Flood — Awareness — Creek

This dataset, created in June 2013, provides an indication of the likelihood of a flood occurring from creeks inside the Brisbane City Council local government area. This layer contributes to the overall Flood Awareness Map. Creek flooding occurs when intense rain falls over a creek catchment. Runoff from houses, streets, parks etc contributes to creek flooding. Once the capacity of the creek is reached, overtopping of the banks will occur which can cause flooding. Creek floodwaters can be very fast moving and rise and recede quickly without much warning. There are four different creek flooding likelihood areas in Flood Awareness Map, namely High, Medium, Low and very low. The creek High likelihood layer consists of a combination of the 5% Annual Exceedance Probability (AEP) (20 year Average Recurrence Interval (ARI)) from BCC’s flood inundation extents usually utilising the surfaces produced as part of a Flood Study where available and the remaining areas from the 5% AEP (20 year ARI) delivered as part of the Citywide Flood Awareness Mapping study (Worley Parsons, 2012). The creek Medium likelihood layer consists of a combination of the 1% AEP (100 year ARI) from BCC’s flood inundation extents (outside high likelihood area) usually utilising the surfaces produced as part of a Flood Study where available and the remaining areas from the 1% AEP (100 year ARI) delivered as part of the Citywide Flood Awareness Mapping study (Worley Parsons, 2012). The creek Low likelihood layer consists of a combination of the 0.2% AEP (500 year ARI) from BCC’s flood inundation extents (outside high likelihood area) usually utilising the surfaces produced as part of a Flood Study where available and the remaining areas from the 0.2% AEP (500 year ARI) delivered as part of the Citywide Flood Awareness Mapping study (Worley Parsons, 2012). The creek Very Low likelihood layer consists of a combination of the 0.05% AEP (2000 year ARI) from BCC’s flood inundation extents (outside high likelihood area) usually utilising the surfaces produced as part of a Flood Study where available and the remaining areas from the 0.05% AEP (2000 year ARI) delivered as part of the Citywide Flood Awareness Mapping study (Worley Parsons, 2012).本数据集创建于2013年6月，用于指示布里斯班市议会(Brisbane City Council, BCC)管辖区域内溪谷发生洪水的概率，是整体洪水感知地图(Flood Awareness Map)的组成图层之一。溪谷洪水多由溪流域遭遇强降雨引发，房屋、街道、公园等区域产生的径流会助推溪谷洪水风险。当溪谷的行洪容量达到上限时，堤岸将发生漫顶，进而引发洪水。溪谷洪水水流流速极快，水位涨落迅速且预警时间极短。该洪水感知地图中共包含四类溪谷洪水概率等级区域，分别为高、中、低、极低概率区。溪谷高概率图层结合了布里斯班市议会洪水淹没范围中5%年超越概率(Annual Exceedance Probability, AEP，对应20年平均重现期(Average Recurrence Interval, ARI))的成果，通常优先采用洪水研究(Flood Study)生成的地表数据，若有相关成果则直接使用；剩余区域则采用2012年沃利帕森斯(Worley Parsons)开展的全市洪水感知绘图研究中5% AEP（20年ARI）的相关数据。溪谷中概率图层结合了布里斯班市议会洪水淹没范围中（高概率区域外）1%年超越概率（对应100年平均重现期）的成果，优先采用洪水研究生成的地表数据，剩余区域采用上述全市洪水感知绘图研究中1% AEP（100年ARI）的相关数据。溪谷低概率图层结合了布里斯班市议会洪水淹没范围中（高概率区域外）0.2%年超越概率（对应500年平均重现期）的成果，优先采用洪水研究生成的地表数据，剩余区域采用上述全市洪水感知绘图研究中0.2% AEP（500年ARI）的相关数据。溪谷极低概率图层结合了布里斯班市议会洪水淹没范围中（高概率区域外）0.05%年超越概率（对应2000年平均重现期）的成果，优先采用洪水研究生成的地表数据，剩余区域采用上述全市洪水感知绘图研究中0.05% AEP（2000年ARI）的相关数据。