Author/Authors :
Zahedikhah ، Hamide Rangeland and Watershed Management Department - Faculty of Natural Resources - Khatam Al Anbia Behbahan University of Technology , Armin ، Mohsen Natural Resources Engineering Department - Faculty of Agriculture and Natural Resources - Yasouj University , Mozayyan ، Maleeha Rangeland and Watershed Management Department - Faculty of Natural Resources - Khatam Al Anbia Behbahan University of Technology
Abstract :
Aims: Check dams are one of the common structures for controlling soil erosion in Iran. Sediment deposits behind them contain reallocated carbon, which plays a significant role in ecosystem carbon sequestration. Most studies related to check dams are in the field of their primary function, i.e., soil and water conservation. However, in this study, we evaluated their capability in carbon sequestration, which has received very little attention. Materials Methods: In this study, which was conducted in the Nehzatabad Watershed in Kohgiluyeh County in the southwest of Iran, using the sediments deposited in 11 check dams while analyzing the amount of sediment yield, the performance of these structures in carbon sequestration during the years 2017 to 2018 has also been investigated. The amount of soil organic carbon (SOC) was determined using the Walkley-Block method. The volume of sediments deposited behind the check dams was measured, and then the resulting sediment yield was measured and then estimated for three different sediment trapping coefficients. Findings: Results show that the mean measured sediment yield in the study check dams is 0.13 t. ha-1. y-1, compared to mean annual soil erosion in Iran (16 t. ha-1. y-1), is simple soil erosion in the studied watershed. The estimated mean values for sediment yield in different check dams are 0.26, 1.69, and 3.59 t .ha-1 .y-1 for different TE coefficients. The mean of SOC deposited in check dams is 20637.79 g, equivalent to 12.9 and 2.16 m2 of Oak forest in carbon sequestration and carbon dioxide absorption, respectively. Conclusion: Erosion and sedimentation can make a net positive contribution to SOC sequestration, and this study reveals that check dams in the Nehzatabad Watershed conserve soil and water and sequester carbon. A small change in the soil carbon pool may cause a significant change in atmospheric carbon dioxide, which may have important implications for global climate. Therefore, building many of these dams in watersheds while controlling erosion and sedimentation makes it possible to deposit considerable carbon in these sediments and prevent the release of carbon dioxide as a greenhouse gas into the atmosphere.
Keywords :
Soil Erosion , Sediment Control , SOC, Carbon Dioxide , Climate Change
