Analysis of floods using satellite images - case study of the 2007 torrential flood in the Selška valley

An application of data mining for the determination of flooded areas was published in the Journal Geodetski vestnik (no. 54/2010-4). This paper analyses the usefulness of these results for further analyses of hydraulic parameters. The velocity and discharges were computed for six locations. The study showed that the flooded areas determined by satellite images can be used for further analyses. Nevertheless, other layers have to be sufficiently precise, especially the digital terrain model (DTM). DTM 12.5 was used. The study showed that DTM 12.5 is not precise enough. The observed area is very rough and the hydraulic parameters (cross sectional area of flow, wetted perimeter, hydraulic radius, river-bottom slope, flow velocity, discharge) cannot be detected with sufficient precision. Consequently the calculated hydraulic radiuses, velocities and discharges are out of expectations. In the first part of the article, some basic information about remote sensing and its techniques is presented. Some practical examples of their usage (especially satellite images) for the observation of natural disasters are also given

Acceptability of a Multifamily Housing Construction in the Ž-S7 Zone in the Žiri Municipality

The present thesis discusses the problem of a multifamily housing construction. Though a common occurence in bigger cities, in smaller rural cities only just undergoing the transformation into cities proper, multi-dwelling buildings raise the question of their acceptability. For this very reason any land development necessitates a prior integral analysis of the area. The thesis is based upon an analysis of acceptability of a multifamily housing construction in the Žiri municipality. The analysis reposes on various factors, namely: spatial limitations, population density, the number of inhabitants and their age structure, and others. The author of the thesis provides solutions to the question of multifamily housing construction acceptability from the aspect of the local population's lifestyle as conditioned by the type of occupation, commute time, the share of immigrants from urban and rural areas, etc. On the basis of the obtained results two verifications were performed, viz. a verification of the construction of the Ž-S7 zone with both, family and multifamily houses, and a verification of the construction in the aforementioned zone with multifamily houses exclusively

Uporabnost podatkov satelitskega in letalskega daljinskega zaznavanja za opazovanje in kartiranje vodnih površin ; Usefulness of satellite and aerial remote sensing data for monitoring and mapping of surface waters

Prispevek prinaša pregled in primerjavo zmožnosti zaznavanja vodnih objektov ali vodnih površin z različnimi sistemi daljinskega zaznavanja: optičnimi in radarskimi satelitskimi senzorji ter optičnimi senzorji na letalih. Zmožnosti zaznavanja vode ocenjujemo z več vidikov, in sicer razlik v prostorski in spektralni ločljivosti posnetkov, zahtevnosti predobdelave in priprave posnetkov, načina obdelave oziroma analize posnetkov ter ustreznosti podatkov za vrsto in namen kartiranja. Pozornost namenjamo tudi vrednotenju uporabnosti podatkov daljinskega zaznavanja glede na uspešnost zaznave območij vode v heterogeno strukturiranih okoljih ; This article presents a review and comparison of the detection capability of water facilities or water surfaces with different systems of remote sensing: optical and radar satellite sensors, as well as optical sensors on aircraft. The capabilities of water detection are estimated from several aspects: differences in the spatial and spectral resolution of imagery, the complexity of imagery pre-processing requirements, and the method of analysis and interpretation feasibilities for the type and purpose of mapping. Particular attention is paid to evaluating the applicability of remote sensing data in light of the detection efficiency of water areas in heterogeneously structured environments

Analiza poplav z uporabo satelitskih posnetkov – primer hudourniške poplave v Selški dolini leta 2007 : Analysis of floods using satellite images – case study of the 2007 torrential flood in the Selška valley

V Geodetskem vestniku št. 54/2010-4 je bil predstavljen postopek strojnega učenja za določitev poplavljenih območij ob poplavah v Železnikih leta 2007 na podlagi satelitskih posnetkov SPOT. V tokratnem prispevku je analizirana uporabnost teh poplavljenih površin, prepoznanih na podlagi satelitskih posnetkov, za nadaljnjo hidravlično analizo. Na šestih izbranih merilnih mestih v strugi Selške Sore so bile določene hitrosti in pretoki reke. Raziskava je pokazala, da natančnost določitve poplavljenih območij na podlagi satelitskih posnetkov omogoča nadaljnje določanje hidravličnih parametrov. Za njihovo natančno določitev pa je potrebna tudi zadostna natančnost preostalih podatkovnih slojev. V našem primeru je bil uporabljen model DMV ločljivosti 12,5 metra, ki na razgibanem terenu s hitro spreminjajočimi se višinami ne omogoča dovolj natančnega izračuna hidravličnih parametrov. Velikost celic 12,5 m × 12,5 m namreč ne omogoča določitve površin pretočnega prereza, omočenega oboda in naklona z zadostno natančnostjo. Zaradi tega izračunani hidravlični parametri (pretočni prerez, omočeni obod, hidravlični radiji, nakloni dna, hitrosti in pretoki) odstopajo od pričakovanih vrednosti. V prvem delu prispevka je podanih nekaj osnovnih informacij o daljinskem zaznavanju in različnih tehnikah njegove uporabe. Bralec se seznani tudi z nekaj praktičnimi primeri uporabe daljinskega zaznavanja (zlasti satelitskega) za opazovanje naravnih nesreč ; An application of data mining for the determination of flooded areas was published in the Journal Geodetski vestnik (no. 54/2010-4). This paper analyses the usefulness of these results for further analyses of hydraulic parameters. The velocity and discharges were computed for six locations. The study showed that the flooded areas determined by satellite images can be used for further analyses. Nevertheless, other layers have to be sufficiently precise, especially the digital terrain model (DTM). DTM 12.5 was used. The study showed that DTM 12.5 is not precise enough. The observed area is very rough and the hydraulic parameters (cross sectional area of flow, wetted perimeter, hydraulic radius, river-bottom slope, flow velocity, discharge) cannot be detected with sufficient precision. Consequently, the calculated hydraulic radiuses, velocities and discharges are out of expectations. In the first part of the article, some basic information about remote sensing and its techniques is presented. Some practical examples of their usage (especially satellite images) for the observation of natural disasters are also given