1631 |
Developing a Soil Moisture-Based Irrigation Scheduling Tool (SMIST) Using Web-GIS TechnologyNikfal, Mohammadreza 05 1900 (has links)
Software as a service (SaaS) is a primary working pattern and a significant application model for next generation Internet application. Web GIS services are the new generation of the Software as a service that can provide the hosted spatial data and GIS functionalities to the practical customized applications. This study focused on developing a webGIS based application, Soil Moisture-Based Irrigation Scheduling Tool (SMIST), for predicting soil moisture in the next seven days using the soil moisture diagnostic equation (SMDE) and the upcoming seven precipitation forecasts made by the National Weather Service (NWS), and ultimately producing an accurate irrigation schedule based on the predicted soil moisture. The SMIST is expected to be capable of improving the irrigation efficiency to protect groundwater resources in the Texas High Plains and reducing the cost of energy for pumping groundwater for irrigation, as an essential public concern in this area. The SMIST comprised an integration of web-based programs, a Hydrometeorological model, GIS, and geodatabase. It integrates two main web systems, the soil moisture estimating web application for irrigation scheduling based on the soil moisture diagnostic equation (SMDE), and an agricultural field delineation webGIS application to prepare input data and the model parameters. The SMIST takes advantage of the latest historical and forecasted precipitation data to predict soil moisture in the user-specified agricultural field(s). In this regard, the next seven days soil moisture versus the soil moisture threshold for normal growth would be presented in the result page of the SMIST to help users to adjust irrigation rate and sequence.
|
1632 |
Quantification of soil properties for analyzing surface processes using spectroscopy and laser scanningHaubrock, Sören-Nils 21 September 2009 (has links)
Oberflächennahe Prozesse werden durch die dynamischen Eigenschaften der Bodenoberfläche besonders beeinflusst. Zwar sind die kausalen Zusammenhänge dieser Prozesse weitestgehend bekannt, doch gibt es einen Mangel an verfügbaren Datenquellen und Erhebungsmethoden, die es erlauben, die Prozesse auf unterschiedlichen Skalen zu quantifizieren. Das Ziel dieser Arbeit bestand darin, das Potential ausgewählter moderner Fernerkundungstechnologien zu bewerten, relevante Bodeneigenschaften zu quantifizieren und damit das Verständnis von oberflächennahen Prozessen in degradierten Landschaften zu verbessern. Das Studiengebiet befand sich in einer Rekultivierunglandschaft des Niederlausitzer Braunkohletagebaus Welzow-Süd. Die Größe von 4 ha ermöglichte eine umfassende, interdisziplinäre und multi-temporale Analyse der Bodeneigenschaften auf Grundlage von Fernerkundungsmethoden sowie hydrologischen und bodenkundlichen Feld- und Labormessungen. Die Quantifizierung der Bodenfeuchte als eine entscheidende Variable für Infiltrations- und Abflussprozesse war das Ziel von labor- und feldspektroskopischen Messungen sowie von hyperspektralen Flugzeugscanner-Messungen. Der hierbei entwickelte Normalized Soil Moisture Index (NSMI) wurde als optimales Quantifizierungsmodell für Oberflächen-Bodenfeuchte im Feld ermittelt. Bodenrauhigkeit wurde in hoher Präzision durch Anwendung eines stationären Laserscanners gemessen und in Form neuartiger multi-skalarer Indizes quantifiziert. Die Analyse der raum-zeitlichen Verteilungen ermöglichte die Identifizierung von Rauhigkeitsmustern, die unter dem Einfluss der Erosion im Feld entstanden. Diese Arbeit entwickelte neuartige Methoden und Indizes zur Quantifizierung von Oberflächen-Bodenfeuchte und Rauhigkeit im Feld. Für die Zukunft verspricht deren Anwendung die Entwicklung eines tieferen Verständnisses von Bodenerosionsprozessen sowie die Sammlung wertvoller Daten durch Monitoring- und Modellierungskampagnen. / Soil processes taking place in the context of erosion and land degradation are highly dependent on the properties of the surface. While the causes and effects of such processes are commonly well understood on a conceptual level, there is a lack of adequate data sources allowing for their quantification at various spatial scales. The main goal of this thesis was to assess the role of state-of-the-art remote sensing methods for the quantification of soil properties with the aim to improve the understanding of surface processes taking place in a degraded landscape. The chosen study area of 4 ha size located in a lignite mine in eastern Germany allowed for a comprehensive, interdisciplinary and multi-temporal analysis of surface properties based on remote sensing, pedological and hydrological measurements. The quantification of surface soil moisture as an important variable for infiltration and runoff processes has been the objective in laboratory and field spectroscopic experiments as well as in airborne hyperspectral measurements. The newly developed Normalized Soil Moisture Index (NSMI) was identified as the most robust quantifier for surface soil moisture in the field. Surface roughness was successfully quantified at high precision in form of novel multiscale indices derived from datasets collected with a stationary laser scanning device. The analysis of spatiotemporal roughness distributions allowed for the detection of distinct patterns that developed under the influence of soil erosion in the field. The thesis developed a set of methods and indices that successfully implement the quantification of surface soil moisture and roughness in the field. For the future, the application of these methods promises further insights into the details of soil erosion processes taking place as well as the collection of invaluable datasets to be used for soil erosion monitoring and modeling campaigns.
