赤水河流域近10年径流特征与变化趋势

Runoff Characteristics and Change Trends of the Chishuihe River Watershed in Recent 10 Years

基于2008—2017年赤水河流域上游-赤水、中游-茅台、下游-鲢鱼溪断面月径流、降水等水文气象数据,分析了赤水河流域径流的时空变化特征及其对降水、工业取水等影响因素的空间对应关系。结果表明:近10年来,赤水河年径流量总体呈现出缓慢增加趋势,幅度随着流域空间尺度的增大而增加,径流量呈现出以1a为周期“减少→增加→减少→增加”交替波动规律,年际和年内变化较为剧烈;径流量与降水量的变化趋势高度一致,降水是驱动流域径流年际和年内变化的主导因素。10年间,除上游径流系数微弱增长外,中、下游均出现略降低趋势;年内径流系数主要受7月、9月、1月和2月降水量影响,这些月份降水量增加会导致湿季和旱季径流系数增大,从而年径流量加大。

Based on the hydro-meteorological data of runoff and precipitation in the upper reaches of the Chishuihe River basin from 2008 to 2017,covering the upstream of Chishui,the middle stream of Maotai,and the downstream of Lianyuxi sections,the temporal and spatial characteristics of the basin were analyzed,as well as the spatial correspondence with precipitation,industrial water intake and other influencing factors.The results showed that in the past 10 years,the annual runoff of Chishui River has demonstrated a slow increasing trend,and its amplitude increased with the increment of the basin spatial scale of the basin.The runoff presented the alternating fluctuation law of"decrease-increase-decrease-increase"within one year as the cycle,and the annual and inter annual changes were more severe.The change trend of runoff and precipitation was highly consistent,and precipitation was the dominant factor driving the inter-annual and intra-annual changes of runoff in the basin.In the past 10 years,except for the slight increase in upstream runoff coefficient,the middle and downstream showed a slight downward trend;the annual runoff coefficient was mainly affected by the precipitation in July,September,January and February,and the increase of precipitation in these months would promote the increase of runoff coefficient in wet and dry seasons,thus raising the annual runoff.