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The Podlipie valley constitutes a typical example of river valleys of the Lublin Upland situated among loess formations fed with underground waters. The aim of the respective investigations was to estimate the functioning efficiency of the existing reclamation networks, to recognize the causes of an exessive moisture and, if possible, to suggest the ways of leading off the excessive water amounts. For this purpose the location of existing drainages was established, measurements of ground water levels, piezometer pressure, and outflow from drains were carried out as well as physico-hydrologic conditions of soils occurring within the range of the profiles examined were characterized. A detailed analysis of the measurement results has proved that the underground runoff, too wide specings between drains and a lack of the possibility of surface outflow lead to bogging of the lowest sites. However, a main factor causing the submergence of meadows is the feeding with underground waters. It seems therefore that much more attention should be paid to an appropriate recognition of hydrogeologie conditions in the complex of factors responsible for the ground water dynamics. It is proposed to carry out on the Podlipie object the works enabling the outflow of surface waters and the works on maintenance of ditches and drain outlets and in further sequence to execute an additional drainage with the gravel or sand backfill.
The value of hydraulic conductivity (K) has considerable theoretical and practical significance for the water economy of soils and plants. Measurements of hydraulic conductivity conducted for peat soils in the process of soil monolith drying and wetting indicated the occurrence of capillary hysteresis in the soils under study. Data presented in the paper may indicate that the phenomenon is directly affected by the physical-hydraulic properties of the soils. The hysteresis loop surface areas determined in the study may be insufficient to fully reflect the true situation as there is a lack of measurements of the soil water potential in the zone close to full saturation. Values of the surface area calculated according to statistical methods differ from values calculated according to Brooks and Corey’s formulae. A significant factor affecting the difference is the value of effective conductivity (Kₑ) which is one half of the conductivity at full saturation (Ks).
The empirical verification of TRANSP and TERGRA models was the main purpose of conducted researches. The models introduced in this paper describe the diurnal patterns of leaf temperature and transpiration when grass is exposed to increasing water deficit under field conditions. The difference simulation results of leaf water potential, leaf temperature and transpiration flux for low and high soil water potential rates and for different meteorological conditions show that these models need more research and measurements for a better identification of function aqd parameters especially for wet conditions, making these models more useful for irrigation scheduling, using the remote sensing techniques.
In this paper especially the SWACROP/GRASS-model is described while only for comparing also a general introduction to GRAGRO - model, is given.
The aim to this paper was to estimate the influence of suction force or the level of the ground water table on the growth and distribution of roots and on yielding of grass. It was noticed that suction force influences the growth of root mass which in turn determines yielding of grass. The results of the crops of dry mass of hay as dependent on the depth of the ground water table show that high moisture and high level of the ground water table in early spring may in some cases limit spring and autumn crop yield.
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