The Benefits to People of Expanding Marine Protected Areas

This study focuses on how the economic value of marine ecosystem services to people and communities is expected to change with the expansion of marine protected areas (MPAs). It is recognised, however, that instrumental economic value derived from ecosystem services is only one component of the overall value of the marine environment and that the intrinsic value of nature also provides an argument for the conservation of the marine habitats and biodiversity

Balance of Threat, Balance of Mind: Nuclear Rivalry and Arms Control

Under what conditions will rivals choose to accept mutual constraints, limitations, and even reductions on their capabilities for waging war? Contemporary political science lacks a strong theoretical basis for understanding this behavior, despite the fact that states in the modern era continue to negotiate and enter into arms control arrangements. This study contributes a theoretical framework and empirical analysis identifying the conditions under which nuclear-armed rivals might choose to curb their deadly arsenals. Traditional theories grounded in classical deterrence theory suggest arms control serves to preserve a deterrent status quo and prevent expensive and destabilizing arms competition; it should therefore only be expected when rivals feel secure in the strength and effectiveness of their respective retaliatory capabilities. This study suggests a more complicated (yet still predictive) causal logic in which this balance of force is dynamically interactive with militarized hostility and rivals convergence or divergence in how they think — both normatively and instrumentally — about the role of nuclear weapons in their national security. The argument is illustrated through qualitative comparative analysis (QCA) of bilateral arms control interactions among nuclear-armed strategic rivals from 1949 to the present. Further analysis is provided through in-depth case studies of arms control dynamics between three pairs of contemporary nuclear rivals — the United States and Russia, India and Pakistan, and the United States and China

Public Health Impacts from Fires in Tropical Landscapes

Fires are the primary method of deforestation and agricultural management in the tropics, but associated emissions such as aerosols, ozone, and carbon monoxide can have negative impacts on ecosystems, climate, and public health. Recent advances in satellite monitoring of fire activity, including using thermal anomalies for active fire detections and burn scar mapping of post-fire effects, have offered an unprecedented level of detail in understanding the magnitude and extent of fire activity. This dissertation aims to quantify the human health impact across populations in tropical regions by determining which areas are the most susceptible to transported fire emissions and how this exposure varies over time. The following chapters can be used to highlight critical conservation regions, not only for conserving ecosystems for biodiversity and climate benefits, but also for protecting public health. To address how fire emissions can affect regional populations, satellite observations of fire activity are combined with models of how tropical fire emissions are transported in the atmosphere. Satellites provide two primary pieces of information for this approach: 1) measurements of the distribution and magnitude of fire activity, and 2) categorization of fire types (such as agricultural burning or deforestation) by overlaying observed fire patterns on land use maps. Atmospheric models perform the crucial step of simulating how emissions evolve and where they are transported after release into the atmosphere. The following dissertation chapters are linked through exploration of fire emissions impacts from continental to local scales, including implementing fire emissions inventories into atmospheric models, quantifying population exposure to fire activity in Equatorial Asia, and projecting fire emissions associated with various future land use scenarios in Sumatra. Model estimates of aerosol concentrations are more influenced than trace gases by using finer temporal resolution fire emissions, due to interactions between emissions and modeled meteorology and transport. This in turn can impact air quality estimates by permitting higher peak concentrations. In addition, model results show that population exposure to fire emissions in Equatorial Asia is highly variable over time depending on the phase of the El Niño cycle; strong El Niño years can have fire contributions to fine particulate matter of up to 200 µg/m³ near fire sources, corresponding to 200 additional days per year over the World Health Organization 50 µg/m³ 24-hour fine particulate matter air quality target. These risks are not confined to people living near fire sources, but expose broad regional populations due to the atmospheric transport of emissions. Health impacts also depend on underlying fuel characteristics, with the future magnitude of Equatorial Asian fire emissions estimated to be strongly dependent on the level of protection given to fuel-rich peatswamp forests (contributing 33-48% of future emissions in the absence of protection). Collectively, these chapters emphasize variability in how tropical fire emissions affect regional population exposures to outdoor air pollution, and the need to consider the dependence of this public health effect on different fuel types and year-to-year variations in climate. The results described in this dissertation quantify direct benefits of conservation for people living near fire areas

