Correlations between weighted VTCI in key growth and development stages of winter wheat and wheat yields in the Guanzhong Plain |
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DOI:10.7606/j.issn.1000-7601.2011.06.32 |
Key Words: impact estimation vegetation temperature condition index subjective weighting method objective weighting method |
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Abstract: |
Selecting drought monitoring results of Vegetation Temperature Condition Index (VTCI) in the key growth and development stages of winter wheat in the Guanzhong Plain, two subjective weighting methods,analytic hierarchy process method and factor rank ordering method, and two objective weighting methods,principal component analysis and entropy method are used to calculate weighted VTCI values. The linear regression analysis is applied to study the correla tion between the weighted VTCI values and wheat yields for the five regions in the Guanzhong Plain respectively,and as well as the drought impact on wheat yield based on VTCI. The results show that there are significant correlations between
wheat yields and weighted VTCI values by using the subjective weighting methods, while there are poor correlations by using the objective weighting methods . These results indicate that the subjective weighting methods are more effective ways to calculate weighted VTCI values,which can be used to establish the linear relationship with wheat yields, prove the feasibility of wheat production forecast by using VTCI approach, and show that monitoring drought in the Guanzhong Plain is very referable. |