三江平原沼泽性河流流域降水、径流变化及影响因素研究

Precipitation and Runoff Changes and Their influence factors of Marshy River in the Sanjiang Plain,China

以三江平原的挠力河流域为研究区 ,选用研究区内 7个雨量站、3个水文站和 3个气象站的降水量资料 ,2个水文站的水位和径流量资料 ,应用倾向率法、累积距平法、Mann Kendall法和灰色关联分析方法等 ,诊断分析了研究区 2 0世纪下半叶降雨、径流的变化事实、趋势和可能驱动机制。结果表明 :从 2 0世纪 5 0年代至今 ,研究区沼泽性河流的年降水量和年径流量都有减少的总趋势 ;年降水量和年径流量分别在 5 0年代和 6 0年代发生一次突变减少现象 ;近 5 0年来 ,随着宝清水文站和菜嘴子水文站之间的沼泽湿地不断减少 ,沼泽性河流流域的滞洪调节作用也发生明显变化 ,5 0年代后期至 70年代末 ,研究区出现年最大出流量小于入流量年份的频次是 5 0 % ,而 80年代至 90年代 ,其频次只有 35 % 。

This study investigated precipitation and runoff changes and their driving forces of marshy river in the Sanjiang Plain over the second half of the 20th century. The study region was located in 46°13′-46°20 ′N and 132°27′-133°20′E, between Baoqing Station in upper course of the Naoli River (that is a mountain-marsh river in the Sanjiang Plain) and Caizuizi Station in the lower course. The data used in the study included annual precipitation and runoff from 7 rain stations,3 hydrometric stations and 3 meteorological stations. The tendency method was used in the research to determine the trends of precipitation and runoff changes. Cumulative anomaly method and Mann-Kendall method were used to analyze the abrupt jumps of precipitation and runoff. The driving forces of precipitation and runoff changes were analyzed by using gray relevancy method. The results showed that annual precipitation and runoff of marshy river had a decrease tendency since the 1950s; annual precipitation and runoff were closely correlated. There were abrupt jumps occurred both in annual precipitation and runoff during the 1960s. There was no increase jump occurred from the 1950s to the1990s, that meant annual precipitation and runoff decreased sharply. With the decrease of wetland and the increase of agricultural fields, change in decades occurred in the relationship between annual precipitation of upper and lower courses of marshy river, which had changed from nonlinear to linear. The characteristic of annual precipitation in the wetland disappeared gradually. And function of flood retarding of marshy river didn't work well. Rate of years in which discharge out of study region was less than that into the region was 50% from the 1950s to the 1970s, however, only 35% from the 1980s to the 1990s, and it decreased by 15%. Research of the driving force illustrated that human activities, such as large-scale reclamation, were probably the most important and direct factor that resulted in abrupt change of annual precipitation and runoff and further affected regional water balance and the hydrological cycle.