A renovated model for spatial analysis of pollutant runoff loads in agricultural watershed

1998 ◽  
Vol 38 (10) ◽  
pp. 207-214 ◽  
Author(s):  
Sung Ryong Ha ◽  
Dhong Il Jung ◽  
Cho Hee Yoon
Keyword(s):  
Stream Water ◽  
Digital Terrain Model ◽  
Pollution Sources ◽  
Agricultural Watershed ◽  
Water Model ◽  
Digital Information ◽  
Gis Technology ◽  
Terrain Model ◽  
Unit Loading ◽  
Pollutant Discharge

Runoff loads of pollutant in agricultural watersheds were spatially analyzed by using geographic information system(GIS) technology. The topological relationship between pollution sources in the watershed was, first of all, identified by using the developed digital map of land use and then the pollutant loads generated from each source was estimated by applying a conventional unit loading factor on the obtained digital information of pollution sources. To evaluate the loads delivered from spatially distributed pollution sources to monitoring stations in down stream via surface of watershed, a renovated empirical model incorporated with the information of pollutant discharge path was developed through introducing a digital terrain model(DTM) technique. In this model, the function of degradation of pollution loads during delivery process was simplified so that each watershed could have a basin-wide self-purification capacity which would be considered to be possessed inherently in each watershed and could retard the discharge of pollutants from sources generated to stream water. Model credibility showed good consistency with comparing the simulated values with observed data. Monte Carlo optimizing technique made it possible to estimate the basin-wide self-purification coefficients.

Operational evaluation of the risk of development of waterflowing for making information in the unified state real estate register using GIS technologies (on the example of the Ob-Tomsk interfluve)

2021 ◽  
pp. 11-21
Author(s):  
K.I. Kuzevanov ◽  
◽  
E.Yu. Pasechnik ◽  
L.N. Chilinger ◽  
◽  
...  
Keyword(s):  
Real Estate ◽  
Digital Terrain Model ◽  
Gis Technology ◽  
Terrain Model ◽  
Gis Technologies ◽  
State Register ◽  
Digital Terrain ◽  
Critical Areas ◽  
Real Estate Register

The article analyzes the existing procedure for entering information on the boundaries of zones with special conditions for the use of territories in the Unified State Register of Real Estate using the example of flooding zones. The basic regulatory documents governing the procedure and procedure for establishing flood zones are identified, in which gaps are identified in the requirements for the content of the work to determine the boundaries of such zones and assess their accuracy. In this connection, it is proposed to use the algorithm developed by the authors to determine the boundaries of the zones of underflooding development based on the analysis of the hydrographic network and digital terrain model using GIS technologies. This methodology is aimed at an operational assessment of the conditions of built-up and built-up territories, which allows to reduce the financial costs of conducting expensive engineering surveys, the need of which remains to clarify the results of computer mapping in the most critical areas. The norms of accuracy of determining the boundaries of flood zones are proposed, which will correspond to the accuracy of determining the boundaries of the lands of the water fund. In order to test the developed algorithm, we chose the territory of the Ob-Tomsk interfluve, for which zoning was carried out according to the depth of groundwater and the territories of moderate and severe flooding were identified for the purpose of further more detailed study. Keywords: GIS technology; occurrence depth; Unified state register of real estate; flood zone; engineering survey; restrictions The groundwater; zoning of the territory; accuracy of determination of coordinates; business activity.

scholarly journals USING REMOTE SENSING AND GIS TO CREATE GEOGRAPHICAL BASES FOR THEMATIC MAPS

2021 ◽  
Vol 26 (5) ◽  
pp. 119-125
Author(s):  
Oyunkhand Byamba ◽  
◽  
Elena L. Kasyanova ◽  
Keyword(s):  
Remote Sensing ◽  
Three Dimensional ◽  
Digital Terrain Model ◽  
Gis Technology ◽  
Gis And Remote Sensing ◽  
Terrain Model ◽  
Digital Terrain ◽  
Terrain Models ◽  
Triangulation Network ◽  
Eastern Mongolia

