scholarly journals A New Method for Rapid Measurement of Canal Water Table Depth Using Airborne LiDAR, with Application to Drained Peatlands in Indonesia

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1486
Author(s):  
Ronald Vernimmen ◽  
Aljosja Hooijer ◽  
Dedi Mulyadi ◽  
Iwan Setiawan ◽  
Maarten Pronk ◽  
...  
Keyword(s):  
Water Management ◽  
Data Collection ◽  
Water Table ◽  
Grid Cell ◽  
Soil Surface ◽  
Field Measurements ◽  
Water Table Depth ◽  
Airborne Lidar ◽  
Lidar Data ◽  
Canal Water

Water management in lowland areas usually aims to keep water tables within a narrow range to avoid flooding and drought conditions. A common water management target parameter is the depth of the canal water table below the surrounding soil surface. We demonstrated a method that rapidly determines canal water table depth (CWD) from airborne LiDAR data. The water table elevation was measured as the minimum value determined in a grid of 100 m × 100 m applied to a 1 m × 1 m digital terrain model (DTM), and the soil surface was calculated as the median value of values in each grid cell. Results for areas in eastern Sumatra and West Kalimantan, Indonesia, were validated against 145 field measurements at the time of LiDAR data collection. LiDAR-derived CWD was found to be accurate within 0.25 m and 0.5 m for 86% and 99% of field measurements, respectively, with an R2 value of 0.74. We demonstrated the method for CWD conditions in a drained peatland area in Central Kalimantan, where we found CWD in the dry season of 2011 to be generally below −1.5 and often below −2.5 m indicating severely overdrained conditions. We concluded that airborne LiDAR can provide an efficient and rapid mapping tool of CWD at the time of LiDAR data collection, which can be cost-effective especially where LiDAR data or derived DTMs are already available. The method can be applied to any LiDAR-based DTM that represents a flat landscape that has open water bodies.

scholarly journals Temporal and Local Heterogeneities of Water Table Depth under Different Agricultural Water Management Conditions

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2148
Author(s):  
Jonathan A. Lafond ◽  
Silvio J. Gumiere ◽  
Virginie Vanlandeghem ◽  
Jacques Gallichand ◽  
Alain N. Rousseau ◽  
...  
Keyword(s):  
Water Management ◽  
Water Table ◽  
Cropping Systems ◽  
Irrigation Management ◽  
Sprinkler Irrigation ◽  
Water Table Depth ◽  
Management Systems ◽  
Integrated Water Management ◽  
Growing Seasons ◽  
Good Drainage

Integrated water management has become a priority for cropping systems where subirrigation is possible. Compared to conventional sprinkler irrigation, the controlling water table can lead to a substantial increase in yield and water use efficiency with less pumping energy requirements. Knowing the spatiotemporal distribution of water table depth (WTD) and soil properties should help perform intelligent, integrated water management. Observation wells were installed in cranberry fields with different water management systems: Bottom, with good drainage and controlled WTD management; Surface, with good drainage and sprinkler irrigation management; Natural, without drainage, or with imperfectly drained and conventional sprinkler irrigation. During the 2017–2020 growing seasons, WTD was monitored on an hourly basis, while precipitation was measured at each site. Multi-frequential periodogram analysis revealed a dominant periodic component of 40 days each year in WTD fluctuations for the Bottom and Surface systems; for the Natural system, periodicity was heterogeneous and ranged from 2 to 6 weeks. Temporal cross correlations with precipitation show that for almost all the sites, there is a 3 to 9 h lag before WTD rises; one exception is a subirrigation site. These results indicate that automatic water table management based on continuously updated knowledge could contribute to integrated water management systems, by using precipitation-based models to predict WTD.

Classification of Airborne Lidar Data by Echo

2012 ◽  
Vol 500 ◽  
pp. 696-700 ◽  
Author(s):  
Sheng Yao Wang ◽  
Xi Min Cui ◽  
De Bao Yuan ◽  
Jing Jing Jin ◽  
Qiang Zhang
Keyword(s):  
Data Collection ◽  
Current Data ◽  
Airborne Lidar ◽  
Classification Method ◽  
Lidar Data ◽  
Collection System ◽  
Continuous Development ◽  
Data Collection System ◽  
Airborne Lidar Data

With the continuous development of Airborne Lidar hardware, the current data collection system will not only collect information on a single echo, multiple echo information also can be available. Through the analysis and discussion of echo principle, this paper compares and elaborates the characteristics of single-echo and multiple echo information, and introduces a filter classification method based on echo information, and illustrates that the method is simple and effective according to an example.

scholarly journals Aboveground biomass estimation with airborne hyperspectral and LiDAR data in Tesinske Beskydy Mountains

