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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Tree Seedling Establishment Under the Native Shrub, Asimina Triloba

Baumer, Marilyn Cabrini 30 July 2007 (has links)
No description available.
12

An Object-Oriented Approach to Forest Volume and Aboveground Biomass Modeling using Small-Footprint Lidar Data for Segmentation, Estimation, and Classification

van Aardt, Jan Andreas Nicholaas 26 August 2004 (has links)
This study assessed the utility of an object-oriented approach to deciduous and coniferous forest volume and above ground biomass estimation, based solely on small-footprint, multiple return lidar data. The study area is located in Appomattox Buckingham State Forest in the Piedmont physiographic province of Virginia, U.S.A, at 78°41’ W, 37°25’ N. Vegetation is composed of various coniferous, deciduous, and mixed forest stands. The eCognition segmentation algorithm was used to derive objects from a lidar-based canopy height model (CHM). New segment selection criteria, based on between- and within-segment CHM variance, and average field plot size, were developed. Horizontal point samples were used to measure in-field volume and biomass, for 2-class (deciduous-coniferous) and 3-class (deciduous-coniferous-mixed) forest schemes. Per-segment lidar distributional parameters, e.g., mean, range, and percentiles, were extracted from the lidar data and used as input to volume and biomass regression analysis. Discriminant classification was performed using lidar point height and CHM distributions. There was no evident difference between the two-class and three-class approaches, based on similar adjusted R2 values. Two-class forest definition was preferred due to its simplicity. Two-class adjusted R2 and root mean square error (RMSE) values for deciduous volume (0.59; 51.15 m3/ha) and biomass (0.58; 37.41 Mg/ha) were improvements over those found in another plot-based study for the same study area. Although coniferous RMSE values for volume (38.03 m3/ha) and biomass (17.15 Mg/ha) were comparable to published results, adjusted R2 values (0.66 and 0.59) were lower. This was attributed to more variability and a narrower range (6.94 - 350.93 m3/ha) in measured values. Classification accuracy for discriminant classification based on lidar point height distributions (89.2%) was a significant improvement over CHM-based classification (79%). A lack of modeling and classification differences between average segment sizes was attributed to the hierarchical nature of the segmentation algorithm. However, segment-based modeling was distinctly better than modeling based on existing forest stands, with values of 0.42 and 62.36 m3/ha (volume) and 0.46 and 41.18 Mg/ha (biomass) for adjusted R2 and RMSE, respectively. Modeling results and classification accuracies indicated that an object-oriented approach, based solely on lidar data, has potential for full-scale forest inventory applications. / Ph. D.
13

Hodnocení sekvestračního potenciálu vegetace/porostů rekultivovaných výsypek metodami DPZ / Assessment of the sequestration capacity of vegetation by remote sensing methods in areas of reclaimed mining dumps

PIKL, Miroslav January 2018 (has links)
The study aims at estimation and mapping the amount of carbon allocated in above ground biomass of wood and in organo-mineral soil horizon at sites where reclamation and spontaneous succession took place on spoil heaps after coal mining. Several categories of data have been used to meet the objectives, namely ground field measurements, laboratory analyses of soil samples, airborne hyperspectral data from VNIR region, and airborne LiDAR scanning data. The digital imagery analysis, GIS modeling and multivariation statistical methods were applied in data assessment. The results show that there is a 7 600 tons of carbon allocated in above ground wood biomass in the area of 209 ha, and 8 100?12 200 tons in the soil A horizon in the region of the same size. The results proofed: 1/ statistically significant negative relationships (p < 0,01) between slope and amount of soil carbon, where higher negative correlation was for broad leaved species; 2/ statistically significant difference (p < 0,05) between amount of soil carbon under broad leaved and needle classes and under different species, the highest between soils under Alnus sp. and Pinus sp.; 3/ statistically significant relationships (p < 0,05) between the amount of carbon allocated in the aboveground wood biomass and that in the soil A horizon under the needle leaved class and under the spontaneous wood vegetation.
14

Effects of Water Holding Capacity and Precipitation on Above Ground Net Primary Production