The development of science always depends on technological progress. Cartography is rapidly changing and developing with the introduction of new computer technologies, such as GIS and remote sensing of the Earth. Recently, there have been qualitatively new types of cartographic products, in particular 3D terrain models, which in cartography are becoming a universal, optimal and operational method for displaying terrain. The article discusses a method for creating a three-dimensional digital terrain model in the form of an irregular triangulation network based on SRTM data and GIS technology on the example of the Khenti aimag of Eastern Mongolia.

scholarly journals VISUALISATION WITH G.I.S OF AGIA EIRINI GORGE AT THE SOUTHERN MARGINS OF THE WHITE MOUNTAINS, SW CRETE

2018 ◽  
Vol 36 (2) ◽  
pp. 1018
Author(s):  
Κ. Μπιζούρα ◽  
Ε. Μανούτσογλου ◽  
Ε. Σπυρίδωνος
Keyword(s):  
Spatial Data ◽  
Digital Terrain Model ◽  
Field Work ◽  
Digital Information ◽  
White Mountains ◽  
Natural Systems ◽  
Terrain Model ◽  
Digital Terrain ◽  
The Creation ◽  
Available Information

Sustainable management of protected areas requires good knowledge of the entire system. Complicated natural systems require for their management the use of digital information systems, that would allow the integration of all the available information on the studied natural system as well as the elements of new researches. Among the natural systems the gorges constitute mainly geological structrures. The aim of the present study is the development of a 3D digital morphotectonic model for the Agia Eirini Gorge, crossing the southern limbs of mountain Lefka Ori in South-Western Crete. The work is divided in two parts, on one side in the creation of suitable backgrounds that is reqi ired for the creation of a 3D model and on the other hand the placement of the spatial data into the model. For the creation of the digital terrain model (DTM) of the gorge area, maps at a 1:5.000 scale, obtained from the Army Geographic Service were digitised using CAD Overlay 2000i software. The data obtained were transferred into SURPAC 2000 supplemented with orthophotomaps of the region with the method of superimposition. The initial data drawn from the existing geological map of the region were evaluated by data obtained from field work. This methodology allows integration of all available information for the system under study, including newly acquired data

scholarly journals POSSIBILITIES OF USING PHASE ONE 190MP AERIAL SYSTEM AERIAL SURVEY RESULTS DURING CREATION OF A TERRITORY GEOINFORMATION SPACE

2021 ◽  
Vol 3 (2) ◽  
pp. 221-227
Author(s):  
Diana M. Khaidukova ◽  
Yaroslava V. Lerman ◽  
Pavel A. Anashkin
Keyword(s):  
Spatial Data ◽  
Digital Terrain Model ◽  
Aerial Survey ◽  
Digital Information ◽  
Terrain Model ◽  
Information Models ◽  
Detailed Surface ◽  
Technical Features ◽  
Digital Orthophoto ◽  
Cloud Of Points

Results of using in Russia Phase One 190MP Aerial System are presented. Qualitative characteristics of the obtained photographic materials and a possibility of its use during creation of territories digital information models are investigated. Technical features and range of Phase One 190MP Aerial System using in aerial survey, specifics of planning software and management of aero survey works and also some results of photogrammetric processing of pictures are discussed. Possibilities of the software for photogrammetric processing of pictures for the purpose of creation of True Ortophoto are tested. An assessment of labor input of photogrammetric works is given. In addition to creation of digital Orthophoto on the basis of the data obtained from the Phase One 190MP aerial camera the dense cloud of points, the detailed surface and 3-D digital terrain model are made. The possibility of use of digital models for specialized engineering calculations in geoinformation space by means of automated design engineering systems for the purpose of replenishment of model of territories is investigated by derived spatial data.

scholarly journals The Effect of LiDAR Sampling Density on DTM Accuracy for Areas with Heavy Forest Cover

