Proceedings of the International Conference on Environmental Changes in Karst Areas -I.G.U.- U.I.S.-ltaly 15- 27 Sept. 1991 ; Quaderni del Dipartimento di Geografia n. 13. 1991 -Università di Padova. pp. 279-287
THE IMPACT OF BOMBS OF WORLD WAR I ON LIMESTONE SLOPES OF MONTE GRAPPA
Monica CELI Via G. Giardino, 89 Romano d'Ezzelino 36060 VICENZA, ITALIA
ABSTRACT
W: Karst pollution, war impact, bombs, artificial dolinas Geogr.K.W: Italy, Venetian Prealps, Monte Grappa
This paper will evalue the impact of the war events in the karstic territory of Monte Grappa. The consequence of the World War I on this karstic territory, that notice here are main1y two: a modification of the natural morphology of the karstic territory and the possible pollution given from the war residuals. The 50% of the closed depressions of various size, that are the results of the bombs and mortars explosion, are now evolving to dolinas. The war residuals are a source of heavy metals, that the meteoric water can carry in the karstic system and polluting the natural underground water.
INTRODUCTION
The war event has represented a very strong impact on the karstic territory. Particularly during the two World Wars the large use of anns as bombs and mortars has left manifest traces in the straked territories. The Massif of Monte Grappa, sited in the Venetian Prealps, reports clear witness of the hard battles, that have saw him as leading character of the World Wars. The leitmotive of the morphology of Massif, particularly near the summit of Monte Grappa, are the innumerable closed depressions of various size, that afe the results of the bombs and mortars explosions. Trenches and galleries afe also presento
GEOMORPHOLOGY OF MASSIF OF GRAPPA MOUNT
The Massif of Grappa Mount falls within the generaI stratigraphy of the Veneto Prealps. In short we can notice main rock units: 1. dolomite (Trias); 2. grey limestones and Ammonitic limestones (Jurassic);3. white and red marly limestones (Cretaceous); 4 marls, sandstones, conglomerates (Eocene, Oligocene, Miocene). The covers of Quatemary age afe represented tram alluvial and slope debris and tills. As the others Prealpine groups (Monti Lessini, Asiago Plateau, Cansiglio) also the Grappa Massif presents typical karstic characteristics, which afe stressed by the natural morphology of the territory and by the presence of springs. In the upper part we can recognize dolinas,
279
G.K. shafts and Karren. Generally don't exist horizontal caves. We can find often caves With vertical spits (Carraro et al., 1990).
SAMPLING
During the spring 1991 we have surveyed 100 basins sited in the side of Coston Maunt in the Grappa Massif, which were originated by the explosion of bombs and mortars during the First World War. The 100 basins selected among the 300 and more of this zone, with a casual sampling, divided in three groups on the grounds of theirlocation: on valley bottom, on slope, on the summit of Monte Costano
PREVIOUS WORK
The impulse far this research was supplied from a previous work (Paoletti et Al., in press), that was realized far to value the impact of the chemical pollution in the karstic systems of Asiago Pl.ateau and Massif of Grappa Mount. The influence of the external usage of karstic territory outside the cave environment and its possible consequences on the geochemistry of substrata and invertebrate troglobitic organisrns afe analyzed in this previous work. We tested far the presences of some heavy metals (Cd, Cf, Cu, Pb, Zn) in mud, water, bat guano and troglobitic invertebrates. For such objective was considered, together others caves, a horizontal cave, Buso della Torta, sited in the side of Massif of Grappa Mount, that turns in the Brenta valley. In this cave was carryed out the chernical analyse of bat guano, abandoned in large deposits from a colony, nowadays extinguished. The results of the analyses haven showed high leve1.s of same metals: Cu, Zn, Cd (Table 1). The comparison with the results obtained from the analyses of bat guano in others cave, sited in different zone of Venetian region (Grotta della Guerra in Berici Mounts, Grotta Grande di Ponte di Veia in Lessini Mounts) have showed that these levels afe anomalous. The heap of contarninants seems a1.soto co.ntinue nowadays. One among the possible causes of this pollution is maybe the enorrnous quantity of war residuals, abandoned in the cave during the retreat and the chips of bombs and mortars, which covered the territory of karstic alimentation. The water in 70 years about, can have dissolved and carryed the metals in this cave. Here a organic substratum, as bat guano, has accumulated the metals and allowed to give prominence to this processo It is a1.soresulted very important to quantify the effects of the war event on the the karstic system and the possible input on the karstic spring.
