Index of Estuarine Condition Estuarine Flow Barriers

IEC2021_BARRIERS indicates locations of estuarine barriers (partial and complete) that were used in the 2021 Index of Estuarine Condition. A combination of existing data sources and field data collection was used to identify the existence of artificial barriers and whether these structures represented partial or complete barriers (Pope et al. 2015). Partial barriers were those that were considered to allow limited or intermittent movement of biota. Complete barriers were those that represented an absolute and permanent barrier to biota. Where artificial barriers were identified, the most likely location of the natural (pre-1750) inland extent (length) of the estuary was derived from historical documents, field observations, elevation data and geomorphology to provide a `natural estuary length¿.

IEC2021_BARRIERS数据集收录了用于2021年河口状况指数（Index of Estuarine Condition）的河口拦挡设施（含部分拦挡与完全拦挡两类）的空间分布位置。本数据集通过整合现有数据源与野外实地采集数据，识别人工拦挡设施的存在性及其所属的拦挡类型（Pope等，2015）。其中，部分拦挡设施指允许生物群落开展有限或间歇性移动的设施；完全拦挡设施则为对生物群落造成绝对且永久性拦阻的设施。当识别到人工拦挡设施时，本数据集将结合历史文献、野外观测、高程数据与地貌学特征，推导该河口在1750年以前的自然内陆延伸范围（长度）的最可能位置，以获取自然河口长度（natural estuary length）。