ARTICLES NEW POSSIBILITIES FOR ASSESSING THE DAMAGE CAUSED BY NATURAL DISASTERS IN SLOVENIA -THE CASE OF THE REAL ESTATE RECORD AUTHORS Blaz Komac, Matija Zorn Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Anton Melik Geographical Institute, Gosposka ulica 13, SI - 1000 Ljubljana, Slovenia blaz.komac@zrc-sazu.si, matija.zorn@zrc-sazu.si Domen Kusar University of Ljubljana, Faculty of Architecture, Zoisova cesta 12, SI - 1000 Ljubljana, Slovenia domen.kusar@fa.uni-lj.si UDC: 91:504.4:347.235(497.47) COBISS: 1.01 ABSTRACT New possibilities for assessing the damage caused by natural disasters in Slovenia - The case of the Real Estate Record This article presents the suitability of the Real Estate Record - a web application of the Surveying and Mapping Authority of the Republic of Slovenia - for assessing the damage caused by natural disasters. We performed an analysis for the village of Čezsoča, which was devastated by an earthquake in 1998 (M5.6). We compared the data on earthquake damage with the data on the real-estate value. Such comparisons make it possible to establish the damage potential of future natural disasters. KEY WORDS geography, natural disasters, damage, prevention, Real Estate Record, Čezsoča, Slovenia IZVLEČEK Nove možnosti preučevanja škod ob naravnih nesrečah v Sloveniji - na primeru registra nepremičnin Predstavljena je uporabnost registra nepremičnin - spletne aplikacije Geodetske uprave Republike Slovenije, ki vsebuje tudi vrednost nepremičnin - za preučevanje škod ob naravnih nesrečah. Za vas Čezsoča, ki jo je prizadel potres leta 1998 (M 5,6) je bila narejena analiza, v kateri smo primerjali podatke o škodi zaradi potresa in podatke o vrednosti nepremičnin. Tovrstne primerjave omogočajo ugotavljanje škodnega potenciala za prihodnje naravne nesreče. KLJUČNE BESEDE geografija, naravne nesreče, škoda, preventiva, register nepremičnin, Čezsoča, Slovenija This article was submitted for publication on January 19, 2012. 1 Introduction The term »natural disaster« denotes natural phenomena and processes in a landscape that affect society to the extent that they cause damage to it. Direct damage occurs during the disaster itself (e.g. damaged buildings and infrastructure, destroyed crops), whereas indirect damage is caused in other areas and can be considerably greater (e.g. lost income due to disrupted industrial production, agriculture, commerce, and power supply). Some authors (Guha-Sapir, Hargitt and Hoyois 2004) also refer to secondary damage, which is financial in nature and connected with lost budget funds, changed interest rates, and debt. The damage caused by natural disasters is increasing around the globe (McBean 2004, 177; Low and Wirtz 2010, 47), not only because of their potentially higher frequency, but also by the increased vulnerability of society. The greater vulnerability of society is connected with a rapid increase in population, the settlement of hazardous locations that were empty until only recently, more frequent increases in population density, and a larger share of urban population. Greater vulnerability is influenced by increasing property and real-estate prices, a more diverse and modern (expensive) infrastructure, and especially human alienation from the natural environment. There is also a resulting lack of knowledge of natural processes, leading to underestimating or even denying them (Zorn and Komac 2011, 12). Damage to real estate and infrastructure is a substantial part of the damage caused by natural disasters. The greatest damage to real estate in Slovenia may be caused by earthquakes, followed by floods, thunderstorms, and some other rarely occurring natural disasters. The data on damage to public infrastructure are publicly available, whereas the data on the resources for renovation work on damaged real estate are only rarely publicly available (Orozen Adamic and Hrvatin 2001). The generalised market value of real estate in Slovenia is set at approximately € 140 billion (Mikos 2012). The process of assessing damage is a complex one. In Slovenia, it is usually carried out after a natural disaster has occurred. If