Discussion of Evaluation Indices of Winter Wheat Drought Based on Ten-days Scale

doi:10.3969/j.issn.1673-7148.2012.01.004

Abstract：It bad important sense to discuss the evaluation indices of drought in small scale for evalu- ating drought of winter wheat dynamically. The paper chose some representative stations in Henan province, the ratio of irrigation area to arable area was relatively small at those stations. Daily meteorologicaldata in winter wheat whole growing season （first ten days of October to first ten days of June of next year） from 1971 to 2008 and unit yield information for the stations above were used, and water deficit indices based on whole growing season and ten-days scale were calculated respectively, meanwhile, the series ofyield variation rate were extracted. The results showed that either water deficit indices based on whole growing season or ten days had highly significant correlation with yield variation rate. Taking the regres-sion equations between water deficit indices and yield variation rate, and the standard of drought degree division method for agriculture, the evaluation indices of drought for winter wheat in Henan province were determined. For whole growing season of winter wheat, the water deficit indices was represented by Hi, and - 1.5≤Hi 〈 1, - 3. 1 ≤ Hi 〈 - l. 5 , - 4.6 ≤Hi 〈 - 3. 1, Hi 〈 - 4.6 corresponded to light, moder- ate, heavy and severe drought respectively. In the scale of ten-days scale, 0.8≤ Hi 〈 1, - 0.7≤ Hi 〈 0.8, - 2.3 ≤ Hi 〈 - 0.7,Hi 〈 - 2.3 corresponded to light, moderate, heavy and severe drought respectively.