INTER-NOISE 2007 28-31 AUGUST 2007 ISTANBUL, TURKEY COMPARISON BETWEEN CALCULATED NOISE CONTOURS AND MEASURED LEVELS AROUND LYON AIRPORT: A REQUEST FROM NEIGHBOURS Michel VALLET (F) Aedifice Institute, 59 ave Lacassagne, 69003 Lyon Jacques ROLAND. CSTB Grenoble, Jean-Claude BRUYERE INRETS-Bron, Rémi FORET Ecole Ingénieurs Généralistes de Marseille (EGIM) FRANCE ABSTRACT The dialogue between airport authorities and neighbours is well established at Lyon Saint-Exupéry airport, through a mandatory Consultative Committee. Additionally, a chart signed by the stakeholders is working around this airport, and the programme is fixed to highlight some technical points. Noise contours around airport are obtained by software (INM), providing short term noise maps, called Plan de Gene Sonore. This map is used to define areas where aids can be granted to inhabitants in order to finance the improvement of the dwellings sound insulation. Delegates from the community have been requested to verify the accuracy of the calculations, compared to the actual noise measurements, continuously provided by the permanent noise monitoring system CONSTAS. A study has been performed to control the correspondence between the two sets of values (6 permanent points and 20 temporary noise measurements) by R.Foret. This study has been reviewed by an independent college of experts. (ODESA) It has been observed a good relationship between the calculated contours and the contours established according the actual noise data: in the noisier zones, the difference is between 0.5 and 1 db(a) in Lden, and around 1.5 dba out of the zones; the calculated levels are always the lower values. The origin of these differences has been pointed out. 1 INTRODUCTION: THE CONTEXT OF THE DIALOGUE AIRPORT AUTHORITIES/ NEIGHBOURS The dialogue between the neighbours, the elected people and all stakeholders involved in the airport of Lyon Saint-Exupéry is primarily defined at the national level, by the presence of a Commission Consultative de l Environnement (CCE) that is under the responsibility of the State: a CCE exits at every airport that has actual environmental problem. Some peculiarity is present airport by airport: at Lyon there is a noise monitoring system, called
CONSTAS, that comprises 6 fixed microphone stations (01dB) and 2 mobiles micros. CONSTAS has been created in 2000. The measurements data are quarterly reported by a 4 pages bulletin (Lden, Lmax, traffic at every point) 46 000 copies of the bulletin are distributed for each issue. Then data from CONSTAS are used by the airport s ombudsman to inform the complainers. At Lyon, a specific Chart, annually updated, is listing the actions commonly adopted and signed by stakeholders; in 2007 the list of noise studies, that are only a part of a long list, (number 22 and 23) includes: a study on the mapping of noises from multiple sources and a study of the coherence between the calculated noise contours and the actual noise levels as measured by CONSTAS. This last item is a request from the associations of neighbours. Studies are performed under the responsibility of the airport s authority, but this is an independent association that is in charge of the validation of the studies; this original body, called ODESA, is a college of scientists professionally involved in noise studies and research (www.odesa.fr) This paper is dealing with the review of a study carried out under the Lyon airport management (Direction du Développement Durable) 2 STUDY OF THE COHERENCE BETWEEN COMPUTERISED NOISE CONTOURS AND ACTUAL NOISE MEASUREMENTS 2.1 Noise contours in France For several decades noise maps around airports are defined in official documents: this is the Plan d Exposition au Bruit (PEB) to manage the long term land use planning in the vicinity of the airport, and a second noise map, called Plan de Gene Sonore (PGS), to precise the zones where houses and flats can be beneficial of budget to improve the insulation against noise: this is an important document, and it is why people would like to check its reliability. At Lyon airport, a study has been carried out as the item 23 of the local Chart. Contours are drawn according the noise index Lden, an INM model is used to draw the maps, under responsibility of the regional office of the Direction Générale de l Aviation Civile: the PGS is mapped according the estimated traffic of year following the publication of the document, and updated when necessary. The last publication of St EXUPERY PEB has been released in 2004 2.2 The main study The main study consists in a comparison between the noise contours of the PGS based on the hypothesis of an expected traffic for the year 2004, and the noise levels measured by the system CONSTAS, both at permanent points and temporary ones. This study was performed by R.Foret and JC Bruyere. The hypotheses for PGS are: traffic:133000 movements: o passengers: 120 000, o freight: 8 000,
o Non commercial: 5 000. 20 classes of aircraft, percentages according the period: o 65% day from 6 to 18 hour, o 28 % evening 18 22h, o 7% at night 22-6h. Use of the runways: o Piste A (4000m) mainly for TO, o Piste B (2700 m) mainly for landing: face to North (QFU 36): 60%, Face to South (QFU 18): 40% Definition of the Zones: Zone I Lden > 70dBA, Zone II 70 < Lden> 65 dba, Zone III: 65< Lden> 55 dba. The noise map PGS is presented below and the measurement points are illustrated on the map: data from permanent measurement stations are in red. In blue, the locations on or near the external limit of the PGS of the measurements carried out in 2004 and 2005. Then 3 points are clearly far from the PGS limit, in order to check a situation where the noise level is rather low. Although the differences in the input data are somewhat different (different traffic, type of aircrafts, tracks, and period of record), a raw comparison is presented. For the 6 permanent points, the measured annual levels are over the calculated ones, in 3 points and below in 2 points; one difference is too high to be considered without explanation (certification point). The mean difference is 0.46 db(a), in Lden, say 0.5 db. For the 7 points within the PGS map and at boundary of the map, the mean difference is 1.5 db(a) Lden, the measured values being higher than the calculation. The 10 points out of the PGS map, the mean difference is of 1.3 db(a), ( measures higher).