we want to evaluate damage from natural disasters or their economic impact, we have to know the economic value of the real estate that has been damaged. In Slovenia, data on the generalised market value of real estate have been available since 2011 (Internet 2). This enables an evaluation of the greatest possible damage to real estate in an area. Consequently, it is possible to produce models for damage assessment in case of different natural disasters or different scenarios on the grounds of the assessment of real estate value in combination with the data on damage from natural disasters. This paper presents such an analysis with the case of the village of Cezsoca near Bovec, Slovenia. We compared the data on damage from the 1998 earthquake and the data on real estate value from Real Estate Register. 2 Damage caused by natural disasters in Slovenia between 1994 and 2008 Slovenian literature most often states that the damage caused by natural disasters amounts from 0.6 to 3.0% of the annual GDP if there is no major disaster. With greater catastrophes, this share is higher; for example, in 1976 damage caused by the earthquakes in the Upper Soča Valley and a few other natural disasters was estimated at approximately 7% of GDP, and in the 1990 floods in the Savinja River Basin the damage amounted to more than 20% of GDP. These figures are fairly high and also include indirect damage caused by these disasters (Zorn and Komac 2011, 9). According to the Slovenian Statistical Office, the direct damage caused by natural disasters between 1994 and 2008 amounted to an annual average of 0.37% of GDP (Figure 1). The last major disaster affecting Slovenia was the September 2010 floods (Komac and Zorn 2011). They affected 60% of Slovenian municipalities (137), and the total damage was estimated at more than € 240 million (including VAT), which exceeded the 0.3% of planned inflows in the 2010 national budget. For comparison, the damage caused by the 1990 floods mentioned above was estimated at more than €500 million (Zorn and Komac 2011, 13). Floods commonly appear in Slovenia. In the previous 15 years, floods (Komac, Natek and Zorn 2008) have caused an average of 15% of the total damage due to natural disasters in the country. The following years have stood out in this regard: 1994 (31.3%), 1995 (18.1%), 1998 (51.9%), 1999 (12.1%), 2004 (15.2%), and 2007 (64.8%). In the period discussed, fires caused substantial damage in 2002 (18.1%) and 2004 (24.5%). During the period discussed, drought caused substantial damage in 1997 (16.3%), 2000 (70.2%), 2001 (56.7%), 2003 (83.3%), 2006 (60.4%), and 2007 (13.4%). Heavy wind caused over 10% of all damage due to natural disasters in Slovenia in 1994 (26.1%), 1995 (37.5%), 1997 (26.6%), 2002 (15.6%), 2005 (31.4%), 2007 (12.7%), and 2008 (19.6%). During the period discussed, hail did not caused more than 10% of overall damage due to natural disasters in only four years (1998, 2000, 2003, 2007). In the other years the damage was 1994 (16.5%), 1995 (16.3%), 1996 (12.4%), 1997 (17.4%), 1999 (11.6%), 2001 (12%), 2002 (20.6%), 2004 (38.7%), 2005 (55.6%), 2006 (23%), and 2008 (75.2%). Among the natural disasters in Slovenia, frost and freezing rain cause the least damage; thus they only proved to be problematic (causing more than 10% of damage due to natural disasters) in 1996 (37.6%), 1997 (27%), and 2001 (23.6%). Unfortunately, the Slovenian Statistical Office collects data on landslides and avalanches as one type of disaster, although these are two completely different processes. Given that avalanches mostly only threaten local infrastructure, the majority of the damage listed includes damage caused by landslides. According to these data, landslides and avalanches caused more than 10% of overall damage due to natural disasters in 1994 (10.2%), 1995 (16%), 1996 (22.4%), 1998 (14.1%), 1999 (32.1%), and 2002 (17.8%). Two powerful earthquakes struck Slovenia during the period discussed and caused substantial damage: 18% (in 1998) and 13% (in 2004) of the total damage (Figure 2) caused by natural disasters in Slovenia as a whole (Figure 1; Zorn and Komac 2011). 