MODELING FUTURE HYDROLOGIC EXTREMES, FLOOD HAZARDS, AND EXPOSURE UNDER A HIGH EMISSIONS SCENARIO IN THE NEUSE RIVER WATERSHED

Flood prone communities often lack predictive hazard maps necessary to inform public policy and efforts aimed at reducing household risks. This study evaluated the independent and combined effects of future climate and land use change scenarios on hydrologic response. I modeled changes in peak flows, volume, and timing between 2020 and 2100 using a large-scale (16,148 km2) physics-based distributed hydrologic model of the Neuse River watershed and mapped the resulting flood depth and extent in Goldsboro, NC. I find that, in general, the effects of climate change on peak stream flow are greater than the effects of land use change; however, the role of land use change on discharge is spatially heterogeneous and dependent on localized patterns of land use change. In Goldsboro, the combined future climate and land use projections result in at least a five-fold increase in building exposure, with the greatest increases occurring for medium-sized storms.Master of Scienc

Tundra Swan (Cygnus columbianus columbianus) Habitat Selection during the Nonbreeding Period

Changes in availability and foraging profitability of agricultural and aquatic habitats have the potential to greatly influence population dynamics of waterfowl. Therefore, the purpose of my research was to understand habitat selection by Tundra Swans during the nonbreeding period and to explore the scale-dependency of these relationships. Habitat selection was influenced by seasonal changes in nutritional requirements and food availability; Tundra Swans selected open water and agriculture in winter, wetlands were weakly selected during migration when open water was strongly selected (especially during autumn), and there was a 2-fold increase in use of agriculture from autumn to spring. It appears that selection for agriculture and wetlands was influenced by continuous changes in habitat availability, whereas selection for open water changed discretely by region. Based upon my results, habitat management for large-bodied waterfowl should focus on protecting and improving aquatic habitats and ensuring availability of agriculture, especially during winter and spring

The influence of sediment blanketing on subduction-zone seismicity

Subduction of oceanic lithosphere is now occurring beneath the Aegean and central Caspian Seas, and beneath the Indo-Burman Ranges in NE India, generating zones of earthquakes that reach depths of more than 150 km. Their existence is surprising. In general, where the temperature of the mantle part of the oceanic lithosphere can be estimated, earthquakes are confined to material whose temperature is below . In these three regions the oceanic lithosphere is overlain by sediments with low thermal conductivity whose thickness is probably 10–25 km. The temperature of the oceanic crust and upper half of the lithosphere should be considerably increased by such a thick sedimentary cover, yet there is no obvious difference between these subduction zones and those where there is little sediment on the subducting plate. Detailed thermal modelling of the temperature shows that, for the first 40 Ma, the deposition of even a thick sedimentary layer has little effect on the thickness of the region of lithosphere whose temperature is below , principally because little heat is conducted across the Moho. The modest effect of sediment blanketing over a period as long as 40 Ma was quite unexpected. Over the next 200 Ma the lithospheric temperature increases, until the Moho temperature reaches . This behaviour has important implications for oil and gas generation in the sediments, and for the existence of large earthquakes at depths of 150 km or more beneath the Hindu Kush, Pamirs and Romania

The influence of climate and prey availability on flatfishes on the Newfoundland Grand Banks

