Assessing the Effects of Alluvial Transport in the Kizilirmak River on Dams with Local, Photogrammetric and Remote Sensing Methods

Abstract

Naturally transported sand, clay, and gravel-like blocks by rivers cause a decrease in water flow and flow velocity. Additionally, uncontrolled disposal of waste materials into the riverbed increases adverse effects and endangers natural life. Over time, the alluvium generated by natural and external factors in river and creek beds leads to flood risks that pose a significant threat to life and property. These sediments, known as alluvium, accumulate in favorable locations in valleys and form alluvial beds with spread movement to broader areas. In Turkey, interventions in river branches and creek beds, as well as insufficient preventive measures, have kept floods a hot topic. To eliminate these issues, it is crucial for every organization to take comprehensive measures and increase environmental awareness by addressing similar areas in large projections. The Kızılırmak River, originating from the Kızıldag slopes in the İmranlı district of Sivas province and passing through the Çorum province before reaching the Black Sea at Bafra Cape, also harbors alluvial risks and adverse effects. It holds significant importance for energy production with 12 dams and hydroelectric power plants (HES) on the river. Additionally, the Pirinçli Hydroelectric Power Plant, with a transmission structure of 13,756 meters between Dodurga district of Çorum province and Güvercinlik and Kumbaba Villages, plays a vital role in electricity production in the region. The Pirinçli HES is located downstream of the Obruk Dam constructed by the State Hydraulic Works (D.S.I.) on the Kızılırmak River. It is known that a significant portion of the sediment accumulation between Güvercinlik Dam and Kumbaba Dam occurred before the construction of the Obruk Dam. Hence, preventing risks that could lead to environmental adversities is of paramount importance. In this study, a combined fieldwork was conducted using different methods to determine the areas where sediments accumulated and the alluvial material being transported cuts off the flow velocity of the Kızılırmak River and causes accumulations between the Güvercinlik Dam and Kumbaba Dam. For this purpose, terrestrial measurements, photogrammetric and remote sensing methods were combined and evaluated together to ensure the integrity of the obtained data.