100 90 80 70 60 50 40 30 20 10 0 10 11 12 13 14 15 Earthquake ■Floods ■Fires ■Drought ■ Heavy wind Hail ■ Frost and freezing rain ■ Landslides and avalanches 5 9 Figure 1: Direct damage caused by natural disasters in Slovenia from 1994 to 2008 by shares of annual GDP (Ocenjena... 2010). and Komac 2011, 16). 3 Damage caused by the 1998 earthquakes in the Upper Soča Valley The Upper Soča Valley is a region in western Slovenia. It is an Alpine region characterized by high mountain karst relief (up to 2800 m a.s.l.), big altitude differences (more than 2000 m) high precipitation (about 4000 mm annually) and torrential waters. The earthquake that struck the Upper Soča Valley on April 12, 1998 (M5.6) was the first strong earthquake to hit the region since the Furlanese earthquake in 1976 (M 6.5). Its epicentre was in the karst region south east of Bovec. Its magnitude reached its highest levels in the villages of Magozd, Drežniške Ravne, Lepena, and Tolminske Ravne. The area where the earthquake reached or exceeded a magnitude of 7 on the EMS scale had a diameter of about 22 kilometres (Geipel 1982; Vidrih 2008; Vidrih, Ribičič and Suhadolc 2001). This earthquake also caused considerable changes in nature. A few hundred rockfalls and a few landslides were triggered during the earthquake. The largest rockfalls were recorded below Mount Lemež in the Lepena Valley, on the south-western slope of Mount Krn, in Polog above Tolmin, and at the source of the Tolminka River (Zorn 2002). The earthquake greatly accelerated normal geomorphic proceses. Average annual sediment production in the discussed area amounts to about 1400 m3/km2. However, earthquake-induced rockfalls and rainfall-induced landslides may release sediment in excess of about 125,000 m3/km2 annually (Mikoš, Fazarinc and Ribičič 2006), which is about twelve times higher than an average sediment production. In the area, 2,543 houses were affected by the earthquake. The majority of them were in Bovec (473), Čezsoča (108), Kobarid (107), Jesenice (103), Soča (96), Tolmin (80), Drežnica (63), Kal-Koritnica (56), Trenta (53), Drežniške Ravne (51), and Poljubinj (51) (Orožen Adamič and Hrvatin 2001). The earthquake caused considerable damage to residential, industrial, and commercial premises and to the infrastructure and cultural heritage sites from WWI in the Soča, Tolminka and Sava Bohinjka valleys. The settlements that were hit by the earthquake stand on Quarternary glacial and fluvial sediments, or on flysch and rubble slopes. The danger of soil-structure resonance is considerable in the area. The damage to houses in some parts of the Bovec basin was enhanced by site amplification and soil-structure resonance (Gosar etal. 2001; Gosar 2007). The damage was recorded in the sixteen of Slovenia's then 192 municipalities, which cover 15% of Slovenia, and in 224 of the 516 settlements in the Upper Soča Valley. In 39 settlements of the Upper Soča Valley, 20% to 40% of the houses were damaged. In Drežniške Ravne and Jezerca, all the houses were damaged (100%), followed by Magozd (96%), Krn (93%), Koseč (91%), Lepena (90%), and Bovec (81%). In eighteen settlements, damage was only evident to the infrastructure network or elsewhere. The damage was the greatest in the Bovec municipality where it reached € 3,230 per individual inhabitant. The damage calculated per inhabitant exceeded € 15,000 in the settlements of Zabrdo, Bavšica, Krn, Magozd and Ukanc and reached € 9,713 in Čezsoča and € 6,005 in Bovec. During reconstruction special attention was devoted to increasing the earthquake safety of old buildings. The highest reconstruction costs by far were assessed in the town of Bovec (€ 10,021,338). In the neighbouring village Čezsoča, which ranked second according to damage, the reconstruction costs was less than one third of this amount (€ 3,205,247) (Orožen Adamič and Hrvatin 2001). The problem of reconstruction is well illustrated by the fact that 43% of the demolished buildings had been rebuilt following the 1976 Furlanese earthquake in the period between 1976 and 1980 (Ribičič, Vidrih and Godec 2000). Similar problems were encountered during the 2004 earthquake (M 4.9) when many buildings were damaged because of faulty reconstruction after the 1998 earthquake (Pipan 2011, 28). 