Aspects concernant l'effet des travaux d'amenagement de certains petits bassins hydrographiques torrentiels de Roumanie

Wien

1988

2 Tab., 4 Lit. Ang.

Unselbständiges Werk

673

200005046

The essay presents the results of the research on the effects of the management woiks carried out in 7 small torrential watersheds characteristic for different zones of Romania. The management works consisted of: the turning of some grazing and arable grounds situated on severe slopes into hayfields or forests: afforestation of degraded lands; improvement of degraded forests etc. All these works were carried out in a proportion of 50-75% of the necessary amounts The hydrotechnical works, on the torrential beds were carried out in a proportion of 25-50% of the necessary amount. 10-25 years after such works were carried out the following most important effects were recorded: - The area affected by active degrading processes (erosion and landslides) decreased by 39-79%, i. e. 55% on an average. On afforested lands the area affected by active erosion processes decreased by 75-100%, i. e. 85% on an average: - The maximum liquid discharge decreased by 16-36%, i.e. 29% on an average; The specific erosion lowered from 15.1 to 9.4 m3/ha/year, i.e. 38%. In watersheds where the management works were carried out in great proportion the specific erosion was below 5 m3/ha/year; - The best results gave the forest cultures of Pinus nigra and P. silvestris (4 m3/ha/year) Robinia pseudoacacia (5 m3/ha/year), Populus euramericana and Salix sp. (7 m3/ha/year) Alnus incana (5 m3/ha/year), Hippophaë rhamnoides etc. 10-25 years after the plantations were established on severe eroded lands a soil layer began to form of 10-25 cm with contents of organic substances of 1.5-5%) in the first 5-7 cm.