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 265
Author(s):  
Mihnea Cățeanu ◽  
Arcadie Ciubotaru
Keyword(s):  
Forest Cover ◽  
Initial Point ◽  
Ground Surface ◽  
Digital Terrain Model ◽  
Morphological Data ◽  
Sampling Density ◽  
Terrain Model ◽  
Digital Terrain ◽  
Point Density ◽  
The Impact

Laser scanning via LiDAR is a powerful technique for collecting data necessary for Digital Terrain Model (DTM) generation, even in densely forested areas. LiDAR observations located at the ground level can be separated from the initial point cloud and used as input for the generation of a Digital Terrain Model (DTM) via interpolation. This paper proposes a quantitative analysis of the accuracy of DTMs (and derived slope maps) obtained from LiDAR data and is focused on conditions common to most forestry activities (rough, steep terrain with forest cover). Three interpolation algorithms were tested: Inverse Distance Weighted (IDW), Natural Neighbour (NN) and Thin-Plate Spline (TPS). Research was mainly focused on the issue of point data density. To analyze its impact on the quality of ground surface modelling, the density of the filtered data set was artificially lowered (from 0.89 to 0.09 points/m2) by randomly removing point observations in 10% increments. This provides a comprehensive method of evaluating the impact of LiDAR ground point density on DTM accuracy. While the reduction of point density leads to a less accurate DTM in all cases (as expected), the exact pattern varies by algorithm. The accuracy of the LiDAR-derived DTMs is relatively good even when LiDAR sampling density is reduced to 0.40–0.50 points/m2 (50–60 % of the initial point density), as long as a suitable interpolation algorithm is used (as IDW proved to be less resilient to density reductions below approximately 0.60 points/m2). In the case of slope estimation, the pattern is relatively similar, except the difference in accuracy between IDW and the other two algorithms is even more pronounced than in the case of DTM accuracy. Based on this research, we conclude that LiDAR is an adequate method for collecting morphological data necessary for modelling the ground surface, even when the sampling density is significantly reduced.

scholarly journals DTM-based analysis of the spatial distribution of topolineaments

2020 ◽  
Vol 12 (1) ◽  
pp. 1185-1199
Author(s):  
Mirosław Kamiński
Keyword(s):  
Laser Scanning ◽  
Digital Terrain Model ◽  
Research Area ◽  
Tectonic Structures ◽  
Empirical Bayesian ◽  
Scanning Method ◽  
Empirical Bayesian Kriging ◽  
Terrain Model ◽  
Digital Terrain ◽  
Airborne Laser

AbstractThe research area is located on the boundary between two Paleozoic structural units: the Radom–Kraśnik Block and the Mazovian–Lublin Basin in the southeastern Poland. The tectonic structures are separated by the Ursynów–Kazimierz Dolny fault zone. The digital terrain model obtained by the ALS (Airborne Laser Scanning) method was used. Classification and filtration of an elevation point cloud were performed. Then, from the elevation points representing only surfaces, a digital terrain model was generated. The model was used to visually interpret the course of topolineaments and their automatic extraction from DTM. Two topolineament systems, trending NE–SW and NW–SE, were interpreted. Using the kernel density algorithm, topolineament density models were generated. Using the Empirical Bayesian Kriging, a thickness model of quaternary deposits was generated. A relationship was observed between the course of topolineaments and the distribution and thickness of Quaternary formations. The topolineaments were compared with fault directions marked on tectonic maps of the Paleozoic and Mesozoic. Data validation showed consistency between topolineaments and tectonic faults. The obtained results are encouraging for further research.

scholarly journals Production, Validation and Morphometric Analysis of a Digital Terrain Model for Lake Trichonis Using Geospatial Technologies and Hydroacoustics

2021 ◽  
Vol 10 (2) ◽  
pp. 91
Author(s):  
Triantafyllia-Maria Perivolioti ◽  
Antonios Mouratidis ◽  
Dimitrios Terzopoulos ◽  
Panagiotis Kalaitzis ◽  
Dimitrios Ampatzidis ◽  
...  
Keyword(s):  
Morphometric Analysis ◽  
Ad Hoc ◽  
Regional Scale ◽  
Digital Terrain Model ◽  
Relevant Information ◽  
Relative Difference ◽  
Systematic Observation ◽  
Qualitative And Quantitative ◽  
Terrain Model ◽  
Digital Terrain

