Abstract:

Based on its attribute of agricultural impact properties, agrometeorological disaster risk early warning integrates forecasting of catastrophic weather with dynamic monitoring and assessment of exposure and vulnerability of agricultural hazard−bearing bodies. It estimates the impact of disasters on agriculture and provides early warning services. This study provided an overview of relevant concepts and terminology for early warning of agrometeorological disaster risk. The three core elements, hazard, exposure and vulnerability, were then quantitatively evaluated to systematically organize agrometeorological disaster risk identification techniques for early warning services and develop operational technical processes for agrometeorological disaster risk early warning. Taking the risk early warning of dry−hot wind disaster for winter wheat (12–18 May 2025) as a case study, this study demonstrated the full process of dry−hot wind disaster risk assessment, risk grade identification and early warning issuance, which was based on 10d forward meteorological element forecasts. The results showed that, unlike conventional technical methods for agrometeorological disaster risk assessment (which focused on evaluating the probability and impacts of historical disasters), agrometeorological disaster risk early warning predicted the likelihood of future disasters and their adverse effects on crops, while issuing corresponding warning information. Its assessment and judgment of disaster hazard and exposure was grounded in real−time meteorological forecasts and dynamic analysis of agricultural condition monitoring, thus exhibiting real−time and dynamic characteristics. The established operational technical processes of agrometeorological disaster risk early warning involved the following key steps: calculation and assessment of disaster risk indices, classification of risk levels and formulation of criteria for early warning issuance. When an agrometeorological disaster was projected to occur, the work of calculating a risk index was initiated: each risk component was evaluated and calculated individually to determine an agrometeorological disaster risk index and the risk assessment results were derived through risk grade judgment. Once the area proportion of risk levels at or above "relatively high risk" met the area ratio specified in early warning issuance criteria, a risk early warning was issued to the public. Notably, specific methods for risk index calculation and early warning issuance criteria varied across different agrometeorological disasters. For current risk early warning of dry−hot wind disaster for winter wheat: (1) exposure was determined via dynamic identification of winter wheat in the flowering and grain−filling stage. (2) Hazard was assessed using various combinations of dry−hot wind days and grades in the upcoming 10d. (3) Vulnerability was evaluated based on dry−hot wind damage reference values specified in the meteorological industry standard Grades of Wheat Dry−Hot Wind Disasters. (4) The early warning issuance criterion was defined as follows: the area with dry−hot wind disaster risk at or above the relatively high level accounts for no less than 15% of the total wheat sowing area in the northern winter wheat region.

Key words: Agricultural meteorological disasters, Risk warning, Technical process, Risk index, Risk classification, Warning issuance indicator