| English Abstract |
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 southwest 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 913000 hm2 of winter wheat, 543000 hm2 of seedrape and 900000 hm2 of sugarcane suffering the drought, respectively. For winter wheat, there would be a damage of 830000 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. |
