Tag Archives: LiDAR

318-325 R. Melniks, J. Ivanovs, A. Lazdins and K. Makovskis
Mapping drainage ditches in agricultural landscapes using LiDAR data
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Mapping drainage ditches in agricultural landscapes using LiDAR data

R. Melniks¹², J. Ivanovs¹, A. Lazdins¹ and K. Makovskis¹

¹Latvian State Forest Research Institute ‘Silava’, Riga street 111, LV-2169 Salaspils, Latvia
²University of Latvia, Faculty of Geography and Earth Sciences, Jelgava street 1, LV-1004 Riga, Latvia
*Correspondence: mailto:raitis.melniks@silava.lv

Abstract:

The aim of this study is to develop a method for identification of the drainage ditch network, which can be used for surface runoff modeling and to increase accuracy of estimation of greenhouse gas (GHG) emissions in croplands and grasslands, using remote sensing data. The study area consists of 11 objects throughout Latvia with a total area of 145 km2. Digital elevation models (DEMs) in two resolutions, which were created using three different interpolation methods, were used for the analysis. Several multi-level data filtering methods were applied to identify ditch network, including flow patterns, which can be used in surface runoff process. The method we developed correctly identified 85–89% of ditches, depending on the DEM used, in comparison to the reference data. Mapped ditches are located within 3 m range of the reference data in 89–93% of cases. The elaborated model is robust and uses openly available source data and can be used for large scale ditch mapping with sufficient accuracy necessary for hydrological modelling and GHG accounting in the national inventories.

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1718-1733 J. Dumpis, A. Lagzdins and I. Sics
Delineation of catchment area for the lake Kisezers for environmental sustainability
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Delineation of catchment area for the lake Kisezers for environmental sustainability

J. Dumpis¹²*, A. Lagzdins¹ and I. Sics²

¹Latvia University of Life Sciences and Technologies, Department of Environmental Engineering and Water Management, 2 Liela Street, LV-3001 Jelgava, Latvia
²Institute of Food Safety, Animal Health and Environment ‘BIOR’, Lejupes Street 3, LV-1076 Riga, Latvia
*Correspondence: janisdumpis94@gmail.com

Abstract:

The study aims to develop a methodology for the delineation of a catchment area. The methodology includes the processing and analysis of LiDAR data, on-field height measurement data, bathymetric data, hydrological data. High definition catchment area maps are successfully constructed. Catchment area influencing factors such as water mass movement and changes in land use are determined. Lake Kisezers was selected as the study site because the location of the lake, the availability of data, the feasibility studies, the economic potential of the catchment area determine the topicality and significance of this study. The lake catchment area covers multiple rivers, urban and rural territories, forests, high and low terrains. In the catchment area of Lake Kisezers many hydrologic monitoring stations with continuous data are situated. In the research area, we can study how those factors interact with the possibility to perform a catchment area delineation. The final result of this study is the catchment area for Lake Kisezers. The research results are high-definition and can be used to understand locations of floodplains, territories with malfunctioning drainage systems. The repetition of this study requires extensive knowledge of cartography, experience in working with terrain and bathymetry data, wide range of GIS knowledge. The research was performed using computer software such as QGIS and GRASS GIS. The application of the methodology used in this study can serve as an example for delineation and analysis of a catchment area for other lakes and rivers. Overall, the study is a success.

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788–798 A. Lupikis, A. Bardule, A. Lazdins, J. Stola and A. Butlers
Carbon stock changes in drained arable organic soils in Latvia: results of a pilot study
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Carbon stock changes in drained arable organic soils in Latvia: results of a pilot study

A. Lupikis, A. Bardule*, A. Lazdins, J. Stola and A. Butlers

Latvian State Forest Research Institute ‘Silava’, 111 Rigas str., LV-2169 Salaspils, Latvia
*Correspondence: arta.bardule@silava.lv

Abstract:

Drained arable organic soils in the most of European countries represent a minor part of the total area of farmlands, but these soils contribute significantly to national greenhouse gas budgets. The aim of the pilot study is to demonstrate methodology for determination of the changes of soil organic carbon stock after drainage of arable land on organic soil by evaluation of subsidence of the land surface from detailed historical pre-drainage topographic maps created during designing of drainage systems and LiDAR. Results of a pilot study show that ground surface level in arable land on organic soil has decreased by 0.8 cm annually after drainage, but soil organic carbon stock has decreased by 4.2 ± 3.3 tonnes C ha-1 yr-1. The results of a study show that pre-drainage topographic maps are suitable for estimation of organic layer subsidence after drainage. The estimated mean CO2 emissions are about 47% less than the default emission factor for drained arable organic soils in boreal and temperate climate zone provided by Intergovernmental Panel on Climate Change Guidelines for National Greenhouse Gas Inventories. The results substantiate the necessity to develop national methodology to estimate emissions from drained organic soils in cropland and grassland.

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