| Risk assessment of drought damage during growing stages for winter wheat in North China |
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| DOI：10.7606/j.issn.1000-7601.2016.04.41 |
| Key Words: winter wheat drought water deficit anomaly index drought risk |
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| Abstract: |
| Using yield data and meteorological data from 1981—2012 in north China, an appropriate method was selected to fit tendency yield for winter wheat in each province, and the key factor was selected by comparing yield reduction rate with water deficit anomaly index and precipitation anomaly percentage in typical drought years. Based on grade criteria of yield reduction rate, drought damage index was calculated upon the model of yield reduction rate and key factor during different period. Risk assessment model was constructed considering drought grade and its risk probability. The drought risk assessment at growth period of winter wheat was conducted considering drought grade and its risk probability. The results indicated that the correlation coefficient between yield reduction rate and water deficit anomaly index varied from 0.355 to 0.656 at the level of P<0.05, being greater than that between yield reduction rate and precipitation anomaly percentage. This finding indicated that water deficit anomaly index was appropriate to be selected as the key factor for drought. The mathematical relationship of yield reduction rate and water deficit anomaly index differed during different growth period, and the critical value determining drought occurrence was 0.297,0.351,0.214,0.159,0.316,0.547 and 0.149 for seedling stage, wintering stage, regreening stage, jointing stage, heading stage, maturation stage and whole growth stage, respectively. Drought damage risk for winter wheat differed during different period that matched well with supplement of precipitation and water requirement in region. Overall, high drought risk for winter wheat was in southern Hebei and northwest Shandong during each period. |
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