OBJECTIVES
First stage of this research is the recording of the princjpal measures for identification of the bombs basins: 1. a) the maximum diameter; b) the relative maximum depth; c) the difference in level between its extremities; 2. a) the maximum depth (between highest and lowest point); b) the relative diameter;
280
I distoD.m. I D.p.m. I disl.p.m.I pr.max. pr.min. pr.D. evol,dol.1 312 104 32512 104 111 7 111 m -.2!.- 98 114 16 114 ~ m 40 257 100 109 9 69 ~ 281 81 225 104 109 5 281 ~ 290 O 220 90 94 4 38 no 400 40- 400 112 124 12 82 no 540 ffi 510 189 203 14 188 no~~ 920 240 920 240 350 110 2350 -soo- 204 500 204 225 21 225 340 O 326 127 136 9 60 no m ffi 715 I 235 340 105 340 ~ ill 221 _585 I 221 265 44 265 ~~ 482illlli 181 430 191 201 lO 201 124 323 168 168 O 124 no O 3'ii5" 19 60 41 48 ~ 446 12 295 18 62 44 56 no 280 42 253 55 73 18 53 no 420 40 405 90 90 O 77 no 458 T5 443 73 94 21 67 no 442 60 392 42 114 72 98 no 635 80 ill 80 122 42 122 no 24ii 30 240 I~70~130 53 23 53 noE.2..-~ ffO 19 19 55 36 55 505 O 440 93 163 70 92 213 17 213 17 33 16 33 ~ m 51 m 57 175 118 175 ~ m 36" m 36 82 46 82 ~~ 730 110 730 110 150 40 150 290~ 29 290 29 67 38 67 no 49 36iiNm49 77 28 77 no ffi O" 52 67 15 45 no 630lli IO 68 172 104 130 no I~- 315 19 42 23 42 no 430 430 40 35 40 ~E- m- lO:1 340 lO 50 40 49 280 20 280 20 44 24 44 no m O 290 56 56 41 ~ m ""i8" ~~'l I ,,~ IE_~~I96 68 96 no m~o n- 173 151 173 ~ O 23 84- -~ 71 ves
LEGEND GB = Gauss-Boaga coordinates Lat. grid = grid latitude Long. grido = grid longitude D.max. = Maximum diameterdisl. D.m. = Denivelation along the maximum diameter D.p.m. = diameter trought the maximum depthdisl.p.m. = Denivelation along the diameter trought the maximum depth pr.max. = maximum depth pr.min.= minimum depth pr.D. = maximum depth along the maximum diameterevol.dol. = evolution as dolinas
282
~]~.=-&~~. valley bottom, slope and ridge sumrnit but we can see that the valley basins more easily afe evolving as dolinas particularly respect to the slope basins. The vallèy gather in fact a greater quantity of water accelerating the karst processes. The doline evolution seem linked to the depth. For lower depth (about less than 1.5 m) we have a probability of about 50% to evolve as dolinas, far depths of more than the 1.5 m nearly all the basins afe evolving as dolinas. For the maximum depths we can see that about 75% of the holes have a dejpth betv~een0.5 and 2 meters. Generally this is valid far all topographic The linear regression between the m lxir sho,NSthere is a direct proportionality. The metal-detector don't allowed th ex thatis present in the soil. The presence of much chips gave a continuous background recording, that disturbed it.
283
~ Frequency distribution of maximum diameter
m 200-300 cm [J 300-400 cm 8400-fXXJcm 8 5(X)-laX) cm [J 600-700 cm 8700-SOOcm D800- Frequency dmlributk>nof rTnxlmum dklmetern valleybottom XI: D. mal. T =:=j~~=j' Can: r ~:() I~ axJ ::IX) 18 4X) 133 133~ '-Mode 200 300 400 500 tOO 700 800 900 lCXX>1100 Frequency dlslributlon of maximum diame'.r In slop. Frequency distribullon 01 Ihe maximum dlameler in rldge 200 300 ~ 500 600 700 800 9(XJ l (XX) 1100 284 Frequency dlslrlbullon 01 maxlmum deplh m o-socm C 50-1 00 cm 8 1 CX>-1SOcm 8 150-200cm C 2CX>-2SOcm 8250-300cm O 300-350cm 8 35().400 cm Frequency dlatribution 01 maxlmum depth in valley bottom XI: PI. rnax rom:() To:«) -~ I lro I ~ I -Mode 50 100 150 200 250 300 350 400 Frequenc;y dis1ribution of Frequ.ncy distributlon of maximum maximum depth In ridge d.pth in liop. 285 ~'elcert: Llnear regression: maximum diameter/maxlmum depth pro max Simpie Regresslon XI: pro max VI: D. max. Count: R: RMS Residual: 100 .79 118.011 Analysis of Varlance Table Source DF: Sum SQuares: Mean SQuare: F-test: REGRESSION 1 2269183.095 2269183.095 162.938 RESIDUAL 98 1364813.655 13926.67 I p = .0001 TOTAL 99 3633996.75 286 advanced to give an explanation to the high levels of CuI Zn and Cd found in the but guano of the Buso della Torta cave. The meteoric water in 70 year can have dissolved the war metallic material and carryed the heavy metals in the karstic system. This contamination is harrnful to the cave ecosystem and also represent a potential danger of polluting the karst waters. Unfortunately the war is among the anthropic interventions the most difficult to control and to forewam. AKNOWLEDGEMENTS I thank Prof. Ugo Sauro of the Departement of Geography of the University of Padova far the useful suggestions and support in this research. I thanks also Piero Canova of the Speleological Club Giara Modon of Valstagna far the help to collect data in the field. A last thank to the Organizers of this Conference far the hospitality. REF~RENCES CARRARO F.,GRANDESSO P. and SAURO U. (1990) -Incontri con il Grappa. I segreti della geologia. Editore Moro. Centro incontri con lo natura Don Paolo Chievacci. Crespano del Grappa. 4-125 pp. Mimo P., SAURO U. (1989) -Le Grotte del Veneto: paesaggi c.;arsici e grotte del Veneto. Regione del Veneto -La Grafica Editrice, 415 pp. PAOLETTIM.G., CELI M., DEL RE A. and BOCCELLI R. -Troglobitic invertebrates: possible ..bioindicators of heavy metals pollution in caves. (First data). in print. SAUro U. (1987) -The impact of man in the karstic environments of the Venetian Prealps. Karst and Man, University of Ljubljana. Study Group on Man's impact in Karst. Proc. Int. Symposium on human influence on Karst, Postojna ,Yugoslavia , 1987,241-254. SAURO U. (1989) -Effetti dell'impatto umano sul carsismo. In "Problemi di Inquinamento e Salvaguardia delle aree carsicheN, Soc. Spelol. It. -C.A.I., 77-94. 287 SCIENTIFIC SESSION ON IMPACT OF TOURISM ON KARST MONUMENTS AND RESOURCES (Frasassi, September 21st, 1991) (Chairman Arrigo A. CIGNA) Proceedlngs of the International Conference on Envlronmental Changes in Karst Areas -I.G.U.- U.I.S.-ltaly 15- 27 Sept. 1991 ; Quaderni del Dipartimento di Geografia n. 13. 