|
1633 |
Looking Outward from the Village: The Contingencies of Soil Moisture on the Prehistoric Farmed Landscape near Goodman Point PuebloBrown, Andrew D 08 1900 (has links)
Ancestral Pueblo communities of the central Mesa Verde region (CMVR) became increasingly reliant on agriculture for their subsistence needs during Basketmaker III (BMIII) through Terminal Pueblo III (TPIII) (AD 600–1300) periods. Researchers have been studying the Ancestral Pueblo people for over a century using a variety of methods to understand the relationships between climate, agriculture, population, and settlement patterns. While these methods and research have produced a well-developed cultural history of the region, studies at a smaller scale are still needed to understand the changes in farming behavior and the distribution of individual sites across the CMVR. Soil moisture is the limiting factor for crop growth in the semi-arid region of the Goodman Watershed in the CMVR. Thus, I constructed the soil moisture proxy model (SMPM) that is on a local scale and focuses on variables relevant to soil moisture – soil particle-size, soil depth, slope, and aspect. From the SMPM output, the areas of very high soil moisture are assumed to represent desirable farmland locations. I describe the relationship between very high soil moisture and site locations, then I infer the relevance of that relationship to settlement patterns and how those patterns changed over time (BMIII – TPIII). The results of the model and its application help to clarify how Ancestral Pueblo people changed as local farming communities. The results of this study indicates that farmers shifted away from use of preferred farmland during Terminal Pueblo III, which may have been caused by other cultural factors. The general outcome of this thesis is an improved understanding of human-environmental relationships on the local landscape in the CMVR.
|
1634 |
The investigation of factors governing ignition and development of fires in heathland vegetationPlucinski, Matthew Paul, Mathematics & Statistics, Australian Defence Force Academy, UNSW January 2003 (has links)
Heathlands typically experience regimes consisting of frequent and intense fires. These fire regimes play important roles in the lifecycles and population dynamics of all species in these communities. Prescribed fire is commonly applied to heathlands to minimise the risk of wildfires as well as to promote biodiversity. Ignitions in heathlands tend to either be unsustainable, or quickly develop into rapidly spreading intense fires. This presents a major problem for the application of prescribed fire and is the primary focus of this thesis. Heathland ignition has been investigated in three sections; litter ignition; vertical development of fire into the shrub layer; and horizontal spread through the shrub layer. These were studied in laboratory experiments using miniature versions of field fuels. Ignition success in litter layers was related to the dead fuel moisture content. Litter type, ignition source, and presence of wind were found to affect the range of ignitable fuel moisture contents of a litter bed. The effect of litter type was best explained by density. Dense litter beds required drier conditions for ignition than low density litter beds. The vertical development of fire into shrubs was mostly dependent on live fuel moisture content, but crown base height, presence of wind, ignition source, shrub height and the percentage of dead elevated fuel were also important. Horizontal spread of fires through shrub layers was most affected by the presence of a litter layer, with nearly all ignitions successful when there was an underlying litter fire. Fire spread would only occur in shrubs without a litter layer when the shrub layer was dense and dry, or had a substantial dead fuel component. Spread was more likely to be sustained when there was wind. Models predicting the moisture content of dead fuels were tested in heathlands, and as would be expected those that can be calibrated for different fuel types were found to have the best performance. Fuel moisture content and fuel load models were reviewed for heathlands, and a number of recommendations for future research were made.
