A tényleges párolgás és a talaj vízkészlet becslése tenyészidoszakban

Ferenc Acs, Hajnalka Breuer, Gábor Szász

Research output: Article

6 Citations (Scopus)

Abstract

The paper deals with the mesoclimatological characteristics of evapotranspiration and soil water content in Hungary. Analysis is carried out using a modified version of the Thornthwaite model (THORNTHWAITE, 1948). Actual evapotranspiration is estimated as the product of Thornthwaite's potential evapotranspiration (PET) and the β function of MINTZ and WALKER (1993). A second order implicit numerical scheme is used to estimate soil water content. The goodness of the model is tested on a 21-year data series from the Agrometeorological Observatory in Debrecen. The correlation between actual evapotranspiration (ET), soil water content (VK) and environmental factors is analyzed in detail. The lowest annual VK values are obtained on sandy areas, irrespective of the territorial distribution of the annual precipitation. The highest annual VK values are recorded on clayey areas, where the territorial distribution of VK is determined by the territorial distribution of annual precipitation, too. The dependence of the territorial distribution of annual VK on the territorial distribution of the annual precipitation increases going from the coarser to finer soil texture. The territorial distributions of annual ET and annual VK are very similar. In spring, autumn and winter ET is independent of the soil texture, but in summer it does depend on both soil texture and the territorial distribution of precipitation. Table 1. Water capacity at the wilting point (VKh) and of field capacity (VKsz) for five soil texture categories. (1) Parameter. (2) Soil texture. (3) Sand. (4) Sandy loam. (5) Loam. (6) Clay loam. (7) Clay. Table 2. Relationship between the evapotranspiration (ET) and soil water content (VK) and the precipitation and temperature for the soil textures occurring at 115 meteorological stations over the selected periods. (1) Period. From top to bottom: months from January to December. a) Year. (2) Soil texture. (3)-(7): See Table 1. A. Correlation between the evapotranspiration (ET) and the air temperature (T), precipitation (P) and actual soil water content (VK). B. Correlation between the soil water content (VK) and the air temperature (T), precipitation (P) and evapotranspiration (ET). Note: -: none of the correlations was significant. Soil texture at the 115 meteorological stations was distributed as follows: sand: 16; sandy loam: 9; loam: 63; clay loam: 21; clay: 7. R2 = coefficient of determination. Fig. 1. P-T diagrams for the 115 meteorological stations in Hungary. (Data refer to the period from 1901-1950). Horizontal axis: annual mean air temperature, °C. Vertical axis: annual precipitation sum, mm·year-1. Fig. 2. Long-term mean annual course of measured and simulated soil water content (VK) and their standard deviations. (Long-term mean and standard deviation values refer to the period from 1972-1992.) Fig. 3. Annual course of soil water content (A) and actual evapotranspiration (B) for the soil texture categories sand, sandy loam, loam, clay loam and clay. Fig. 4. Territorial distribution of mean annual soil water content (VK) (A), evapotranspiration (ET) (B) and annual precipitation sum (P) (C) in Hungary. Fig. 5. Territorial distribution of actual evapotranspiration (ET) (A) and air temperature (T) (B) in Hungary in March. Fig. 6. Territorial distribution of actual evapotranspiration (ET) (A) and soil water content (VK) (B) in Hungary in June. Fig. 7. Territorial distribution of actual evapotranspiration (ET) (A) and precipitation (P) (B) in Hungary in September.

Original languageHungarian
Pages (from-to)217-236
Number of pages20
JournalAgrokemia es Talajtan
Volume56
Issue number2
DOIs
Publication statusPublished - dec. 1 2007

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ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Soil Science

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