Noise map around Lyon Saint Exupéry Airport : PGS 2004 Niévroz Jonage Villette d Anthon L abbaye Balan Jons Villette d Anthon Mons Villette d Anthon Asnières PGS 2004 Aéroport Lyon-Saint Exupéry Mars 2004 Zones I > 70 Lden, II ( 70-65, and III (65-55) Pusignan Janneyrias Colombier Saugnieu Point de Certification Satolas et Bonce St Laurent de Mure Grenay Chamagnieu Heyrieux Saint Quentin Fallavier CONSTAS permanent point Non permanent points Micro Diemoz
Campagne de mesure Mesures permanentes Places Lden measured Difference in db(a) Date measures Position / PGS Villette d'anthon - 6/9-6/10 Out L'abbaye 52,5 54,4 1,9 2004 PGS Balan 2004 53 53,3 0,3 15/7-30/7 Out Balan 2005 53 54,1 1,1 13/7-3/8 Out 11-17/ 03 limit St Quentin 2004 55 56,1 1,1 02-08/4 St Quentin (2005) 55 57 2 20/-02/8 limit Niévroz 2004 51 51,4 0,4 15/1-6/02 Out Niévroz 2005 51 52,9 1,9 24/2-17/3 Out Diémoz 50 50,6 0,6 6-28/10 Out Villette - Mons 46,5 48,8 2,3 16/11-7/12 Out Jonage 2004 45 48,3 3,3 04-25/03 Out Jonage 2005 45 46,7 1,7 17/03-05/04 Out Villette - Asnières 45,5 44,5-1 28/10-16/11 Out Heyrieux <45 42 OK 3-22/06 Far Saint Laurent de Mure <45 40,8 OK 24/6-15/07 Far 8- Far Chamagnieu <45 38,6 OK 22/12/2005 9-24/02/2005 Jons 58 56,4-1,6 5/17-08 limit Colombier (all) 54,5 56,6 2,1 06-17/08 limit Colombier (without ««limit reverse) 54,5 55,4 0,9 Satolas et Bonce 52,5 54,2 1,7 19/31-08 limit Grenay 56 59,3 3,3 26/08-07/09 Limit Pusignan 52,5 53 0,5 2005 Jons 56 57,1 1,1 Janneyrias 53 52,3-0,7 Point de certification 69 63,6-5,4 Grenay 48,5 49,4 0,9 St Quentin 51,5 52 0,5 Table 1 Comparison between calculation and measured values without corrections 3. CONTROL OF THE RESULTS BY ODESA Several factors should be considered to explain these differences: Total traffic (traffic for calculation: 133 000 in 2004; actual traffic 2004: 122 673) Take off and landing bearing (QFU)(North course: forecast 60%, actual 66%) the composition of the fleet,, flight paths The raw measured data have been corrected accordingly and presented on the figure below: PGS is the calculated value according to PGS rules
Mesure is the raw measured value Correction Atter/Dec is measured value corrected according to actual QFU ratio Correction traffic reel is measured value corrected according to actual traffic (even for the fixed points, the measurement period over one year do not cover the reference period for the PGS) Correction traffic PGS is measured value corrected according to PGS traffic The most sensible factor is the QFU ratio. The average difference is improved by 0;9 db(a) when this correction is applied Differences between the results from the corrections of the traffic for PGS and actual traffic is 0.4 db(a), that is relatively moderate 60 db(a) 58 56 PGS Mesuré 54 Correction Atter / Déc. 52 Correction Trafic PGS 50 Correction Trafic réel 48 Jons Colombier Saugnieu Satolas et Bonce Grenay St Quentin fallavier The composition of the traffic has been checked and some difference in this composition could explain a part of the observed results.
Type PGS Traffic 2004 Type PGS Traffic 2004 B727 1,60% 0,60% BE1900 7,10% 1,77% B737-300+ 14,80% 14,52% E120 2,20% 2,42% B757 2,20% 1,51% ATR42-72/ATP/SB2000 17,50% 7,57% A300 1,10% 0,31% CRJ 3,80% 24,23% A319+ 9,30% 12,16% E135-145 21,90% 15,52% BAE146 4,40% 3,06% SF330-340 1,10% 0,00% F70-F100 8,20% 11,29% Others 4,90% 5,06% Some aircraft, like Be 1900 and Embraer 135 have a smaller percentage in the traffic, and as they are less noisy, the final calculated noise levels are less than the actual ones According an ODESA expert, the more important factor seems to be the actual flight paths at landing, that are not precisely taken into account in the noise levels calculation. 4 CONCLUSION On the whole, this type of technical checking is appreciated by the neighbours, because the dialogue between stakeholders needs to get solid basis. Naturally the major trend that show a smaller noise level from calculation is pointed by the associations, but this lead to some flexibility when a special commission has to fix which houses can be insulated, with a financial help from noise taxes collected by the airport. This technical aspect in the dialogue between stakeholders are numerous, and an important one consists in checking the correspondence between individual noise events at airport, like in Japan, (Katsuta & al) where a comparison of actual flyover noise and noise certification data are systematically carried out. This item is mainly use for examination of the noise level charge systems at airports 5 REFERENCES Katsuta K, Oshio K, Ogata S, Shinohara N: New landing charge at Narita International Airport, paper n 240, Proceedings of Internoise Congress 2006, D.Holger editor