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The study used methods based on remote sensing to analyze the dynamics of a silage corn crop and predict biomass production. The corn crop, the Micado hybrid, was organized within the Didactic and Experimental Station of the "King Mihai I" University of Life Sciences in Timisoara, under the specific conditions of the 2021-2022 agricultural year. The soil in the crop plot was of chernozem type, and the crop was in a non-irrigated system. To obtain the satellite data, the Sentinel 2 system was used. To characterize the plot and the crop of silage corn, 14 sets of images were taken, in the interval March - July 2022. From the analysis of the images, the spectral data were obtained, and based on the consecrated formulas MSAVI, NDMI, NDVI and NBR indexes were calculated. The ANOVA test confirmed the reliability of the data and the presence of variance in the data set (F>Fcrit, p

The aim of the study was to evaluate the phenomenon of land tilting and the tilting distance as a secondary effect of surface coal mining in the Jiu Valley area, Romania. To evaluate the tilting phenomenon, through the two considered elements (inclination – Lt, tilting distance – Td) 16 control points (CP1 to CP16) were used whose coordinates were measured in the Stereographic 1970 projection system, the 1975 Black Sea elevation system at an initial moment (t0) and at the current moment (t1). The static method was used by GPS technology to measure the elevations of the control points. Through descriptive statistical analysis, a general characterization of the set of recorded values was obtained, and the ANOVA test confirmed the safety of the data and the presence of variance in the data set. From the analysis of the recorded values, a Spline type model was obtained that described the variation of Lt in relation to Td, under conditions of statistical safety ( ɛ¯ = 0.137302). Regression analysis facilitated the obtaining of equation-type models, which described the variation of Lt and Td in relation to the X, Y and Z coordinates of the control points (t0, t1), under conditions of statistical certainty (R2 = 0.697, p=0.014 for Td variation according to Z0 and Z1; R2 = 0.722, p=0.0094 for Td in relation to X0 and Z0). According to PCA, PC1 explained 61.303% of variance, and PC2 explained 38.697% of variance. The cluster analysis facilitated the obtaining of a dendrogram based on Euclidean distances, regarding the grouping based on the similarity of the control points in relation to the studied phenomenon, under conditions of statistical safety (Coph. corr.=0.957).

The study aimed to characterize a peri-urban area through the LST index. 12 localities were studied, which fall within the peri-urban area of Timisoara, Timis County, Romania. In relation to the intended purpose, a satellite scene was used, Landsat 8, with a component of 11 spectral bands. The satellite scene was subjected to a processing in order to extract the information necessary to determine the LST (Land Surface Temperature). The authors built a logical scheme, as a synthetic model for determining LST, based on consecrated formulas. The analyzed LST index presented values between LST = 26.857 in the case of Ghiroda locality and LST = 30.198 in the case of Sanandrei locality. According to PCA, PC1 explained 51.41% of variance, and PC2 explained 48.59% of variance. It was found an independent positioning of the localities Dumbravita (Dum), Ghiroda (Ghi), Remetea Mare (Rem M) and Mosnita Noua (Mos N) in relation to LST as biplot, due to the lower values for this index. Cluster analysis led to the grouping of the localities studied, based on Euclidean distances, in relation to LST values, in statistical safety conditions (Coph. Corr = 0.826). The highest level of similarity, in relation to LST, was registered in the case of Dudestii Noi and Sanandrei localities (Dud N_San), sub-cluster C2-2 (SDI = 0.025). In ascending order of SDI values followed the localities Becicherecu Mic and Giroc (Bec M_Gir), sub-cluster C2-1, SDI = 0.026; Giroc and Sag localities (Gir_Sag), subcluster C2-1, SDI = 0.040; Becicherecu Mic and Sag localities (Bec M_Sag), sub-cluster C2-1, SDI = 0.066.