1991 -UnlversltO di Padova. pp. 289-298 THE KARST SYSTEM "GROTTA GRANDE DEL VENTO-GROTTA DEL FIUME" AND THE CONSERVATION OF ITS ENVIRONMENT Mario BERTOLANI(*), Arrigo A. GIGNA (**), Sergio MAGGIO' (***), Lucio MORBIDELLI (§), Gian Paolo SIGHINOLFI (*) (*) 1st. Mineralogia, Univ. di Modena; ( * * ) Area Ambiente, ENEA, Saluggia VC; ( * * * Jesi; (§) Dip. Sc. Terra, Univo di Roma: ABSTRACT G.K. W: speleology, human impact, protection, hydrology, biology. R.K. W: Italy, Marche, Frasassi. Just three years after its discovery the cave was opened to tourists. A Scientific Commission was immediately established in arder to ad vice the management of the cave with respect to environmental protection and scientific research. The tourist part of the cave is permanently monitored far many climatological parameters. INTRODUCTION The IIGrotta Grande del vento" is one of the most interesting show caves of Europe and belongs to a larger karst system which also includes the nearby Il Grotta del fiumell. It is also known under the name of IIGrotte di Frasassill, but it must be recalled here that in old literature such a name was generically attributed to some minor caves in the same area. The cave was discovered on 27 September 1971 by some cavers of the Gruppo Speleologico Marchigiano of the Italian Alpine Club (Ancona). During the Summer of 1973 the IIConsorzio Frasassill, an organization formed by the Commune of Genga and the Province of Ancona, was founded with the aim of developing and operating a show cave. The inherent works started immediately: an artificial entrance with a tunnel 223 metres long was excavated andon the 1st September1974the tourists were admitted to visit the first 850 metres of the cave. A sdentific commission formed by some experts (chosen by the Consorzio Frasassi) of different disciplines was established in 1975. Since its formation, the Commission acted as an advisory committee far the Consorzio in arder to guarantee the protection of the cave environment. 289 In particular, the Commission sei up amonitoring network of the mogi important environmental parameters (air and water temperature, air currents, relative humidity and CO2 concentration) in some suitable locations and studied the best solutions to avoid algae and other plants proliferation in the vicinity of light sources. Then the Commission promoted and directed also researchesin the karst system under a strict co-operation with the Consorzio Frasassi which funded them. Some sdentific papers resulted from these researches. GEOLOGY The karst system of the "Grotta Grande del Vento -Grotta del Fiume" is developed in the right side of the Frasassi gorge, a deep valley cut by torrent Sentino which is a tributary to river Esino. The karstified rock is the limestone "Calcare Massiccio" (Hettangian-Sinemurian) forrning the anticline core of Mt. Valmontagnana with a thickness of more than 500 metres. The most eastem part of the "Grotta del Fiume" only reaches the limestone "Maiolica" (Cretaceous) in tectonic contact with the "Calcare Massiccio" (Coltorti, 1981). The rock is a very pure limestone (more than 99% CaCO3) frequently oolithic or pseudo-oolithic, with compact layers from 1 to 15 metres thick (Bertolani et al., 1976). THE VISITORS TO THE CAVE When the cave was opened to the public the trail was limited to the Abisso Ancona; then in two successivesteps it was farther extended to the area of "Candeline" (named after some formations with the shape of small candles) and to the present situation. Table l -The visitors of the Grotta Grande del Vento (Genga, Ancona) since September 1974 after its development as a show cave. /1Year '!.Visitors per year Visitors from the beginning 1974 117,840 117.840 1975 468.648 586,488 1976 460.891 1.047.379 1977 456,233 1,503.612 1978 471,662 1.975.274' 1979 438.574 2A 13.848 1980 434.658 2.848.8)6 1981 432.630 3.281.136 1982 382.154 3.663.290 1983 I 420.394 4A94.844 1985 I 426.075 4.920.919 1987986 412.658 5.333.577 408.028 5.741.605 1988 389.655 6.131.260 367.376 6A98.636 ~~ I 1~ I 363.343 6.861.979 290 E The number of visitors reached a rather high value just from the beginning: in fact the 118 thousand during the last four months of 1973 correspond to an annual average of about 354 thousand which is not far from the figures reached later on. In Table 1 and Fig. 1 the data on the visitors afe reported. The saturation and decrease of the number of visitors is a common effect well known in similar situations (as, e.g. in natural parks) which should be faced with some specific intervention. The problem is dealt in some detail in another paper presented to this conference (Burri & Cigna, 1991). In any case, it is imperative that the generaI management, both, of the karst system and the whole region, be carried on with a global view by taking into account the interactions among the different aspects of the tourist star in the region itself. 500 """" CI) o 400 «z CI) o=> :I: 300 C ~ « L.U 200 ;:=:. CI)~ of- C75 > 100 o .: 1970 1980 1990 Year Fig. l -The visitors of the Grotta Grande del Vento CGenga. Ancona) after its development as a show cave. SCIENTIFIC RESEARCHES CO-ORDINATED BY THE SCIENTIFIC COMMISSION The Scientific Commission had initially the task of investigating the environmental implications of the cave development. Then the Commission played also the role of advising the "Consorzio Frasassi" on the scientific researches to supported and developed to achieve a better and wider knowledge of the whole karst system. 