• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 21
  • 19
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 48
  • 48
  • 20
  • 18
  • 8
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Evaluation of soil moisture in a water harvesting system with supplemental bubbler irrigation system

Achour, Hichem. January 1985 (has links) (PDF)
Thesis (M.S. - Soils, Water and Engineering)--University of Arizona, 1985. / Bibliography; leaves 70-72.
2

Soil and water conservation programs in action the Vernon County Wisconsin experience /

Goto, Junko. January 1981 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1981. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 167-176).
3

Plant available water

Borg, Heinz. January 1980 (has links)
Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 68-78).
4

Water relations of soil fungi

Adebayo, Adewale Ayoade, January 1970 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1971. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
5

Mechanisms of water colour release from organic soils and consequences for catchment management

Miller, Christopher James. January 2008 (has links)
Thesis (Ph.D.)--Aberdeen University, 2008. / Title from web page (viewed on Feb. 25, 2009). Includes bibliographical references.
6

Baseline stream chemistry and soil resources for the Hinkle Creek Research and Demonstration Area Project /

George, Robert Lance. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 89-95). Also available on the World Wide Web.
7

An improved dual-permeability model of solute transport in structured soils : model development and parameter identification in laboratory and field experiments /

Larsbo, Mats, January 2005 (has links) (PDF)
Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 3 uppsatser.
8

Mechanisms of water colour release from organic soils and consequences for catchment management

Miller, Christopher James January 2008 (has links)
Water colour is the naturally occurring yellow-brown 'tea like' discolouration which can be observed in freshwaters, and is typically composed of high molecular weight organic carbon. Water discolouration is a major problem for the water industry as over the past 30 years, water colour release has more than doubled, greatly increasing treatment costs and making land management a more feasible option for improving water quality. This project was developed in conjunction with Yorkshire Water Plc, to investigate the mechanisms of water colour production, and the implications that these mechanisms have for land management to improve water quality. In particular, the study aimed to identify the key relationships between drainage water quality and quantity, soil processes and vegetation type that are pivotal to the understanding of water discolouration.
9

Phosphorus sorption behaviour of some South African water treatment residues /

Norris, Matthew. January 2009 (has links)
Thesis (M.Sc.) - University of KwaZulu-Natal, Pietermaritzburg, 2009. / Full text also available online. Scroll down for electronic link.
10

Estabilidade temporal da distribuição espacial da armazenagem, do gradiente de potencial total e do potencial mátrico da água, em um solo cultivado com citros. / Temporal stability of the spatial distribution of water storage, total potential gradiente and matric potential, in a soil cropped to citrus.

Rocha, Genelicio Crusoé 15 April 2004 (has links)
O presente trabalho teve como objetivo quantificar e caracterizar a variabilidade espaço-temporal da armazenagem, do gradiente de potencial total e do potencial mátrico da água em um Latossolo Amarelo argissólico cultivado com citros. A parcela experimental foi montada em um solo sob uma cultura de citros com 10 anos de idade, consistindo de 40 pontos de observação ao longo de duas transeções, com espaçamento de 4 m x 7 m. Em cada ponto de observação foram instalados a) um tubo de acesso à sonda de nêutrons até a profundidade de 1,20 m, para a quantificação da armazenagem da água no solo, e b) três tensiômetros nas profundidades de 1,00 m, 1,10 m e 1,20 m, para a quantificação do potencial mátrico e do gradiente de potencial total da água no solo. As medições foram feitas ao longo de dois anos, em períodos compreendidos entre novembro e julho do ano seguinte. As medições de potencial mátrico foram feitas diariamente e as de armazenagem semanalmente. Em cada ponto de observação foram retiradas amostras de solo com estrutura deformada para a quantificação das frações granulométricas ao longo do perfil. Em área adjacente instalou-se um pluviômetro acoplado a um "data logger" para a quantificação da entrada de água na área por precipitação pluvial. Os valores das frações granulométricas apresentaram distribuição normal e foram uniformes em todos os pontos, apontando para um gradiente entre o horizonte A e o B textural. Isso permitiu o uso da média dos valores dos 40 pontos por profundidade, para fins de comparação. Os valores de armazenagem, de gradiente de potencial total e de potencial mátrico da água no solo não tiveram correlação significativa a 5% de probabilidade com os valores de argila e areia, entretanto os valores de correlação entre armazenagem/gradiente e argila foram, na maioria das datas analisadas, positivos, enquanto que para os valores de areia a correlação foi negativa. A distribuição dos valores de gradiente de potencial tornou-se mais dispersa quanto mais seco o solo esteve. A estabilidade temporal foi observada pelo comportamento dos valores para os 40 pontos ao longo do tempo, mostrando que os pontos mantiveram a sua característica independentemente do tempo de amostragem, evidenciando desta forma a estabilidade temporal, o que pôde ser comprovado por meio do coeficiente de correlação de Pearson entre datas. Por meio da técnica da diferença relativa foi possível identificar os pontos que, independentemente tempo, estimam a média real do campo, os mais secos e os mais úmidos. O ponto 12 foi escolhido, em função do valor da diferença relativa, como o ponto representativo da média para o gradiente de potencial total, para os valores de armazenagem identificou-se como o ponto 15 como o mais seco e o 05 como o mais úmido. O teste não-paramétrico de Spearman, como sugerido por Vachaud et al. (1985), não diferiu significativamente do teste paramétrico, mais simples, sugerido por Kachanoski & De Jong (1988). / The objective of this work was to quantify and to characterize spatial and temporal variability of water storage, total potential gradient and matric potential in a yellow latosol cropped to citrus. The experiment was carried out at campus of Escola Superior de Agricultura "Luiz de Queiroz", University of São Paulo, in the municipality of Piracicaba (22º42’43’’ S, 47º37’10’’ W, 546 m). The experimental plot was installed in the soil under a 10 years old citrus crop, being made up of 40 observation points along two transects in a 4 m x 7 m spacing. In each observation point were installed a) one aluminum tube to access a neutron probe till the depth of 1.20 m, to quantify the soil water storage and b) three mercury tensiometers at depths of 1.00 m, 1.10 m and 1.20 m to estimate matric potential and total potential gradient. Measurements were made during two years in the periods between November and July of the next year. Matric potential measurements were made daily and those of soil water storage, weekly. From each observation point were also taken disturbed soil samples for soil mechanical analysis along the profile. A rain gage coupled to a data logger were also installed just beside the transects. The percent values of sand clay and silt were normal distributed and uniform in all points, which permitted the use of a mean of the 40 points in each sampled depth. Soil water storage, matric potential and total potential gradient values did not have significant correlation, at the level of 5% of probability, with the percent values of clay and sand, eventhough the correlation values between storage/gradient and clay were, in almost all analyzed date, positive, whereas those for sand, negative. The dispersion of matric potential and total potential gradient values was higher as the soil became dryer. All the 40 points showed temporal stability for the measured parameters, that is, they maintened their characteristics independently of sampling time; this was proven by means of the Pearson correlation coefficient among dates. By means of the relative difference technique, it was possible to identify the points that, independently of time, estimate the real field mean, the dryer points and the moister points. Point 12 was chosen, by this technique, as the representative for the mean total potential gradient; for the soil-water storage, point 15 was identified as the dryer point and point 05 was identified as the moister one. The non-parametric test of Spearman, as suggested by Vachaud et al. (1985), was not significantly different of the simpler parametric test, suggested by Kachanoski and De Jong (1988).

Page generated in 0.078 seconds