THE EFFECTS OF FOREST CANOPY COVER AND ALTITUDE ON SNOW ACCUMULATION AND MELTING IN THE UPPER WATERSHEDS


DUYAR A.

FRESENIUS ENVIRONMENTAL BULLETIN, cilt.27, ss.9642-9649, 2018 (SCI İndekslerine Giren Dergi) identifier

  • Cilt numarası: 27
  • Basım Tarihi: 2018
  • Dergi Adı: FRESENIUS ENVIRONMENTAL BULLETIN
  • Sayfa Sayıları: ss.9642-9649

Özet

A significant amount of water falls down on the ground with snowfall. Therefore, the snow cover accumulated in the upper watersheds can reservoir very large amounts of water. Snow masses may melt at different speeds depending on climate conditions. These reservoirs can regularly feed water resources in slow melting conditions or cause floods with sudden melts. Knowing some of the effective environmental characteristics on the accumulation of snow masses can render possible the estimated amount of water reserves and the extent of flood risks. For this purpose, the snow accumulation and the amount of snow water equivalent at the open area and under the different forest canopies were investigated in the upper watersheds. The selected study area is located in southeast of Bolu province (northwestern Turkey) and consists sampling points on route of Kartalkaya Ski Center (2000 m a.s.l.). In total 11 permanent sample areas were determined between 936 m and 1930 m (a.s.l.) altitudes. Three sampling points were selected as the open area, the semi closed and the fully closed forests at each sample area. The samples were collected three times in a week from December to April. The snow depths (SD) were measured at all sampling points. Snow densities and snow water equivalents (SWE) were determined in the laboratory by using snow core samples taken from the sites. In the evaluation of the samples, Correlation, ANOVA and Duncan analysis were applied to the data, such as independent variables of time, forest cover, altitude and aspect affecting the snow accumulation and dependent variables of SD, SWE and snow density. When the data obtained is evaluated, SD and SWE negatively correlated with forest closures, and positively correlated with altitudes. SD (762 mm) and SWE (170 mm) reached maximum values at open areas in February. Forest canopies significantly reduced the snow accumulations compared to the open areas. The average snow depth was observed in different values within open areas (371 mm), semi closed forests (229 mm) and fully closed forests (165 mm). Similarly, the water equivalent of snow was observed as 86 mm in open areas, 53 mm in semi closed forest, and 38 mm in fully closed forest. Although the snow density did not show a significant difference depending on the forest canopies, it increased based on altitudes and dates (221 g/l in December and 368 g/l in April). The amounts of SD and SWE in open areas were formulated according to altitudes by using the findings. In this way, it is considered that snow accumulation, water reserve and possible water regimes in the upper watersheds can be estimated depending on the snowfall information in a region.