2912000 The first research promoted by the Commission and funded by the "Consorzio Frasassi" was a study on the cave water chemistry directed by G. P. Sighinolfi (University of Modena). Three different kinds of water were identified: rain water by percolation (with different ages), deep sulphureous water, infiltration water from the Torrent Sentino (Sighinolfi, 1990). Another research was directed by A. Taddeucci (University of Roma) and concemed the 230Thdating of cave formations. The oldest age measured was 190,000 years (Taddeucci & Conte, 1987). In 1988 the a team of specialists, the Golder Associates Geoanalysis of Turin, was entrusted with the task to investigate the stability of some fractured rock pillars. The following instruments were installed: 3 Stress-meters 2 Deformometers 3 Convergence-meters 4 Crack-meters Laboratory tests were also carri ed on many rock samples to determine relevant parameters. After four years of measurements it has been ascertained that no breakdowns afe expected in the next future (Barla et al.,1991). A br-produci of this study was a series of rock temperature measurements showing a sinusoidal variation with an amplitude of about 0.5 °C and a phase shift of nearly two months with respect to the outside air temperature with a variation amplitude of about 18°C. According to the forrnulae currently used the phase shift is too short and the amplitude is too large for the propagation of a thermal wave through limestone some ten of meters thick; therefore this phenomenon needs further investigation. A research concemed the fauna of the cave system and was directed by R. Bertolani (University of Modena). More than 50 species were identified: the most interesting ones resulted to be the coleopter Gnathoncus cerberus and the pseudoscorpion Roncus sp. In addition cariologic, genomic and biochernical investigations on the geotriton Hydromantes were carried on (Bertolani et al., 1990). Then a research was directed by V. Castellani (University of Roma) and studied the speleogenetical processesgiving a special role to the condensation water (Dragoni & Verdacchi, 1990). The last research, directed by A. Rossi (University of Modena), started just now and concems the study of minerals and rocks whose interest was emphasized in previous investigations. Other studies, directed by A.A. Cigna (ENEA), were carried on in the frame of the ENEA's environrnental research programme regarding the prc>blemof Radon in caves (Cigna & Clemente, 1981; Cigna, 1986)and the tritium dating of cave waters (Cigna & Giorcelli, 1989). THE MONITORING OF ENVIRONMENTAL PARAMETERS The monitoring of environmental parameters was developed in three steps. Firstly, after its establishment, the Commission started a monitoring programme of air temperature and humidity in about 20 stations with measurements carried on at irre~ar intervals (1975-77). In 1982 an automa tic network consisting of two stations for the measurement of 292 Table 2 -Characteristics of the sensors. _Temperature, mo~e/ PT-700 by TeGno-E/,Ro~a, /ta/y Range -SO+lSOOC Nominai resistance at QoC 1(XX):t 0.09 ohm I Linearity :t 0.05 % I Temperature coeff. J~~_~..12 ppmjOC Time constant 1.85 Il Selt heating coeff. ~C/mW I Long. term stability :t: 0,04% I Measurement current lmA Air speed, model Kurz 435 DC by Kurz, Inc, USA (Ceramic coated (or high humidity_operation) Range Accuracy :tO.5% fui! scale I Analogic output 0715voltDC I Relative Humidity, model Rotronic C83 by Rotronic AG, Switzerland Range o- l 00 % rei. humidity Temperature range -10.:,-50°C Accuracy :t1% Precision <0.5 % Hysteresis <0.5 % Mean lite 15 years Calibration every 6 months AtmosPheri~ pressure, mode/ ~O97 by Tecno-E/,_~oma, /fa/y. Range 96071060mbar Accuracy :t0.15 % full scale Temperature coeff. 0.005% per °C Temperature range -lO..,.80°C Rainfall. model E06 by by Tecno-EI. Roma.ltaly. ..- Surface I Output I temperature, humidity and air velocity and a fixed infrared system with lO sensors far the measurement of CO2 concentration in air along the tourist trail was set up. Such a system (Mod. Lira 202, measurement range: 1 to 1000 ppm) was supplied by the firm MSA. Notwithstanding the characteristics given by the firm, the system was quite unreliable with frequent failures due to the working conditions inside a cave. Since 1989 a new network is in operation with the following sensors: 6 thermometers far air temperature 2 thermometers far water temperature 5 anemometers 6 hygrometers 2 pluviometers 2 barometers 293 Such sensors (Table 2) supply data on-line to a personal computer to record them and for any further elaboration. This new network was assembled and put in operation by ISELQUI, Ancona; the sampling points afe reported in fig. 2. The set-up of this network required a rather long time on account of some troubles given by storrns resulting in spurious impulses and failure of some sensors. Such problerns were solved by an accurate grounding of the shielding and a power supply through an uninterruptible power supply to avoid main spikes, surges and black-outs. After some time of operation the humidity sensor gave also unreliable results on account of a saturation effect due to the working condi.tions close to 100 % of relative humidity. Another type of sensor (Table 3) was tested with better results; therefore the forrner sensors will be substituted to avoid the troubles reported before. Tab/e 3 -Characteristics of the humidity sensor, mode/ Humicap H 0062, by Vaisa/a, Fin/and. Measuring Range O:t 100 % Error at 20 °C (including calibration accuracy, .-- :t 20;0 (0-,:-900;0) linearity and repeatability) :t 30;0(90-,:-1000;0) Temperature dependence of sensor at: 0% rei. humidity and trom -5 to +55 °C < l % rei. humidity 75% rei. humidity and tram -5 to + 10 °C +0.35% rei. humidityjOC 75% rei. humidity and tram + lOto +55 °C < l % rei. humidity THE CONTROL OF VEGETAL POLLUTION The vegetaI pollution is one of most serious problems in show caves. It is nearly impossible to avoid it, because the visitors carry in with their clothing the spores tram the outside. The cave environment is suitable far the growth of the spores and the artificiallight supplies the energy required far this. Some experiments of keeping a cave in the dark far rather long times were unsuccessful. Ultra-violet light is harmful to the vegetation, but may also affect the formations by decreasing their shine. The lamp flora can be controlled by using "cold lamps" (such as those used in