Matija Zorn

Soil erosion on agricultural land in Slovenia – measurements of rill erosion in the Besnica valley

The article describes soil erosion in Slovenia. There is little concrete data on soil erosion due to the lack of awareness of this process and the fragmentation of farmland. Long-term measurements of soil erosion have only been done at one location; elsewhere, there have only been short observations and calculations and modeling on the basis of empirical equations. To increase our knowledge of this phenomenon, we took measurements of soil erosion on a field in the Besnica Valley northwest of Kranj. With the decrease of agricultural land use in Slovenia due to natural, social, and economic factors, the amount of material lost to erosion has decreased in the last few decades. For protection from erosion, various preventive methods such as terracing, mulching, and contour plowing are employed. The awareness that protection against erosion is a demanding and long-term task is gradually increasing, but nothing can replace the soil that has been lost due to erosion.

Damage caused by natural disasters in Slovenia and globally between 1995 and 2010

This paper describes the damage caused by natural disasters in Slovenia and around the world between 1995 and 2010. The fundamental purpose of the article is to present damage caused by different natural hazards in Slovenia and abroad together with the analysis of the amount of damage caused by natural disasters together and a discussion on the comparability of data. Described is the damage caused by earthquakes, floods, fires, droughts, strong winds, hail, frost and ice, and landslides and avalanches. From the analyzed material on the amount of damage we can evaluate the financial importance of prevention, which is be a key activity in the field of protection against natural disasters.

Erosion processes in Slovene Istria – part 2: Badlands

This article is a continuation of the article on soil erosion in submediterranean Slovene Istria from the first issue of the 2009 (49-1) journal. In this article we present geomorphic processes in the badlands of the same area (Dragonja River basin, SW Slovenia): sediment production from steep bare (Eocene) flysch slopes (rockwall retreat), movements of flysch debris along erosion gullies, and geomorphic processes on talus slopes. Sediment production of flysch rocks was determined by measurements on erosion plots and totals around 80 kg/m2 per year on average, which means that steep bare flysch rockwalls retreat at a speed of 35 to 50 mm per year. The badlands not only contain flysch walls but also slopes already eroded by erosion rills and gullies. A dam in one of the erosion gullies with the catchment area of 0.1 ha captured 20 tons of debris in fourteen months. Monitoring on talus slopes of the badlands revealed their dual character because erosion here alternates with accumulation.

Erosion processes in Slovene Istria – part 1: Soil erosion

In 2005 and 2006 intensive measurements were made of various erosion-denudation processes in the Dragonja River basin. The measurements included geomorphic processes in the badlands: the rockwall retreat of steep bare flysch slopes, movements of flysch debris along erosion gullies, and geomorphic processes on talus slopes. At the same time, measurements of soil erosion were made in three different land use areas: bare soil in an olive grove, an overgrown meadow, and a forest. The results are presented in two parts. Part One presents the measurements of soil erosion, and Part Two in the next issue of the journal (No. 49-2) will present geomorphic processes in the badlands. The measurements of soil erosion made on one-meter-square closed erosion plots south of the village of Marezige revealed that the greater part of the annual erosion was caused by only a few major erosion events. Between May 2005 and April 2006, interrill erosion amounted to 9,013 g/m2 (90 t/ha) on bare soil in an olive grove with an inclination of 5.5o and an average weekly proportion of specific runoff of 23%, 168 g/m2 (1.68 t/ha) on an overgrown meadow with an inclination of 9.4o and an average weekly proportion of specific runoff of 8%, and 391 g/m2 (3.91 t/ha) in a forest with an inclination of 7.8o and 415 g/m2 (4.15 t/ha) in a forest with an inclination of 21.4o with an average weekly proportion of specific runoff of 6% regardless of the inclination. The amount of precipitation during the reference year was slightly below the long-term average.