The present study evaluated the relationship between dimensional parameters of annual growth of shoots in woody species. The biological material was represented by the species Tilia cordata L., from the area of the Cenad Forest Protected Area, Timis County, Romania. The length of the internodes (IL) and the diameter of the internodes (ID) were determined in relation to the position of the internodes on the shoot (IP). The length of the internodes (IL), in relation to their position on the shoot, was described by a polynomial equation of degree 3, in statistical safety conditions, according to R2 = 0.832, p = 0.00014. The diameter of the internodes (ID), in relation to their position on the shoot (IP), was described by a polynomial equation of degree 2, in statistical safety conditions, according to R2 = 0.982, p

The study analyzed forest vegetation in the "Bazos Dendrological Park" area, Timis County, Romania, in order to describe the seasonal variation of the vegetation through imaging analysis based on satellite images (Sentinel 2). The study took place in the period 2021-2022, and each year 7 sets of images (T1 - T7) were taken between the months of April and August. NDMI, NDVI and NBR indices were calculated from the analysis of satellite images. Among the calculated indices, very strong correlations were found between NBR and NDMI (r=-0.928, year 2021), between NBR and NDVI (r=0.947, year 2021; r=0.928, year 2022). Moderate correlations were found between NDVI and NDMI (r=-0.769, year 2021), and weak correlations were found between NDMI and t (r=-0.655, year 2021), between NDVI and NDMI (r=0.617, year 2022). Other weak intensity correlations were also recorded. The variation of the NDVI indices in relation to NDMI and the NBR index in relation to NDMI or to NDVI was described by polynomial equations of 2nd degree, under statistical safety conditions (p les than 0.001, R2>0.9 for the year 2021; p=0.007, R2 >0.9 in the case of NDVI vs NDMI; p=0.014, R2=0.877 in the case of NBR vs NDVI, respectively p less than 0.001, R2 bigger than 0.9 in the case of NBR vs NDMI for the year 2022). In relation to the time interval (t, days), spline models faithfully described the variation of the calculated indices during the study period, under statistical safety conditions ( ? = .0 0061 in the case of NDMI vs t, ? = 0017.0 in the case of NDVI vs t, ? = 0067.0 in the case of NBR vs t, under the conditions of 2021; ? = 0317.0 in the case of NDMI vs t, ? = 0024.0 in the case of NDVI vs t, ? = 0077.0 in the case of NDMI vs t, under the conditions of 2022).

A thematic map contains a spatial database that allows the user to add new information to that database. The ability to combine a variety of datasets in a variety of ways makes any GIS a useful tool for almost any field of knowledge. From routinely performing work-related tasks to scientifically exploring the complexity of our world, GIS offers people the geographic advantage of becoming more productive, more aware, and more receptive to the planet Earth. A GIS can be defined as a system designed to capture, store, manipulate, analyze, and visualize geographically referenced data. Thematic maps are the result of spatial analysis sets made in GIS programs. Spatial analysis includes the techniques by which the relationships between entities are studied, from a topological, geometric or geographical point of view. Depending on the requirements and the existing data in the database, the maps may have different thematic results: demographic, social, economic, analysis, prediction, evaluation, anticipation maps, etc., depending on what you want to do analyze.

Starting from the fact that in the mining industry and in general in the field of underground constructions, the topographic activity, regardless of which of its manifestations, conditions and substantiates the achievement of economic and technological objectives, implicitly resulting in the dependence between topographic precision and qualitative and quantitative performance of mining. The level at which the professional responsibility of the topographic activity, as a whole is engaged in the achievement of some proposed objectives, depends on the framework resulting from the technological complexity of the mining activity in the conditions of its restructuring and efficiency. Spatial representations of useful mineral deposits in the earth's crust, which meet the quality conditions necessary for the design of underground mining works, can be used to choose the most efficient methods of opening, preparation and exploitation of useful mineral deposits. These analyzes are the basis for the realization of underground topographic networks that have a precise connection with the topographic base at the surface. The use of stereographic projection and stereographic networks can be achieved by faithfully representing the tectonics and positioning of deposits of useful mineral matter inside the earth's crust.

Observation of surface water is a very important for studying hydrological processes and last advances in satellite-based optical remote sensors have promoted the field of sensing surface water of a certain area or from a catchment area. This paper has considered analysing data from satellite image and geographical information system (GIS) for a catchment area. Banat hydrographical area is situated in the western part and south-western part of Romania and Barzava River basin drains a relatively small area in Banat Hydrographical Area. GIS techniques were used for extract data NDWI, MNDWI, AWEI indexes from in Landsat-8 satellite in images to evaluate their performances for the extraction of surface water. This paper shows the monitoring of Barzava river basin based on the indices resulting from the processing of satellite images. The objective of this research was to extract the surface water bodies from the hydrographic basin of river Barzava. Then, these data are utilized for purpose finding correlation and regression equations between the reflectance of the satellite image and the water parameters. NDWI being an indicator of plant water stress, it is observed that for 2018 compared to 2019 the basin of the Barzava River was affected by the drought.

