ارزيابي مقايسه اي اثر بخشي عمليات آبخيز داري درحوضه هاي دوراهان، قلنگان و ديمه

A Comparative eva‎luation of the Effectiveness of Watershed Management Operations in the Dorahan, Qalangan an‎d Daymeh Basins

جغرافياي طبيعي

Abstract In recent decades, the water, soil, an‎d plant resources of Iran have faced serious crises due to factors such as improper management of natural resources, climate change, an‎d socio-economic challenges. In this context, the implementation of watershed management projects has been recognized as one of the primary strategies for the protection of these resources. However, despite the high costs, challenges such as a lack of coordination between research an‎d implementation activities, weak monitoring an‎d eva‎luation, an‎d insufficient scientific information at the execution level have posed obstacles to the effectiveness of these projects. In order to assess the effects of watershed management operations, studies were conducted in three watersheds: Dorahan, Qalangan, an‎d Dimeh by Saravan Green Engineers (2019), where the impact of these projects was analyzed an‎d compared. The results indicate that watershed management operations in these areas, particularly in reducing soil erosion, controlling surface runoff, an‎d mitigating flood risks, have had positive effects. In the Dimeh watershed, mechanical operations, such as the construction of rock an‎d mortar structures, have significantly reduced the peak flood discharge; however, these effects are less evident in other areas due to deficiencies in the comprehensive completion of watershed management operations. In the Qalangan watershed, mechanical measures demonstrated noticeable impacts in controlling soil erosion, while biological operations, especially in overgrazed regions, did not yield favorable results. Additionally, in the Dorahan watershed, the design an‎d implementation of various watershed management structures have proven to be very effective in reducing peak flood discharge an‎d improving hydrological conditions. This research indicates that the combined implementation of mechanical, biological, an‎d biomolecular measures can be effective in reducing soil erosion an‎d preventing floods, provided that precise monitoring, greater coordination between research an‎d execution centers, an‎d the completion of comprehensive watershed management packages are taken into consideration. Keywords: Watershed management, Soil erosion, Dorahan, Qalangan, Dimeh.

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