the window of a confectioner's shop) as well as some "discharge lamps" which emit light in a narrow band only, which is not useful far the chlorophyllian processo Nevertheless, the more effective solution to the problem is a direct destruction of the flora when it appears; such a decontamination must be carried out in the whole cave also in hidden and remote places. Both physical (brushing, water jets, etc.) and chemical methods can be adopted. The latter must not have negative effects on the formations nor pollute cave waters. Along the tourist trail of the " Grotta Grande del Vento" the lamp flora appeared just a short time after the lamps were in operation. Very short times of lighting afe sufficient to supply energy far the life and growth of green flora. The organism more common in the tourist part is a moss, identified by the Botanical Institute of the University of Modena as Didymodon tophaceous(Brid) Jur, a species commonly found on wet limestone in Atlantic and Mediterranean regions. 294 Firstly some experiments were carri ed out with different chemicals on an old wall (with westerly exposure) of the medioeval castle of Formigine (Modena) covered by Tortula muralis Hdw. The following chemicals were tested: "Karmexll TM DuPont (powder and water solution 3 g/liter); sodium hypochlorite (2.75 % Cl); sodium chlorate (30 g/m2). The liSe of Karmex was suggested by V. Caumartin (1973). The treatment requires rather long times (longer than 25 days) and it must be repeated. The substances used gave similar results, but the sodium hypochlorite had a faster effect while the results obtained with sodium chlorate were less homogenous. At the Institute of Mineralogy and Petrography of the University of Modena a test on some broken formations found in the "Sala delle Candelinell was carried out in order to evaluate the corrosive action of sodium hypochlorite. After lO minutes of treatment about 41 mg/ m2 were dissolved without any further increase also when the treatment was extended over 17 hours. Sodium hypochlorite is not toxic and is usually used for the disinfection of the water in swimming-pools and to obtain waters fit to drink. Both for this reason and its faster effect sodium hypochlorite was selected for the treatment of lamp flora in the IIGrotta Grande del Vento". A solution of sodium hypochlorite is sprayed at the first appearance of the lamp flora and the formations afe successively washed with water. After 16 years this procedure was adopted no disadvantages were found and the formations afe as shining as when they were discovered. CONCLUSIONS According to a rather widespread feeling a show cave is a cave "lost" from the point of view of scientific research. The "Grotta Grande del Vento" is a clear example of the contrary. Not only the cave environment is well preserved as it was confirmed by the number of species identified by a biological research, but the cave itself became a natural laboratory and a number of scientific researches could be promoted, co- ordinated and funded. Obviously the situation of this cave was perhaps rather particular because many favourable factors met at the right pIace and the right time: some show caves less important could have some problerns to start researchprogrammes as those previously described. Also far this reason the lntemational Show Caves Association was founded at Genga in 1989 in arder that the experience gained by major show caves could be shared by the smaller ones. Conceming the monitoring of environmental parameters it must be emphasized that the main problem to be faced is due to the unusual characteristics requested by such a facility. In fact the sensors must work in rather extreme conditions (e.g. dose to saturation far the relative humidity) and must have high accuracy and precision because of the narrow range of variation of the quantity to be measured (e.g. cave air temperature varies along a year within few tenths of °C). In generaI commerciaI firrns have little or no specific experience and therefore a great co-operation is necessary between the firm charged with the task of setting up an environmental network and the scientists utilizing it. Sometimes a special effort is necessarybecause they speak different languages and have different minds. 295 REFERENCES BERTOLANI M., CIGNA A.A. (1990) -Activity of the scientific commission of MGrotta Grande del Vento- (Genga, Ancona, Centralltaly). Proc. 1st Congress Int. Show Caves Association, Genga, 1-4 November 1990. BARLA G., ANGELINO C., JARRE P., MATTALIAC., NALDI M. (1991) -Studio delle condiziorn statiche delle strutture carsiche della Sala Bianca della Grotta Grande del Vento. Geoanalysis Report RL 144/2206/02 (unpublished). BERTOLANI M., GARUTI G., ROSSIA., BERTOLANIMARCHETTI D. (1976) -Motivi d'interesse mineralogico-petrografico nel complesso carsico MGrotta Grande del Vento - Grotta del Fiume- (Genga, Ancona). Le Grotte d'Italia, (4) 6: 109/144. BERTOLANI R., MANICARDI G.C., REBECCHI L. (1990 )- Faunistic study in the karst complex of Frasassi (Genga, Ancona,Centralltaly). Proc. 1st Int. Congr. ISCA, S. Vittore Terme, 1-4 Nov. 1990 (in press). BURRI E., CIGNA A.A. (1991) -Some considerations on the potential far revitalization of show caves. Proc. I.C.E.C.K.A., Session on impact of tourism on karst monuments and resburces. (these proceedings) . CAUMARTIN V. (1973) -La conservation des grottes amenagées. ANECAT,l. CIGNA A.A., CLEMENTE G.F. (1981) -Radiation hazards in natural caves. Proc. 8th Int. Cong. Speleology, Bowling Green, Kentucky, USA, 2: 420/423. CIGNA A.A. (1986) -Radon Concentration in Some Italian Caves. Proc. 9th Int. Congr. Speleology, Barcelona, Spain,2: 84/88; also 05: ENEA Report RT/PAS/86/19. CIGNA A.A., GIORCELLI F.G. (1989)- Underground water dating by tritium measurement. Proc. 10th Int. Congr. Speleology, Budapest , Hungary ,2: 562/563; also as: ENEA Report RT/PAS/89 /24. COLTORTI M. (1981) -Geomorphologic evolution of a karst area subject to neotectonics movements in the Umbria Marche Apennines (Centralltaly). Proc. 8th Int. Congr. Speleology, Bowling Green, Kentucky, USA,l: 84/88. DRAGONI W., VERDACCHI A. (1990) -First results of the monitoring system of the karstic complex of MGrotte di Frasassi-Grotta Grande del Vento- (Centrai Apennines, Italy). Proc. Int. Symp. and Field Seminar on Hydrogeologic Processes in Karst Terrains, Antalya, Turkey 7-17 October 1990 (in press). SIGHINOLFI G.P. (1990) -Studio chimico delle acque del complesso MGrotte di Frasassi- (Ancona). Implicazioni spelogenetiche ed ambientali. Mem. 1st.It. Speleol. s. 2,4: 109/122.