In the case of foliar area studies on vines, with a large number of determinations, a simple, fast, sufficiently accurate and low-cost method is very useful. The typology of leaves on the vine is complex, characterized by several descriptive parameters: median rib, secondary venations of the first and second order, angles between the median rib and the secondary venations, sinuses, length and width of the leaf. The present study aimed to evaluate models for calculating the leaf area based on descriptive parameters and KA (KA as the surface constant used to calculate the leaf area) for six vine cultivars, ‘Cabernet Sauvignon’ (CS), ‘Muscat Iantarnîi’ (MI), ‘Muscat Ottonel’ (MO), ‘Chasselas’ (Ch), ‘Victoria’ (Vi) and ‘Muscat Hamburg’ (MH). The determined KA surface constants had subunit values (0.91 to 0.97), except for the cultivars ‘Muscat Iantarnîi’ and ‘Muscat Ottonel’ where the surface constant KA2 (in relation to the second-order secondary venations) had supraunitary values (1.07 and 1.08, respectively). The determination of the leaf area was possible under different conditions of statistical accuracy (R2 = 0.477, p = 0.0119, up to R2 = 0.988, p &lt, 0.001) in relation to the variety and parametric descriptors considered. The models obtained from the regression analysis facilitated a more reliable prediction of the leaf area based on the elements on the left side of the leaf, in relation to the median rib, compared to those on the right. The accuracy of the results was checked on the basis of minimum error (ME) and confirmed by parameters R2, p and RMSE.

In the last decade, in Romania, the management of large and very diverse agricultural areas from the point of view of the relief has been imposed especially the for the case of permanent grasslands. These ecosystems that are in balance due to the interdependence between the biotic and abiotic factors should be exploited according to correct management practices, supervised so that their level of production and quality should not be damaged. With the help of computer systems, the management and exploitation plan was established for 10-year periods corresponding to the period of renting these areas to livestock breeders. The present study aims at using the aerial monitoring with drone systems, the aerial surveillance of the correct implementation of management practices contractually assumed by the users and the breeders respectively. Thus, it is analyzed the quadratic processing of the surfaces, the compliance with the limits of rented areas, the observance of the load with animals per hectare (livestock unit LU) as well as of other management elements imported for maintaining and improving the condition of the permanent grasslands of Romania.

Modern technology plays a fundamental role in the engineering activities undertaken in day-to-day operations, in order to obtain the necessary material for construction or to obtain certain useful materials that are found near the surface. A special contribution of this branch of terrestrial measurements, of the topography, using modern technology, is materialized by specific studies carried out from a preliminary phase of design of the operation and up to the phase in which the perimeter is ecologized. The present article aims to test and evaluate the accuracy of the data for volumetric measurements of exploited material, using modern technology and specialized software based on topographic altitude, with which we will be able to realize the three-dimensional model of the operating perimeter. For this purpose, an exploitation has been chosen on the appropriate surface, materialized through a case study, with reference to the Doman Quarry, Caras Severin, in which we determined the volumes exploited during the activity period.

The study aimed to development a prediction model for soil erosion degree by image analysis techniques. The spectral information was obtained by image analysis in the RGB and HSB color system, and by calculus resulted rgb normalized values. Specific indices were calculated: intensity (INT), normalized difference index (NDI) and dark green color index (DGCI). The correlation analysis emphasized the existence of high levels of interdependence between specific indices and normalized color data rgb, respectively luminance (L). The regression analysis has enabled the creation of estimation models for soil erosion degree (DSE), in the form of linear equations in relation to luminance (R2=0.999, p<

The analysis of the physical-geographical conditions determines and influences the formation and the regime of the water resources from a hydrographic basin. This paper aims to analyse spatial data based on raster models, more precisely the terrain analysis, later used in hydrological modelling. For the elaboration of the digital model of the terrain, methods of interpolation of certain data are used - the level curves - after which, by running the ArcGIS program will result the structure of the irregular triangulation network (TIN). Next, based on the TIN model, a set of analyses is obtained regarding the morphology of the terrain: the slope map; slope exposure map, etc. The slope is one of the most important factors for controlling surface and intermediate water runoff. The exposure of the slopes depends very much on the direction of the slope of the land. With the help of the analysis of the slope and slope exposure it is possible to: calculate the solar lighting for each location in a region; find all slopes in the southern part of a mountainous region to identify locations where the snowmelt process will start earlier than in other areas, thus avoiding the danger of flooding due to runoff from the slopes and the danger of soil erosion; the value and speed of surface runoff; identify the spread and abundance of flora and fauna, precipitation; identify the productivity classes of the land; find all the north-facing slopes on a mountain as part for the search of the best ski slopes.

