Page 74 - Studia Universitatis Hereditati, vol 12(2) (2024)

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based on the region’s digital elevation model ples. As we will discuss below, the differences
(DEM). Second, we generated the cumulative between these simulations are minimal for San-
viewshed of all the parishes in the Àneu dean- ta Maria d’Àneu but provide some thought-pro-
ery to determine whether Santa Maria was sit- voking insights.
uated in a more or less visible area compared to Finally, all procedures accounted for the
the surrounding churches. Finally, we construct- earth’s curvature and atmospheric refraction, set
ed a network of intervisibility between these re- at 0.13000. However, all simulations assumed
ligious centers, establishing which churches were optimal visibility conditions without consider-
visible to each other and which were not. ing adverse weather effects, such as fog, which
could significantly impact visibility.
To build these models, we used the same
coordinates file and 10x10 meters DEM for the Results of the Simulation of Sound
74 sound propagation simulations. However, vis- Propagation
ibility analysis requires converting the original The sound propagation is simulated for six
points into ‘viewpoints,’ which necessitates es- weather scenarios: without wind (A.1., B.1., C.1.)
studia universitatis hereditati, letnik 12 (2024), številka 2 / volume 12 (2024), number 2
tablishing the height above ground for both the and with wind (A.2., B.2., C.2.). Fig. 6 displays
observers and the target objects. For the individ- the sound propagation maps for these scenarios,
ual viewshed of Santa Maria d’Àneu, we assumed using different colors to indicate seven ranges of
the observation would be from ground level, as sound levels (5-15 dB, 15-30 dB, 30-45 dB, and so
the church has only a small modern bell gable. on).
Therefore, we set the observer height to the av- Scenario A.1. represents the most common
erage height of a person: 1.60 meters. The same mild weather conditions without wind. In this
value was applied for the cumulative viewshed of case, the total area coverage is the largest, about
2
the Àneu valley and the intervisibility network 16.5 km (tab. 5). However, bell ringing reaches
between its parishes, as our interest lies in views half of this area with less than 15 dB. Whether
of daily life, not those from the tops of steeples. this low sound level could have been heard de-
pended on several factors, primarily if the back-
Determining the height of the target ob- ground noise (such as river or traffic) was suf-
jects—the medieval parish churches—was more ficiently quiet. Our acoustic measurements of
challenging. These churches undoubtedly stood background noise at the site Santa Maria d’Àneu
above ground level, but most have been exten- range from an L of 30 to 45 dB. However,
Aeq, 2min
sively rebuilt in modern times, making it dif- given that no motor vehicles existed in the medi-
ficult to determine their original height in the eval period, the background noise was undoubt-
Middle Ages. To address this uncertainty, we edly lower than today.
set the target height at 7.50 m for the two views- Observing the maps in the left column of
hed analyses, a reasonable estimate for medieval fig. 6, we notice a more extensive coverage area
churches (for example, Santa Maria d’Àneu rises than the maps on the right. This is because the
to 11 m). For the intervisibility network, in order maps on the left show scenarios without wind,
to avoid misleading results, we conducted three allowing the sound of the bell to propagate fur-
different simulations: one assuming all build- ther into the landscape. According to the simu-
ings were approximately 7.50 m tall, another lations, the sound of the bell reaches the church-
considering the maximum current height of the es Sant Vicenç d’Esterri d’Àneu and Sant Martí
buildings (including their modern bell towers), d’Escalarre (numbers 12 and 14 on the map, re-
and a third assuming both the observer and tar- 4 The height of the different buildings has been obtained
thanks to an inventory of all the bells and steeples in the
get points were at the top of the respective stee- Àneu valley (Dalmau Argemir and Orriols Sendra 2001).