Evaluation Of Meteorological Disaster Standard System For Major Grain Crops In China

In order to ensure grain production security under the background of global warming and frequent meteorological disasters,it is very significant to establish a sound technical system of agricultural disaster prevention and reduction.And the primary task is to evaluate the standards and system of meteorological disasters for major grain crops.This paper firstly selected the research objects of the meteorological disasters and standards for major grain crops in China by summarizing the situation and experience.It secondly developed the evaluation requirements of the standard system for major grain crops for the purpose of achieving refined functions such as pre-disaster forewarning,mid-disaster monitoring,and post-disaster assessing from the perspective of agricultural production management using.Finally,it evaluated the operability of the disaster standards and the integrity of the standard system through standardized processing and qualitative and quantitative analysis of the research objects.(1)The main grain planting structure in China's main grain production areas was clear.The Northeast China region was dominated by spring maize and single cropping rice,the Huanghuai-hai region(hereafter referred to as HHH)was dominated by winter wheat and summer maize,and the middle and lower reaches of the Yangtze River was dominated by single or double cropping rice.This paper determined thirteen meteorological disasters for major grain crops in China by the division method of “region + crop + abnormal meteorological factor”,including: drought of spring maize in the Northeast China region,chilling injury of spring maize in the Northeast China region,waterlogging of spring maize in the Northeast China region,chilling injury of single cropping rice in the Northeast China region,drought of winter wheat in the Huang-huai-hai region,frost of winter wheat in the HHH region,hot and dry wind of winter wheat in the HHH region,drought of summer maize in the HHH region,heat injury of summer maize in the HHH region,chilling injury of early double cropping rice in the middle and lower reaches of the Yangtze River,chilling injury of late double cropping rice in the middle and lower reaches of the Yangtze River,drought of single cropping rice in the middle and lower reaches of the Yangtze River,heat injury of single cropping rice in the middle and lower reaches of the Yangtze River.(2)Meteorological disaster standards for major grain crops must be operable,including the availability of data and applicability of index,in which the applicability of index also considered the conditions of analysis factors,time scales,threshold differences,etc.Disaster standards system must have functional integrity and technical integrity.Based on a qualitative analysis of the standard's operability,a quantitative formula was established to calculate the level of operability index when the disaster standard achieved each evaluation purpose,thereby comparing the excellent operability of each standard.The summary results of disaster standards can clearly reflect the integrity of the meteorological disaster standard system for major grain crops,and provide research directions for the revision and improvement of the agricultural meteorological disaster standard system in the future.(3)By quantifying the applicability of index and availability of data,and then quantifying the level of operability index,the operability evaluation of the standard can be made more objective and scientific.The evaluation results of standard operability showed that there were 18 drought standards and 7 of which were operable;there were 10 waterlogging standards and 3 of which were operable;there were 14 chilling injury standards and 12 of which were operable;there were 7 frost standards and 4 of which were operable;there were 5 heat injury standards and 2 of which were operable;there were 4 hot and dry wind standards and 3 of which were operable.(4)The evaluation results of standard system integrity showed that the current meteorological disaster standard system for major grain crops can basically fulfill the functions of disaster level evaluation in various links,but lack standards that can achieve disaster range and disaster loss evaluation.The entire standard system need to improve its integrity of functions and technologies.The meteorological disaster standard system of abnormal water condition and abnormal multivariate condition for the level evaluation was relatively completed,and there were operable disaster standards for each type and each link;but the meteorological disaster standard system of abnormal temperature condition can achieve the level evaluation of chilling injury for each link,and the the level evaluation of frost and heat injury only for assessing.