From the group of parasitic protozoa, Giardia and Cryptosporidium are the most common pathogens spread in surface water sources, representing a continuous threat to public health and water authorities. The aim of this survey was to assess the occurrence and human infective potential of these pathogens in treated wastewaters and different surface water sources. A total of 76 western Romanian water bodies in four counties (Arad, Bihor, Caraș-Severin and Timiș) were investigated, including the effluents of wastewater treatment plants (n = 11) and brooks (n = 19), irrigation channels (n = 8), lakes (n = 16), and ponds (n = 22). Water samples were collected through polyester microfiber filtration. Giardia cysts and Cryptosporidium oocysts were isolated using immunomagnetic separation, according to the US EPA 1623 method, followed by their identification and counting by immunofluorescence (IF) microscopy. All samples were screened through PCR-based techniques targeting the gdh gene for Giardia spp. and the 18S rRNA gene for Cryptosporidium spp., followed by sequencing of the positive results. Cryptosporidium-positive samples were subtyped based on sequence analysis of the GP60 gene. Giardia spp. was found in all tested water types with a cumulative detection rate of 90.1% in wastewaters, 26.3% in brooks, 37.5% in irrigation channels, 31.2% in lakes, and 36.4% in ponds. Except for ponds, all monitored water bodies harbored the Giardia duodenalis AII subassemblage with human infective potential. In addition, the ruminant origin assemblage E was widely distributed, and the domestic/wild canid-specific assemblage D was also recorded in a pond. Three (27.3%) wastewater samples were Cryptosporidium positive, and the identified species was the zoonotic Cryptosporidium parvum, with IIaA15G2R1 (n = 2) and IIdA18G1 subtypes. The results highlight that this threat to the public health must be brought to the attention of epidemiologists, health officials, and water authorities.

The Geographical Information Systems technology is used in many fields where the spatial information is very important and relevant, that means in all fields that use a system for saving, analyzing and representing the data which are processed. The aim of this paper is using modern technology for monitoring the environment. Geographical Information System together with remote sensing have a very important role in decision process regarding the environment. Integration of remote sensing images in a Geographical Information System which enables complex spatial analysis is a useful and modern solution for environmental management and decision-making process. Satellite images contain various information that can support environmental monitoring, images that can be analyzed and interpreted in various ways by using the Geographical Information System tools.

Many images of agricultural crops are made at different times of the day, images with different spectral information about the same crop in relation to conditions when the picture was taken. A set of 30 digital images of a wheat crop in the BBCH 3-Stem elongation code 32&ndash, 33 stage was captured between 9 am and 14 (UTC+3), in the 0&deg, &ndash, 180&deg, variation range of the image acquisition angle on the E-W axis (cardinal directions). A high variation of the spectral data given by the combination of the hour (h) and angle (a) at which the images were captured was found. The interdependence relationship between the analyzed parameters (r, g, and b), and the time (t) and the angle (a) of image acquisition was assessed with the linear correlation coefficient. By calculating the roots of the mathematical expressions of the correlation coefficients dependence on the angles (a) or times of day (t), the optimal angle and time were determined as a combination of the two variables for capturing images and obtaining optimal ro, go, bo values. The correction coefficients of the normalized r, g, and b values obtained out of the optimal field were determined. To this end, the multiplication of the r(a,t), g(a,t), and b(a,t) values with the &rho, a,t, &gamma, a,t, and &beta, a,t correction coefficients was suggested to reach the optimal values for sustainable decisions.

