Hortobágy National Park
- An Island of Undisturbed Nighttime Environment
Istv&a=
acute;n Gyarmathy1,2,*, Zoltán Koll&aacut=
e;th2
[1]<=
/a> 1Horto=
bágy
National Park, Debrecen, H-4024, Hungary
2Eötvös Loránd Univers= ity, Savaria Department of Physics, Szombathely, H-9700, Hungary
Received 12 December 2016, Accepted 17 May 2017
Abstract
National parks and protected areas hav=
e an
important role in protecting starry sky and the undisturbed
nighttime environment. Hortobág=
y which is
one of the darkest areas in Hungary, became an International Dark Sky Parks
recently. Its significance is mostly related to the protection of the high
biodiversity which is endangered by the effects of light pollution. A speci=
al
monitoring program has been started to survey the nocturnal species and als=
o to
monitor the quality of the night sky using digital cameras. Stargazing =
night
walks are frequently organized. There is a high interest by the general pub=
lic
to attend these night adventures.
Keywords: light pollution and national parks, da=
rk-sky
parks, light pollution monitoring, astro-tourism
1.
Introduction of
Hortobágy National Park
The Hortob&aacut=
e;gy
National Park is situated on the former floodplain of the Tisza river (the
park¡¯s area is 82000 hectares, the nearest city is Debrecen, 35 kms East f=
rom
the park¡¯s border, see Figzre 7. too).The park is the first proclaimed and
biggest Hungarian national park, also a World Heritage site, Ramsar site,
Natura 2000 site and UNESCO Biosphere reserve.
Hortobágy=
is an
almost flat plain landscape, great and continuous grassland area with wetla=
nd
mosaics, the most extended in its category in Europe. It is occupied by
alkaline marshes, meadows, dry alkaline pastures and remnant loess-steppe
vegetation [1].
Hortobágy=
is most
famous for its rich avi-fauna. The number of nesting species is 159 and the=
re
are additional 178 species which are regular or irregular visitors.
Hortobágy=
is
generally the best birding place in Hungary (possibly in the whole Karpathi=
an
Basin) and the most important IBA (Important Bird Area) too. Migration is
particularly significant (Fig. 3.).
The masses of
migration are remarkable too: for instance 100,000-300,000 of grey geese (A=
nser
sp.), appr. 100,000 cranes (Grus grus), or 50,000-200,000 Ruffs stop at
Hortobágy (the last one basically while shallow-water covered condit=
ions occur
in grasslands). 10-20 years ago hundreds of thousands of different duck sto=
pped
here too, but their mass has been less significant recently.
![](3D"01_Gyarmathy_files/image002.jpg")
Fig.
1. The first slogan of the park expresses the main feature of the landscape:
the endless flat grassland area is like the sea: Hortobágy, where th=
e Earth and
Sky meet (photo: Gábor Kovács)
![](3D"01_Gyarmathy_files/image004.jpg")
Fig.
2. Hortobágy from above. You can see the Hortobágy river and =
the typical steppe
with wetland mosaics (photo: Szilvia Gőri)
![](3D"01_Gyarmathy_files/image006.jpg")
Fig.
3. The obtrusive light-free environment is essential for the wildlife as e.=
g.
insects at night and the protection of migratory birds [2] (photo: Attila
Szilágyi)
![](3D"01_Gyarmathy_files/image008.jpg")
![](3D"01_Gyarmathy_files/image010.jpg")
Fig.
4. The „Nine-hole bridge¡± is one of the symbols of the WH site, with=
the Milky
Way can be the symbol of the Dark-sky park (left) and a traditional shepherd
building with the Milky way (right) photo: Tamás Ladányi.
Hortobágy=
got its
World Heritage (WH) Diploma in the cultural category – as it is relat=
ed to
traditional land use and ancient shepherd culture, however Hortobágy=
¡¯s
biodiversity –as it was mentioned above - is also very high and the p=
ark¡¯s
significance is very important in preserving nature (Figure 4).