|
1635 |
The roles of seed banks and soil moisture in recruitment of semi-arid floodplain plants: the River Murray, Australia.Jensen, Anne Elizabeth January 2008 (has links)
The decline of floodplain vegetation along the Lower River Murray, South Australia, has evoked recommendations for ‘environmental flows’ to restore and maintain the health of the ecosystem. To assist managers to maximize benefits from environmental flows, this thesis considers the significance of water for germination and recruitment in key floodplain plant species. Three dominant species are considered, including two trees, river red gum (Eucalyptus camaldulensis) and black box (E. largiflorens), and an understorey shrub, tangled lignum (Muehlenbeckia florulenta). The soil seed bank was dominated by terrestrial annual native plants. Among 1400 seedlings, a single river red gum was found, and no black box or lignum, suggesting that these species do not contribute to the persistent soil seed bank and rely instead on aerial seed banks (serotiny). Sampling of the soil seed bank was continued to determine when seed fall might coincide with appropriate soil moisture conditions. Responses of the soil seed bank to varied water regimes were compared to determine requirements for seedling survival. The results indicated that species richness, rapidity of response and survival time were all promoted by sustained soil moisture. Stands of eucalypts in various states of health (from very stressed to very healthy) were monitored to identify seasonal patterns in bud crops, flowering, fresh leaves and volumes of seed released from the aerial seed bank. Distinct seasonal phenological patterns were apparent, and suggested alternating flowering among individual trees (biennial for red gum, bi-annual for black box), producing an annual peak in summer. Peak seed rain occurred in summer (December–March) in healthy trees for both red gum and black box, with light seed rain continuing throughout the year. Seed fall from stressed trees was much reduced. Stressed trees responded after a second watering event, with much more varied and extended annual seed fall patterns. Lignum showed a spring peak in flowering and seed production. There was a prolific response of flowering and seeding to rainfall, but few seedlings survived. Vigorous vegetative growth occurred in existing plants in response to rainfall and watering but no new cloned plants were found during the study. An investigation of chromosomes as a potential tool to appraise the balance between sexual and asexual reproduction in lignum proved inconclusive, although a previous report of octoploidy in lignum was confirmed. Seeds from all three species and lignum cuttings were tested for their responses to varied watering regimes, based on combinations of simulated rain and flood conditions. The optimal soil moisture for continued growth and survival in all seeds and cuttings was 10 25%, with moisture values <10% causing wilting and death. The results also suggested that red gum and black box seeds which germinate in water under flooded conditions need to be stranded onto moist soil at the water’s edge within 10 days, for the seedling to continue to grow. It was also concluded that germination on rain-moistened soil is a key supplementary mechanism for recruitment, particularly between irregular flood events. For greatest benefit, the timing of environmental flows should complement any seasonal rainfall and irregular flooding that may occur. Extension of suitable soil moisture conditions (10-25%) for as long as possible after >5 mm rainfall, or after over-bank flows, would increase chances for survival of seedlings. December is the most likely month for maximal benefit from watering in the Lower Murray Valley, for germination and recruitment, based on regional rainfall and flooding patterns. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1344528 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008
|
1636 |
Assessing Soil-Water Status Via Albedo MeasurementIdso, Sherwood B., Reginato, Robert J. 20 April 1974 (has links)
From the Proceedings of the 1974 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 19-20, 1974, Flagstaff, Arizona / Reliable information on soil-water status is required in order to make accurate water balance studies of watersheds, to determine the survival probabilities of various types of vegetation between rainfalls in low rainfall areas, and to determine the susceptibility of the uppermost soil to wind erosion. Simple solarimeters may help to accomplish this objective. Bare soil albedo was a linear function of the water content of a very thin surface layer of soil, and albedo correlated well with water contents of thicker soil layers. In addition, albedo measurements could be used to delineate the 3 classical stages of soil drying. Albedo may also be used to differentiate between the initial potential rate phase of evaporation following an application of water, and the succeeding falling rate phase. Results of applying this technique to a field of Avondale clay loam indicate that 20% to 25% of the water applied by either irrigation or rain will be lost by stage 1 potential evaporation, independent of seasonal variations in evaporative demand. Presently the techniques developed are applicable only to bare soil surfaces.
