| Cause analysis and drought characteristics during rice growing season in Kunming based on crop water deficit index |
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| DOI：10.7606/j.issn.1000-7601.2016.03.30 |
| Key Words: crop water deficit index rice crop water requirements drought characterestic path analysis |
| Author Name | Affiliation | | LI Chuang | Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China | | LIU Yan-wei | Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China | | FU Na | Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China | | YANG Qi-liang | Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China | | LIU Xiao-gang | Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China |
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| Abstract: |
| Based on the daily meteorological observed data from 1952 to 2013 in the Kunming Station, the daily reference evapotranspiration (ET0) and the rice water requirements in growing season during 62 years in Kunming Station has been calculated by the Penman-Monteith Formular recommended by the Food and Agriculture Organization (FAO) in 1998. Using the Mann-Kendall trend test method has researched the change regular of the crop water requirements. At the same time, the concept of crop water deficit index (CWDI) has been introduced. According to the water deficit index of rice, has researched the effects of each meteorogical factor to the water deficit index by using the path analysis method. The results showed that: In recent 62 years, the average ten days crop water requirements in Kunming Region was 32.55 mm. The drought distribution in rice growth season was obviously uneven. With the increase of the growth season, the drought grade was from light drought level to the heavy drought level, the most serious drought occurrence period was the ripening stages. In whole rice growing season, the average water deficit index was 38.07%, it indicated that rice was at the heavy drought status. In the research of the coefficient of variation, the variation coefficient of the water deficite index was total small. In the six growth stages as turnning green, tillering, jointing, heading, milk muturity and yellow muturity, the variation coefficients were 1.8%, 1.9%, 1.3%, 1.1%, 0.8% and 0.8%, respectively. It indicated that change of the drought grade was rather small in recent years in Kunming Region. The maximal positive correlation factor for affecting the water deficit index was the sunshine hours and the negative correlation factor was the water vapor pressure. |
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