巴尔喀什湖流域气候变化特征分析

根据巴尔喀什湖流域5个气象站20世纪的逐月气温和降水资料,利用滑动平均法和差积曲线法,分析流域20世纪的气候变化特征及其与巴尔喀什湖自身水文特征的联系,并从能量转换角度进行解释.结果表明:空间上,年均气温从南向北、从东向西逐渐降低,年际变化从南向北变大;年降水量从四周向中心腹地逐渐减小,年际变化从北向南变大.时间上,年均气温总体上升且大致具有10~23 a的周期性;年降水量整体上表现为增长,20世纪90年代初期略有减少.年内月均气温的最低和最高值分别出现在1月和7月,且低温月份气温上升趋势较高温月份明显;降水量的年内分布呈双峰型.20世纪50年代中期至70年代中期,整个流域的气候要素变化较大.

Characteristics of climatic change in the Balkhash Lake Basin

In order to identify the characteristics of climatic change in the Balkhash Lake Basin and their relationship with the hydrological characteristics of the lake from the point of view of energy conversion,monthly temperature and precipitation data of five meteorological stations in the basin in 20th century were analyzed using the moving average method and residual mass curve method.The results show that the annual mean temperature decreases from south to north and from east to west,while inter-annual variation increases from south to north.The annual precipitation decreases gradually from the periphery to the centre,while the inter-annual variation increases from north to south.The mean annual temperature increased in a cycle of between 10 a and 23 a.Annual precipitation in the region increased over the century as a whole,even though it decreased in the early 1990s.The minimum and maximum mean monthly temperatures appear in January and July,respectively,and the value in low-temperature months has ascended greatly while that in high-temperature months only slightly.The inter-annual precipitation curve is of a two-peak type.Climatic factors from the mid-1950 s to the mid-1970s have changed significantly.