This study compared oak butt-log volume estimations gained through terrestrial measurements in the forest stand with a remote approach using an unmanned aerial system (UAS) and photogrammetric ...post-processing. Terrestrial measurements were conducted in the lowland part of Croatia after a completed motor–manual final felling of a 140-year-old even-aged oak stand. Butt-logs’ volumes were estimated with four methods: the sectioning method and Huber’s, Smailan’s and Riecke–Newton’s methods. Measuring diameters and lengths and estimating volumes remotely were based on orthophotos using four different software: ArcGIS, QGIS, AutoCAD and Pix4D. Riecke–Newton’s method for volume estimation had the smallest relative bias of +1.74%, while for Huber’s method it was −8.07% and with Smailan’s method it was +21.23%. Log volume estimations gained remotely via ArcGIS and QGIS were, in the case of Huber’s method, at +3.63% relative bias, and in the case of Riecke–Newton’s method at +1.39% relative bias. Volume estimation using the sectioning method resulted in a total of 51.334 m3 for the whole sample, while the sectioning method performed with the help of AutoCAD resulted in 55.151 m3, i.e., +7.43% relative bias. Volume estimation of thirty oak butt-logs given by Pix4D software (version 4.8.4) resulted in +9.34% relative bias (56.134 m3). Comparing terrestrial measurements and the volume estimations based on them to those gained remotely showed a very high correlation in all cases. This study showed that using a UAS for log volume estimation surveys has the potential for broader use, especially after final felling in even-aged forests where the remaining trees in the stand would not block photogrammetric analysis.
Rutting measurements are a significant part of scientific research on the impact of forest vehicles on the forest soils and damage to the forest transport infrastructure. Although photogrammetric ...methods of measurement or measurements based on LiDAR (light detection and ranging) data are increasingly being used for rutting measurements, the previous research conducted using these methods indicated the challenge of recording water-filled ruts. For this reason, it is necessary to define a reliable method of rutting field measurement in lowland forest stands characterized by a high level of groundwater that fills the ruts shortly after the passage of forest vehicles. This research analyzed the measurement accuracy using a total station and a GNSS RTK device with a CROPOS correction base in relation to the measuring rod that represented the reference method. Based on recorded and processed data, ruts are displayed in two ways: as net and as gross value of rut depth. The analysis of net rutting revealed a statistically significant difference between the calculated rut depths based on measurements with a GNSS RTK device and other methods. On average, the net rutting measured by the GNSS RTK device was 2.86 cm smaller than that of the reference method. When calculating the gross rutting, which consisted of the net rut depth and the bulge height, no statistically significant difference was found between the measurement methods used. Based on this result, the bulge height was also analyzed, and showed a statistically significant difference between the data recorded by the GNSS RTK device and other methods. It can be concluded that measuring the depth of ruts with a total station gives accurate data and represents the optimal modern field measurement method for the same or similar terrain conditions. In contrast, the GNSS RTK device, which constantly gives higher elevation points, can be used to measure gross rutting.
Forest roads, as a prerequisite for high-quality forest management, should be optimally distributed in order to avoid negative environmental impacts and to best fulfill their task. In the design ...phase of forest roads, it is necessary to know which factors influence most the volume of earthworks to enable the designer to best adapt to the terrain requirements. In this paper the impact of an average cross terrain slope and carriageway value of a forest road on cut and fill volume is analyzed. The research was carried out in the area of the management unit Trovrh–Kik, characterized by irregular terrain with slopes ranging between 27 and 58%, and on some micro locations even up to 84%. On eight forest roads, based on standard cross-section profiles, the influence of the average cross terrain slope and carriageway value (difference between ground level and grade level) of the forest road on the cut and fill volume per 1 m of the forest road route was analyzed. The obtained coefficients of determination indicate a strong correlation between the cut volume and carriageway value (R2 = 0.6841), and a moderate correlation between the fill volume and carriageway value (R2 = 0.5619). Unlike the influence of carriageway value on the cut and fill volume, the correlation between the cross terrain slope and fill volume is weak (R2 = 0.2076) or moderate in the case of the cut volume (R2 = 0.3167). On the basis of the analyzed standard cross-section profiles, it was determined that the carriageway value was 0.051 m, where the difference between the cut and fill volume was minimum and the average actual carriageway value was determined to be −0.09 m. It can be concluded that, on terrains with large and varying slopes, there is no unique model or terrain factor that could describe the earthworks required in the construction of a forest road. However, it is beyond doubt that the increase in the carriageway value and cross terrain slope caused the increase in the aforementioned volumes.