January 2019 (has links)
abstract: Aboveground net primary production (ANPP) is an important ecosystem process that, in drylands, is most frequently limited by water availability. Water availability for plants is in part controlled by the water holding capacity of soils. Available water holding capacity (AWHC) of soils is strongly influenced by soil texture and depth. This study drew upon localized rain gauge data and four data-sets of cover-line and biomass data to estimate ANPP and to determine annual precipitation (PPT). I measured soil depth to caliche and texture by layer of 112 plots across the four landscape units for which estimation of ANPP were available. A pedotransfer function was used to estimate AWHC from soil depth increments to depth of caliche measurements and texture analysis. These data were analyzed using simple and multivariate regression to test the effect of annual precipitation and available water holding capacity on aboveground net primary production. Soil texture remained constant among all plots (sandy loam) and depth to caliche varied from 15.16 cm to 189 cm. AWHC and the interaction term (PPT*AWHC) were insignificant (p=0.142, p=0.838) and annual PPT accounted for 18.4% of the variation in ANPP. The y-intercept was significantly different for ANPP ~ annual PPT when considering AWHC values either above or below 3 cm. Shrub ANPP was insensitive to precipitation regardless of AWHC (R2=-0.012, R2=0.014). Results from this study indicate that a model incorporating annual PPT and AWHC may not serve as a good predictor for ANPP at a site level where there is little variation in soil texture. / Dissertation/Thesis / Masters Thesis Sustainability 2019
15

Above-ground biomass estimation in boreal productive forests using Sentinel-1 data

Roc Roc, David January 2019 (has links)
Estimation of biomass has high importance for economic, ecologic and climatic reasons due to the multiple ecosystem services offered by forested landscapes. Measurements that are taken in the field incur personal and economic costs. Nevertheless, biomass surveying based on remote sensing techniques offer efficiency thanks to covering large areas. The European Space Agency (ESA) Sentinel-1 satellite offers promising capabilities for above-ground biomass (AGB) estimation through synthetic aperture radar (SAR) based microwave remote sensing. In this study, experimental AGB estimations based on Sentinel-1 C-band data were produced over the Remingstorp estate (Västergötland County, Sweden) to analyze its performance over boreal productive forests. The obtained measurements were compared against reference values obtained by combining photogrammetric, aerial laser scanning (ALS) and field measurements. Thus, a reference high-resolution canopy height model (CHM) was produced from the difference between photogrammetric digital surface model (DSM) values and ALS digital terrain model (DTM) values. The comparison of CHM observations against diameter at breast height (DBH) field measurements revealed the existence of a vegetation height - vegetation volume relationship for the study species (Pinus Sylvestris and Picea Abbies), which allowed bole volume estimation based on vegetation height values. SAR-based AGB estimates were produced by defining statistical relationships between backscatter intensity and interferometric coherence measurements against reference CHM values. Additionally, evaluation of biomass estimation through interferometric (InSAR) height was possible by comparing against reference photogrammetric DSM. Backscatter signal saturation of C-band at low biomass volumes prevented quantification of biomass but permitted differentiation between forested and non-forested surfaces. Estimation of AGB through interferometric coherence was possible through modeling volumetric decorrelation, which on the contrary prevented biomass retrieval from InSAR height. Due to the given frequency properties at C-band, HV cross-polarized channel was used in all cases for better detection of the canopy layer. Image acquisition under stable conditions was a priority to avoid noise derived from variable dielectric properties, acquisition geometry effects and temporal decorrelation. Hence, image acquisitions under stable hydrometeorological conditions (i. e. stable frozen or dry) and for the lowest repeat-pass interval (i. e. 6-days) were prioritized.
16

Hotel / Hotel

Koudelová, Kateřina January 2018 (has links)
The aim of the diploma thesis is design a hotel in Žďár nad Sázavou. The hotel is designed for 36 guests. The building is with partial basement and it is composed of three parts. These parts have one, two and five above-ground floor. Structural system is frame and load-bearing elements are columns and beams. The roof is flat. Part of the design is also a thermal assessment and fire safety assessment.
17

Mateřská školka / Kidsgarden

Kubů, Michal January 2020 (has links)
The aim of a diploma thesis is design of a kidgarden in Humpolec in Highlands Region. The building is designed as a detached building with two above-ground floors and a partial basement. The building has four separate units of kidgarden. External walls are designed from aerated concrete blocks. Basement masonry is made of the permanent concrete formwork. The roof of the building is designed as flat. Project documentation was prepared according to valid legal and technical regulation.
18

Polyfunkční dům v Liberci / Multifunctional Building in Liberec

Hůlková, Lucie January 2013 (has links)
The subject of my master´s thesis, called „ multifunctional house in Liberec” is to design and elaborate project documentation of the multifunctional house in Liberec. Design of the building respect Land Use Plan of the town on side, and existing build-up area on the street on the other side. Building has one underground floor and three above ground stories. The Ground Floor is partly roofed by flat roof. The third floor has terrace and it´s roofed by saddleback roof.
19

