inscription
PORTAIL D'INFORMATION GÉOGRAPHIQUE

Résultats de la recherche (8514 résultats)

Affinez votre recherche

Par Collection Par Auteur Par Date Par Sujet Par Titre Par ville ? Par pays ? Par continent ?
  • Seasonal dynamics of soil-water pressure in a cracking clay soil
  • Clay ; England ; Model ; Oxfordshire ; Precipitation ; Seasonal variation ; Soil ; Soil properties ; Soil water ; United Kingdom
  • This paper describes the results of an investigation of changes in soil water pressure head and its relationship to the macropore network in a cracking clay soil at Brimstone Farm, Oxfordshire, UK.
  • Assessment and utilization of soil water resources
  • Agriculture ; China ; Groundwater ; Irrigation ; Northern China ; Water ; Water budget ; Water management ; Water resources
  • Based on the analyses of water interactions and water balance, this paper discusses the issues on the assessment and regulation of soil water resources, which lays the scientific basis for limited irrigation and water-saving agriculture.
  • Modelling soil water supply to crops
  • The supply of water by the soil to meet the transpirational demand of crops, has been modelled on the assumption that water supply is directly related to soil water potential. Results of field testing and discussion.
  • Regulation of the soil water regime under furrow irrigation
  • Agropedology ; Arid lands ; Irrigation ; Mathematical model ; Methodology ; Soil ; Soil moisture;Soil water ; Water balance ; Water cycle;Water circulation
  • An experimental computational method is proposed for determining the irrigation regime of agricultural crops and losses of irrigation water by infiltration beyond the root zone of the soil, based on information on soil moisture suction or soil
  • . A relationship is proposed approximating the curve of soil water intake. Results of calculations of the irrigation regime of cotton by the proposed method showed that the irrigation rate and the rate of infiltration of irrigation water decrease as the soils
  • wetness. It was established that under furrow irrigation the soil immediately below furrows is wetted approximately to maximum moisture capacity, while in the furrow spacing the moisture content of the soil usually does not exceed field capacity
  • become finer in texture and the water table rises.
  • Soil compaction and water uptake of plants in Impact of water and external forces on soil structure. Selected papers of the 1st Workshop on soilphysics and soilmechanics, Hannover 1986.
  • This paper describes a method for studying the influence of soil compaction and soil structure on the water uptake of plants under controlled conditions.
  • Mineral soil surface crusts and wind and water erosion
  • Soil surface characteristics : dynamics and impact on soil erosion. Special issue
  • Agricultural practice ; Duricrust ; Land use ; Mineralogy ; Soil ; Soil erosion ; Soil moisture ; Soil properties ; Water erosion ; Wind erosion
  • The AA. briefly review how permanent and time-dependent soil properties influence surface seals and crusts and how these affect soil erosion by wind and water. They conclude with some comments on strategies for management of soil surface conditions.
  • The influence of soil interstitial waters on the physicochemistry of major, minor and trace metals in stream waters of the Green Lakes valley, Front Range, Colorado
  • Colorado ; Ecosystem ; Human impact ; Hydrochemistry ; Hydrology ; Mountain ; Soil erosion ; Soil properties ; Trace-element ; United States ; Water quality ; Watershed
  • The objective of this research is to study the physicochemical characteristics of major, minor and trace metals in soil interstitial and stream waters across an alpine watershed, with special emphasis on potentially geochemical reactive areas
  • , and to assess the influence of soil interstitial waters on stream water quality.
  • Modeling daily soil water dynamics during vertical drainage using the incoming flow concept
  • Belgium ; Comparative study ; Cultivated land ; Drainage ; Georgia (USA) ; Model ; Soil ; Soil water ; United States of America ; Water balance
  • The aim of this study was to develop a quasi-analytic model to calculate the daily soil water dynamics during vertical drainage with reasonable accuracy for diverse soils, i.e., light, medium and heavy soils using the incoming flow concept. Three
  • models for the simulation of vertical drainage in soils are compared : RMSD, SRVDM and Hydrus-1D. They are tested using data of a Eutric Regosol in Bekkevoort, Belgium and a sandy soil in Georgia, U.S.
  • A review of soil erodibility in water and wind erosion research
  • Concept ; Erodibility ; Human impact ; Measurement ; Methodology ; Soil ; Soil erosion ; Soil properties ; Water erosion ; Wind erosion
  • In this paper, soil erodibility in water and wind erosion research is discussed on analyzing the concept and mechanism of soil erodibility, methods to measure and calculate soil erodibility. At the same time, the defect and researching orientations
  • of soil erodibility in water and wind erosion are also discussed.
  • Effect of soil moisture on the interrelation between the rate of movement of soil water under the effect of the temperature gradient and the concentration of the soil solution
  • Variation in water content and wetting patterns in Dutch water repellent peaty clay and clayey peat soils
  • Clay ; Netherlands (The) ; Peat ; Runoff ; Soil ; Soil moisture ; Soil properties ; Soil water
  • The variation in water content of grass-covered peaty clay and clayey peat soils was studied at 6 sites in the Netherlands. The topsoils were water repellent during dry spells. However, the measurements revealed that preferential flow