Izvoženje drva forvarderima, obilježava kotrljanje drva na kotačima, prihvat i sakupljanje sortimentnom metodom izrađenoga drva hidrauličnom dizalicom, iz čega proizlazi i zahtjev za paralelnom ...mrežom sekundarnih šumskih prometnica međusobnoga razmaka dvostrukoga dosega dizalice.
Rad se bavi prikazom: 1) dimenzijskih i masenih značajki forvardera u svijetlu norme ISO 13860 (2016) te 2) plana raspodjele tereta forvardera kojega je razvio njemački Kuratorij za šumski rad i šumsku tehniku (KWF), s ciljem pomoći šumarskim stručnjacima pri nabavci, odnosno korištenju ovih šumskih vozila.
Za primjerni forvarder odabran je teški osmokotačni forvarder Komatsu 875, za koji su na osnovi mjerenja prikazane njegove dimenzijske i masene značajke, kao i plan raspodjele tereta s ciljem njegove ocjene.
Kritički osvrt je dan i na normu ISO 13860 (2016) s obzirom na neobuhvaćanje nekih dimenzijskih (duljina i visina prednjeg te stražnjeg prepusta forvardera, kutovi i polumjeri prohodnosti vozila) i masenih (položaj točke težišta) pokazatelja forvardera, a koje opisuju i/ili služe modeliranju njegove kretnosti pri izvoženju drva s obzirom na smjer i uzdužni nagib terena. Isto tako, norma izrijekom ne spominje niti jedan pokazatelj okolišne pogodnosti (npr. nominalni tlak na podlogu).
Timber forwarding is characterised by carrying timber clear of the ground and loading timber assortments by a hydraulic crane, which results in the requirement for a parallel network of secondary forest infrastructure network where the distance between trails equals to double span of the hydraulic crane.
The paper presents 1) dimensional and mass characteristics of forwarders considering ISO 13860 (2016) standard and 2) forwarder load distribution plan developed by the German Kuratorium für Wadarbeit und Forsttechnik (KWF) to assist forestry experts in the purchase and use of these forest vehicles.
The heavy eight-wheel forwarder Komatsu 875 was selected as an example. Its dimensional and mass characteristics are shown based on measurements and the load distribution plan, aiming to evaluate the vehicle.
A critical comment is also given regarding the ISO 13860 (2016) standard due to the lack of some dimensional (length and height of the front and rear overhangs of forwarders, approach and departure angles and clearance radii) and mass (position of the centre of gravity point) of forwarders. These characteristics describe and serve to model its mobility during timber forwarding concerning the direction and longitudinal slope of the terrain. In addition, the ISO 13860 (2016) standard does not explicitly mention any indicator of environmental suitability (e.g. nominal ground pressure).