- TADDEUCCI A., CONTE A. (1987) -Datazione col 23Orh di alcuni speleotemi del complesso carsico MGrotta Grande del Vento -Grotta del Fiume- (Ancona). Boll. Soc. Geol.lt., 106: 807/812. 296 DISCUSSION J. Jomes: The meosurement of CO2 concentrotion in oir con be corried on 0150 by devices meosuring the thermol conductivity with the odvontoge to be simpler thon the infrored systems. A.A. Cigno: This is o rother interesting point but the interference from ony other parometer different from the CO2 concentration should be negligible J. James: The chemicals used to wash the formation and kill the algae would not be dangerous to the microfauna of the cave? A.A. Cigno: The largest part of the solution used to wash the formation is normally taken away. therefore only minor amounts spread on site. On the other hand the microfauna moved in advance out from the tourist trail and therefore any interference would not be important. J. Choppy: Wos it possible to correlate the results of the deformometers ond similor instruments with some seismic event ? Probobly the instollotion of a seismometer in the cave would be useful. A.A. Cigno: Unfortunotely not, becouse such instruments were reod ot long intervols only ond not continuously. Concerning the seismometer we hod one in operotion some yeors ago but it wos no longer ovoiloble. W. Halliday: t wonder if there was any possibility of an introdution of algae and microfauna from foreign environments being carried into the cave by the tourists. A.A. Cigno: The algae found in the cave were extensively studied by professor Daria Bertolani Marchetti of the University of Modena and she found only loca! common species. U. Sauro: Perhaps the decrease of the number of visitors both in Costellano and in Frasassi caves could be due to a reciprocal effect of competition. A.A. Cigno: An influence of one cave on the other seems rather dubious because a detailed examination of the trend of visitors does not support this hypothesis. On the contrary the decrease of the number of visitors is a well known effect found in many instances far museums. national parks. etc. It is a kind of saturation of the interest of people: in particular this problem is considered in the next paper by Burri and myself. N.N.: Hove you never meosured the Rodon concentrotion in the cave? A.A. Cigno: Ves. we hove meosured the Rodon concentrotion in "Grotta Grande del vento. ond some other Itolion coves. The results ore reported in a poper published some yeors ago: Cigno A.A.. (1986) -Rodon Concentrotions in Some Itolion Coves. Proc. 90 Congr. Int. Espeleologio. Borcelono. 2:84/88; 0150 05: report ENEA RT/PAS/86/19. N.N.: Have you performed any oxigen isotopic analysis together with the dating of the formations reported before? P. Tuccimei: Up to now the team of the Earth Sciences Dept. of the University of Roma has not carried on analysis of this kind. Probably in the future it will be possible to include them 0150in our programme. N.N.: Have you found any variation of the growth velocity of the formations you have dated?P. Tuccimei: Ves. we have. During the interglacial Riss-WOrmand the post glacial WOrm higher accretion rates were found of speleothem in comparison to other periods. The results of this research have been reported in a paper: Taddeuccl A.. Tuccimei 297 P. & Voltaggio M. (1990) -Th-230 dating and related implications of the speleothems from "Grotta del fiume -Grotta grande del vento. karst cave at Frasassi (A N). Proc. First Congr. of the Int. Show Caves Assoc.. Genga Nov. 1-4. 1990 (in press). 298 Proceedings ofthe Internatlonal Conference on Envlronmental Changes in Karst Areas -I.G.U.- U.I.S.-ltaly 15- 27 Sept. 1991 ; Quaderni del Dipartimento di Geografia n. 13. 1991 -Università di Padova. pp. 299-303 SOME CONSIDERATIONS ON THE POTENTIAL FOR REVITALIZATION OF SHOW CA VES Ezio BURRI" and Arrigo A. CIGNAo " Dip. Sc. Amb. -Università L'AQUILA; o Area Ambiente, ENEA, Saluggia VC ABSTRACT G. K. W... speleology, cave use and management, show caves, management strategies,. Geogr. K. W... Yugoslavia, Postojna, Italy; Castellana. The interest in natural caves far tourist uses inevitably tends to reach a saturation point followed by a decline in interest aver the medium or long term. It is however possible to revitalize these structures, by means of some technical solutions programmed in advances, without compromising the delicate environmental balance. THE ASPECTS OF THE PROBLEM In the last few years many projects have been carried out or afe waiting to be realised because of the increasing demand by tourists for show caves. In any case the flow of tourists should be controlled because if numbers afe too great the lnconveniences caused to the environment tend to be irreversible (CIGNA, 1989). This is particularly important at least for those caves which have a middle energy (HEATON,1986). Such limitations afe not unique for the cave environment: it may be recalled here that the tourist flow restriction is very great in museum rooms where works of art (which afe particulary sensitive to variations of temperature and humidity) afe displayed. In these casestourists must be divided in small groups rather than enter alI at once. Both private and public bodies afe interested to show caves development sometimes with financial incentives from the National Govemment. With