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.

本数据集为基于人工流量测量所建立的水位-流量关系，由连续水位观测数据转换得到的河道流量序列，采样间隔为15分钟，单位为立方米每秒（m³/s）。该水文站位于扎克enberg河（Zackenberg River）入峡湾处上游约2.5公里处。2014年起，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份；1996年至2013年期间，水位则通过安装在河岸绞架式支架上的距离传感器测量，辅以河道内的压力传感器进行校准。该水文站曾因积雪条件恶劣迁移过一次，且多次遭受洪水侵袭，部分年份因此导致站点停运，时序数据出现缺失，详细信息请参见元数据文本文件中的时序注释。该流域西北部的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）。此类洪水曾多次大幅改造河道床面，后续需重新建立水位-流量关系。由于高水位与不断变化的河床条件，GLOF时段测得的流量相较于其他时段存在更大的不确定性。扎克enberg河秋季封冻，冬季无径流，仅极少数年份在冬季发生GLOF时例外。春季径流在冬季冰层之上流动，直至河道完全消融至河床；此阶段的水位需校正冰层影响，以计算准确流量。每年封冻期与解冻期的冰影响时段，均通过基于人工流量测量得到的冰校正因子进行修正。若某年份无法开展人工流量测量，则该年份的冰影响时段数据将被排除在时序数据集之外，未执行该处理的年份详见元数据文件。请查阅随数据附带的元数据文件，获取本时序数据的相关注释说明。