Mass Movement Susceptibility Maps in Slovenia: the Current State
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Geografski vestnik 84-1, 2012, 99–112 Articles ARTICLES MASS MOVEMENT SUSCEPTIBILITY MAPS IN SLOVENIA: THE CURRENT STATE AUTHORS Matija Zorn, Blaž Komac Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Anton Melik Geographical Institute, Gosposka ulica 13, SI – Ljubljana, Slovenia matija.zorn@zrc -sazu.si, blaz.komac@zrc -sazu.si Špela Kumelj Geological Survey of Slovenia, Dimičeva ulica 14, SI – 1000 Ljubljana, Slovenia spela.kumelj@geo -zs.si UDC: 911.2:551.435:528.94(497.4) COBISS: 1.02 ABSTRACT Mass movement susceptibility maps in Slovenia: The current state Mass movement susceptibility maps offer a quick and effective way to determine areas that people should not exploit or where it is known that any development would require special construction and other mea - sures. In recent years, such maps have been made for landslides, rockfalls, and debris flows at the national scale for Slovenia, and the first maps for municipalities have also been created. This article presents the current state of production of such maps in Slovenia. KEY WORDS geography, natural disasters, mass movement, prevention, susceptibility maps, Slovenia IZVLEČEK Zemljevidi nevarnosti za večje pobočne procese v Sloveniji: trenutno stanje Zemljevidi nevarnosti za večje pobočne procese omogočajo hitro in učinkoviti določanje območij, ki se jim je bolje izogniti oziroma na katerih je kakršenkoli poseg povezan z posebnimi gradbenimi ali drugimi ukrepi. V zadnjih letih so bili v Sloveniji v državnem merilu izdelani zemljevidi nevarnosti zaradi zemeljskih plazov, skalnih podorov in drobirskih tokov. Poleg tega so bili izdelani tudi prvi tovrstni zemljevidi za občine. Pred - stavljeno je trenutno stanje na področju izdelovanja tovrstnih zemljevidov v Slovenji. KLJUČNE BESEDE geografija, naravne nesreče, pobočni procesi, preventiva, zemljevidi nevarnosti, Slovenija The article was submitted for publication on August 14, 2011. 99 Matija Zorn, Blaž Komac, Špela Kumelj Mass movement susceptibility maps in Slovenia: … 1 Introduction Mass movement is a geographical constant in certain areas in Slovenia, and in the past some writ - ers have used expressions such as slippage -prone region or landslide -prone region for certain parts of the country (see sources in Zorn and Komac 2011a). Nonetheless, spatial planning encounters diffi - culties in such areas because these geomorphic processes are still considered to be interfering factors rather than component parts of them. On average, the landslide hazard is the greatest in Slovenian alpine (and pre -alpine) regions, where areas most susceptible to landslides cover more than 20% of the entire area. In the Pannonian regions, the most landslide -prone areas cover around 10% of the area, and in Mediterranean regions around 8%. The areas least threatened by landslides are the (predominantly) limestone Dinaric regions, where the areas most susceptible to landslides represent around 7% of the area (Zorn and Komac 2008a; Komac and Zorn 2009). From 1994 to 2008, damage caused by landslides and avalanches amounted to 0.033% of GDP, or nearly 8% of the annual damage due to natural disasters (Figure 1; Zorn and Komac 2011a; 2011b; 2011c). With regard to this damage, landslides and avalanches are ranked fifth, behind drought (nearly 26% of average annual loss due to natural disasters), hail (just over 20%), flooding (nearly 19%), and strong winds (just over 12%). This article presents the efforts made with regard to mass movement prevention after the adop - tion of the Waters Act (Zakon o vodah 2002) and some other intervention acts (e.g., Act on the Measures to be Taken to Repair the Damage Caused by Certain Large -Scale Landslides in 2000 and 2001; Zakon o ukrepih … 2002), and after the occurrence of some major landslides (e.g., the Stovžje landslide above Log pod Mangartom: 2,500,000 m3 (in 2000), the Slano blato landslide near Ajdovščina: 1,000,000 m3 (in 2000), the Koseč landslide above Kobarid: 675,000 m3 (in 2001); Zorn and Komac 2008, 36). Article 83 of the Waters Act (Zakon o vodah 2002) defines areas threatened by hydro -geomorphic processes and stipulates that these areas should be classified into various hazard categories. This can be achieved by producing susceptibility maps, which are one of the basic methods of mass movement prevention. However, the problem is that there is no uniform methodology for producing these types of maps (neither between various disciplines nor within the disciplines themselves). Specifically, the Waters Act (Zakon o vodah 2002) does not define this methodology and leaves it to a different legal document, which has not been adopted yet. In Slovenia, national funds are primarily used for recovery, and