the initial availability of public capita! a quick recovery of the money invested may not be needed and therefore development project have less constraints. . Unfortunately past experience has clearly shown that the tourists flow is systematically not controlled with the obvious negative effects (e.g.: the case of the Grotte di Castellana near Bari, to quote only one of the possible examples). Besides the consistent problerns of environmental decay it seernsthat others may have in show caves. The saturation of interest on the part of the users is probably one of the most important. Such a phenomenon has stilI not been examined in detail and consequently here only a preliminary discussion of the problem is given. The saturation of interest leads to a slow, but unstoppable, decreasein use with an 299 obvious financial decline. No show caves is immune to this problem, although cases vary in relation to the characteristics of the complex. Some of these characteristics afe here listed: a) the extension of the caves -An extended cave system is obviously able to offer a longer and more varied trail with a consequent increase in interest. b) mo~hological characteristic -The hydrologically active caves offer a particular recall in relation to differences in the water flow. The scenografic result generated by a water stream increases possible motivation even if it is a fairly rare element in show caves. These caves afe endowed with sufficient energy (HEATON, 1986), so it is often not worthwhile to give them a particular enviromental protection. Besides a varied morphology with falls and huge caverns is able to provide more interest also in relation to the genesis and to the evolution of the underground complex. c) the ~resence and variet~ of s~eleothems -It is perhaps this element which causes major demand even if their mineralogical nature (e.g. aragonite) induces the major caution in evaluating the limits of the receptive capacity. d) the ~resence of archaeloglcal evidence -It is also difficult in this case to quantify the interest but it is obvious that it depends on the quality of the remains (from the simple traces of settlements right up to the rock paintings of notable artistic and scientific value). e) the s~atial relationshi~ with tourist recall of other nature -The record of cases is exceptionally varied. It ranges from the artistic valency (artistic cities, museums, archaelogical settlements, etc., to the classical "landscape") and even to those which have a more generical tourist interest (beaches,spas, mountain resorts, etc.). f) the relationshi~ with the main road conditions -Even if at the moment any tourist piace at any stage of development has often rather good road connections, any major improvement of the main road system may have a great role in the development of the pIace. The interaction of more parametres leads to a major or minor notoriety of the underground tourist complex. The first users to be involved afe obviously the local ones, who afe also those for whom it is easier to reach the saturation level, subsequently this reaches also those even further away in relation to the direct or indirect advertising which is carried out. The saturation of interest for the further away users 1s slower, however, to develop because the catchment area of users is obviously much larger. THE POSSIBLE REMEDIES The most extensive karst systerns have already, in part, attempted to resolve the problem by means of creating new paths which afe often ramified and intersect each other. This remedy has been adopted also in many Natural Parks where the classic path has often been vaÌied to offer new motivation and introduce new observation angles. This pratice also permits a physiological rest of the park tram the biological point of view. Considering the availabity of space that a Natural Park offers it is rather convenient both technically and economically to periodically make use of new visiting paths, nothwhitstanding the zoning which only allows a visitto certain areas. On the other hand the tourlst layouts in the caves cannot be changed easily on account both of the cost and the impact on the Cave environment. Infact rather often the cave morphology forces a precise choice of pathway without any real alternative. 300 Therefore possible solutions cannot be adopted with radical interventions, but with those of support and those able to produce a revitalization in interest of a degree quite independent from the extension of the karst complex and its characteristics. The solutions here reported do not intend to supply remedies whose validity is based on a rigorous scientific analysis but to list initiatives already used in larger territorial areas with appreciable success (BURRI and SAURO, 1989). 1) -Naturalistic itineraries The attention of the tourist should be drawn to the ,karst phenomena at large present in the surrounding area and not to the single cave. Furthermore, the creation of naturalistic itineraries will increase the naturalistic valency of a morphological type. This will allow a greater acquisition of information and understanding about the complex karst phenomena and thus a major protection of the environment. The possibility to act in the open wil1 also permit the opportune variation of layout types, or to create a certain number of them. 2) -Visits to more show caves This is a solution which could suitably be adopted in regions where show caves afe reasonably near one another. The idea is to invite the tourist to also visit the other show caves. A sort of lIecho" effect would occur in which more underground environments afe bound to naturalistic intineraries in a complex monothematic circuit which is able to guarantee a tourist presence in the area also far more than one dar. 3) -Sounds and lights It is known that many of human artistic manifestations afe intimately linked to those more specifically natural. As an example the inspiring principle of a natural