Svrha ovog članka detaljno je pojašnjenje problematike funkcionalnog pristupa utvrđivanja dostupnosti šumske površine, odnosno jednoznačnog i ujednačenog utvrđivanja gustoće cesta i relativne ...otvorenosti promatrane šumske površine koja se najčešće prikazuje na razini gospodarske jedinice. Navedena dva parametra predstavljaju neizostavne čimbenike u kasnijoj fazi planiranja optimalne mreže šumskih prometnica. Kao vodič postupka otvaranja šuma poslužio je važeći Pravilnik o provedbi mjere M04 »Ulaganja u fizičku imovinu«, podmjere 4.3. »Potpora za ulaganja u infrastrukturu vezano uz razvoj, modernizaciju i prilagodbu poljoprivrede i šumarstva«, tipa operacije 4.3.3. »Ulaganje u šumsku infrastrukturu« iz Programa ruralnog razvoja Republike Hrvatske za razdoblje 2014. – 2020. (NN 106/2015, 65/2017, 77/2017 i 84/2018), koji propisuje način izrade Elaborata učinkovitosti mreže šumskih prometnica – primarne šumske prometne infrastrukture. U ovome radu prikazani su korisni alati unutar dva najzastupljenija GIS programska paketa: komercijalnog ArcGIS programa te besplatnog QGIS programa (eng.
open source
). Detaljno su prikazani i pojašnjeni GIS alati unutar oba programa, a koji mogu pomoći pri izradi Elaborata učinkovitosti mreže šumskih prometnica – primarne šumske prometne infrastrukture. Ovaj stručni rad sadrži korisne informacije za sve koji se bave problematikom utvrđivanja dostupnosti šumske površine, odnosno optimalnog planiranja šumskih cesta, te za utvrđivanje stvarnog stanja gustoće cesta i relativne otvorenosti šuma kojom gospodare.
The purpose of this paper is a detailed explanation of determining the accessibility of the forest area by calculating road density and the relative forest openness on the examples of two management units. The mentioned two parameters represent indispensable factors in the later phase of planning the optimal forest traffic infrastructure network. As a guide for increasing forest accessibility, a valid Bylaw on measure implementation M04 »Investments in physical assets«, by-measure 4.3 »Grant for investments in development, modernization and customization of agriculture and forestry«, operation type 4.3.3 »Investments in forest infrastructure« from the Program of Rural Development in the Republic of Croatia in the period from 2014 to 2020 (NN 106/15) (NN 106/2015, 65/2017, 77/2017 and 84/2018), which in its appendix No. 1 – Form for the Effectiveness Study of Primary Forest Road Traffic Infrastructure prescribes the preparation of the Effectiveness study of the forest road network. This paper presents valuable tools within the two most common GIS software packages: the commercial ArcGIS program and QGIS, an open-source program. The GIS tools within both programs, which are necessary for preparing the Effectiveness study of the forest road network, are presented and explained in detail. This professional paper contains valuable information for all who deal with the problem of determining the availability of forest area, i.e. the optimal planning of forest road layout, as well as for determining the actual state of road density and the relative openness of the forests.
Izvoženje drva forvarderima, obilježava kotrljanje drva na kotačima, prihvat i sakupljanje sortimentnom metodom izrađenoga drva hidrauličnom dizalicom, iz čega proizlazi i zahtjev za paralelnom ...mrežom sekundarnih šumskih prometnica međusobnoga razmaka dvostrukoga dosega dizalice.Rad se bavi prikazom: 1) dimenzijskih i masenih značajki forvardera u svijetlu norme ISO 13860 (2016) te 2) plana raspodjele tereta forvardera kojega je razvio njemački Kuratorij za šumski rad i šumsku tehniku (KWF), s ciljem pomoći šumarskim stručnjacima pri nabavci, odnosno korištenju ovih šumskih vozila.Za primjerni forvarder odabran je teški osmokotačni forvarder Komatsu 875, za koji su na osnovi mjerenja prikazane njegove dimenzijske i masene značajke, kao i plan raspodjele tereta s ciljem njegove ocjene.Kritički osvrt je dan i na normu ISO 13860 (2016) s obzirom na neobuhvaćanje nekih dimenzijskih (duljina i visina prednjeg te stražnjeg prepusta forvardera, kutovi i polumjeri prohodnosti vozila) i masenih (položaj točke težišta) pokazatelja forvardera, a koje opisuju i/ili služe modeliranju njegove kretnosti pri izvoženju drva s obzirom na smjer i uzdužni nagib terena. Isto tako, norma izrijekom ne spominje niti jedan pokazatelj okolišne pogodnosti (npr. nominalni tlak na podlogu).
