青海省近45年霜冻变化特征及其对主要作物的影响

Characteristics of Frost Variation in Recent 45 Years over Qinghai Province and Its Impact on Major Crops

利用青海省22个地面气象站1961-2005年霜冻气候资料及日最低气温资料，对东部农业区、柴达木盆地等地的霜冻气候变化特征以及对主要作物的影响进行研究。结果表明：45年来，青海省大部分地区早（秋）霜冻初日推迟，晚（春）霜冻终日提前，无霜冻期延长。东部农业区霜冻初日推迟、终日提前的趋势最为明显，柴达木盆地次之，祁连山地区和青南高原霜冻初日推迟趋势较明显，而终日提前趋势不明显；大部分地区重霜冻频数减少，强度减弱，春霜冻期低温强度变化趋势较秋霜冻期明显；气候变暖使早霜冻危害减轻，晚霜冻危害加重。

Using the frost and daily minimum temperature data from 22 ground weather stations in Qinghai Province from 1961 to 2005, the characteristics of frost variation and the main impact on major crops are studied, especially in the Qaidam Basin. The results show that in the past 45 years over the most parts of Qinghai Province, the beginning date of early （autumn） frost postponed, and the ending date of late （spring） frost advanced, most obviously in the eastern agricultural area and then the Qaidam Basin; frostfree periods extended; in the most part of Qinghai Province, the occurrence frequency of heavy frost reduced and the intensity weakened; the intensity variation of spring frost was more obvious than that of autumn frost; and the climate warming mitigated the autumn frost damage and enhanced the spring frost damage.