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| DOI：10.13522/j.cnki.ggps.20190041 |
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| The Spatial and Temporal Characteristics of Drought During Summer Maize at Different Growth Stages in Yunnan Province Based on Crop Water Deficit Index |
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CAO Yan, WANG Jie, LI Youliang, WANG Shupeng, QI Na
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Yunnan Institute of Water Resources and Hydropower Research, Kunming 650228, China
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| Abstract: |
| 【Objective】In order to provide scientific basis for the rational distribution of summer Maize and the prevention of drought during the growth stages, the variation of drought in different growth stages of summer Maize in Yunnan province was studied. 【Method】 Based on the daily meteorological data from 1960 to 2014 of 32 typical?meteorological stations in Yunnan province, crop water drought Index (CWDI) in every ten days of summer maize growth stages were calculated, the temporal and spatial variation of summer Maize drought in different regions of Yunnan province were analyzed by the linear trend estimate and M-K method, and the correlation coefficient of CWDI at different stages and summer maize yield was researched. 【Result】①The ratios of drought occurring stations for summer maize during the initial stage, crop development stage, mid-season stage, late season stage and whole growing season were 50.30%, 12.36%, 5.88%, 6.00% and 10.35%, respectively. ②The ratios of drought occurring stations and CWDI of summer maize during the initial stage exhibited a declining trend; However, the ratios of drought occurring stations and CWDI of summer Maize during the crop development stage, mid-season stage, late season stage and whole growing season showed an increasing trend, and the increasing amplitude of the drought occurring stations and the strength (CWDI)?was?relatively large in the crop development stage and mid-season stage, the increasing trend was mainly concentrated in southwest Yunnan.③The drought frequency basically showed that the characteristics of the spatial distribution from the middle to the surrounding was more and more?higher during the different stages of summer maize in Yunnan province, the highest of drought frequency were concentrated in central Yunnan, and the lowest in southwest Yunnan; The areas with great increase of drought strength was mainly concentrated in the southwest and northeast Yunnan during different stages of summer maize, and the areas with less increase of drought strength was mainly concentrated in the western and northwest Yunnan.④The condition of water supply and demand in the mid-season stage of summer maize affect summer maize yield greatly in Yunnan province.【Conclusion】The drought strength increasing is favorable to the yield of summer maize in western Yunnan province, especially in southwest Yunnan; while the drought strength increasing has a passive effect on the yield of summer maize in the central and eastern Yunnan province, especially in northeast Yunnan. |
| Key words: summer maize; CWDI; growth stage ; drought characteristics; Yunnan province |
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