Theoretical Lidar Point Density for Topographic Mapping in the Largest Scales

When ordering LiDAR data, LiDAR point density per surface unit is important information with decisive influence on the price of the LiDAR survey. The paper first deals with the theoretical calculation of the minimum LiDAR point density, necessary for the acquisition of topographic data of the largest scales. For this purpose the sampling theorem is used. However, since topographic objects (roads, water bodies, etc.) and phenomena represented on topographic maps and in topographic bases are in many cases located under vegetation, also the rate of laser beam penetration through vegetation for the area where the topographic data are to be gathered has to be known. In a research on a test case conducted in the area of the town Nova Gorica we calculated the rate of laser beam penetration for four different vegetation types: scarce Mediterranean vegetation, thick thermophilic deciduous forest, mixed vegetation (meadows, orchards and forest) and built-up area. By connecting the theoretic minimum LiDAR point density with the rate of penetration, we defined the minimum LiDAR point density for the needs of data acquisition on topographic maps of the largest scales or in topographic bases of comparable detail (from 1 : 1000 to 1 : 10,000)

Grassland Recognition with the Usage of Thermal Weights

In this paper we apply the usage of thermal weights, a new variable for geostatistical analysis and we present the method for their determination. In the case study we tested a data fusion between Sentinel-2 and Landsat 7/8 data, to incorporate also the thermal factor in the detection of land cover changes. The process distinguishes grasslands from other crops with similar vegetative appearance and offers us the possibility to create a new statistical sample with just grasslands. The data fusion is incorporated in the calculation of Land Surface Temperature (LSTFU) by combining the Sentinel-2 derived Normalized Difference Vegetation Index (NDVI), and from it derived land surface emissivity, with the Landsat 7/8 derived Top of Atmosphere Brightness Temperature (TOABT). The experimental LSTFU is modified into a normalized assessment variable by a time-series analysis. The result is a thermal weight layer which can help us in further object-based image analyses and classification. The thermal weight is calculated from Sentinel-2 and Landsat 7/8 datasets that has small acquisition time gaps between them. The accuracy assessment due to time gaps and sensor differences was evaluated with Cohens’s kappa (κ) and correlation matrix validation. The data fusion is made to test if a Sentinel-2 fusion approach could improve the Thermal Weight created just by Landsat imagery. The purpose was to evaluate the importance of thermal bands for LU/LC cover

Thickness and geodetic mass balance changes for the Triglav Glacier (southeastern Alps) from 1952 to 2016

Various geodetic and lidar measurements performed on the Triglav Glacier (Julian Alps, Slovenia) make it possible to study not only the extent of the glacier but also changes in its thickness and volume. These measurements also make it possible to calculate the geodetic mass balance of the glacier. Thickness and volume changes were calculated using glacier area measurements from 1952, 1975, and 1992, and annually between 1999 and 2016. The mean thickness decreased from 39.2m in 1952 to 2.45m in 2012. The maximum thickness decreased from 48.3 m in 1952 to 5.2 m in 2007. The mean specific mass balance was calculated for the area of 1 hectare that the glacier covered in 2016. From 1952 to 2016, the annual specific mass balance was −0.45m w.e.a−1

Optimization of the data processing methodology and accuracy analysis of airborne laser scanning data applied for local spatial planning

Aerial laser scanning (lidar) has become a widely used technique for spatial data production. Although various rigorous error models of aerial laser scanning already exist and examples of a-posteriori studies of aerial laser scanning data accuracies verified with field-work can be found in the literature, a simple measure to define a-priori error sizes is not available. In this work the aerial laser scanning error contributions are described in detail: the basic systematic error sources, the flight-mission-related error sources and the target-characteristic-related error sources. A review of the different error-source sizes is drawn from the literature in order to define the boundary conditions for each error size. Schenk’s geolocation equation is used as a basis for deriving a simplified a-priori error model. By changing different geometrical parameters the simulation of error sizes is made and the influence of different error sources is studied. This simplified error model enables a quick calculation and gives a-priori plausible values for the average and maximum error size, independent of the scan and heading angles as well as being independent of any specific aerial laser scanning system’s characteristics. Spatial data production by aerial laser scanning is also limited by acquisition precision. The acquisition precision is defined by spatial data products (in our case: geodetic data for local spatial planning). The acquisition precision of spatial data products also defines the minimum point density of aerial laser scanning. The minimum point density when applying aerial laser scanning as a stand-alone-technique is defined through minimal sampling density or Nyquist frequency. Through measuring penetration rate for different vegetation classes in the test area the total usable point density is defined. The a-priori aerial laser scanning accuracy and spatial data product precision defines when the aerial laser scanning can be applied in data extraction process in Slovenia. Through this the acquisition methodology for different geodetic data for local spatial planning production can be optimized. The review on legal acts defining the local spatial planning is given. The current and proposed data processing methodology for different geodetic data used for local spatial planning is described

Changes in the Skuta Glacier (southeastern Alps) assessed using non-metric images

The Skuta Glacier in the Kamnik–Savinja Alps (in northern Slovenia) is one of the two remaining glaciers in Slovenia. It is located in a cirque oriented toward the northwest, which shields it from sunlight for most of the year. The glacier lies at an average elevation of 2070m. In recent years, its average area has measured around 1.5 hectares. Monitoring of the glacier has been performed since 1946. In 1962, regular photographing of the glacier with various cameras started from various non-fixed standpoints. Using the single image interactive orientation acquisition method, in which a single photograph is compared with the projection of a modern digital terrain model, seventeen photographs covering the period from 1970 to 2015 were used to acquire the 3D-perimeters of the glacier. The data shows that the elevation of glacier’s upper edge decreased by approximately 40m in the last half-century. Changes in the glacier’s area and average upper edge elevation were compared with average annual temperature and maximum seasonal snow cover depth