The objective of this study was to establish the prevalence, contamination level, and public health significance of Giardia duodenalis and Cryptosporidium spp. in the primary rivers of western Romania. A total of 53 sampling points in the 24 most important western Romanian rivers in four counties (Arad, Bihor, Caraș-Severin, and Timiș) were investigated from March to September 2016. Surface water samples were collected by microfiber filtration. Cryptosporidium and Giardia (oo)cysts were isolated using immunomagnetic separation (IMS) according to the USEPA 1623 method and, after staining with fluorescently labeled (FITC) monoclonal antibodies, were identified and counted under a microscope. The Cryptosporidium and Giardia (oo)cysts were identified to species and assemblage/sub-assemblage level through the nested PCR–RFLP procedure targeting the 18S ribosomal RNA and gdh genes, respectively. PCR-based techniques were utilized for all water samples. Overall, 22 samples (41.5%) were determined to be positive for Giardia cysts (ranging from 0.05 to 300 cysts per liter), and four samples (7.5%) tested positive for Cryptosporidium oocysts (0.17–48 oocysts/l). G. duodenalis was molecularly identified in 13 water samples (24.5%), indicating the presence of the sub-assemblage A-II (n = 12) and assemblage E (n = 1). PCR–RFLP showed that two samples (3.8%) contained Cryptosporidium DNA, and the identified species were Cryptosporidium parvum and Cryptosporidium canis. All positive results were successfully confirmed by DNA sequencing. Subtyping of the zoonotic C. parvum isolate based on sequence analysis of the GP60 gene revealed the occurrence of the IIaA16G1R1 subtype. The results of this study highlight considerable contamination of river waters with pathogenic Giardia spp. and Cryptosporidium spp., suggesting a potential risk for the public and animal health. This report presents the first extended published description of the presence of Giardia spp. and Cryptosporidium spp. in the aquatic environment in Romania.

Flood risk assessment in Timis River basin - the Caransebes -Lugoj sector- using GIS technique. Over time freshets, thus floods constituted and constitute a particularly important issue that requires attention. In many cases, flood damages are extensive to the environment, to the economy and also socially. The purpose of this paper is to identify flood-prone areas between Caransebes and Lugoj, land that is part of the Timis river basin. This paper is based on a theoretical model in which we considered the building elements of the flood produced on the Timis river in April 2005 (levels and flows). to represent the zones flood – prone, we used the numerical model of the terrain, created for the abovementioned area. On this model , according to levels measured at hydrometric stations, were defined those flood prone areas. The Timis river hydrographic basin includes a varied terrain (mountains, hills and plains), with pronounced differences in altitude and massiveness, resulting from tectonic movements that have affected the region, this fact has affected water flow processes, both directly through fragmentation and slope, and indirectly, by creating the vertical climate, vegetation and soils zones. Using GIS technology to study hydrological phenomena and their impact on the geographic area are of particular importance due to the complexity of these techniques, which enables detailed analysis and analytical precision as well as an increased speed of the analysis. Creating theoretical models that give scale to the hydrological phenomena, in this case representing the flood areas, is of great practical importance because based on these models the areas can be defined and viewed, having the possibility of taking measures to prevent environmental effects on the natural and / or anthropogenic environment. In the studied area review of the flood of 2005, were represented flood areas, therefore, according with the researches, several villages, located in Timis valley or in the low lands, where the landscape decreases in altitude, were partially affected, also transport infrastructure (roads and railways) was covered by water in some areas, resulting in the isolation of villages; agricultural land located near or within the localities were flooded, situation that had negative consequences on their productivity. The data presented in this study support the importance and opportunity of using GIS techniques in the evaluation of the hydrological risk assessment, techniques through which tackling the problems that address the geographic area is of a global importance, thus giving clear indications to prevent and protect against destructive phenomena.