Fishing and environmental variability interactively affect fish population dynamics, where fishing can increase population variability in response to environmental change. Therefore, developing fisheries management strategies that account for these interactions is necessary for managing recovering populations in a changing climate. Using a combination of ecological and population dynamics approaches, this thesis investigated the interactive effects of overfishing and environmental variability on yellowtail flounder (Limanda ferruginea) and American plaice (Hippoglossoides platessoides) populations on the Newfoundland Grand Banks, Canada. These populations were selected given their different recovery patterns following population collapse in the early 1990s, despite sharing similar life history characteristics, inhabiting similar environments, and having been managed under the same fishing moratoria. Specifically, the yellowtail flounder population recovered in four years, while the American plaice population has yet to recover 30 years after collapse. By coupling spatiotemporal models of bottom water temperature and population distributions, I revealed that variability in spatial population distribution was influenced by a combination of density-dependent processes and spatiotemporal variability in temperatures. By developing a novel statistical method to integrate stomach contents and bottom trawl research data to estimate prey dynamics I also showed that northern sand lance (Ammodytes dubius), an important forage fish prey species for American plaice, has exhibited oscillatory dynamics over time, which may affect the productivity of their predators. Furthermore, expanding on indications that American plaice population dynamics may be influenced by natural mortality, results from a metapopulation dynamics model identified that natural mortality was not a primary driver of juvenile dynamics following population collapse. Finally, through the development of a modeling framework to underscore the importance of incorporating various population and ecosystem processes in population dynamics models, I revealed that American plaice population dynamics were strongly affected by variability in recruitment and adult natural mortality over time and that both stocks were influenced by an integrated regional climate index. Overall, by coupling ecological and population dynamics research, this thesis adds to the growing base of research that indicates that understanding how fishing and the environment interact is necessary to produce ecosystem-informed management advice to identify appropriate rebuilding strategies for collapsed populations

Site-specific irrigation: Improvement of application map and a dynamic steering of modified centre pivot irrigation system