4 Damage assessments according to real estate valuation on the example of Čezsoča village The Čezsoča village is situated in the Bovec basin south of the town of Bovec. It is situated on the Pleistocene plain and the terraces of the Soča River. According to the data of the Statistical Survey of Slovenia (SI-Stat .2012) 343 people live in 150 households. As noted above, the village was seriously hit by the 1998 earthquake. The data on the damage caused by the earthquake were collected and analysed based on previous work of the Department of Natural Hazards of the Anton Melik Geographical Institute ZRC SAZU (Orožen Adamič and Hrvatin 2001). The data on the damage caused by the earthquake were compared to the generalised market value of real estate. In order to make the comparison possible, the data on damage caused by the 1998 earthquake were first translated from the then Slovenian national currency (Tolar, SIT) to Euros (€) and then revalorized according to the data of the Statistical Survey of Slovenia (SI-Stat .2012). Only then could they be compared to the data on the generalised market values of the properties that were obtained from the web application of the the Surveying and Mapping Authority Figure 3: Real Estate Register provides generalised market property value of real estates in Slovenia (Internet 1). of the Republic of Slovenia (Si: register nepremičnin) (Internet 1). The evaluation of real estate was made for all the territory of the Republic of Slovenia for the purposes of the taxation; the results of the evaluation are public (Figure 3). In order to obtain correct assessments, different models of real estate valuation according to the type of property were used to calculate their values (Prostor .2012). If we compare these data with the data on actual damage, it is possible to produce assessments on the potential damage of future disasters (Mikoš 2012; see also Kumelj and Geršak 2011; Brundletal. 2010). We analysed the data on earthquake damage and generalised market value for 94 houses, i.e. app. 60% of houses in the settlement. Only properties with available data on damage as well as value could be assessed. The damage on all houses in the village amounted to almost one third of the overall generalised market value (28%). The damage was about € 1,654,000, while the generalised market value of the properties was €5,882,000. The average property market value was € 62,582 and average damage caused by the 1998 earthquake was € 17,406. The minimum property market value was € 11,978 and the maximum € 265,477. The minimum damage caused by the 1998 earthquake was € 514 and the maximum as high as € 139,060. Average generalised property value is about € 380/m2, while average damage was about € 100/m2. The amount of damage per area unit depends on the number of floors in a building; in four-floor buildings it is almost a third greater than in single-floor buildings (Figure 5). It should be noted that property value is positively correlated to the age of buildings (r = 0.72, p = 0.0005) and to the type (stone, brick, concrete) of building material (r = 0.29, p = 0.0025), while the correlation with the type of the building (individual, duplex, apartment block) is low and negative (r = -0.12, p = 0.04). Damage is positively correlated to age of buildings (r = 0.29, p = 0.0025) and with the type of building material (r = 0.23, p = 0.0025), but correlations were low. The older the building is, the higher is the expected damage potential. The damage was the highest in prefabricated buildings and the lowest in the buildings built of bricks (Figure 4). Half of the buildings that were damaged by the earthquake were built before 1940, especially in the decades after WWI (1920-1930) and during and after WWII (1940-1950) (Figure 6). The damage caused by earthquake is generally higher for younger buildings (exceeding € 150/m2) and lower for older buildings (in the range between 50 and € 100/m2) (Figure 7).