Beskydy ◽  
2015 ◽  
Vol 8 (1) ◽  
pp. 35-46 ◽  
Author(s):  
Olga Brovkina ◽  
František Zemek ◽  
Tomáš Fabiánek
Keyword(s):  
Aboveground Biomass ◽  
Field Measurements ◽  
Airborne Lidar ◽  
Biomass Estimation ◽  
Lidar Data ◽  
Predicting Model ◽  
The Third ◽  
Study Results ◽  
Airborne Lidar Data ◽  
Forest Aboveground Biomass

The study presents three models for estimation of forest aboveground biomass (AGB) for plot level using different categories of airborne data. The first and the second models estimate AGB from metrics of airborne LiDAR data. The third model estimates AGB from integration of metrics of airborne hyperspectral and LiDAR data. The results are compared with plot level biomass estimated from field measurements. The results show that the best AGB estimate is obtained from the model utilizing a fusion of hyperspectral and LiDAR metrics. Study results expand existing research on the applicability of airborne hyperspectral and LiDAR datasets for AGB assessment. It evidences the efficiency of using a predicting model based on hyperspectral and LiDAR data for study area.

scholarly journals Alleviating peatland fire risk using water management trinity and community involvement

2021 ◽  
Vol 914 (1) ◽  
pp. 012037
Author(s):  
N I Fawzi ◽  
I Z Qurani ◽  
R Darajat
Keyword(s):  
Water Management ◽  
Water Table ◽  
Community Involvement ◽  
Swot Analysis ◽  
Negative Impact ◽  
Fire Risk ◽  
Water Table Depth ◽  
Water Regulation ◽  
Soil Drainage

Abstract Conventionally, agriculture in peatland requires soil drainage to enable the crops to grow. This often results in being over-drained and makes it vulnerable to fires. The risk can be contained by applying water management trinity (WMT), which creates canals for water regulation and reservoirs instead of drainage. This study aimed to examine, elaborate, and validate the WMT effect and community involvement in minimizing fire risk in peatland. We collected water table depth every two weeks from 1 April 2017 to 31 December 2020 in a coconut plantation under WMT and employed Focus Groups Discussions (FGD) in five villages in Pulau Burung District, Indragiri Hilir Regency, Riau. The result showed that the existence of WMT for more than three decades has successfully maintained water table depth between 30 and 70 cm that is influenced by seasons. The fire occurrence based on the FGD interview has been validated with hotspot data from NASA’s FIRMS. This research also employed SWOT analysis to examine the local fire mitigation strategy. The progress in lowering fire incidents and risk should be intervened with finding long-term solutions to increase farmers’ capability on sustainable agriculture. Our finding reveals that the main strength in lowering fire risk is people’s awareness in every village on the negative impact of land burning, along with the existence of WMT.

scholarly journals Relative Radiometric Calibration of Airborne LiDAR Data for Archaeological Applications

2019 ◽  
Vol 11 (8) ◽  
pp. 945 ◽  
Author(s):  
Christopher Sevara ◽  
Martin Wieser ◽  
Michael Doneus ◽  
Norbert Pfeifer
Keyword(s):  
Data Collection ◽  
Laser Scanning ◽  
Feature Detection ◽  
Field Measurements ◽  
Airborne Lidar ◽  
Environmental Research ◽  
Archaeological Research ◽  
Radiometric Calibration ◽  
Data Set ◽  
Radiometric Data

Airborne laser scanning (ALS) data can provide more than just a topographic data set for archaeological research. During data collection, laser scanning systems also record radiometric information containing object properties, and thus information about archaeological features. Being aware of the physical model of ALS scanning, the radiometric information can be used to calculate material information of the scanned object. The reflectance of an object or material states the amount of energy it reflects for a specific electromagnetic wavelength. However, the collected radiometric data are affected by several factors that cause dissimilar values to be recorded for the same object. Radiometric calibration of such data minimizes these differences in calculated reflectance values of objects, improving their usability for feature detection and visualization purposes. Previous work dealing with calibration of radiometric data in archaeological research has relied on corresponding in-field measurements to acquire calibration values or has only corrected for a limited number of variables. In this paper, we apply a desk-based approach in which radiometric calibration is conducted through the selection of homogenous areas of interest, without the use of in-field measurements. Together with flight and scan parameters, radiometric calibration allows for the estimation of reflectance values for returns of a single full-waveform ALS data collection flight. The resulting data are then processed into a raster reflectance map that approximates a monochromatic illumination-independent true orthoimage at the wavelength of the laser scanner. We apply this approach to data collected for an archaeological research project in western Sicily and discuss the relative merits of the uses of radiometric data in such locations as well as its wider applicability for present and future archaeological and environmental research. In order to make the approach more accessible, we have developed a freely available tool that allows users to apply the calibration procedure to their own data.

scholarly journals INFLUENCE OF FLIGHT CONFIGURATION USED FOR LiDAR DATA COLLECTION ON INDIVIDUAL TREES DATA EXTRACTION IN FOREST PLANTATIONS