Einleitung: Ein Management Konzept für nachhaltige und effiziente Nutzunglandwirtschaftlicher Maßnahmen ist bekannt als teilflächenspezifische Landwirtschaft (PA – Precision Agriculture). Wird das teilflächenspezifische Konzept im Bewässerungsmanagement eingesetzt, wird es teilflächenspezifische Bewässerung genannt (PI – Precision Irrigation). Bei der teilflächenspezifische Bewässerung kann die Bewässerung zwischen den Bereichen eines Feldes auf Grund der Variabilität der Bodeneigenschaften oder dem Anbau von verschiedenen Pflanzen auf dem selben Feld variieren. Die räumliche Veränderung der nutzbaren Feldkapazität als Primärfaktor bedingt die räumliche Veränderung der Bewässerungshöhe und der Bewässerungsfrequenz. Die Bewässerungssysteme verteilen das Wasser bis heute gleichmäßig, so dass die Flächen teilweise überbewässert oder unterbewässert sind. Bezogen auf dieses Problem ist die teilflächenspezifische Beregnung geeignet, das Wasser an der richtigen Stelle zum richtigen Zeitpunkt unter Benutzung des richtigen Bewässerungssystems auszubringen. Folglich sind die Schlüsselziele dieser Arbeit: a) die Abgrenzung von Beregnungsmanagementzonen (IMZs – Irrigation Management Zones) unter Nutzung von sensorbasierten Messungen der elektrischen Leitfähigkeit (ECa – depth-weighted apparent soil electrical conductivity) des Bodens mit EM38 und VERIS 3100, b) die Entwicklung und Evaluierung einer teilflächenspezifischen mobilen Tropfbewässerung und c) Auswertung von drahtlosen  Bodenfeuchtesensoren (EnviroSCAN) und der klimatischen Wasserbilanz (AMBAVModell) zur Bestimmung der Bodenfeuchte bzw. der Bewässerungshöhe.Material und Methoden: EC25-Daten (ECa bei 25° C) wurden unter Verwendung von EM38 und VERIS 3100 Geräten bei Feldkapazität auf einem 16,6 ha großen Feldstück der FAL, Braunschweig, Deutschland, gemessen. Die ECa Daten wurden im Sekundenintervall mit zwei bis drei Metern Messabstand und in Reihenabständen von etwa vier bis sechs Metern gemessen. Zur Erstellung der EC25- und Bodenfeuchte Karten wurde die Software ArcView genutzt, nachdem die Messdaten mit Hilfe des sphärischen Kriging-Verfahren interpoliert wurden. 29 Kalibrierungspunkten wurden mit Hilfe von DGPS lokalisiert, um die beste sensorbasierte Methode zur Abgrenzung der Beregnungsmanagementzonen zu bestimmen. Bodenproben wurden in 0 - 60 cm Tiefe entnommen. Der zweite Bogen der Kreisberegnungsmaschinen wurde für die teilflächenspezifische mobile Tropfbewässerung umgerüstet. Eine kontrollierte Wassermenge konnte, durch Installierung einer Pulstechnik mit Magnetventilen (SV – Solenoid Valve), einem Computer gesteuerten Programm (PLC – Programable Logic Control) und Auswechseln der Düsen durch Siplast Tropfrohre ausgebracht werden. Ein Teil des Feldversuches wurde durch EnviroSCAN Bodenfeuchtesensoren gesteuert und der andere Teil wurde durch das AMBAV-Modell gesteuert, um die Beregnungshöhe zu bestimmen. Die hydraulische Genauigkeit der Siplast Tropfrohre wurde im Labor bei unterschiedlichen Wasserdrücken von 50, 100, 150 und 200 kPa untersucht.Ergebnisse und Diskussion: Die Untersuchung zeigt, dass EC25-Daten von verschiedenen gewerblichen Sensoren auf Grund der unterschiedlichen Gewichtung der Tiefe quantitativ unterschiedlich sind. Das höchste Bestimmtheitsmaß wurde zwischen EM38_h und EM38_v (R2 = 0,55) gefunden. In dieser Arbeit wurde ein gutes Bestimmtheitsmaß zwischen nFK und den VERIS 3100 Werten gefunden. Eine Kalibrierungsgleichung zur Abschätzung der nFK von VERIS 3100-sh zeigte eine hohe Ähnlichkeit zu den nFK Daten auf und hatte das höchste Bestimmtheitsmaß (R2 = 0,77). Die Bestimmtheitsmaße zu EM38-v- und EM38-h-Daten waren niedrig und anscheinend nicht ausreichend, um die räumliche Variabilität der nFK reflektieren zu können. Ein Grund kann die größere Messtiefe von EM38 sein. Sechs Beregnungsmanagementzonen (IMZ1: 99 bis 105, IMZ2: 105 bis 116, IMZ3: 116 bis 127, IMZ4: 127 bis 138, IMZ5: 138 bis 149 und IMZ6: 149 bis 152 mm/60 cm) wurden als optimale Anzahl an Beregnungsmanagementzonen auf dem Versuchsfeld, basierend auf den fuzzy-k-Mittelwerten (Boydell and McBratney, 1999) der zufälligen Einteilung, erkannt. Es wurde gefolgert, dass unter konventioneller Beregnung IMZ1 und IMZ2 überbewässert und IMZ4, IMZ5 und IMZ6 unterbewässert wurden. Das entwickelte Konzept der