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Comparing Three Approaches of Evapotranspiration Estimation in Mixed Urban Vegetation: Field-Based, Remote Sensing-Based and Observational-Based MethodsNouri, Hamideh, Glenn, Edward, Beecham, Simon, Chavoshi Boroujeni, Sattar, Sutton, Paul, Alaghmand, Sina, Noori, Behnaz, Nagler, Pamela 10 June 2016 (has links)
Despite being the driest inhabited continent, Australia has one of the highest per capita water consumptions in the world. In addition, instead of having fit-for-purpose water supplies (using different qualities of water for different applications), highly treated drinking water is used for nearly all of Australia's urban water supply needs, including landscape irrigation. The water requirement of urban landscapes, particularly urban parklands, is of growing concern. The estimation of evapotranspiration (ET) and subsequently plant water requirements in urban vegetation needs to consider the heterogeneity of plants, soils, water, and climate characteristics. This research contributes to a broader effort to establish sustainable irrigation practices within the Adelaide Parklands in Adelaide, South Australia. In this paper, two practical ET estimation approaches are compared to a detailed Soil Water Balance (SWB) analysis over a one year period. One approach is the Water Use Classification of Landscape Plants (WUCOLS) method, which is based on expert opinion on the water needs of different classes of landscape plants. The other is a remote sensing approach based on the Enhanced Vegetation Index (EVI) from Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on the Terra satellite. Both methods require knowledge of reference ET calculated from meteorological data. The SWB determined that plants consumed 1084 mmyr(-1) of water in ET with an additional 16% lost to drainage past the root zone, an amount sufficient to keep salts from accumulating in the root zone. ET by MODIS EVI was 1088 mmyr(-1), very close to the SWB estimate, while WUCOLS estimated the total water requirement at only 802 mmyr(-1), 26% lower than the SWB estimate and 37% lower than the amount actually added including the drainage fraction. Individual monthly ET by MODIS was not accurate, but these errors were cancelled out to give good agreement on an annual time step. We conclude that the MODIS EVI method can provide accurate estimates of urban water requirements in mixed landscapes large enough to be sampled by MODIS imagery with 250-m resolution such as parklands and golf courses.
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Proposing an improved surface dryness index to estimate soil moisture based on the temperature vegetation dryness indexLuo, Lei January 1900 (has links)
Master of Arts / Department of Geography / Douglas Goodin / In this thesis, I proposed a new surface dryness index based on the slope of soil moisture isolines in the Land Surface Temperature/Normalized Difference Vegetation Index (LST/NDVI) feature space. This index, referred to here as Dryness Slope Index (DSI), overcomes the problem of Temperature Vegetation Dryness Index (TVDI) having different basis when calculating TVDI values across different images. This problem is rooted in the definition of TVDI whose calculation depends on the position of the “dry edge” and “wet edge” of pixels’ values in the LST/NDVI space of a specific image. The “wet edge” has a fairly stable physical meaning, which represents soil at field capacity or above, and it remains stable across a time series of images. However, the position of “dry edge” represents the driest condition in the image, which does not necessarily mean that the soil is completely dry. Therefore, the value of TVDI calculated from different images is not based on an invariant dry edge value as its baseline, and it is therefore likely to lead to incorrect conclusion if used without extra examination. This problem manifests itself when comparing TVDI values from different images with meteorological data. Results from similar analyses done with DSI showed more reasonable match with the validation data, indicating DSI is a more robust surface dryness index than TVDI.
Having verified DSI can be effectively used in estimating soil moisture, I applied DSI on Landsat5 TM to study the relationship between soil moisture and land cover, slope, aspect, and relative elevation. Results showed that land cover accounts the most for variations of estimated soil moisture. I also applied DSI on a long time-series (2000 to 2014) of MODIS data trying to explore the temporal evolution of soil moisture in the entire Flint Hills ecoregion. Results showed little correlation between time and estimated soil moisture, indicating that no noticeable changes in soil moisture has been found through all these years.