|
1637 |
Root System of Shrub Live Oak in Relation to Water Yield by ChaparralDavis, Edwin A. 16 April 1977 (has links)
From the Proceedings of the 1977 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 15-16, 1977, Las Vegas, Nevada / The root system of shrub live oak (Quercus turbinella) was studied in an initial effort to classify the major Arizona chaparral shrubs as potential users of soil water based on root system characteristics. The root system was of the generalized type with a taproot, many deeply penetrating roots, and a strong lateral root system. Roots penetrated 21 feet to bedrock through cracks and fractures in the rocky regolith. A dense network of small surface laterals radiated from the root crown and permeated the upper foot of soil. Because of its root system, shrub live oak is well adapted to utilize both ephemeral surface soil moisture as well as deeply stored moisture. Emphasis is placed on the importance of a knowledge of the root systems of chaparral shrubs and depth of the regolith in planning vegetation conversions to increase water yield.
|
1638 |
Untersuchung zur Praxis der Atemgasklimatisierung auf deutschen Intensivstationen. Eine nationale Studie. / Study on the medical practice of conditioning the respiratory air on German intensive care unitsGlismann, Tobias Michael 06 March 2012 (has links)
No description available.
|
1639 |
Bauklimatische Simulationsverfahren zur Lösung von Entwurfs-, Planungs- und Sanierungsaufgaben in Syrien / Building climatic simulation methods for the solution of design, planning and renovation projects in SyriaBishara, Ayman 13 January 2014 (has links) (PDF)
Die vorliegende Dissertation befasst sich mit der Entwicklung, Implementierung, Verifizierung und beispielhaften Anwendung eines thermohygrischen Modells zur Lösung bauklimatisch anspruchsvoller Planungsaufgaben. Als Anwendungsbeispiele dienen zwei Planungsprojekte an kritischen Standorten, ein Sanierungsentwurf für ein Wohngebäude in der warm-trockenen Klimazone (Damaskus) und ein Neubauentwurf für ein Kirchengebäude in der warm- feuchten Klimazone (Latakia).
Die Entwicklung des thermohygrischen Berechnungsmodells wurde auf der Grundlage einer vereinfachten Gebäude- Energie- und Feuchtebilanz vorgenommen. Das Modell prognostiziert den thermischen und hygrischen Raumklimaverlauf in Abhängigkeit des Außenklimas, der Baukonstruktion und der Raumnutzung. Die Validität des Modells konnte in einem ersten Schritt am Beispiel eines Archivbaus am Standort Dresden nachgewiesen werden. In einem zweiten Schritt wurde das Modell in seiner Funktionalität (Eingabeparametervariabilität und -flexibilität) erweitert und in das Programm CLIMT (Climate-Indoor-Moisture-Temperature) implementiert. Die Validität der erweiterten Funktionalität des Programms konnte mit Hilfe von Messergebnissen eines Testhauses am Standort Partwitzer See (Brandenburg) sowie den für dieses Gebäude durchgeführten Simulationsergebnissen (Software TRNSYS) nachgewiesen werden. Die Anwendung des entwickelten Programms CLIMT wurde für zwei gehobene bauklimatische Problemstellungen demonstriert. In beiden Fällen handelt es sich um Gebäude, deren historisch gewachsenes Umfeld und deren bautypologische Traditionen maßgebende Planungsaspekte darstellen. Die Standort- Klimazonen beider Gebäude bringen besondere Schwierigkeiten mit sich.
