Ravines and gullies, a review about impact valuation

Gullies and ravines affect human lives and the environment in many countries worldwide, however, few studies have assessed the impacts of the damage caused by these large linear erosions and clarified their influencing parameters. This work systematizes available information about the variables relevant to analyze the impacts of ravines and gullies on socioeconomic conditions and ecosystem services. Based on keyword searches performed in the Scopus, Web of Science and Dimensions databases, more than 120 articles from 27 countries were identified that addressed and valuated these different types of impacts. Although many studies discuss the impacts of ravines and gullies, few studies have performed valuations of these impacts. We compiled the impacts in urban and rural areas, considering the changes caused by ravines and gullies throughout a hydrographic basin. The results allowed for the elaboration of a theoretical model of the possible impacts of gullies and ravines and how they can be valued. The results demonstrate that the most significant impacts, according to the literature, are in South America, Africa, China and India, which are related to disordered land occupation. In some cases, the lack of capacity to respond to environmental and social problems aggravates the scenario and leads to significant losses. Implementing the evaluation is challenging due to the high number of different forms of possible impacts, in the short, medium and long term, related to environmental, economic and social changes.