【摘要】 以天山伊犁河流域为背景 ,通过冰川动力模型模拟 ,研究了统计意义上不同规模冰川及其径流对气候变化的响应过程的差异性 .结果表明 ,不同规模冰川对气候变化的敏感性有较大差异 ,冰川径流变化与气候的变化亦不一致 .在气温变暖、冰川退缩的过程中 ,冰川径流有一个增大的过程 ,冰川径流的峰值大小和出现时间取决于冰川大小和升温速率 .根据径流峰值出现时间与升温过程的一致与否 ,提出冰川径流增大的临界升温速度概念 .更多还原

【Abstract】 A glacier dynamics model that simulates the change ofvalley glaciers in various sizes and their runoff in response to climate change is presented for the Yili River basin in the Tianshan Mountains. In order to parameterize the shapes of glaciers with various sizes, some characteristic values of more 2000 glaciers in the Yili River basin have been statistically analyzed based on the glacier inventory. The values include glacier area, length, difference between the maximum and the minimum elevation, the maximum elevation and average slope. It is suggested that: 1) the sensitivity of glaciers to climate change is determined by glacier sizes. Smaller glaciers are more sensitive to climate warming than larger ones, and their relative changes are greater than those of larger glaciers, while their absolute change is contrary. 2) The relative change of the glacier volume with climate warming is most remarkable as compared with that of glacier length and area. For larger glaciers, the change of length (retreat) is more significant than that of area; on the contrary, for smaller glaciers (with the area < 0.6 km 2), the change of area is more significant than that of length. 3) The glacier runoff does not change synchronously with climate change. As climate warming and glacier retreating, the glacier runoff tends to increase and then to decrease. Under climate warming, the smaller glaciers with the higher runoff peaks tend not only to vary greatly but also to retreat quickly as compared with the larger ones. The magnitude and appearance time of runoff peak depend not only on the glacier size but also on the rising rate of air temperature. The faster the air temperature rises, the higher the peak, and the earlier the appearance time of the peak takes place. 4) For a given warming range, with a decrease of temperature rising rate, the appearance time of runoff peak tends to be earlier than the occurrence time of the maximum air temperature. The temperature rising rate in such a circumstance is defined as critical rising rate. The critical rising rate has negative correlation with glacier sizes.更多还原