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SAR remote sensing of soil moistureSnapir, Boris January 2014 (has links)
Synthetic Aperture Radar (SAR) has been identified as a good candidate to provide high-resolution soil moisture information over extended areas. SAR data could be used as observations within a global Data Assimilation (DA) approach to benefit applications such as hydrology and agriculture. Prior to developing an operational DA system, one must tackle the following challenges of soil moisture estimation with SAR: (1) the dependency of the measured radar signal on both soil moisture and soil surface roughness which leads to an ill-conditioned inverse problem, and (2) the difficulty in characterizing spatially/temporally surface roughness of natural soils and its scattering contribution. The objectives of this project are (1) to develop a roughness measurement method to improve the spatial/temporal characterization of soil surface roughness, and (2) to investigate to what extent the inverse problem can be solved by combining multipolarization, multi-incidence, and/or multi-frequency radar measurements. The first objective is achieved with a measurement method based on Structure from Motion (SfM). It is tailored to monitor natural surface roughness changes which have often been assumed negligible although without evidence. The measurement method is flexible, a.ordable, straightforward and generates Digital Elevation Models (DEMs) for a SAR-pixel-size plot with mm accuracy. A new processing method based on band-filtering of the DEM and its 2D Power Spectral Density (PSD) is proposed to compute the classical roughness parameters. Time series of DEMs show that non-negligible changes in surface roughness can happen within two months at scales relevant for microwave scattering. The second objective is achieved using maximum likelihood fitting of the Oh backscattering model to (1) full-polarimetric Radarsat-2 data and (2) simulated multi-polarization / multi-incidence / multi-frequency radar data. Model fitting with the Radarsat-2 images leads to poor soil moisture retrieval which is related to inaccuracy of the Oh model. Model fitting with the simulated data quantifies the amount of multilooking for di.erent combinations of measurements needed to mitigate the critical e.ect of speckle on soil moisture uncertainty. Results also suggest that dual-polarization measurements at L- and C-bands are a promising combination to achieve the observation requirements of soil moisture. In conclusion, the SfM method along with the recommended processing techniques are good candidates to improve the characterization of surface roughness. A combination of multi-polarization and multi-frequency radar measurements appears to be a robust basis for a future Data Assimilation system for global soil moisture monitoring.
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Tok vlhkosti a atmosférické srážky v Evropě / Moisture fluxes and precipitation in EuropeLemarie, Petr January 2012 (has links)
The present thesis deals with the influnence of moisture flux and variables, it is derived from, on rainfall in Europe. Sources of this thesis are the NCAR/NCEP and the ERA-40 reanalysis and the GPCC and the ECA&D rainfall databases. A western moisture flux prevails on studied 850 hPa isobaric level, it reaches the highest intensities over the Atlantic around 55th parallel of latitude. There is the highest correlation between moisture flux magnitude and monthly rainfall in winter on the western coast of Europe and it decreases in summer and eastwards. The correlation is very weak or none in some parts of Europe, especially in the eastern Mediterranean. Extremely wet months are related with different intensive moisture flux directions in different parts of Europe, for example there is the highest correlation of monthly rainfall with the northern moisture flux in the Czech Republic. Several selected heavy precipitation episodes in Europe are presented in this thesis - during them the moisture flux anomaly is observed, but it differs in orientation and intensity. A high wind speed causes this anomaly more frequently than a humidity. This does not apply to every event, furher research is needed to draw general patterns of moisture flux during high precipitation events.
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Vlhkost a její transport v připovrchové zóně kvádrového pískovce / Moisture and its transport in shallow subsurface of quartz sandstoneSvobodová, Eliška January 2015 (has links)
The thesis deals with moisture transport in porous medium of quartz sandstone. Capillary water and its movement is crucial for processes such as salt and frost weathering, growth of organisms and development of honeycombs and tafone. However, moisture transport is still not well described. I focused particularly on two new methods applied to sandstone investigation. In the laboratory I studied moisture transport in sandstone samples by means of repeated injection of uranine solution. I observed the evolution of evaporation front based on the changes in solution concentration indicated by difference in color of uranine solution. Additionally I investigated moisture content in the shallow subsurface of sandstone outcrops in the field using suction pressure and moisture content measurements by microtensiometers and TDR in three locations in the Bohemian Cretaceous Basin. Uranine proved to be an excellent tracer for visualization of the evaporation front geometry and its evolution in time. The results suggest that moisture transport is considerably affected by the presence of biofilms which are hydrophobic and retain moisture transport to surface. In addition, the values of suction pressure measured in honeycombs and a tafone are in agreement with the salt weathering model proposed by Huinink et al. (2004).
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Use of high-volume reclaimed asphalt pavement (RAP) for asphalt pavement rehabilitationSabahfar, Nassim January 1900 (has links)
Master of Science / Department of Civil Engineering / Mustaque Hossain / Because of recent rises in asphalt binder prices, state agencies and contractors are now willing to use higher volumes of reclaimed asphalt pavement (RAP). In this project, the effects of increasing RAP percentage and using fractionated RAP (FRAP) in hot-mix asphalt (HMA) mixtures have been studied. Fractionation involved processing and separating of RAP materials into at least two sizes, typically a coarse fraction and a fine fraction. This study evaluated the effects of increasing the proportions of RAP and FRAP on moisture resistance, rutting, and fatigue cracking of Superpave mixtures. Furthermore, the effect of using different sources of RAP in the mix has been investigated. HMA mixtures with five varying RAP and FRAP contents (20, 30, and 40% RAP, and 30 and 40% FRAP) were studied. The Hamburg wheel-tracking device (HWTD) test (TEX-242-F), the Kansas standard test method no. 56 (KT-56), or modified Lottman test, and the dynamic modulus test (AASHTO TP: 62-03) were used to predict moisture damage, rutting potential, and fatigue cracking resistance of the mixes. HMA specimens were made based on Superpave HMA mix design criteria for 12.5-mm (1/2-inch) nominal maximum aggregate size (NMAS) and compacted using the Superpave gyratory compactor. For the first source of RAP, results of this study showed that although mixture performance declined as the percentage of RAP increased, mixtures with even 40% RAP met minimum performance requirements. The second source of RAP, however, almost failed to meet minimum requirements even at 20% RAP. Results proved the maximum percentage of RAP allowed in the mix is highly influenced by its source. Although some improvements have been observed, especially for the second source of RAP, when RAP is compared to FRAP, FRAP does not seem to considerably affect performance of the HMA mixture.
