云南红河流域径流的时空分布变化规律

利用红河流域32个气象站1960-2000年逐月降水、气温、蒸发等实测资料,元江、李仙江和盘龙河1956-2000年径流量资料,使用GIS技术支持以及Kendall检验法、方差分析法、累积距平法,分析云南红河流域径流的时空变化规律,重点探讨径流时空分布变化与红河流域河谷与山脉的"通道-阻隔"作用的关联,得出如下结论:(1)在红河流域河谷与山脉的"通道-阻隔"作用的影响下,降水量和径流深等值线在空间上呈西北-东南向分布,分布模式与河谷/山脉的走向基本一致,并在哀牢山北段和李仙江下游地区形成两个高值区.(2)在多年平均尺度上,红河流域河谷与山脉的"通道-阻隔"作用对径流变化的地域差异影响最大,其次是降雨,对气温则不明显:李仙江的降水量明显大于哀牢山东部的元江和盘龙河区,其降水量变化的相对偏差则小于它们,反映出哀牢山的阻隔效应;三个区的平均气温差别不大,反映出在较大的时间尺度上受该区特殊环境格局的"通道-阻隔"作用不明显;多数降雨、径流和气温特征值及其出现时间的变化,在盘龙河与元江及李仙江都明显不同,反映出红河流域山脉的阻隔作用明显.(3)在区域气候变化及红河流域河谷与山脉"通道-阻隔"作用的叠加影响下,红河流域的径流变化在东西方向上差异明显:沿红河断裂发育的元江流域的径流量表现出上升的趋势,而西部的李仙江和东部的盘龙河径流量呈现出减少的趋势;元江和李仙江的年径流有一个准5年的变化周期,而盘龙河则有一个准8年的变化周期;三个区域的径流量变化表现出不一致的阶段性.

The Variation of Runoff of Red River Basin in Yunnan

This paper studies the variation of runoff of Red River Basin and discusses the influence of "corridor-barrier" functions of valleys and mountains on variation of runoff by using GIS and statistic methods based on the monthly precipitation, temperature and evaporation data from 1960 to 2000 at 32 meteorological stations in the Red River Basin, and the annual runoff data of the Yuanjiang, Lixian and Panlong rivers from 1956 to 2000. The results showed out: (1) Under the effect of "corridor-barrier" functions of valleys and mountains in the Red River, the patterns of annual precipitation and runoff depth present in spatial change a NW-SE distribution, which was similar with the trend of the Red River valley and Ailao Mountains. (2) In the long temporal scale averaged over years, the most obvious effect of the "corridor-barrier" functions was on runoff variation, and the second was on the precipitation, but not obvious on the temperature: the precipitation in Lixian River Basin was greater than that in the Yuanjiang and Panlong rivers of the eastern Ailao Mountains, but the standard deviation was smaller than the latter two, an indication of the "barrier" effect from Ailao Mountains. The mean temperature difference was not obvious among the three regions. (3) Under the superposed effect of climate changes and the "corridor-barrier" functions of valleys and mountains in the Red River Basin, the difference in runoff variation was obvious in the east-west direction: the runoff variation of the Yuanjiang River along the Fault presented an ascending trend, but the Lixian River on the west side of the Fault and the Panlong River on the east presented a descending trend; the annual runoff of the Yuanjiang River and Lixian River had a quasi-5a period, and the Panlong River a quasi-8a period; and the runoff variations were quite inconsistent in different periods among the three river basins.