Covering an area of approximately 97 km2 and with a maximum depth of 58 m, Lake Trichonis is the largest and one of the deepest natural lakes in Greece. As such, it constitutes an important ecosystem and freshwater reserve at the regional scale, whose qualitative and quantitative properties ought to be monitored. Depth is a crucial parameter, as it is involved in both qualitative and quantitative monitoring aspects. Thus, the availability of a bathymetric model and a reliable DTM (Digital Terrain Model) of such an inland water body is imperative for almost any systematic observation scenario or ad hoc measurement endeavor. In this context, the purpose of this study is to produce a DTM from the only official cartographic source of relevant information available (dating back approximately 70 years) and evaluate its performance against new, independent, high-accuracy hydroacoustic recordings. The validation procedure involves the use of echosoundings coupled with GPS, and is followed by the production of a bathymetric model for the assessment of the discrepancies between the DTM and the measurements, along with the relevant morphometric analysis. Both the production and validation of the DTM are conducted in a GIS environment. The results indicate substantial discrepancies between the old DTM and contemporary acoustic data. A significant overall deviation of 3.39 ± 5.26 m in absolute bottom elevation differences and 0.00 ± 7.26 m in relative difference residuals (0.00 ± 2.11 m after 2nd polynomial model corrector surface fit) of the 2019 bathymetric dataset with respect to the ~1950 lake DTM and overall morphometry appear to be associated with a combination of tectonics, subsidence and karstic phenomena in the area. These observations could prove useful for the tectonics, geodynamics and seismicity with respect to the broader Corinth Rift region, as well as for environmental management and technical interventions in and around the lake. This dictates the necessity for new, extensive bathymetric measurements in order to produce an updated DTM of Lake Trichonis, reflecting current conditions and tailored to contemporary accuracy standards and state-of-the-art research in various disciplines in and around the lake.

scholarly journals Modeling Streamflow and Sediment Loads with a Photogrammetrically Derived UAS Digital Terrain Model: Empirical Evaluation from a Fluvial Aggregate Excavation Operation

Drones ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 20
Author(s):  
Joseph P. Hupy ◽  
Cyril O. Wilson
Keyword(s):  
Soil Erosion ◽  
Point Cloud ◽  
Empirical Evaluation ◽  
Digital Terrain Model ◽  
Surface Flow ◽  
Sediment Loading ◽  
Terrain Model ◽  
Digital Terrain ◽  
Statistical Measures ◽  
Geospatial Datasets

Soil erosion monitoring is a pivotal exercise at macro through micro landscape levels, which directly informs environmental management at diverse spatial and temporal scales. The monitoring of soil erosion can be an arduous task when completed through ground-based surveys and there are uncertainties associated with the use of large-scale medium resolution image-based digital elevation models for estimating erosion rates. LiDAR derived elevation models have proven effective in modeling erosion, but such data proves costly to obtain, process, and analyze. The proliferation of images and other geospatial datasets generated by unmanned aerial systems (UAS) is increasingly able to reveal additional nuances that traditional geospatial datasets were not able to obtain due to the former’s higher spatial resolution. This study evaluated the efficacy of a UAS derived digital terrain model (DTM) to estimate surface flow and sediment loading in a fluvial aggregate excavation operation in Waukesha County, Wisconsin. A nested scale distributed hydrologic flow and sediment loading model was constructed for the UAS point cloud derived DTM. To evaluate the effectiveness of flow and sediment loading generated by the UAS point cloud derived DTM, a LiDAR derived DTM was used for comparison in consonance with several statistical measures of model efficiency. Results demonstrate that the UAS derived DTM can be used in modeling flow and sediment erosion estimation across space in the absence of a LiDAR-based derived DTM.

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