Polyfunkční dům v Českých Budějovicích / Mixed-use building

Honner, Jan January 2017 (has links)
The aim of my master´s thesis is a design of mixed-use building. The new building is designed to be a permanent resident with offices and café. The objech has one basement and three above floor. In the basement is amenities of house, office premises and café. All the above floor are designed for housing. The object is on sloping terrain on the selected pieces of land in north-west part of city Ceske Budejovice. Structural system is from permanent formwork. The house is roofed with warm flat floor. Drawing part processed in a computer program Archicad.
20

Effets des contraintes mécaniques du sol sur la limitation des rendements du tournesol / Impact of soil mechanical constraints on sunflower yield limitation

Mirleau-Thebaud, Virginie 09 May 2012 (has links)
La production de tournesol inclue des interactions complexes entre le génotype et l'environnement tout au long du cycle de la culture. La profondeur de l'enracinement du tournesol est fortement liée au sol, à sa structure et à la disponibilité en eau. La compaction du sol représente un enjeu important dans le contexte actuel de la durabilité des systèmes agricoles, et se caractérise par une diminution de la disponibilité hydrique du sol, une augmentation de la densité apparente et la résistance du sol à la pénétration. L’altération de l'exploration du système racinaire et de ses conséquences sur la croissance du système aérien sous contraintes mécaniques du sol a été explorée pour de nombreuses cultures (maïs Zea mays, Blé Triticum durum, ou de soja Glycine max). Peut d’études ont été réalisée sur le tournesol (Helianthus annuus L.). Parmi ces études seules quelqu’une incluent des cinétiques de croissance, encore moins incluent la qualité de la production. Le but de ce travail est d'étudier i) les modifications du système racinaire causée par la compaction du sol, ii) l'altération du système aérien causé par la modification du système racinaire, et iii) les interactions entre les systèmes. Une synthèse réalisée à partir la littérature et du schéma conceptuel du modèle STICS a permis d’établir un schéma conceptuel théorique retraçant le mécanisme des actions de la compaction du sol sur la plante de tournesol. A partir de ce schéma, deux expérimentations au champ et une expérience en conditions contrôlées ont été construites. En présence de compaction du sol, une diminution de la disponibilité hydrique, une augmentation de la densité apparente et la résistance du sol à la pénétration ont été observées conformément à la littérature. Le stress causé par la contrainte mécanique du sol a induit une réduction de la croissance et de l'exploration du système racinaire. Ceci a engendré une diminution de la surface foliaire, de la biomasse aérienne, et de la hauteur des plantes. Les pertes d'efficacité de l'utilisation des ressources et de rendement ont été observées par des indicateurs indirects. Les analyses de sensibilité de STICS ont été effectuées sur les paramètres d'intérêts, confirmant le seuil à partir duquel la compaction du sol conduit à des effets négatifs sur la plante de tournesol. Des propositions ont été faites pour adapter le modèle à la croissance du système racinaire de tournesol, i) en établissant une liaison directe entre les appareils aérien et souterrain, et ii) en réajustant l'indice de stress provoqué par les variations de densité apparente / The sunflower production takes place throughout complex interactions between the genotype, the crop management and the environment. Sunflower rooting depth is strongly related with soil structural behavior and gravimetric water availability. Soil compaction represents an important issue in the actual context of agricultural system durability, and is characterized by a decrease of soil available water, an increase of bulk density and soil resistance to the penetration. Variation of root system exploration and their consequences on above ground growth and development under soil mechanical constraints have been explored for many crops (Maize Zea mays, Wheat Triticum durum, or Soybean Glycine max), but only few researches have been carried out on sunflower (Helianthus annuus L.). Among them only few includes kinetic aspects and less quality of production. The aim of this work is to study i) the root system modifications caused by soil compaction, ii) the above ground system alteration caused by root system modification, and iii) the interactions between the systems. An analysis carried out from literature and the model STICS conceptual framework lead to the construction of a conceptual framework explaining the mechanism of soil compaction actions on sunflower plant. From this knowledge, two field experiments and a controlled experiment were built. In presence of soil compaction a decrease of soil water availability and an increase of bulk density and soil resistance to penetration were observed as reported in literature. The stress caused by soil mechanical constraint induced a reduction of root system growth and exploration. This induced a decrease of leaf area, shoot biomass, and plant height. The use efficiency of resource and yield lost were observed by indirect indicators. Sensitivity analyses of STICS were done on parameter of interest, confirming the threshold above which soil compaction lead to negative impact on sunflower. Proposition were made to adapt the model to sunflower root system growth, by implementing a direct link between shoot and root growth, and by readjusting the bulk density stress index

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