scenery far the composition of sublime musical works can be recalled. In this case also the organisation of musical manifestations inside a cave, or at its entrance, can allow otherwise unhoped far results. The idea is not à recent one: e.g. the concerts organised at the beginning of this century in the Caves of Postojna or, more recently, in the Grotta di Castellana's Grave. An intelligent choice of particular musical compositions to be broadcast may give good results according to the experience carried out in some European show caves. Also the possibility of a simple "concert" of dripping water during a short interval of total darkness must not be overlooked. More delicate a problem is the lighting solution. This element is naturally extraneous to the undeground environment and it is easy to lise bad taste. However, a rational "ilIumination game" which is able to extol the morphological valency, even fairly far from the visiting circuit, can both recall attention which has flagged during the visit and lend itself to numerous variations on a theme, remotivating the user's interest, having already previously passed that section. StilI the possibility of other artistic presentations such as theatrical manifestations must not be understimated. 4) -Basic didactics In the most well-known show caves and in the periods of major présence, the waiting before entering can increase notably. This is without doubt the opportunity to liven up the tourist by means of simple videos that illustrate, e.g., the morphological evolution of the cave and surrounding karst environment. 5) -The Qualit~ cf the ~ide service 301 The quality of the preparation of the guides, as can so happen in museums, is in generaI rather lacking. These persons bave the important task of correctly informing the tourist about what he is seeing at any particular moment, but they afe rarely professionally trained for the job. This is not a new problem and in ltaly some Regional Govemments bave attempted to resolve it with suitable initiatives (LUCREZI, 1982). However, everything is stilI nearly alI assigned to individuaI show cave adrninistrations. The results obviously vary in relation to the cultural level of the people employed. CONCLUSIONS The examination of the trend of visitors in many show caves (as well as other tourist attr~ctions) shows a tei",dency to reach a maximum followed by a decrease becaus~( a "saturation" affecting the interest of the public involved. Therefore; some inter;:ventionsafe mandatory to avoid serious consequences on the management of the caves. When natural parks afe involved some new trails may, e.g., revitalize the interest. I~ the case of caves such a solution is obviously impossible because trails afe a real hardware which cannot be moved or modified without important environmental implicptions. TÌ\'efefore the problem should be faced by other solutions in the domaine of software ~f the cave management. Some new performances of "son et lumière", exibitions of materials connected with caves, archaeology or local history, connectionns with other tourist attractions in the vicinity of the cave, etc., could play an important rate in the revitalization of the show cave. The planning of such solutions must be studied well in advance before reaching the saturation of tourists' interest to avoid the negative effects above mentioned. BURRIE., SAURO U. (1989) -Turismo culturale nelle aree carsiche. Atti Conv. Int. "Turismo e Ambiente nella Società Post-lndustrialeN, Milano: 9-10 marzo 1989: 399/411. CIGNA A.A. (1989) -La capacità ricettiva delle grotte turistiche quale parametro per la salvaguardia dell'ambiente sotterraneo. Il caso delle Grotte di Castellana. Atti XV Congr. Noz. Speleologia, Castellana Grotte, 10-13 settembre 1987: 999/1011. HEATON T. (1986) -Caves. A Tremendous Range in Energy Enviromnents on Earth. National Speleological Society News, August 1986: 301/304. LUCREZIA. (1982) -La legge no28 del 2 Maggio 1980 della Regione Abruzzo sulle guide speleologiche. Atti Conv. Int. sulle Grotte Turistiche: aspetti scientifici, tecnici ed economici, Borgio Verezzi 20-22 marzo 1981, Le Grotte d'Italia s.4, 10: 299-304. 302 REFERENCES DISCUSSION U. Scuro: How con you prove thot there is no reciprocol influence between Costellano ond Frosossi ?A.A. Cigno: The decreose of the number of visitors of Costellano storted seven yeors ofter the opening of the Frosossi system os o show cove. therefore there is no connection betweeen them. In porticulor the decreose far Costello no wos due to the poor environmentol conditions of the cave on occount of the sewers dischorging into the cave through the fissures of the limestone. On the controry the shorp drop far Frosossi in 1982 wos the consequence of o decision of o judge to close the troffic in the rood leoding to the cave to ovoid injuries from rock folling. After mountoin obove_the road was cleared the road was reopened. But at the some time Costellano has no sign of any advantage from the local troubles in Frosassi. Few yeors later the decreose of tourists in the Adriatic beaches on account of the algae blooming influenced also the visitors of Frasassi. According to our view two show caves will in generai develop a symbiosis ond not a competition. In addition the distance between the two most important Itolian show caves is so great that it iS really difficult to find an overlapping of their ~morkets.. Nevertheless both far Costellano and Frasassi a negative trend is clearly observed: according to our hypothesis such a negative trend is the effect of the saturation described in our papero I. Gams: Do you have data on the country of provenance of visitors for these caves ?A.A. Cigno: I do not have data because this information is not obtained when visitors buy their tickets. W. Halliday: Do you ha ve data on the advertising budget of the cave? A.A. Cigno: The advertising budget is around 300.000.000 lire per year (corresponding to 250.000 US $). 303