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The relative controls on forest fires and fuel source fluctuations in the Holocene deciduous forests of southern Wisconsin, USAMueller, Joshua Robert January 1900 (has links)
Master of Arts / Department of Geography / Kendra K. McLauchlan / Reconstructing fire regimes and fuel characteristics is an important aspect of understanding past forest ecosystem processes. Fuel sources and disturbance regimes throughout the upper Midwestern United States have been shown to be sensitive to regional climatic variability such as drought periods on millennial timescales. Yet, records documenting the complex connections between disturbance activity and the corresponding fuel source fluctuations in mesic deciduous forests and oak savanna forests in this region are limited. Thus, it has been difficult to provide a framework to evaluate drought conditions on fire activity and the relationships with fuel source fluctuations in this region. Here, I conducted high-resolution charcoal analyses of lake sediments from four sites in southeastern-southcentral Wisconsin (USA) to characterize fire activity and fuel source fluctuation in mesic deciduous forests and prairie-oak savanna over the last 10,000 years. I found that fire regimes across the four study sites have been asynchronous throughout the Holocene, due to site-specific differences that have strongly influenced local fire regimes. I also found that during periods of high fire activity the primary fuels were from arboreal sources, and during periods of low fire activity the primary fuels were from non-arboreal sources. However, fluctuations in fuel sources did not always correspond to changes in vegetation, or changes in fire frequency.
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Simulating moisture stress and southwestern corn borer effects on corn yieldsParsons, Lynn Laverne January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
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DESIGN OF AN INSTRUMENT FOR SOIL MOISTURE AND ABOVE GROUND BIOMASS REMOTE SENSING USING SIGNALS OF OPPORTUNITYBenjamin R Nold (7043030) 15 August 2019 (has links)
Measurements of soil moisture are a crucial component for understanding the global water and carbon cycle, weather forecasting, climate models, drought prediction, and agriculture production. Active and passive microwave radar instruments are currently in use for remote sensing of soil moisture. Signals of Opportunity (SoOp) based remote sensing has recently emerged as a complementary method for soil moisture remote sensing. SoOp reuses general digital communication signals allowing the reuse of allocated wireless communication signal bands for science measurements. This thesis developed a tower based SoOp instrument implementing frequencies in the P-Band and S-Band. Two field campaigns were conducted using this new instrument during the summers of 2017 and 2018 at Purdue's Agronomy Center for Research and Education.
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Investigating the effect of substituting fractions of imported coals with coke oven tar on coke quality: pilot plant studyMakgato, Seshibe Stanford 23 January 2015 (has links)
In this study, coke oven tar addition over a range of 0 – 8 wt.% was evaluated as a possible
substitute for imported coals fractions. Coke oven tar used was collected from coke oven tar
decanters of the by-products section of the coke making plant. Moisture content in coke oven
tar varied depending on the residence time and water carryover from coke oven tar separators
to storage tanks. Therefore, various moisture ranges were considered in order to observe its
effect on coal blend, carbonization and coke properties. The optimum moisture content in
coke oven tar was found to be 3% with a coke oven tar addition of 6 wt.% in the coal blend.
At the same coke oven tar addition of 6 wt.% in the coal blend but with 6% moisture content
in coke oven tar, coke properties improved, coke yield showed up to 4% decrease. On the
other hand, with 1% moisture content in coke oven tar of 6 wt.% in the coal blend, coke
yield increased by 1% and low coke properties such as I40 of 42.9 and Stability of 50.3 were
achieved. The latter process was characterized by excessive increased in wall pressure and
pushing energy. Both wall pressure and pushing energy increase are less desirable due to
their detrimental effect on the physical condition of the oven walls. Furthermore, addition of
coke oven tar with 1% moisture content to coal blend can be prohibited by its high viscosity.
At 3% moisture content in coke oven tar addition of 6 wt.% in the coal blend, coke properties
improved. When the amount of coke oven tar was increased to 8 wt.% at the optimum coke
oven addition, coke yield was not affected but low CSR of 57.8 against a target of ³60 was
achieved as opposed to CSR of 65.4 at 6 wt.%. Also, coke stability of 52.2 at 8 wt.% as
opposed to 56.1 at 6 wt.% was achieved. Moreover, the highest I40 of 50.9 was achieved at 6
wt.% whereas with 8 wt.% coke oven tar, I40 of 47.9 was achieved. However, up to 2%
decrease in coke yield was observed. Despite this 2% decrease in coke yield, coke oven tar
addition is a positive and viable option based upon economic factors (i.e. this reduces the
quantity and cost of imported coals and still achieves improved coke quality which result in
improved blast furnace operation and better hot metal quality).
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