Pulsbewässerung hat sich als eine zuverlässige Technik bewährt. Die Wasserapplikationsmenge war direkt proportional zur Öffnungsdauer des Ventils, und das System war in der Lage, die Wassermenge entsprechend des Bewässerungspulses zu variieren. Weiterhin war es in der Lage, 15 Reihen mit jeweils 15 Düsen zu steuern. Es gab keine offenkundigen Probleme mit dem gepulsten Wasserabgabesystem in den durchgeführten Feldversuchen. Die Kreisberegnungsmaschinengeschwindigkeit und Pulstechnik zur Bereitstellung verschiedener Wassermengen hatten einen geringen nachteiligen Einfluss auf die Gleichmäßigkeit der Beregnungshöhe. Die Gleichmäßigkeitskoeffizienten wurden durch sinkende Pulszeiten und steigende Kreisberegnungsmaschinengeschwindigkeiten gesenkt. Die Kontrolleinheit war wie erwartet in der Lage die Bodenfeuchtedaten mittels Fernmesstechnik von dem EnviroSCAN Sensor zum zentralen Modem zu senden. Obwohl der EnviroSCANBodenfeuchtigkeitssensor empfindlich und kompliziert zu benutzen und zu kalibrieren ist, wurden die Bodenfeuchtigkeitsdaten fast störungsfrei von der Kontrolleinheit empfangen, gespeichert und zum Mobiltelefon gesendet. Für die Übertragung auf den PC wurde die Software „Kurznachricht Pro 2.2“ genutzt. Anschließend wurde die differenzierte Bewässerungshöhe kalkuliert. Die Ergebnisse zeigen, dass die EnviroSCAN-Sensoren in der Lage sind, den Verlauf der Bodenfeuchte während der Wachstumsperiode erfolgreich zu verfolgen. Weniger gut arbeitet der Sensor, um die Feuchtigkeitsverhältnisse auf sandigen Böden (unter 40 cm Tiefe), trotz bodenspezifischer Kalibrierung zu bestimmen. Während dessen hat sich das AMBAV-Modell als eine Alternative zum kostenintensiven EnviroSCAN erwiesen, das in der Lage ist, die Bodenfeuchtigkeit in der Wurzelzone der Graspflanzen als eine preiswerte und verlässliche Methode zu simulieren. Das Tropfbewässerungssystem sollte auf verlässlichen Testergebnissen und nicht auf Herstellerangaben beruhen. Die Laborexperimente zeigten, dass der Einfluß des Betriebsdrucks auf den Durchfluss am Siplast Tropfer hoch signifikant war und der Tropferdurchfluß stark vom Betriebsdruck abhing. Die CV-Werte wurden auf dem ISO-Standard basierend als gut eingestuft. Aus den Laborexperimenten wurde herausgefunden, dass der in-line Siplast Tropfer eine hohe Ausbringungsgleichmäßigkeit und einen geringen Variationskoeffizienten aufweist. Das Rohrmaterial des Siplast Tropfer ist hart und unflexibel. Es sollte nach weiteren Produkten gesucht werden, die flexibler sind und somit die Kulturen schonen. Die ökonomische Analyse dieser Arbeit zeigt, dass der Kapitalbedarf pro Hektar unter teilflächenspezifische mobile Tropfbewässerung um etwa 338 € und 250 € höher liegt als bei entsprechender Tropfbewässerung in Deutschland und im Iran. Die jährlichen Fixkosten sind geringer, als bei der Tropfbewässerung (111 und 128 [€/(ha x Jahr)] in Deutschland oder im Iran). Obwohl die teilflächenspezifische mobile Tropfbewässerung teurer ist als die Beregnung mit Kreisberegnungsmaschinen, verursacht sie weniger Wasser- und Energiekosten als die Kreisberegnungsmaschinen und hat das Potenzial den Ertrag qualitativ und quantitativ, sowie den landwirtschaftlichen Gewinn zu steigern. Die Ergebnisse zeigen, als wichtige Folge des Verfahrens, dass die teilflächenspezifische mobile Tropfbewässerung nicht notwendiger Weise eine wassersparende Technologie ist, aber es kann den Wasserbedarf optimieren. Der Energiebedarf kann um 70 % und der Wasserbedarf kann um 25 % durch die teilflächenspezifische mobile Tropfbewässerung gegenüber der Kreisberegnungsmaschine gesenkt werden. Die Modellbetrachtungen zeigten, dass durch die teilflächenspezifische mobile Tropfbewässerung im Vergleich mit der konventionellen Kreisberegnungsmaschine bei Salat, Zuckerrübe,  Kartoffel und Erdbeere etwa 575, 378, 462 und 588 kWh Energie pro Hektar gespart werden können.Schlussfolgerung: Die sensorbasierte Messung der elektrischen Leitfähigkeit bei Feldkapazität von nicht salzigen Böden ist eine preiswerte, schnelle und das Bodengefüge nicht zerstörende Alternative, um die Beregnungsmanagementzone räumlich abzugrenzen und ist den Methoden der Bodenprobenahme und Luftbildauswertung vorzuziehen. Feldstudien mit größeren Bewässerungssystemen und Felder mit verschiedenen Bodentypen, Topographie