Water is essential to life on Earth. Since water exists in all three phases (solid, liquid, and gas) on Earth, it exists in various reservoirs throughout the planet that compose the hydrologic cycle, and its movement through these reservoirs requires energy. Thus, water is a key component of the energy balance of the Earth. Despite its importance, its representation in modeling and dataset generation is problematic. Here, the depiction of three phenomena, ocean surface turbulent fluxes, humidity inversions, and groundwater, are assessed, and suggestions for improvements of their representations are made. First, ocean surface turbulent fluxes, including those of moisture (latent heat flux), heat (sensible heat flux), and momentum (wind stress), from reanalysis, satellite-derived, and combined products which are commonly used to produce climatologies and to evaluate global climate models are compared to in situ observations from ship cruises to ascertain which products are the least problematic. The National Aeronautics and Space Administration’s reanalysis, the Modern Era Retrospective Analysis for Research and Applications, is the least problematic for all three fluxes, while a couple of others are the least problematic for only one of the three fluxes. Also, the product biases are disaggregated into uncertainties from the grid cell mean quantities, or bulk variables, used plus the residual uncertainties which includes the algorithm uncertainties due to the parameterization used to relate the small-scale turbulent processes to the large-scale bulk variables. The latter contribute the most to the majority of product latent heat fluxes, while both uncertainties can contribute the most to product sensible heat fluxes and wind stress. Thus, both algorithms and bulk variables need to be improved in ocean surface flux datasets. Second, humidity inversion climatologies in five reanalyses are evaluated. Humidity inversions, similar to its thermal counterpart, are layers in which specific humidity increases with height rather than the usual decrease with height. These are especially persistent in the polar regions in autumn and winter. However, Arctic inversions are the strongest in summer corresponding to the time of year that low cloud cover is the highest. Comparing the reanalysis inversions to radiosonde observations reveals some problems with the realization of humidity inversions in reanalyses including the misrepresentation of the diurnal cycle and of the overproduction of inversions in areas outside the polar regions. Finally, the simulation of groundwater in the Community Land Model (CLM) as used in the Community Earth System Model is made more realistic by including variable soil thickness. Because the bottom of the model soil column is placed at effectively bedrock, the unconfined aquifer model currently used in CLM is removed and a zero bottom water flux is put in place. The removal of the unconfined aquifer allows the simulation of groundwater to not be treated separately from soil moisture. The model is most affected where the number of soil layers is reduced from the original constant 10 layers and largely unaffected where the number of soil layers is increased except for baseflow where the mean annual range in rainfall is large.

Resumo: O objetivo deste trabalho foi a aplicação de métodos de agricultura de precisão e modelos matemáticos em um argissolo com variações na forma do relevo sob cultivo de cana-de-açúcar na região de Catanduva (SP). A área estudada apresentou duas diferentes pedoformas (uma côncava, C+P+, e outra convexa, C-P-). Numa área total de 200 ha, instalou-se uma malha contendo 623 pontos espaçados por uma distância de 50 metros a fim de analisar a variabilidade espacial dos atributos granulométricos e químicos do solo, e a qualidade da matéria-prima (ART - açúcares redutores totais). Nessa mesma área, foi confeccionada outra malha contendo 188 pontos espaçados por uma distância de 150 metros para análise espacial da espessura do horizonte A + E. Amostras de solos foram coletadas em todos os pontos da malha, na profundidade 0,0-0,2 metro, e análises granulométricas, químicas e de qualidade foram feitas em laboratórios. Calculou-se a estatística descritiva, e a dependência espacial entre as amostras foi determinada utilizando-se semivariogramas. Mapas de krigagem foram confeccionados para os atributos estudados. Os resultados mostraram que a utilização da agricultura de precisão e modelo matemático é a forma mais eficaz na redução de custos para aplicação de adubos. Nessas condições, a pedoforma côncava necessitou de 12% a menos de fertilizantes quando comparada com a pedoforma convexa. Esses resultados corroboram a maior fertilidade da área côncava, que também possui menor taxa de erosão e maior espessura do horizonte A + E. Ressalta-se que a modelagem matemática apresenta índices para a redução de custos. Com isso, o uso de técnicas de agricultura de precisão poderá, ao longo dos anos, trazer ganhos significativos nos sistemas de produção, pois este identifica zonas específicas de manejo. / Abstract: The aim of this work was to apply precision agriculture and mathematical models in order to reduce the fertilization cost of a red-yellow Argissol cultivated with sugar cane in different pedoforms (concave, C + P +, and convex, CP-) located in the region of Catanduva (SP) . A grid having 623 points was