  • was not limited to macropore flow: irregular, fingerlike wetting patterns were also formed in the soil matrix. Due to these typical wetting patterns, soil water content varied over short distances at all sites at all sampling dates.
  • [b1] DLO Winand Staring Centre for Integrated Land, Soil and Water Research, Wageningen, Pays-Bas
  • Soil erosion and soil structure in Impact of water and external forces on soil structure. Selected papers of the 1st Workshop on soilphysics and soilmechanics, Hannover 1986.
  • Recent studies show that measured soil losses due to water erosion differ significantly from estimated values using nomographs derived from loess soils. Under identical environmental conditions these deviations seem to be caused by the parent
  • material affecting soil structure. The final questions show that research on the interaction between soil loss and soil structure needs to be forced.
  • Soil forming processes as revealed by soil water chemistry in an alfisol and in an inceptisol, Denmark
  • Brown soil ; Clay mineral ; Denmark ; Geochemistry ; Hydrochemistry ; Loam ; Pedogenesis ; Podsol ; Soil properties ; Soil water ; Weathering
  • In this paper the solution profiles of an eluviated loamy soil and a podzolized sandy soil are presented, and the soil formation processes as reflected in the soil solutions are related to the models proposed by Ugolini.
  • A partial explanation of the dependency of hydraulic conductivity on positive pore water pressure in peat soils
  • Hydrology ; Natural gas ; Peat ; Porosity ; Soil ; Soil properties ; Soil water
  • Part of the relationship between positive pore water pressures and hydraulic conductivity in peat soils may be explained by accumulations of methane bubbles. The AA. show how compression and expansion of gas bubbles with changes in pore water
  • pressure could cause changes in hydraulic conductivity and thus help to explain some observations of dependency of hydraulic conductivity in peats on pore water pressure. Consideration is also given to the effect on hydraulic conductivities of methane gas
  • going into solution with increase in pore water pressure.
  • On using the effective contact angle and the water drop penetration time for classification of water repellency in dune soils
  • Water repellency is commonly measured in one of two ways : by determining the contact angle between the water drop and the soil surface, and by counting the number of seconds it takes the water drop to penetrate into the soil. The purpose
  • of this study is to investigate which of the two tests is more suitable for measuring water repellency in dune soils.
  • Water movement in a structured soil in the south-east of Ireland : preliminary evidence for preferential flow
  • Infiltration ; Ireland ; Leaching ; Pollution ; Porosity ; Precipitation ; Soil ; Soil properties ; Soil water
  • A study was carried out on a structured soil in the south-east of Ireland to investigate flow patterns of water in soil. The results provided preliminary evidence for preferential flow in the soil. Nitrate leaching data, from a grazing study, tended
  • is discussed. Soils having physical characteristics conducive to preferential flow are illustrated.
  • Water table depths and color patterns in soils developed from red parent materials in Michigan, USA
  • Humid environment ; Land use ; Michigan ; Mineralogy ; Soil classification ; Soil properties ; Soil science ; Soil water ; United States
  • Relationships between soil color patterns and depth and duration of water tables were studied using piezometers in three soil hydrosequences that had developed from different colored parent materials. Insufficient low chroma colors was the primary
  • reason for misclassification of soils developed from red parent materials and is thought to be related to the presence of hematite.
  • From soil and water conservation to sustainable land management
  • Agricultural practice ; Environment ; Environmental management ; Land use ; Soil ; Soil conservation ; Soil erosion ; Sustainable development ; Water
  • Part III of this volume II with 6 chapters : sustainable land use management - policies, strategies and economics; institutional and planning aspects of soil and water conservation; approaches to soil and water conservation and watershed development
  • ; technologies for soil and water conservation and sustainable land management; adoption of soil and water conservation practices; land tenure and soil and water conservation.
  • Crater formation in soils by raindrop impact
  • Experimentation ; Geomorphometry ; Impact crater ; Micromorphology ; Soil ; Soil erosion ; Splash ; Water erosion
  • This paper reports on a comprehensive investigation into crater formation in soil, sand, pastes of various simple chemicals and water targets by free-falling water drops of different sizes, heights of fall and fall velocities. This study offers
  • a new approach to rain erosion research in which the behaviour of the raindrop and soil surface as the 2 colliding bodies is considered.
  • The effect of initial soil water content and rainfall intensity on near-surface soil hydrologic conductivity : a laboratory investigation
  • Canada ; Experimentation ; Model ; Ontario ; Precipitation ; Soil erosion ; Soil properties ; Soil water ; Water erosion
  • This study describes an attempt to design and construct systems capable of measuring soil water content, soil water potential, water flux, and hence (indirectly) soil hydraulic conductivity in a laboratory. The experimental results indicate