oder Pflanzenbeständen sind weiterhin zu untersuchen, um die Genauigkeit des Bewässerungskonzeptes zu validieren. Vor dem Hintergrund, dass teilflächenspezifische Bewässerung in den Anfängen steckt und eine weitere Verbreitung dieser Technologie zu erwarten ist, könnten die zusätzlichen Kosten für industrielle Ausrüstungsteile gesenkt werden. Beträchtliche Forschung und Entwicklung ist noch nötig, um die möglichen Vorteile der teilflächenspezifischen Beregnung und der Flüssigdüngung besser zu realisieren, um ein positives ökonomisches Ergebnis für den Erzeuger zu sichern.Introduction: A management concept for sustainable utilization and the efficient use of agricultural inputs is known as “Precision Agriculture” (PA). The PA concept, when applied to irrigation management is known as Precision Irrigation (PI). In PI, the need for irrigation may differ between zones of a particular field due to the spatial variation of soil properties or the cropping of different plants on the same field. Spatial variation of total available water content (TAWC) as a primary factor causes spatial variation of irrigation depth and frequency within fields. While moving irrigation systems apply water at constant rates, some areas of the field may receive too much water and others not enough. In this regard, precision irrigation (PI) is capable of applying water in the right place in the right amount at the right time using the right irrigation system. Therefore the key objectives of the present study were a) Delineation of irrigation management zones (IMZs) using sensor-based soil electrical conductivity (ECa) measurement with the aid of EM38 and VERIS 3100, b) Developing and evaluating a precision mobile drip irrigation (PMDI) and c) Evaluating wireless EnviroSCAN sensors and AMBAV-models to measure the soil moisture content.Materials and methods: EC25 data (ECa in 25° C) were collected using EM38 and VERIS 3100 at field capacity on a 16.6 ha non-saline field in the FAL, Braunschweig, Germany. ECa data were obtained in 1-s intervals corresponding to a 2 to 3 m data spacing on transects spaced approximately 4 to 6 m apart. An ArcView (ESRI) software program was used to create the EC25 and TAWC maps after the readings were interpolated using a spherical kriging model. 29 calibration points taken at a depth of 0 - 60 cm depth were located using DGPS based on the ECa spatial variability pattern and with the objective of covering the whole range of ECa values present to determine the best sensor-based method to monitor TAWC. The second span of the centre pivot irrigation machine (CP) was modified to PMDI and controlled for variable-rate water application with a pulsing technique by installing solenoid valves (SV), programmable logic control (PLC) and using a Siplast drop tube instead of sprinklers. One quarter of the study field was controlled by the EnviroSCAN soil moisture sensor and another quarter was controlled by the AMBAV-model to determine irrigation depth. In addition, the hydraulic performance of the Siplast drop tube was evaluated in the laboratory by collecting discharge rates at different pressure of 50, 100, 150 and 200 kPa.Results and discussion: This study showed that, while qualitatively similar, EC25 data obtained with different commercial sensors were quantitatively different because of different depth-weighted response functions. The highest coefficients of determination (R2) were generally found between EM38_h and EM38_v (R2 = 0.55). In this study, a better value of R2 between TAWC and the VERIS 3100 readings was found. The R2 value from VERIS 3100-sh data for TAWC estimation was maximally (0.77) and matched the TAWC data quite well, whereas R2 values to EM38-h and EM38-v data were low and apparently could not adequately reflect the spatial variability of the TAWC due to the higher influence of the EM38 on deeper layers. Six IMZs (IMZ1: 99 to 105, IMZ2: 105 to 116, IMZ3: 116 to 127, IMZ4: 127 to 138, IMZ5: 138 to 149 and IMZ6: 149 to 152 mm/60 cm) were identified based on fuzzy-k-means unsupervised classification as an optimum number of IMZs within the study field. It was concluded that under conventional uniform irrigation, IMZ1 and IMZ2 were over-irrigated, whereas IMZ4, IMZ5 and IMZ6 were under-irrigated. The developed concept of pulse