Hortobágy=
is one of
the last guardians of living shepherd tradition. Shepherd culture has deep
interrelation and interdependence with the natural environment. Pastures of
Hortobágy are scattered with traditional buildings of ancient pastor=
al
activity. There are many evidences in ethnographical works of the starry-sky
knowledge of the shepherds (Figure 4, right panel).
„... Regar= ding the Great Plains in today's Hungary, the knowledge of stars of Hortobágy= people, folk traditions associated with the stars is richer, more colorful than anywhere else in Hungary ...¡± (Győző Zsigmond ethnographer) [3]<= o:p>
„The sheph=
erds knew the hours from the procession=
of
stars. The Big Dipper, the Pleiades, the Kaszáscsillag (Sirius) and =
the Milky
Way all turn and indicate where we are in the night.¡±
(local ethnograp=
hic
collection)
Sándor Sz=
űcs famous
ethnographer writes in the Puszta Chronicle that „they only informed =
about the
world in „pastoral style¡± observing the stars and the ground and gra=
sses.¡± [4]
As we can see fr=
om
the citations above, shepherds had very good knowledge of the stars, the
phenomena related to the sky. Their mythology and also their daily life has=
got
many connections with the starry sky. So the protection of dark sky is
important in preserving folk traditions too.
Shepherd culture=
was
an important part of the World Heritage nomination. Now Hortobágy ac=
cording to
our opinion should be part of UNESCO Astronomy and World Heritage program t=
oo,
as an archeo-astronomy or ethno-astronomy site (see Figure 5).
![](3D"01_Gyarmathy_files/image012.jpg")
Fig.
5. Star-gazing horse-herds - old postcard from the early 1900s (image: Photo
archive of HNP)
2. Hortobá=
;gy as a
dark sky park
Hortobágy=
is one of
the biggest unpopulated and darkest areas in Hungary. Hortobágy got =
its
international dark sky park (or Starry Sky Park - SSP) diploma from the
International Dark Sky Association in 2011 according to the nomination
submitted in 2010 (Fig.6.).
The starry sky
park¡¯s significance is mostly related to undisturbed nighttime landscape, =
the
shepherd tradition related to starry sky and the protection of the high
biodiversity, especially the great number of migrating bird species and spe=
cial
nocturnal insect species. It is notable that many of the important breeding=
and
nesting bird species (geese, cranes, spoonbills, etc.) and other species,
especially many rare insect species are light pollution sensitive.
To be a starry s=
ky
park is an important tool to protect the nocturnal wildlife habitats as wel=
l as
the landscape values of Hortobágy [5] as an outstanding and an unalt=
ered
wilderness area in the Great Hungarian Plain, in the middle of Europe. Now =
the
dark-sky values also provide new attraction to the area: the park became al=
so
an astro-tourism destination.
![](3D"01_Gyarmathy_files/image014.png")
Fig.
6. Hortobágy National Park on the Google Earth nighttime satellite m=
ap and on
the new World Atlas of artificial sky brightness [6] Both maps show: the ar=
ea
is as intact and undisturbed nighttime as daytime. The lack of light-pollut=
ion
can be one of the measures of naturalness!
Astro-tourist is
traveling for the purpose of astronomy or only enjoys the beauty of the
pristine starry sky. Starry sky parks can be main places for developing
astro-tourism and amateur astronomy.
These darkest
corners of the planet where the environment is not disturbed at night by
artificial light, have not only ecological functions, but also educational =
and
touristic values.
Hortobágy=
Starry Sky
Park organizes nighttime walks, special interpretive programs related to the
dark-sky values and good lighting practices. There is a high interest by the
general public to attend these night adventures. The Park has different
programs designed to show the values of the park (Fig.7.), and is planning a
new visitor center with exhibition dedicated to the dark sky park).
Astronomy became
part of the park¡¯s Field Study Center¡¯s curriculum. The park has recently
established a public astronomical observatory as part of the development of=
the
Center (Fig.8). It is equipped also by all-sky camera and permanent SQM too=
.
![](3D"01_Gyarmathy_files/image016.jpg")
Fig.