less so for prevention. It would cer - tainly be good if a greater portion of these funds could be earmarked for prevention; only 15% of the funds that were used from 2002 to 2010 alone to clean up seven major landslides (approximately 30.5 million; Koliko denarja … 2011) would, in theory, have been sufficient to produce quality mass -movement susceptibility maps for all of Slovenia’s municipalities (Komac and Zorn 2005, 92). Such maps are also defined in Article 57 of the Spatial Management Act (Zakon o urejanju prostora 2002), which also legislates the presentation of threatened areas. This is also prescribed by Article 87 of the Spatial Planning Act (Zakon o prostorskem načrtovanju 2007). Figure 1: Damage ( 000) due to landslides and avalanches in Slovenia by statistical region from 1994 to 2008 (Zorn and Komac 2011b, 25). p Figure 2: Landslide susceptibility map on a national scale (Zorn and Komac 2008a). p str. 102–103 Figure 3: Some Slovenian municipalities already have mass movement (predominately landslide) susceptibility maps, whereas for others they are still being produced (state: spring 2012). p str. 104 Figure 4: Rockfall susceptibility map on a national scale (Čarman et al. 2011). p str. 105 Figure 5: Debris -flow susceptibility map on a national scale (Komac, Kumelj, and Ribičič 2010). p str. 106 Figure 6: Landslide susceptibility map for the Municipality of Idrija (Komac and Zorn 2010, 103). p str. 107 100 G e o g r a f s 100000 k i 10000 v e 1000 s t 100 n 100000 i 10 k 10000 1 8 2006 2008 1994 1996 1998 2000 2002 2004 1000 4 - 100 100000 1 1 , 10 10000 2 1 3 1000 0 1994 1996 1998 2000 2002 2004 2006 2008 1 100 2 2 10 100000 100000 1 10000 10000 1994 1996 1998 2000 2002 2004 2006 2008 1000 1000 100 100 10 4 10 1 1 1994 1996 1998 2000 2002 2004 2006 2008 1994 1996 1998 2000 2002 2004 2006 2008 Statistical region (NUTS-3 level): 100000 9 10000 Pomurska 1000 1 5 100 2 Podravska 10 100000 11 100000 8 1 3 Koroška 10000 10000 1994 1996 1998 2000 2002 2004 2006 2008 1000 1000 4 Savinjska 100 100 Zasavska 10 10 6 100000 5 1 1 10000 1994 1996 1998 2000 2002 2004 2006 2008 1994 1996 1998 2000 2002 2004 2006 2008 6 Spodnjeposavska 1000 100 7 Jugovzhodna Slovenija 10 Osrednjeslovenska 1 8 2004 2006 2008 7 1994 1996 1998 2000 2002 100000 100000 9 Gorenjska 10000 10 10000 1000 1000 10 Notranjsko-kraška 100000 12 100 10000 100 Goriška 10 11 1000 10 1 1 Obalno-kraška 1994 1996 1998 2000 2002 2004 2006 2008 100 1994 1996 1998 2000 2002 2004 2006 2008 12 10 1 1994 1996 1998 2000 2002 2004 2006 2008 Scale: 1 : 1,350,000 Author of the content: Matija Zorn A Author of the map: Manca Volk r t i 1 c 0 l © Anton Melik Geographical Institute ZRC SAZU e 1 s Matija Zorn, Blaž Komac, Špela Kumelj Mass movement susceptibility maps in Slovenia: … i a A u s t r `a Me K o k r S a av in ja Sa va So~a y Sora Id r ij ca l a ica an blj Lju t I Vipava P i v k a A d r i a t i c Re ka sea ja Dragon 102 Geografski vestnik 84-1, 2012 Articles H u n g a r [ ~ y a v n M ic u a ra L ed a va Drava P e s n i c a M isl inja Dravinja Sa va a l t o S Legend M i rn a landslide susceptibility rate I 0 1 Krka 2 a 3 i 4 t 5 a t i c state border o s border of municipality r 01020304050 C km Authors of the content: Blaž Komac, Matija Zorn K Authors of the map: Blaž Komac, Manca Volk, Matija Zorn ol pa © Anton Melik Geographical Institute ZRC SAZU 103 M 1 0 a 4 t i j a Z o r n , B l a ž K o m a c , Š p e l a K u m e l j Municipality susceptibility maps M (elaborated or work in progress) a s s work in progress by Geological Survey of Slovenia m 1 to 14 o elaborated by Geological Survey of Slovenia v e 1 (Bavec, Budkovič and Komac 2005) m elaborated by Geological Survey of Slovenia e 15, 16 (Bavec et al. 2010) n t elaborated by Geoingeniring s u 17 (Beguš 2002) s 18 (Beguš 2011) c e elaborated by Anton Melik Geographical Institute p t ZRC SAZU i b 19 (Komac and Zorn 2008) i l i 20 (Komac and Zorn 2010) t 21 (Klabus et al. 2009) y elaborated by Department of Geography, m Faculty of Arts, University of Ljubljana a p 22 (Natek et al. 2010) s i 0 10 20 30 40 n km S l o Author of the content: Špela Kumelj, Matija Zorn v e Author of the map: Špela Kumelj n i a © Geological Survey of Slovenia : … G e o g r a f s k i v e s t n i [ k ~ L a e v M d 8 ni u a ca ra va 4 - D 1 rava , 2 P e 0 s n 1 i c 2 Me`a a Sav in avinja ja Dr So~a a j n i v a S Sor S a ava Id r ij ca Sa Legend va rockfall susceptibility rate a ca l ni t lja o b S Lju Mirna 0 V 1 ipava ka Kr 2 3 P i 4 v k a 5 Re J A D R A N S K O ka 0 10 20 30 40 50 M O R J E km Author of the content: Magda Čarman, Špela Kumelj, Marko Komac Dragonja Ko Author of the map: Špela Kumelj A lp a r t i 1 © Geological Survey of Slovenia c 0 l e 5 s M 1 0 a 6 t i j a Z o r n , B l a ž [ ~a L K v M ed n a o ic ur v a a a m Drav a a c , P e Š s n p i c e`a a e M l a K