installed in an area of 200 ha, whith points spaced by 50 meters, in order to analyze the spatial variability of the texture parameters, soil fertility and amount of raw material (TRS-total reducing sugars). In the same area another grid having 188 points was installed, with minumum distance of 150 meters, in order to provide the spatial analysis of the A+E soil horizon thicknesses. Soil samples were collected in all grid points in the depth of 0,0-0,2 meters. They were submitted to texture, fertility and quality analyzes in a laboratory. Descriptive statistics was calculated and spatial dependence of samples determined by using semivariograms. Maps of kriging were made for all the studied attributes. Results showed that the use of precision agriculture coupled with mathematical modelling is the most effective way to reduce costs for fertilizers application. The concave pedoform needed 12% less fertilizer when compared to the convex pedoform. These results are in accordance with the higher fertility of concave pedoform that has also lower erosion rates and higher horizon thickness. Another result obtained from the mathematical modeling is the derivation of specific indexes for cost reduction. We believe that the application of precision agriculture over the next years could bring significant gains in production, as this technique identifies areas demanding specific management. / Orientador: José Marques Junior / Coorientador: Gener Tadeu Pereira / Banca: Marcílio Vieira Martins Filho / Banca: Ailto Antonio Casagrande / Banca: Zigomar Menezes de Souza / Banca: José Paulo Molin / Doutor

Made available in DSpace on 2014-06-11T19:33:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-12-14Bitstream added on 2014-06-13T20:05:56Z : No. of bitstreams: 1 sanchez_rb_dr_jabo.pdf: 1897729 bytes, checksum: 456c8e2c0db50350e6d784e568134d78 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Funep / O objetivo deste trabalho foi a aplicação de métodos de agricultura de precisão e modelos matemáticos em um argissolo com variações na forma do relevo sob cultivo de cana-de-açúcar na região de Catanduva (SP). A área estudada apresentou duas diferentes pedoformas (uma côncava, C+P+, e outra convexa, C-P-). Numa área total de 200 ha, instalou-se uma malha contendo 623 pontos espaçados por uma distância de 50 metros a fim de analisar a variabilidade espacial dos atributos granulométricos e químicos do solo, e a qualidade da matéria-prima (ART – açúcares redutores totais). Nessa mesma área, foi confeccionada outra malha contendo 188 pontos espaçados por uma distância de 150 metros para análise espacial da espessura do horizonte A + E. Amostras de solos foram coletadas em todos os pontos da malha, na profundidade 0,0-0,2 metro, e análises granulométricas, químicas e de qualidade foram feitas em laboratórios. Calculou-se a estatística descritiva, e a dependência espacial entre as amostras foi determinada utilizando-se semivariogramas. Mapas de krigagem foram confeccionados para os atributos estudados. Os resultados mostraram que a utilização da agricultura de precisão e modelo matemático é a forma mais eficaz na redução de custos para aplicação de adubos. Nessas condições, a pedoforma côncava necessitou de 12% a menos de fertilizantes quando comparada com a pedoforma convexa. Esses resultados corroboram a maior fertilidade da área côncava, que também possui menor taxa de erosão e maior espessura do horizonte A + E. Ressalta-se que a modelagem matemática apresenta índices para a redução de custos. Com isso, o uso de técnicas de agricultura de precisão poderá, ao longo dos anos, trazer ganhos significativos nos sistemas de produção, pois este identifica zonas específicas de manejo. / The aim of this work was to apply precision agriculture and mathematical models in order to reduce the fertilization cost of a red-yellow Argissol cultivated with sugar cane in different pedoforms (concave, C + P +, and convex, CP-) located in the region of Catanduva (SP) . A grid having 623 points was installed in an area of 200 ha, whith points spaced by 50 meters, in order to analyze the spatial variability of the texture parameters, soil fertility and amount of raw material (TRS-total reducing sugars). In the same area another grid having 188 points was installed, with minumum distance of 150 meters, in order to provide the spatial analysis of the A+E soil horizon thicknesses. Soil samples were collected in all grid points in the depth of 0,0-0,2 meters. They were submitted to texture, fertility and quality analyzes in a laboratory. Descriptive statistics was calculated and spatial dependence of samples determined by using semivariograms. Maps of kriging were made for all the studied attributes. Results showed that the use of precision agriculture coupled with mathematical modelling is the most effective way to reduce costs for fertilizers application. The concave pedoform needed 12% less fertilizer when compared to the convex pedoform. These results are in accordance with the higher fertility of concave pedoform that has also lower erosion rates and higher horizon thickness. Another result obtained from the mathematical modeling is the derivation of specific indexes for cost reduction. We believe that the application of precision agriculture over the next years could bring significant gains in production, as this technique identifies areas demanding specific management.

