Inspire Strategic noise maps. Noise contour map for major railways — Lden

This is a polygon Dataset of the strategic noise mapping of rail, which were identified as those rail exceeding the flow threshold of 30,000 vehicle Passages per year, in the form of noise contours for the Lden (day, evening, night) period for Dublin and Cork agglomerations and the major roads outside of the agglomerations.
The dB value represents the average decibel value during the Lden time.

Any direct comparison of the Round 3 versus Round 2 results should be carefully considered, as changes to the model input datasets used between these rounds may be significant. This may especially apply to the terrain model used, while there may be improved building height data, & improved traffic flow data with fewer assumed flows. There may also be some revisions to the actual road network modelled in Round 3.

The noise maps are the product of assimilating a collection of digital datasets, and over the last 10 years there has been significant improvements to the quality of the digital datasets describing the natural and built environment in Ireland. This has led to the strategic noise models giving much more reliable noise results with much less Tendency to over predict the impact.

本数据集为都柏林与科克都市区及都市区外主要道路的铁路战略噪声测绘多边形数据集，筛选标准为年车辆通行量超过3万次阈值的铁路线路，采用Lden（昼间、傍晚、夜间）时段噪声等值线形式呈现。
此处的分贝（dB）值为Lden时段的平均声压级。
在对第3轮与第2轮的结果进行直接对比时需审慎考量，因为两轮间所使用的模型输入数据集可能存在显著差异。这一点尤其体现在所采用的地形模型上，同时第3轮可能使用了精度提升的建筑高度数据与交通流量数据，且假设通行量更低。此外，第3轮建模所采用的实际道路路网也存在部分修订。
本噪声地图为整合多组数字数据集的成果。近十年来，爱尔兰用于描述自然与建成环境的数字数据集质量得到显著提升，使得战略噪声模型能够生成更为可靠的噪声评估结果，且高估影响的倾向大幅降低。