Ograniczanie wyników

Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 42

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 3 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 3 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
14
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Ocena ekonomiczna retencyjnych właściwości lasu

100%
The article attempts to calculate the economic value of the natural water storage capacity of forests. The impact of forests on the volume of the river runoff and on the delay of the water cycle from the precipitation to the runoff was an indicative measure of storage capacity of the forest. Data from long−term research aimed at determining forest−water interactions in small catchments were used. Four weakly−correlated parameters of runoff characteristics were determined, reflecting the scale of retention capacities of forested areas. These parameters included mean annual runoff (HR), coefficient of the annual runoff irregularity of (HRmax/HRmin), summer to winter half−year runoff ratio (HL/HZ) and the volume of the discharge (Wq/Sq). Equations were developed interpreting the range of changes of the parameters with the increase of forest cover from 0 to 100% (fig. 1−3), and the volume of water stored by the forest per 1% of the forest cover per year was calculated. Using simplifying assumptions, the total volume of water stored per hectare of the forest in the average year was calculated to 9.05 m3. The unit cost of 1 m3 of water was determined on the basis of the lowest price which the State Forests (in the territory of the Garwolin Forest District) spent to increase the volume of the water stored in small reservoirs. No difference was made between natural and artificial water storage in terms of utility. According to such simplified calculations, the natural storage capacity of forests was estimated at 1,089 PLN per year. Apart from the water storage function, forests provide other benefits resulting from a wide range of hydrological, water−protecting effects. Water resources safeguard, inter alia, the sustainable development of forests: affect the climatic conditions, reduce the level of environmental contamination. These functions can be intensified through the use of appropriate methods of forest management.
The study concerned changing status of water retention within an unique nature complex of the Białowieża Primeval Forest. The retention was evaluated based on an analysis of research results on water outflow from the lowland catchment of the river Łutownia – representative for physiographic conditions as well as those of habitats and tree stands in Poland’s part of the Forest. The catchment in the lowland hydrometric dissection at the Pogorzelce village – Old Białowieża Wilderness, covers the area of 120.1 km2 with natural flow conditions preserved. A unified sequence of measurements carried out since 1966 using unchanged methodology with respect to precipitation, air temperature and forest management status allowed to separate different phases of changes occurring in water resources of this protected forest complex. There were appraised periodical runoff changes and cycles including a decrease in water resources which occurred at the turn of the century. The retention capacity of the catchment was determined based on periodical changes in rainfall-runoff relations and the ongoing process of deteriorating water conditions of forest ecosystem was interpreted.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 3 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.