7. Group of astro-tourists in the park (photo: István Gyarmathy)
3. Lighting
regulations
According to the
Park¡¯s regulations the following conditions should be satisfied by any out=
door
lighting in Hortobágy [7]:
- Only fully shielded fixtures can be used, and they should be insta=
lled
and serviced so that no light should be emitted above the horizontal plane.=
- Color temperature cannot exceed 3000 K.
- The maximum allowable light output (luminous flux) per fixture is =
1800
lumens.
If the total
luminous flux of a premise or realty exceeds 10000 lumens, a detailed light=
ing
permit plan should be prepared.
- Any construction should be started only after approval by Hortobagy
National Park Directorate as the competent nature conservation management
organization, and by IDA Hungary.
- The illumination levels cannot exceed the minimum norms available =
for
the given purpose.
- Outdoor lights can only be used when pedestrian or considerable
vehicular traffic is expected. Motion sensors or time switches are preferre=
d in
locations with infrequent traffic.
- Use the most energy efficient lamps are preferred.
The Park included
the articles of the Lighting Plan of the Starry Sky Park to its Management =
Plan
to protect the natural and scenic values of the undisturbed nighttime
environment. The lighting regulation and zoning policy provide a possibilit=
y to
control artificial lights within the park.
The park has
cooperation agreements with local and national conservation and astronomy N=
GOs
to protect the area¡¯s dark sky values as well as with the local stakeholde=
rs.
4. Sky Quality at
the Hortobágy National Park
At Hortobá=
;gy we have
used the same methods as in the case of the Zselic Landscape Protection Are=
a.
[8]
In general, it c=
an
be concluded, that inside and in the close neighborhood of the Hortobagy
National Park there are no light sources which contribute to the luminance =
of
the night sky. Then a few measurements at the perimeter can be sufficient to
describe the quality of the night sky. However, a more thorough project has
been started, since the markings of Hortobágy SSP (almost perfectly =
plain
territory, good view along the horizon) provide good opportunity to scienti=
fic
studies based on the observed data.
Our SQM measurem=
ents
show that the quality of the night sky is everywhere in the National Park is
better than 21.0 mag/arcsec2 (we use here
mag/arcsec2 as standard unit). The typical values are around 21.3-21.4=
,
in ideal weather conditions, it can reach 21.5 – 21.,6 (Figure 8). Al=
l of our
measurements were taken with the device pointing to the zenith. The necessa=
ry
conditions to perform a field survey were the followings:
• Moonless=
night.
• No cloud=
s or fog.
• The Sun =
is at
least 18 degrees below the horizon (astronomical twilight).
• No direc=
t light
from artificial sources reaches the detector of the device.
![](3D"01_Gyarmathy_files/image018.jpg")
Fig.
8. SQM measurements map of Hortobágy based on our survey (image: Goo=
gle Earth
Nighttime Satellite Map with our measurement results)
We prove the qua=
lity
of Hortobágy¡¯s sky quality using permanent SQM, the data can be rea=
ched on the
internet (Figure 9) [9].
![](3D"01_Gyarmathy_files/image020.jpg")
Fig.
9. Permanent SQM data on SQM Network (image: SQM Network)
Local settlements
have only a minimal effect on the quality of the sky. The luminance is only
slightly increased in the vicinity of small villages. The lights from the
cities of Hajdúszoboszló (population 23000, 11 kms South-East=
from the park¡¯s
border), Balmazújváros (population 18000, at the park¡¯s NE b=
order), Karcag
(population 20000, 8 kms from the park¡¯s SW border), Nádudvar (popu=
lation 9200,
at the park¡¯s Southern border), Tiszafüred (population 11200, 7 kms f=
rom the
Western border), Nagyhegyes (population 2700, at the park¡¯s Eastern border=
) and
Polgár (population 8400, 6 kms NW
from the park¡¯s border) are the main sources of light pollution. However t=
hese
cities do not have any significant effect on the SQM values, i.e. the quali=
ty
of the night around the zenith inside the park (see also Figure 12).