irrigation was a feasible and a viable technique. Water application was directly proportional to the fraction of time the valve was opened as the system was capable of controlling fifteen banks of fifteen nozzles. There were no apparent problems with the pulsing water delivery system where the field tests were conducted. CP speed and the pulsing technique used to deliver variable amounts of irrigation had little adverse effect on system uniformity and the nozzle flow rate. Uniformity coefficients were reduced by decreasing the pulsing level and increasing CP speed. The control unit was able to monitor wireless soil moisture sensors via radio telemetry and communication from the EnviroSCAN sensors to the central ISM modem, which worked as expected. Although the EnviroSCAN soil moisture sensor was found to be delicate and intricate to use and calibrate, soil moisture data were easily sent from the control unit and received by the mobile phone and then transferred to an Excel table on a computer using easy and suitable “Kurznachricht Pro 2.2” software to calculate irrigation depth. The results suggest that EnviroSCAN sensors are able to follow the general trends successfully as soil water content measured by sampling changed during the growing season, but are not a reliable sensor to repeat moisture conditions on sandy soils (at greater depths than 40 cm ) despite its soil-specific calibration. Meanwhile, an AMBAV model as a cheap and reliable alternative instead of the expensive EnviroSCAN sensor was capable of determining and simulating soil moisture in the root zone of grass crops. Drip irrigation design should be based on reliable data sets, but not on data supplied by the manufacturer. The laboratory experiments showed that the effect of operating pressure on the discharge of Siplast emitters was highly significant and the emitter discharge was strongly influenced by the operating pressure, while some deviation from the design flow rate claimed by the manufacturer occurred. CV values were classified as good, on the basis of the ISO standard. Based on the laboratory experiments, it was found that the in-line Siplast emitter has high emission uniformity and a low coefficient of variation. In spite of high emission uniformity and a low coefficient of variation of the Siplast drop tube, it must consist of hard and inflexible material. To have a shorter drip tube installed on CP, using an in-line drop tube lateral with higher emitter discharge at low operation pressure and less emitter distance is proposed. The economic analysis of this study showed that although capital requirement per hectare under PMDI is about € 338 and € 250 more than for drip irrigation in Germany and Iran, respectively, it causes perceptibly less annual fixed cost than drip irrigation (111 and 128 [€/(ha x year)] cheaper than drip irrigation in Germany and Iran, respectively). Although PMDI causes more annual fixed expenses than CP irrigation, it has less total irrigation cost per hectare and year than CP and drip irrigation and has the potential benefit to increase yield quantity, quality and farming benefit. The results showed as an important policy implication that PMDI is not necessarily a water saving technology and it does not necessarily involve a reduction in total water use, but that it can optimize water consumption. Given a reduction of energy and water consumption of 70 % and 25 %, respectively, achieved by the PMDI as compared with the CP, results showed that about 575, 378, 462 and 588 kWh energy per hectare can be saved by PMDI in comparison with the conventional CP irrigation of lettuce, sugar beet, potato and strawberry.Conclusion: Sensor-based ECa measurement at F.C. in non-saline soil can be used as a cheap, rapid and non-destructive alternative to delineate IMZ instead of using soil sampling and aerial photography methods. Field studies using larger irrigation systems and fields with different soil types, topographic or crop characteristics are recommended to validate the precision irrigation concept and to realize and ensure a positive net economic return to the producer. With due attention to the success of PI in the early stages and developments in industrial technology in the coming years, the extra costs of industrial accessories could be minimised