FLORESTA ◽  
2014 ◽  
Vol 44 (2) ◽  
pp. 279 ◽  
Author(s):  
Mauricio Muller ◽  
Ana Paula Baungarten Kersting ◽  
Nelson Yoshihiro Nakajima ◽  
Roberto Tuyoshi Hosokawa ◽  
Nelson Carlos Rosot
Keyword(s):  
Data Collection ◽  
Cost Benefit Analysis ◽  
Tree Height ◽  
Flight Time ◽  
Airborne Lidar ◽  
Lidar Data ◽  
Forest Plantations ◽  
Operational Parameters ◽  
Individual Trees ◽  
The Impact

AbstractIn the last decades, several studies have been conducted aiming to the extraction of forest variables from LiDAR data. Although such studies have indicated great potential, the high cost associated with LiDAR data acquisition process inhibits the technology to become an operational technique for forestry applications. The cost of a LiDAR survey, as for any other data collection techniques, is composed of fixed and variable costs. The variable portion, which can be optimized, is dependent, among other factors, on the number of flight hours. The flight time is mainly dependent on the flight configuration used for the survey. The objective of this paper is to investigate the impact of using different operational parameters on different species of forest plantations, to provide inputs for an adequate cost-benefit analysis. The different configurations are evaluated in terms of the number of individual trees automatically detected, individual height and volume, using the forest inventory as the reference data. The experiments have shown that compatible results are obtained using different configurations with flight time varying by a factor of 3.5 to 10 times. Also, for a given point density, preference should be given to the configuration based on a lower flying height.Keywords: Airborne LiDAR; remote sensing; progressive densification; forest mensuration; operational parameters; tree height; volume. ResumoInfluência da configuração de voo para aquisição de dados LiDAR na extração de dados de árvores individuais em plantios florestais. Nas últimas décadas, vários estudos têm sido realizados visando à utilização dos dados obtidos através da tecnologia LiDAR (Light Detection And Ranging) na obtenção de variáveis florestais. Embora tais estudos indiquem alto potencial do LiDAR para aplicações florestais, o elevado custo do levantamento dificulta sua operacionalização no meio florestal. O custo de um levantamento LiDAR, como em outros tipos de levantamentos, é composto de custos fixos e variáveis. A parcela de custos variáveis, a qual pode ser otimizada, encontra-se associada, dentre outros fatores, ao número de horas de voo. O tempo de voo depende principalmente da configuração de voo utilizada no levantamento. Este artigo visa analisar a influência da utilização de diferentes parâmetros operacionais para diferentes espécies de plantios florestais, objetivando prover insumos para uma adequada análise custo-benefício. As configurações são avaliadas em termos do número de árvores automaticamente identificadas, altura individual e volume, tendo como referência os dados do inventário florestal. Os experimentos realizados demonstraram que resultados comparáveis são obtidos com a utilização de diferentes configurações com tempo de voo variando de um fator de 3,5 a 10 vezes. Observou-se também que para uma dada densidade de pontos deve-se dar preferência à configuração que utilize menor altura de voo.Palavras-chave:      Laser scanner; sensoriamento remoto; parâmetros operacionais; altura; volume.

Effect of water-table management and nitrogen supply on yield, plant growth and water use of corn in undisturbed soil columns

1996 ◽  
Vol 76 (2) ◽  
pp. 229-235 ◽  
Author(s):  
C. S. Tan ◽  
C. F. Drury ◽  
J. D. Gaynor ◽  
I. van Wesenbeeck ◽  
M. Soultani
Keyword(s):  
Zea Mays ◽  
Stomatal Conductance ◽  
Plant Growth ◽  
Water Use ◽  
Water Table ◽  
Soil Surface ◽  
Water Table Depth ◽  
Grain Yields ◽  
Water Table Management ◽  
N Rates

The effect of three water-table depths (30, 60 and 80 cm below the soil surface) and four N rates (0, 45, 90 and 135 kg ha−1) on plant growth, yield and water use were evaluated for corn (Zea mays L.). Research was conducted in a greenhouse, using 36 undisturbed foil columns (20 cm i.d. and 90 cm length) collected with a Meta-Drill vibrating core sampler from a Fox sandy loam soil at Harrow Research Centre. Corn grown in the 80-cm water-table depth had the greatest degree of water stress, as indicated by low volumetric soil water content, low stomatal conductance and transpiration rates, and elevated soil-surface and leaf-surface temperatures. There was a substantial increase in plant dry weight and grain yields as the N rates increased from 0 to 135 kg ha−1 with the 30- and 60-cm water-table depths. Under our experimental conditions, maximum grain yields were obtained with a 60-cm water-table depth. Grain yields were significantly reduced with the 80-cm water-table depth. With this water-table depth, grain yield was also reduced by N addition. Key words: Water-table management, Zea mays, yield, stomatal conductance, leaf temperature

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