青海省春小麦干旱灾害风险评估与区划

基于青海省1961-2010年47个气象站和8个农气代表站气象资料、 干旱灾情资料的收集和整理, 分析了春小麦生育期土壤相对湿度与降水距平百分率的关系, 确定了青海省春小麦不同生育期干旱风险评估的实际阈值, 并对青海省春小麦不同生育期干旱进行风险区划.结果表明: 在青海省春小麦营养期, 轻旱易发生在祁连山地区、 青海湖地区西南部及东部农业区的少数地区, 轻旱的频率大都在15%以上; 中旱易发生在柴达木地区大部及东部农业区大部, 频率大都在10%以上; 重旱和特旱出现频率均在柴达木盆地西部较高, 频率分别为10.7%、 34%以上.生殖期的轻旱易发生在祁连山地区, 频率在15.3%~23.3%之间; 中旱易发生在青海湖地区南部及东部农业区少数地区, 频率大都在4.0%~5.7%之间; 重旱频率从东南部到西北呈现带状递减趋势, 频率最高的主要发生在东部农业区, 出现频率为8.3%~9.6%; 特旱易发生在柴达木盆地地区, 出现频率为27%~44.3%之间.产量形成期的轻旱、 中旱、 重旱均易发生在东部农业区, 频率分别为2.3%~3.3%、 8.7%~13.3%、 6.0%~9.0%之间, 特旱易发生在柴达木地区, 出现频率为43.3%~51.3%之间.

Risk Assessment and Division of Drought Disaster on Spring Wheat in Qinghai Province

In this paper, thresholds are determined for spring wheat in different growth stages and the values of risk assessment of drought disaster are put forward, through analyzing the correlation of soil humidity and precipitation anomaly percentage, based on data from 47 meteorological stations and eight agriculture representative stations and drought disaster investigation. Risk assessment and division for drought disaster are made through establishing fitting equations of disaster frequency in relation to elevation, longitude, latitude and percentage in growth stage. It is found that 1) in vegetative stage, light-drought (frequency of 15%) takes place in the Qilian Mountains, the southwest of Qinghai Lake and a little part of the eastern agricultural region; medium-drought (frequency of more than 10%) takes place in most part of the Qaidam Basin and most part of the eastern agricultural region; and the heavy-drought and extra-heavy-drought (frequency of more than 10.7% and 34%, respectively) take place in the western Qaidam Basin. 2) In the jointing to booting stage, light-drought (frequency of 15.3％~23.3％) takes place in the Qilian Mountains; medium-drought (frequency of 4%~5.7％) takes place easily in the south part of Qinghai Lake and a little part of the eastern agricultural region; heavy-drought (frequency of 8.3％~ 9.6％) takes place in the eastern agricultural region; extra-heavy-drought (frequency of 27％~44.3％) takes place in Qaidam Basin. 3) In the milk to ripeness stage, light-drought, medium-drought and heavy-drought all take place in the eastern agricultural region, of which the frequency is 2.3％~3.3％, 8.7％~13.3％ and 6.0％~9.0％,respectively; extra-heavy-drought (frequency of was 43.3％~51.3％) takes place in Qaidam Basin.