Interstellar and intergalactic scattering as astrophysical probes

The scattering of radio waves and multipath propagation in the interstellar medium (ISM) of our Galaxy produces various observable phenomena such as the interstellar scintillation (ISS) and angular broadening of compact radio sources, as well as the temporal smearing of impulsive radio bursts. These effects have been harnessed as probes of the ISM and of the background sources themselves. On the other hand, scattering in the intergalactic medium (IGM) has yet to be incontrovertibly detected, and is a main target of future surveys and instruments, since the IGM constitutes the main reservoir of baryons in the Universe. The first part of this thesis makes use of observational data from a survey of interstellar scintillation (ISS) of compact Active Galactic Nuclei (AGNs) to further investigate the nature of these sources, the ISM, ISS, and methods of handling variability data in the presence of stochastic and systematic errors. This study therefore acts as a technical and scientific demonstrator for future large-scale surveys of ISS and the variable radio sky.The results of this study further strengthen the link between AGN variability at radio wavelengths with ISS, and show how the spectral indices and mean flux densities of the sources, as well as observing frequencies, all influence the observed ISS characteristics. Six new rapid scintillators with characteristic time-scales of . 2 hours were identified in the sample, providing new insight into the origin of rapid and extreme scintillation. This thesis also presents the first detailed investigation into the origin of the suppresion of ISS for AGNs at z & 2 as discovered by the Micro-Arcsecond Scintillation Induced Variability (MASIV) Survey, a precursor to the present work. I determined that the redshift dependence of ISS is partially linked to the steepening of source spectral indices (_8.4 4.9) with redshift, caused either by selection biases or AGN evolution, coupled with weaker ISS in the _8.4 4.9 < −0.4 sources. Selecting only the −0.4 < _8.4 4.9 < 0.4 sources, the redshift dependence of ISS is still significant, but is not significantly steeper than the expected (1 + z)0.5 scaling of source angular sizes due to cosmological expansion for a brightness temperature and flux-limited sample of sources. No significant evidence of scatter broadening in the IGM was found, placing the strongest upper limit to date of . 8μas at 4.9 GHz for sight-lines to the most compact, _ 10μas sources.The second part of the thesis makes use of this observational limit on IGM scattering, together with extensions of ISM scattering models to cosmological scales, to investigate the detectability of the IGM with next generation radio arrays. While angular broadening in the IGM is insignificant for most sight-lines and appears difficult to resolve even with space VLBI, significant temporal smearing of extragalactic radio transients cannot be ruled out, and provides the best chance of detecting IGM scattering. However, the corresponding reduction in the signal-to-noise ratio of these bursts potentially places crippling limits on the detectability of such transient pulses in the first place, particularly at frequencies below _ 1 GHz. This has important ramifications for the optimization of observational strategies for detecting extragalactic radio transients with low-frequency instruments such as the Murchison Widefield Array (MWA), the Low Frequency Array (LOFAR) and the low frequency component of the Square Kilometre Array (SKA)

USCID water management conference

Presented at Meeting irrigation demands in a water-challenged environment: SCADA and technology: tools to improve production: a USCID water management conference held on September 28 - October 1, 2010 in Fort Collins, Colorado.Includes bibliographical references.The Colorado Satellite-Linked Water Resources Monitoring System: 25 years later -- Using state water law for efficient water use in the West -- On-farm strategies for deficit or limited irrigation to maximize operational profit potential in Colorado's South Platte Basin -- Economics of groundwater management alternatives in the Republican Basin -- Effects of policies governing water reuse on agricultural crops -- Flow calibration of the Bryan Canal radial gate at the United Irrigation District -- Considering canal pool resonance in controller design -- Synthetic canal lining evaluation project -- South Platte Ditch Company: demonstration flow monitoring and data collection project -- The case for ditch-wide water rights analysis in Colorado -- Bore wells: a boon for tail end users -- Irrigation efficiency and water users' performance in water management: a case study on the Heran distributary, Sanghar, Sindh, Pakistan -- Initiating SCADA projects in irrigation districts -- Use of GIS as a real time decision support system for irrigation districts -- Interaction of Advanced Scientific Irrigation Management (ASIM) with I-SCADA system for efficient and sustainable production of fiber on 10,360 hectares -- Improving irrigation system performance in the Middle Rio Grande through scheduled water delivery -- Cost-effective SCADA development for irrigation districts: a Nebraska case study -- Accomplishments from a decade of SCADA implementation in Idaho's Payette Valley -- Critical success factors for large scale automation experiences from 10,000 gates -- Mapping ET in southeastern Colorado using a surface aerodynamic temperature model -- Alfalfa crop coefficients developed using a weighing lysimeter in southeast Colorado -- Turfgrass ET from small lysimeters in northeast Colorado -- Monitoring turf water status with infrared thermometry -- Training tool for on-farm water management using heuristic simulation software -- Water production functions for high plains crops -- Assessment of economic and hydrologic impacts of reduced surface water supply for irrigation via remote sensing -- Developing corn regional crop coefficients using a satellite-based energy balance model (ReSET) in the South Platte River area of Colorado