Nordost om Uppsala finns sedan 1977 en av Uppsala Vatten och Avfall AB:s mindre grundvattentäkter, och inför en tillståndsansökan om ett ökat vattenuttag behöver den befintliga kunskapen om täkten utökas. Syftet med detta arbete är att ta fram en modell för att undersöka storleken på ett hållbart vattenuttag, om enskilda avlopp kan ligga bakom mikrobiella föroreningar i vattnet och om en alternativ placering av brunnen i så fall skulle åtgärda problemet. Sveriges Geologiska Undersökning har beräknat formen på grundvattenmagasinet och dess tillrinningsområde, ett område som består av en flack lertäckt dal omgiven av morän och berg. På 1960- och 1970-talen undersöktes området med slagsondering och rörsättning tillsammans med provpumpning, vilket lade grunden för detta examensarbete. I början av arbetet genomfördes ytterligare sonderingar och rördrivningar följt av en fyra veckor lång provpumpning vars resultat användes för att kalibrera modellen. Denna modell byggdes i programmet FEFLOW som använder sig av finita element för att lösa ekvationer som beskriver flöde i porösa media. Modellen byggdes upp av lager som motsvarade jordlagerföljden, där markytan baserades på Lantmäteriets nationella höjdmodell. Bergytan och gränsen mellan friktionsmaterial och lera togs fram genom interpolering av sonderingsdata. Ytterligare vertikal uppdelning skedde utifrån jordarter och magasinform. Värden på hydraulisk konduktivitet, vattenavgivningstal och grundvattenbildning i lagren togs fram genom en litteraturstudie. Dessa parametervärden kalibrerades sedan med hjälp av mätvärden från provpumpningen, följt av en känslighetsanalys. Ett tak för storleken på ett hållbart uttag beräknades utifrån grundvattenbildningen tillsammans med areorna för jordarterna i området. Påverkansområden modellerades för det nuvarande uttaget och två hypotetiska uttag. För det nuvarande uttaget undersöktes den kortaste transporttiden från det närmast liggande bostadsområdet till dricksvattenbrunnen. Med grundvattenbildningen från den kalibrerade modellen blev taket för vattenuttaget 3 L/s, med initialvärdena blev taket i stället 4 L/s. Dessa värden är sannolikt underskattningar då den verkliga grundvattenbildningen troligtvis är högre. De beräknade påverkansområdena indikerar platser för närmare undersökning i framtiden. Det befintliga uttaget på 1,3 L/s hade pågått under lång tid utan kända negativa konsekvenser, och ligger därför sannolikt under gränsen för ett hållbart uttag. I modellen var transporttiden mellan bostadsområde och brunn dubbelt så lång som Havs- och vattenmyndighetens rekommendation. Modellen kan därför inte styrka att de mikrobiella föroreningarna skulle komma från enskilda avlopp, och någon alternativ brunnsplacering undersöktes därför inte närmare. / The Lejsta well field, located northeast of Uppsala, has supplied public drinking water since 1977 and is managed today by Uppsala Water and Waste AB. Further investigation of the aquifer is needed in preparation for increasing withdrawal of groundwater and application for required permits. The purpose of this thesis is to develop a model for investigating the size of a sustainable water yield, whether individual sewage treatment may be the source of microbial contaminants in the water and if an alternative location of the well would solve that problem. The Geological Survey of Sweden previously delineated the aquifer and its catchment basin, the basin consisting of a flat clay-covered valley surrounded by till and bedrock. In the 1960s and 70s the area was surveyed using test drilling and installation of observation wells combined with pumping tests, which laid the groundwork for this thesis. At the beginning of the project, further test drillings and installations of observation wells were carried out followed by a four-week pumping test, the result of which was used to calibrate the model. This model was built in the program FEFLOW which uses finite element analysis to solve equations for flow in porous media. The model was constructed with layers corresponding to the soil layer sequence where the ground surface was based on the Swedish Mapping, Cadastral and Land Registration Authority’s national height model. The bedrock surface and the boundary between clay and coarser material were constructed by interpolating borehole data. The layers were further divided vertically based on soil types and the aquifer delineation. Values for hydraulic conductivity, specific yield, and groundwater recharge in the layers were decided based on a literature review. These parameter values were then calibrated using measurements retrieved from the pumping test, followed by a sensitivity analysis. A limit for the size of a sustainable yield was calculated based on groundwater recharge and the areas of the different soil types. Areas of impact were modeled for the current yield and two hypothetical yields. For the current withdrawal, the shortest transport time from the nearest residential area to the drinking water well was examined. When applying the groundwater recharge of the calibrated model, the water yield limit was 3 L/s, for the initial values the limit was 4 L/s. These values are likely underestimations as the actual groundwater recharge is likely higher. The estimated areas of impact indicate locations for closer examination in the future. The current withdrawal of 1.3 L/s had been sustained without any apparent negative consequences and is therefore likely below the limit of a sustainable yield. According to the model, the shortest transport time from the residential area to the well was twice the minimum time recommended by the Swedish Agency for Marine and Water Management. The model therefore cannot support that individual sewage treatment is the source of microbial contaminants, and no alternative well location was investigated.