Für das Sanierungsplanungsbeispiel „Damaszener Wohnhaus“ wurden die Hauptmerkmale der historischen städtebaulichen Einbindung, der Gebäudezonierung sowie der traditionellen gestalterischen und bautechnischen Gebäudeelemente herausgearbeitet. Im Anschluss daran wurde die historisch- bauklimatische Funktionsweise dieses Gebäudetypus mit zahlreichen CLIMT- Variantenrechnungen näher betrachtet. Die besondere klimatische Schwierigkeit des Standortes Damaskus besteht in den permanent hohen Lufttemperaturen von bis zu 42°C, verbunden mit sehr niedrigen Luftfeuchten und Luftgeschwindigkeiten. Es wurden die beiden wesentlichen bauklimatische Funktionsbereiche, deren maßgebende Eigenschaften und deren Wirkungsweise für das Standortklima analysiert. Die Ergebnisse dieser Analyse bilden eine Hilfestellung für die traditionsbewusste bauklimatische Konzeption ähnlicher Gebäudetypen in dieser Klimazone.
Auch für den Anwendungsfall der Neubauplanung eines Kirchenbaus am Standort Al-Rwda (Latakia) wurde eine umfassende bauhistorische Analyse des Gebäudetypus durchgeführt. Es konnten die historisch gewachsenen Hauptmerkmale des byzantinischen bzw. syrischen Sakralbaus in Bezug auf die Gebäudekubatur, Fassadengestaltung, Baustoffwahl und Innenraumgestaltung herausgestellt werden. Die bauklimatische Optimierung des neu zu errichtenden Kirchenbaus wurde mit Hilfe von CLIMT- und DELPHIN- Simulationsstudien vorgenommen. Am Gebäudestandort Latakia bestand die besondere Problemstellung in der Berücksichtigung hoher Luftfeuchten und Temperaturen welche ein erhöhtes Schadenspotenzial für die Außenbauteilkonstruktionen bedingen. Trotz der zahlreichen Randvorgaben der Planung konnten die bauphysikalischen Eigenschaften der gewählten Konstruktionen so weit wie möglich den vorteilhaften historischen Konstruktionseigenschaften angenähert werden so dass Schadensfreiheit gewährleistbar ist und der Energiebedarf weitestgehend minimiert wurde. Auch die Erkenntnisse dieses Kapitels bieten Planungshilfestellungen für den Entwurf ähnlicher Gebäudetypen und sind des Weiteren auf andere Klimazonen, so auch die gemäßigte Klimazone, übertragbar.
Die Dissertation leistet einen wichtigen Beitrag zur Verbesserung des Entwurfsprozesses indem sie ein praxistaugliches aber dennoch exaktes Bewertungsmodell zur Verfügung stellt und dessen Anwendung im Zusammenspiel der zahlreichen Entwurfsaspekte wie z.B. Städtebau, Nutzungsanforderungen, Statik, Liturgie, Baugeschichte und vor allem Bauklimatik, beispielhaft aufzeigt. Die Ableitung bauklimatischer Regeln bzw. Erkenntnisse konnten für zwei bauklimatisch bedeutende Klimazonen, die warm- feuchte und die warm- trockene Zone, an Hand zweier Entwurfsfelder bzw. Entwurfsbeispiele aufgestellt werden. Die erzielten Erkenntnisse beruhen dabei nicht nur auf der Anwendung des thermohygrischen Gebäudemodells sondern auch auf einer theoretischen Analyse der baugeschichtlichen Vorbilder für die Entwurfsbeispiele der jeweiligen Klimazone.
|
1640 |
Teplotně-vlhkostní posouzení prvků krovu s nadkrokevním systémem zateplení / Temperature-moisture Assessment of Members in Truss with Above-rafter Thermal InsulationSoudek, Pavel January 2014 (has links)
This thesis deals with the temperature-moisture assessment of members in truss with above-rafter thermal insulation. Within this system it focuses on the details of creating a roof overhang because that is where the timber elements are under the greatest amount of moisture stress. Different variations of this detail are presented including the extent to which thermo-technical requirements and requirements surrounding the built-in timber elements are satisfied. Theoretical calculations are then compared with measurements which were performed on a real building. This task of measurement involved developing a new measuring device. The development of this device is also described in this paper.
|
Page generated in 0.0186 seconds