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Nanjing University of Information Engineering (2008)

Winter wheat drought risk analysis and assessment techniques

Liu Rong Hua

Titre : Winter wheat drought risk analysis and assessment techniques

Auteur : Liu Rong Hua

Grade : Doctoral Dissertation 2008

Université : Nanjing University of Information Engineering

Résumé
Henan is the biggest province of winter wheat production in China, and drought is the major agrometeorological disaster which has great affections for winter wheat growing in the province. Analysis of drought risk and risk assessment is significant for governments and production departments in all levels to achieve drought information timely, formulate measures for drought prevention and reduction, and bring about the conversion from disaster emergent management to risk management.Data used here is historic yield of winter wheat published by Henan Bureau of Statistics, meteorological data in 1949 - 2005 from 117 stations in Henan Province, and experiment data from Henan Institute of Meteorological Sciences. Based on the on the study of water supply and demand and soil water variation during the growing process of winter wheat, the paper analyzed the relationship between yield reduction and drought, determined a set of winter wheat drought indices including climatic indices expressed with negative precipitation departure and crop indices expressed with water deficit ratio.According to the objectivity of climate and practicality of production, the drought intensity and occurrence probability were analyzed and the model of drought risk was established. Combined with anti-disaster ability, a comprehensive drought risk assessment model was founded. Using the models, the whole province was regionalized according to single and comprehensive drought risk. The loss caused by drought was divided into direct economic loss of yield reduction and cost loss for anti-disaster and then the comprehensive economic risk assessment model was built, which would provide technique support for risk analysis and assessment.Taking advantage of field experiment and crop simulating model, the coefficients of drought-caused loss in different stages of wheat were determined and the dynamic loss assessment model was provided. The dynamic model would follow the tracks of the drought and evaluate the risk quantitatively and dynamically during crop growing stages.Finally, integrated the risk analysis and assessment model, the drought assessment service system for winter wheat, including corresponding software, for Henan Province was built. The system was composed of basic parameters, risk indexes, regionalization, loss assessment and help, etc, and a new way for agrometeorological service and operational application was provided. The paper aims to intensify and broaden agrometeorological operational level and ability, and could provide scientific base for better service in making policy decision for agricultural production and food security on provincial scale.

Mots clés : winter wheat drought risk alynisis risk assessment model

Présentation (Dissertationtopic)

Page publiée le 3 mai 2013, mise à jour le 10 janvier 2018