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

Triglavski ledenik

The Triglav Glacier lies on the southeast edge of the Alps, in the Julian Alps below Mount Triglav, Slovenia’s highest peak. Its upper edge lies at 2,500 m. The glacier has been regularly measured, observed, and studied since 1946 by the Anton Melik Geographical Institute at ZRC SAZU. When measurements began it covered 14.4 ha, but today it covers less than half a hectare. The glacier no longer has all glacial features. Thus one may only speak of a glacier because of its past, when it clearly had the basic features of an alpine glacier. Analysis of the geomorphic forms of the Triglav Mountains allows reconstruction of past glaciation. Moraine deposits above the upper edge of Mount Triglav’s North Wall indicate the glacier’s extent during the Little Ice Age. When this ended in the nineteenth century, visits to the Triglav Mountains started increasing, and so there are many written and pictorial sources available from this time.Triglavski ledenik od leta 1946 redno merijo, opazujejo in preučujejo sodelavci Geografskega inštituta Antona Melika ZRC SAZU. Na začetku meritev je bila njegova površina 14,4 ha, do danes pa se je skrčil na slabo polovico hektarja. Zdaj ledenik nima več vseh ledeniških značilnosti. O ledeniku lahko govorimo le še zaradi njegove preteklosti, na osnovi analize geomorfnih oblik Triglavskega pogorja ter pisnih in slikovnih virov iz 19.in 20. stoletja. Obdobje meritev z vidika kolebanja ledenika kronološko delimo na štiri dele. Prva leta do leta 1964 je zaznamovalo krčenje ledenika. Leta 1952 je bil ledenik prvič geodetsko izmerjen. Na podlagi teh meritev smo lahko izračunali tudi prostornino ledenika. Drugo obdobje od leta 1965 do leta 1982 je zaznamovala stagnacija v krčenju ledenika. V večini let je ledenik tudi ob koncu talilne dobe prekrival sneg. Tretje razdobje med letoma 1983 in 2003 je zaznamoval najhitrejši umik ledenika. V devetdesetih letih 20. stoletja smo posodobili meritve, leta 1999 smo začeli z rednimi fotogrametričnimi meritvami, tega leta smo prvič izmerili debelino ledu z georadarjem. V zadnjem razdobju po letu 2003 se je krčenje ledenika znova upočasnilo

Rock glaciers and mountain hydrology: A review

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.In mountainous regions, climate change threatens cryospheric water resources, and understanding all components of the hydrological cycle is necessary for effective water resource management. Rockglaciers are climatically more resilient than glaciers and contain potentially hydrologically valuable ice volumes, and yet havereceived lessattention, even though rock glacier hydrologicalimportance may increase under future climate warming. In synthesising data from a range of global studies, we provide the first compre-hensive evaluation of the hydrological role played by rock glaciers. Weevaluate hydrological significanceover a range of temporal and spatial scales, alongsidethe complex multiple hydrological processes with which rock glaciers can interact diurnally, seasonally, annually, decadally and both at local and regional extents.We report that although no global-extent, complete inventory for rock glaciers exists currently, recent research efforts have greatly elaborated spatialcoverage.Using these research papers,we synthe-sise information on rock glacier spatial distribution, morphometric characteristics, surface and subsurface features, ice-storage and hydrological flow dynamics, water chemistry, and future resilience, from which we provide the first comprehensive evaluation of their hydrological contribution. We identify and discuss long-, intermediate-and short-term timescales for rock glacier storage, allowing a more balanced assess-ment of the contrasting perspectives regarding the relative significance of rock glacier-derived hydrological contributions compared to other water sources.We show that further empirical observations are required to gain a deeper hydrological understanding of rock glaciers, in terms of(i) their genesis and geomorpho-logical dynamics (ii) total ice/water volume; (iii) water discharge; and (iv) water quality. Lastly, we hypothesisethat at decadal and longer timescales, under future climate warming, degradation of ice within rock glaciers may represent an increasing hydrological contribution to downstream regions, and thus in-creased hydrological significance while rock glacier water stores persist.Royal Geographical SocietyNatural Environment Research Council (NERC

Meje katastrskih občin pod Krimom: po sledeh meje med Bistro in Engelshausi iz leta 1726 (= The cadastral municipality boundaries under Krim: the boundary between Bistra and Engelshaus from 1726)

The borders of the cadastral municipalities that are still valid today are, in many cases, based on much older landowners’ borders of feudal lordships. Thus, in central Slovenia, in the forests below Mount Krim, we find the old boundary marks representing today’s cadastral municipality of Preserje, based on the former border between the Carthusia Bistra and the Ig estate from 1726. The main purpose of this paper is to present the current state of the preserved boundary marks along this border. The preserved boundary marks are about 80 cm high, have carved sequential letters, the year 1726 and coats of arms of the Carthusia Bistra and the earls Engelshaus (the owners of the Ig estate at that time). In 1748, this boundary was adopted as the boundary between the Notranjska (Inner) and the Gorenjska (Upper) districts of the Carniola region in the Habsburg Monarchy. As part of the Franciscan cadastral survey in 1823, this border was used as the border of cadastral municipalities, and it has retained this role until today. On the Franciscan cadastral maps, we find eleven locations numbered with the year 1726 and the consecutive letter from B to M. Today, at these locations, we can still find two original boundary marks decorated with coats of arms and the year 1726, two destroyed original boundary marks and three probably later replaced boundary marks without inscriptions and coats of arms. We also examined locations on the even older eastern border of the Carthusia Bistra, on which today mainly only post-war trigonometric points of lower orders can be found; only on the Smrekovec hill under Rakitna did we find another older boundary mark without additional inscriptions or coats of arms