、贵州西南部和云南的中部与东北部,冬小麦、油菜、甘蔗等作物生长过程受到明显抑制,受旱面积分别达到9.13×105hm2、5.43×105hm2与9.00×105hm2,冬小麦产量损失达到8.3×105t,约占2009年四省市冬小麦总产量的13.7%、全国冬小麦总产量的0.8%和全国粮食总产量的0.16%,对我国粮食总产量影响不大,但云南和贵州的冬小麦减产分别达到48%和31%,对区域粮食供应影响较大。

The authors carried out drought monitoring and its impacts assessment in Southwest China using CCD and IRS data obtained from China-made satellite HJ-1 in the spring of 2010.The following techniques were proposed：1） Drought monitoring using LST and NDVI derived from HJ-1 CCD and IRS;2） Water resource assessment by comparison of water area sampled within the severe drought regions;3） Effects of the drought on crops.Crop growing curves from time series MODIS NDVI were compared to assess the effects of drought on crop conditions,arable land area,crop planting proportion.Crop planting structure and area fraction of different drought grades were used to introduce crop area under the drought condition.A crop yield loss look-up table was also built-up based on field-experiment results digested from articles.The results showed that：i） the drought occurred mainly in Guangxi,Yunnan,Guizhou,Sichuan and Chongqing,especially in the northwest of Guangxi,central and northeast of Yunnan and the southw...更多est of Guizhou.ii） the severe drought resulted in the withdrawal of surface water bodies,and more than 2/3 of water bodies disappeared.iii） Since last October,crop growing curves have presented obvious restrain due to the drought,Among the crops,winter wheat,seedrape and sugarcane has been greatly affected.There were about 9.13×105 hm2 of winter wheat,5.43×105 hm2 of seedrape and 9.00×105 hm2 of sugarcane suffering the drought,respectively.For winter wheat,there would be a damage of 8.3×105 t,and 13.7% of the total production of Chongqing,Sichuan,Guizhou and Yunnan,accounting for only 0.8% of the country.The damage would not do harm to the country＇s food security but will exert influence on regional grain supply-demand balance.The drought has also affected the nursery of autumn crops and transplant of rice.