The number of inhabitants and their distribution in a given area varies within very large limits of tolerance, both in time and space, regardless of geographic region considered. The natural and anthropogenic frame of the area studied in this paper, namely the upper and middle basin of the river Bega, was described on the basis of existing scientific literature, supplemented by produce maps to work with, such as digital elevation model generated with using Global Mapper software, model used to delimitate the analyzed area; the map of communal territories included in the investigated area was prepared by extracting them from the administrative-territorial map of Timis county, overall population density map and the map of population density developments, compiled from data of population censuses in each communal area, obtained by processing using GIS software. The purpose of this study is to highlight trends in the evolution of the population and to identify areas at risk of depopulation, which means, on the one hand knowledge of the number of inhabitants and for variations in this indicator, on the other hand density analysis population synthetic indicator used to highlight differences in the land surfaces occupied by humans. The upper and middle basin of the river Bega is characterized by a variety of natural and socio-economic conditions, resulting in major differences in the evolution of the number of inhabitants and their spatial distribution. In the period considered (1880 - 2011), the most populous census occurred in 1910, since then a definitely downward trend in this indicator can be observed, until the current period, in some cases "losses " were very large (village Bara, Balinţ, Ohaba Lungă, etc). The downward trend in the number of inhabitants has direct implications on the overall density of the population, over time, this indicator registered a continued reduction in most cases and time periods considered. Estimates on future population numbers are difficult to achieve because some variables can not be predicted or quantified, such as political decisions, migrations and general demographic balance values.

The study of vegetation cover, forests, orchards or vineyards and crops through satellite techniques is increasingly promoted as a result of facilities they offer. A number of methods and techniques for processing and analysis of satellite images are developed to increase the precision of the working, given the diversity of vegetation structure analysis and expected results. This study aimed to analyze the capabilities of object-oriented image analysis (OBIA) for recognition forest and vineyard areas. OBIA is automated process of object extraction by modelling of human visual system for image interpretation. The basis for classification process is object, which is created according to the set of characteristics. In object-oriented approach classification description is based on classification rules including spectral characteristics, size, shape, as well as content and texture information. Analysis is done on multispectral imagery of high and very high spatial resolution. Represented results show the usefulness of RapidEye and WorldView2 images as well as importance of classification based on OBIA. Object-oriented image analysis (OBIA) method based on satellite imagery has facilitated the recognition forest and vineyard areas with high accuracy.

The satellite image is the current graphic document, containing the real data of the terrestrial surface when it was acquired, based on which the soil and the vegetation cover can be evaluated. The NDVI index is used for a large number of the vegetation properties. In this research we analyzed the variation of NDVI index depending on R, G, B and NIR spectral bands, based on the LANDSAT 8 images. The relation between NDVI index with the respective spectral bands was describe most accurately by an exponential regression equations of curves with negative coefficient in the case of R,G,B spectrum and by a logarithmic function for the NIR spectrum. The results show statistical certainty for all the relations of NDVI index with the analyzed spectral bands (RED:NDVI p<

Satellite and aerial images are objective photographical representations of the reality from the field, related to spatial – temporal frames. The purpose of the present study is to create a comparative analysis of a LANDSAT 8 satellite image by supervised and unsupervised classification methods. The algorithms used in this research were maximum likelihood algorithm for supervised classification and ISODATA algorithm for unsupervised classification. From the multitude of possible combinations of spectral bands we chose the combination bands near infrared-red-green (543), image which has been subjected to the supervised and unsupervised classification process. This combination includes in addition the two bands from visible (R, G) the band near-infrared (NIR) which represents an area where the response of the vegetation is tinted and the cloudy formations are easier t penetrate. By analyzing the satellite image through supervised classification it enabled a result of 5 thematic classes defined by the user based on information in the field, leaving an unclassified fraction. Unsupervised Classification generated 16 classes covering the entire area of interest. Comparative analysis of satellite images by the two methods facilitates increased accuracy of image classification.

This paper aims to highlight the behavior in time monitoring of a hydrotechnical construction by establishing the displacements compared to the base tranche and the previous tranche, processing these measurements and establishing conclusions on the behavior of the analyzed construction. The main purpose of this paper is to study if there are any displacements of the studied hydrotechnical construction between different measurements tranches. Field measurements were performed between September - December 2016, after which the data was processed at the office with specially developed programs for this purpose. For the micro-triangulation stage, respectively for measuring the directions and distances, were used Leica TS02 Plus R500 total stations. The measurement accuracy of this total station is 1” for directional determination and 1.5mm + 2ppm for distances. Tracking the behavior in time of hydrotechnical constructions are of great importance, because it can prevent many calamities like breaking the dam, floods etc.

The lignite mining extraction within the mining perimeter in Rovinari is carried out through mining works in the open, by using large equipments for the excavation, transport and storage of the mining material. These surfaces are currently being set up in the area of level two of the dump, the west and north-west part of Rovinari pit. In order to carry out the set-up works and of follow-up of the stability of the pit levels it is necessary to maintain the triangulation network.