Discharge at a cross section of the river, (m3/s)

River discharge measured with continuous water level measurements converted by a stage-discharge relation based on manual discharge measurements. 15 min sample values in m3/s. The hydrometric station is located ~2.5 km upstream of where the Zackenberg river enters the fjord. After 2014, water level in the river is measured by sensors logging the vertical distance from the bridge down to the water surface, backed up by pressure sensors in the river. The time series starts in 1996. Before 2014, water level was measured by a distance sensor mounted on a gallows rack on the river bank, supported by pressure sensors in the water. The station was moved once because of bad snow conditions, and was also exposed to floods, in some years this resulted in downtimes for the station and subsequent gaps in the timeseries (see timeseries comments in the metadata text file for details). Nearly every year, a glacier lake outburst flood (GLOF) is released from the A.P. Olsen glacier which lies in the northwestern corner of the river catchment. Several of these GLOFs have modified the river bed to a large degree, and a new stage-discharge relation has had to be established afterwards. The discharge measured during the GLOF period is subject to larger uncertainties than other periods due to high water levels and changing bed conditions. Zackenberg river freezes in Autumn and has no flow through winter, except in rare years when the GLOF happens during the winter months. The spring flow runs on top of the winter ice until the channel has melted down to the river bed, and the river stage in this period needs to be corrected for the influence of the ice in order to calculate correct discharge. Ice affected periods at both the start and the end of the season are corrected for by ice correction factors based on manual discharge measurements. For years when manual discharge measurements could not be made, data for the ice-affected periods are excluded from the time series. Years where this has not been done are given in the metadata. Please read the metadata file provided with the data for comments related to the data in this timeseries.本数据集为河道径流量数据，通过基于人工流量实测建立的水位-流量关系（stage-discharge relation），将连续水位观测数据转换得到。采样间隔为15分钟，单位为立方米每秒（m³/s）。水文站位于扎克enberg河（Zackenberg River）注入峡湾处上游约2.5公里处。2014年之后，河道水位通过传感器测量桥面至水面的垂直距离获取，并以河道内的压力传感器作为备用监测手段。本次时间序列的观测始于1996年。2014年之前，河道水位由安装在河岸绞架式支架上的距离传感器测得，并辅以水中的压力传感器作为辅助验证手段。该水文站曾因积雪状况恶劣搬迁过一次，且多次受洪水影响，部分年份会导致站点停机，进而造成时间序列出现数据缺失（详细信息请参阅元数据文本文件中的时间序列注释）。该流域西北角的A.P.奥尔森冰川（A.P. Olsen Glacier）几乎每年都会引发冰川湖溃决洪水（Glacier Lake Outburst Flood，GLOF）。此类溃决洪水中有多次大幅改变了河床形态，因此后续需重新建立水位-流量关系。由于溃决洪水期间水位较高且河床形态持续变化，该时段测得的径流量相较于其他时段具有更大的不确定性。扎克enberg河（Zackenberg River）秋季会封冻，冬季通常无径流，仅在极少数冬季发生冰川湖溃决洪水的年份例外。春季径流会在冬季冰层之上流动，直至河道完全融化至河床；此阶段的河流水位需针对冰层影响进行校正，方可计算得到准确的径流量。封冻季始末的受冰层影响时段，均通过基于人工流量实测得到的冰层校正因子进行校正。若某年份无法开展人工流量实测，则该年份受冰层影响时段的数据将被排除出时间序列；未执行此项剔除操作的年份详见元数据文件。请阅读数据附带的元数据文件，以获取本时间序列相关的数据注释。