Zmienność odpływu wody ze zlewni rzeki Łutowni (Puszcza Białowieska) w latach 1966–2000

Autorzy

• Edward Pierzgalski Instytut Badawczy Leśnictwa, Zakład Siedliskoznawstwa, Pracownia Gospodarki Wodnej, Sękocin Las, 05-090 Raszyn, Poland
  e-mail: E.Pierzgalski@ibles.waw.pl
• Jan Tyszka Forest Research Institute, Department of Forest Ecology, Sękocin Stary, Braci Leśnej 3, 05– 090 Raszyn, Poland
  phone: 48 22 7150526, fax: 22 7150507, e-mail: j.tyszka@ibles.waw.pl
• Andrzej Stolarek Instytut Badawczy Leśnictwa, Zakład Siedliskoznawstwa, Pracownia Gospodarki Wodnej, Sękocin Las, 05-090 Raszyn, Poland

Abstrakt

The paper defines the scope and trends of changes of the outflow from the Łutownia river catchment area located in the Białowieża Primeval Forest. The annual outflow and outflows in the summer and winter half-years were calculated on the basis of measurement results carried out in 1966-2000 in the Pogorzelce hydrometric cross-section. Particular attention has been drawn to the fluvial outflow during the summer half-year, a period considered important for forests. Its amount is affected by current precipitation, field evaporation rate, catchment retentive capacity, and the state of water resources in the preceding winter half-year. Analysing the variation in precipitation over the studied period, a conclusion could be drawn that the amount of the outflow in the summer half-year and low flows had a declining tendency. The reason for this state of affairs can be looked for in an increase in air temperature recorded over the last two decades, resulting in a growing transpiration and evaporation.

Słowa kluczowe

• Primeval Forest Białowieża
• specific discharge
• outflow