基于树轮水文研究的提孜那甫河径流量长期变化

Long-term Variation of Streamflow in Tizinafu River Based on Tree-ring Hydrology

西昆仑山北坡山区分布的雪岭云杉是开展树轮水文研究的良好载体,为重建历史水文变化提供了重要的代用资料。分析了西昆仑山北坡雪岭云杉树轮宽度年表对提孜那甫河径流量的响应特征,发现树轮宽度年表与提孜那甫河年径流量(上年8月至当年7月)的显著正相关关系,建立了二者之间的一元线性回归方程,重建了提孜那甫河1665~2013年径流量序列。重建径流量序列中存在7个枯水期和8个丰水期。重建径流量序列平均值为27.87 m3/s,与实测期平均值接近,但重建序列中的极端旱涝的强度和发生频率均更高。基于树木年轮宽度重建更长时间的径流量序列,对于流域水资源科学管理和分配以及下游水库和防洪工程等项目建设的风险评估等具有重要意义。

Tree-ring of picea schrenkiana provides optimum proxies for dendrohydrological research on the northern slope of the western Kunlun Mountains. The response analysis of tree-ring width standard chronology to the streamflow in the Tizinafu River reveals the significantly positive correlation between the ring width index and annual streamflow from August of last year to July of the current year during 1957-2013. The linear transfer function was established to reconstruct the annual streamflow in the Tizinafu River during 1665-2013. Low frequency characteristics of the reconstructed streamflow series show seven drought periods and eight flood periods. The mean value of the reconstructed streamflow is close to the observed, however, the intensity and frequency of extreme hydrological events of the reconstructed streamflow are higher than the observed.The reconstructed long-term streamflow record provides more reliable reference for the scientific planning and allocation, and the risk evaluation of the downstream reservoirs and other flood-preventing construction projects.