Based on fisheye=
all
sky DSLR images the luminance distribution on the night sky is determined. =
(Our standard
settings for light pollution monitoring in dark locations are the following=
s:
• Canon EO=
S 50D
camera (some parallel tests with EOS 350D, 450D and 300D)
• Sigma 4.=
5mm f2.8
EX DC circular fisheye lens
• ISO 800 =
setting
• T=3D180 =
s exposure
time
• f=3D 2.8=
-3.5
aperture
The processing of
DSLR images is described in Kolláth & Dömyén, this v=
olume.)
These images show
that the effect of nearby settlements is significant only close to the hori=
zon.
The deterioration of the nocturnal sky for zenith distances less than 80
degrees is acceptable. This fact is proved by the total light flux of the s=
ky
more than 20 degrees above the horizon.
![](3D"01_Gyarmathy_files/image022.jpg")
Fig.
10. Hortobágy¡¯s light pollution map: our processed DSLR fish-eye le=
ns photos on
Google-Earth nighttime satellite map
The luminance
calibrated images are displayed on a false color scale to display the lumin=
ance
distribution on the sky. The major obtrusive sources can be clearly identif=
ied
when such images (after a mirroring) are displayed on a map of the region
(Figure 10). It is also possible to get the spatial dependence of sky quali=
ty
inside the park.
![](3D"01_Gyarmathy_files/image024.png")
Fig.
11. Light pollution at the No=
rthern„Cserepes¡±
site (No 4 on Fig. 10.) The biggest light dome is of Polgár
The full sky
luminance maps give the opportunity to determine the sky brightness as a
function of zenith distance. =
For
the derivation of this function, we selected concentric rings at different
zenith angles of a width of 2 degrees. For each rings the maximum, the mini=
mum
and the mean value of the radiance is calculated. On the right panel of Fig=
ure
12, we present all these three curves. This method provides a compact summa=
ry on
the luminance distribution in the sky. The local maximum in brightness in t=
he
maximum curve is due to the presence of the Milky Way.
Such profiles of=
sky
quality at different azimuths provide quantitative data on the light pollut=
ion
from different sources. According to our experience, at zenith distances mo=
re
than 70-75 degrees the measurements strongly depend on the neighborhood, as
plants and buildings obscure the view. A useful quantity is the average
luminance in a narrow range of zenith distance (e.g. 0-30 or 30-60 degrees)=
. At
low light pollution locations the nearby sources have only limited effect on
the sky at less than 40 degrees below the zenith. As seem from Figure 12, t=
he
mean value drops below 21 mag/arsce2 only below 50 degrees zenith angle at =
the
specific location.
|
|
|
![](3D"01_Gyarmathy_files/image026.jpg")
=
![](3D"01_Gyarmathy_files/image028.jpg")
=
Fig.
12. Full sky luminance map at Cserepes location
That is clear, t=
hat
all anthropogenic light sources within hundreds of kms should be taken into
consideration to fit perfectly the nigh sky luminance. Light domes of citie=
s at
larger distances cannot be identified on the images, but they can contribut=
e to
the general increase of sky luminance.
The best solution
would be a nationwide law against light pollution, which has been already
initiated.
All the measurem=
ents
prove that the quality of the sky at the Hortobagy National Park is better =
than
the minimal limits for ¡°silver tier¡± (according to International Dark Sky
Association¡¯s terminology and requirements), and this state can be conserv=
ed
for further generations.
5. Conclusion
The conservation=
ist
community has growing interest in light pollution and its ecological effects
worldwide.
The Hungarian
protected area network (national parks, wildlife reserves) almost overlaps =
with
the dark sky areas. This fact supports their mission in protecting dark ski=
es.
They also provide
possibility for light pollution monitoring with both physical and biological
methods. Hortobágy Starry Sky Park leads light pollution monitoring =
using DSLR
camera with fisheye-lens across its area and a permanent SQM has been
installed. A biomonitoring program on the effects on nocturnal species,
especially insects is under construction. The sky brightness measurements p=
rove
the good quality of the undisturbed night sky. These results strengthen the=
commitment
of the park administration to continue the program.
Hortobágy=
SSP is
also a good destination for astro-tourism which is a new and developing typ=
e of
eco-tourism.
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/a>
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