The Triglav Glacier between the years 1999 and 2012

The Triglav glacier is situated in the Julian Alps in the northwest of Slovenia. Presented are the results of investigations and measurements of the Triglav glacier done between the years 1999 and 2012. It was for the first time during this period that its depth was measured by means of georadar. Its area was measured on a yearly basis by means of various land surveying methods which are stated in detail. We explained the dynamics of the glacier’s shrinking on the grounds of weather conditions of each respective year. Due to the glacier’s concave form, snow in the past few years remained all until the late summer, particularly in the central and lower sections of the glacier. If such weather conditions continue, and the amount of winter precipitation further increases, the remainder of the Triglav glacier, though small in size, will continue to exist for a few years.

Deterministic modeling of landslide and rockfall risk

The article presents two deterministic methods for the elaboration of landslide and rock-fall source area maps and, considering human activity in the landscape, for the elaboration of landslide and rockfall risk maps. Risk maps are one of the fundamental bases for protection against natural disasters since they illustrate the risks to areas of human activity due to various natural processes. Using the weighting method and for the first time the matrix method, we established the extent of land-slide and rockfall source areas in the Upper Savinja Valley and the risk due to these processes relative to settlement, roads, land use, and rivers and streams. The methodology for elaborating maps using both approaches is described in detail as well as the differ-ences between them. The basic purpose of risk maps is to direct human encroachment in the landscape to safe areas.

Classification of natural disasters between the legislation and application: experience of the Republic of Serbia

The paper discusses the definitions of natural disasters and recommends the implementation of definitions and classifications of natural disasters in accordance with those decreed at the Centre for Research on the Epidemiology of Disasters (CRED) and Munich Re insurance Company (Munich RE) for administrative use in the Republic of Serbia. For the Republic of Serbia, the issue of natural disasters is presented both through government documents (e.g. the Law on Emergencies and the National Strategy of the Protection and Rescue in Emergencies) and the survey of the frequency and typology of disasters. Significant discrepancies exist between older and more contemporary classifications of disasters in Serbia. They are especially emphasized in comparison to the CRED and Munich RE classifications and databases. This causes problems in the monitoring, recording and assessment of the effects of natural disasters. It is proposed that definitions be adapted and implemented into legislative and other documents.

Is hail suppression useful in Serbia? – General review and new results

Anthropogenic influence on weather has been increasingly published and discussed in the last decades. Climate changes caused by inadvertent anthropogenic influence are well underway. Hail suppression, which has been proven to have no influence on weather, will be considered in the article. Even though hail suppression as scientifically ungrounded activity seemed to promise certain success several decades ago, it has spread over the whole territory of the Republic of Serbia after abundant experience, when many developed countries have given up on this activity. Reasons will be presented for the senselessness of hail suppression based on the latest research. By processing all hail data from the territory of Serbia in the period from 1967 to 2010, it was found out that the hail trend is rising which is in contrary to expectations and previous claims that hail suppression decreases hail frequency.

The History of Acta geographica Slovenica

Acta geographica Slovenica is a research journal for geography and related disciplines published by the Anton Melik Geographical Institute of Scientific Research Centre of the Slovenian Academy of Sciences and Arts. It has been published since 1952 and is the second-oldest Slovenian geographical journal. Volume 50 was published in 2010, and this article is dedicated to this special anniversary. The journal was only published occasionally until 1976, when the volume 14 appeared, but afterwards it began to be published annually, with two volumes a year since 2003 (volume 43). With volume 43, the journal was included in Science Citation Index Expanded (SCIE). Since 2010, it has also had an impact factor. For 2009, this factor was 0.714, which ranks the journal in third place among all indexed Slovenian journals. In all the volumes, a total of 273 research articles have been published on more than 12,000 pages; half of these articles were written by the institute members.

Probability modelling of landslide hazard

In this journal, the authors (Zorn, Komac 2004) previously described the use of two deterministic methods for establishing the possibility of landsliding. This time, they take a step forward and using the example of the flysch Goriska Brda hills present the probability modelling of landslide hazard. In probability methods, the intensity and distribution of the processes are established by comparing indirectly determined landscape elements and the actual situation, while in deterministic methods, subjective decisions have an impact on the result. We have elaborated a probability map for landslides with a fixed return period using the Dempster-Shafer method on the basis of the data on 800 landslides that occurred with intensive precipitation in the fall of 1998.