Sažetak Svrha ovog članka detaljno je pojašnjenje problematike funkcionalnog pristupa utvrđivanja dostupnosti šumske površine, odnosno jednoznačnog i ujednačenog utvrđivanja gustoće cesta i relativne ...otvorenosti promatrane šumske površine koja se najčešće prikazuje na razini gospodarske jedinice. Navedena dva parametra predstavljaju neizostavne čimbenike u kasnijoj fazi planiranja optimalne mreže šumskih prometnica. Kao vodič postupka otvaranja šuma poslužio je važeći Pravilnik o provedbi mjere M04 »Ulaganja u fizičku imovinu«, podmjere 4.3. »Potpora za ulaganja u infrastrukturu vezano uz razvoj, modernizaciju i prilagodbu poljoprivrede i šumarstva«, tipa operacije 4.3.3. »Ulaganje u šumsku infrastrukturu« iz Programa ruralnog razvoja Republike Hrvatske za razdoblje 2014. – 2020. (NN 106/2015, 65/2017, 77/2017 i 84/2018), koji propisuje način izrade Elaborata učinkovitosti mreže šumskih prometnica – primarne šumske prometne infrastrukture. U ovome radu prikazani su korisni alati unutar dva najzastupljenija GIS programska paketa: komercijalnog ArcGIS programa te besplatnog QGIS programa (eng. open source). Detaljno su prikazani i pojašnjeni GIS alati unutar oba programa, a koji mogu pomoći pri izradi Elaborata učinkovitosti mreže šumskih prometnica – primarne šumske prometne infrastrukture. Ovaj stručni rad sadrži korisne informacije za sve koji se bave problematikom utvrđivanja dostupnosti šumske površine, odnosno optimalnog planiranja šumskih cesta, te za utvrđivanje stvarnog stanja gustoće cesta i relativne otvorenosti šuma kojom gospodare.
Rad obrađuje dimenzijske značajke utovarnoga prostora forvardera, a koje norma ISO 13860 (2016) određuje trima dimenzijama zasnovanim na neposrednom mjerenju (duljina utovarnoga prostora, širina ...između držača tereta, visina držača tereta) te dvjema posrednim (računske) dimenzijama (površina poprečnoga presjeka utovarnoga prostora forvardera i visina težišta tereta). Iako za te pokazatelje utovarnoga prostora forvardera norma ISO 13860 (2016) daje definicije, za dva računska pokazatelja nije objašnjen način njihova izračuna te na kojim se dimenzijama utovarnoga prostora zasnivaju.Poticaji za pisanje ovoga rada jesu: 1) pojašnjenje važnosti poznavanja dimenzijskih pokazatelja utovarnoga prostora forvardera, 2) izrada prijedloga načina izračuna poprečnoga presjeka utovarnoga prostora forvardera i visine težišta tereta forvardera te 3) određivanje dodatnih potrebnih mjernih dimenzijskih značajki utovarnoga prostora.Na osnovi predloženih mjerenja prikazane su dimenzije, ali i računske značajke utovarnoga prostora osmokotačnoga forvardera Komatsu 875.
The paper deals with the dimensional characteristics of the forwarder loading space, which is determined by ISO 13860 (2016) through three dimensions based on direct measurement (distance of load bunk headboard to rearmost bunk, width across stakes, stake height) and two indirect (calculative) dimensions (cross-sectional area of load space and height of load centre). Although the ISO 13860 (2016) standard provides definitions for the listed indicators of the forwarder loading space, the method of their calculation, as well as the dimensions of the loading space, are not explained for the two calculative indicators. The aim of this paper was to: 1) clarify the importance of knowing the dimensional indicators of forwarder loading space; 2) draft a proposal for calculating the cross-sectional area of forwarder load space and height of load centre; and 3) determine additional (required) dimensional characteristics of loading space. Based on the proposed measurements, the dimensions and computational characteristics of the loading space of the eight-wheeled Komatsu 875 forwarder are presented.
