Published in Scientific Papers. Series "Journal of Young Scientist", Vol. 3
Written by Iulia Diana GLIGA, Madalina PRESECAN
The aim of this study is to determine the ecotop parameters used for restoration of degraded lands, which are not recommended to other uses. Afforestation reduces the extreme values of climatic factors (temperature, Evapotranspiration, wind speed): improves the air humidity and soil moister; and favors site conditions for maintaining herbaceous and forestry vegetation development. The decreasing of land degradation and the gradually restoration of productive capacity under the direct effect of forest cultures could be analyzed by variation of precipitation retention by canopy. The results regarding canopy retentions were obtained by placing in situ several rain gauges with height of 25 cm and 100 cm2. The precipitations retentions by canopy values were computed by the difference between the amount of rainfall recorded in open grounds and average values recorded at rain gauge installed in land cover with trees (in forest). Rains were grouped into classes, and the rainfall for each class being calculated as mean value of precipitation retained. The data obtained were highlighted with correlation between rainfall inside the forest and rainfall outside the forest. The curves of retention in the canopy layer were plot according to the height of rainfall and some characteristics of trees (species, age, consistency).The frequency of days with precipitation ranged from one month to another and from one season to another. The data set analyzed showed that rainfall triggered surface runoffs in seven day (5% of the total days computed). The slope of regression between monthly average rainfall index and the amount of rainfall previously recorded expresses an increase from a drought year to a rainy year. The average rainfalls per square meter inside the stand increased with the amount of rainfall quatity, the highest values were registered over 70 mm. Maximum discharge coefficients, determined by class of precipitation, highlighted the influence upon runoffs: the maximum value (0,219) being achieved by precipitation from 0 to 10 mm, although the maximum rainfall is obtained in the precipitation of more than 50 mm. Based on the computed data were determined regression equations between the runoffs amount and precipitation quantity, also, between rainfalls quantity and standard deviation of previous monthly.
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