When it comes to forests, the razed cuts are those cuts that plan the entire vegetation of an area. Strongly limited in Italy and used only in exceptional cases, in other countries like the United States is instead a tool still exploited in certain conditions (in addition to being lawyer in private woods).
Well, a study published on Journal of Hydrology He warns against this already controversial practice of his: the razi cuts, says the University of British Columbia, They worsen the situation of the floods, making them more frequent and more devastating.
Decades of floods. The study is the result of a job that has been going on for decades: in North Carolina, at the Coweeta Hydrologic Laborati, there is a “experimental” forest On which studies and experiments have been conducted since 1934. The presence of such a rich historical record has allowed UBC scientists to study the effects of the razed cuts on two adjacent hydrographic basins in the forest, both “shaved” in the 1950s. One of the two overlooks the north, the other to the south: it is an important detail, as we will see.
Different results. The analysis has in fact demonstrated very different effects in the two basins. The one overlooking northwhich receives less direct sunlight and therefore retains more humidity, was devastated by floods. The one overlooking the south, however, has not undergone any effect. When we say “devastated” we are not exaggerating: in the last seventy years, the floods in the pelvis turned to the north have become 18 times more frequent. They also “grown up” in terms of mobile quantity of water: on average 47%, with peaks of 105%.
We do not simplify floods! These data are important because they deny many hypotheses used in climatic models. So far, in fact, the calculations on the effects of the razed cuts on floods have always based on a very simple reasoning: cutting a certain percentage of trees, the amount of water that is added is proportional to this percentage. The study of the UBC, on the other hand, explains that the calculation is not so direct, and We must also take into account the form of the landscape, and the extreme effects of the most powerful floods, which can modify it in a radical way.
Look for alternative solutions. The recommendation of the authors of the study, therefore, is to take into account this element of randomness when making predictions on the effects of razed cuts, and ideally seek alternative solutions if you want to cut the trees to make it timber or to free soil.
Also because the study shows that the Effects of a radical cut are also felt tens of years later: a problem not only for the present, in short, but also for the future.
