Contents lists available at ScienceDirect Catena journal homepage: www.elsevier.com/locate/catena Assessment of soil particle erodibility and sediment trapping using check dams in small semi-arid catchments Ali Reza Vaezi a,⁎ , Mohammad Abbasi a , Saskia Keesstra b , Artemi Cerdà b,c a Department of Soil Science, Agriculture Faculty, University of Zanjan, 45371-38791, Zanjan, Iran b Soil Physics and Land Management Group, Wageningen University, Droevendaalsesteeg 4, 6708NX Wageningen, The Netherlands c Soil Erosion and Degradation Research Team, Departament de Geografia, Universitat de València, Blasco Ibàñez 28, 46690 Valencia, Spain ARTICLE INFO Keywords: Cement rock check dam Grain size distribution Rainfall erosivity Remaining capacity Sediment yield ABSTRACT Check dams can be used as a source of information for studies on sediment characteristics and soil particle erodibility. In this study, sediment yield and grain size distribution (GSD) were measured in twenty small catchments draining into a rock check dam in NW Iran for different runoffs during 2010–2011. Significant correlations were found between sediment yield and slope steepness, vegetation cover and soil erodibility factor (K) of the catchments. The erodibility of soil particles was determined using the comparison of GSD between sediment and original soil. Clay was the most erodible soil particle which showed 2.05 times more percentage in sediment than the original soil. The erodibility of soil particles were strongly affected by the rainfall erosivity (EI 30 ). Check dams showed more effectiveness in trapping coarse particles (sand and gravel). The effectiveness of check dams in trapping coarse particles enhanced with increase in the remaining capacity of check dams. 1. Introduction Semi-arid areas cover about 24% of the world's surface and are characterized by limited rainfall, annual precipitation ranges from 300 to 600 mm, and periodic droughts that restrict rainfed crop production (Araya et al., 2011). In these areas, soils are usually shallow, poorly structured and low in organic matter content, and vegetation cover is often inadequate to protect the surface, especially when agricultural practices of crop cultivation and grazing further reduce this cover (Cammeraat et al., 2010). They are considered to be one of the most vulnerable areas to the impacts of water erosion processes, and this is why restoration strategies are applied (Keesstra et al., 2016; Prosdocimi et al., 2016). Soil erosion is the most important factor in land degradation or desertification in these areas (Ligonja and Shrestha, 2015; Zhou et al., 2016). Soil erosion by water is the major factor controlling sediment production in all catchments in semi-arid areas (Wang et al., 2016; Ochoa et al., 2016). Total sediment outflow from a catchment, measurable at a point of reference and for a specified period of time is defined as sediment yield (Vanmaercke et al., 2014). It can be expressed in absolute terms (Mg year -1 ) or per unit area (Mg km -2 year -1 )(Jain and Das, 2010). The sediment yield of a catchment represents only a part of the total soil erosion within the catchment, as often-important masses of sediment are deposited before they reach the outlet (Lee and Yang, 2010; Masselink et al., 2016). It is dependent on all variables that control erosion and sediment delivery in a catchment, and determine the connectivity of the system (Baartman et al., 2013; Marchamalo et al., 2016). Sediment delivery is influenced by catchment characteristics, regional climate, and reservoir character- istics (Syvitski et al., 2005). Thus, sediment yield can be controlled by the environmental conditions of the watershed, such as climate, soil, topography, land use and its spatial distribution, vegetation cover, drainage network characteristics, and various forms of human distur- bances (Syvitski et al., 2005; Boix-Fayos et al., 2007; Shi et al., 2012; Naden et al., 2016). The determination of sediment yield and the factors controlling it is of essential importance for sustainable manage- ment of catchments (Akrasi, 2011). The particle/grain size distribution of sediment (GSD) can be used as additional information to evaluate the soil particles susceptibility to water erosion in the catchment scale. Soil particles are different in their potential to be eroded by water. The susceptibility of soil particles to different erosion processes; detachment, transport and deposition can be defined as the soil particle erodibility. This term is different from the soil erodibility concept developed for soils, which reflects the soil's susceptibility against erosive forces (Wischmeier and Smith, 1978; Vaezi et al., 2016). The soil particle erodibility can be influenced by both inherent soil particle characteristics (size, mass/weight, shape etc.) and the transport mechanism (surface runoff, concentrated runoff, http://dx.doi.org/10.1016/j.catena.2017.05.021 Received 13 June 2016; Received in revised form 27 January 2017; Accepted 19 May 2017 ⁎ Corresponding author. E-mail address: vaezi.alireza@znu.ac.ir (A.R. Vaezi). Catena 157 (2017) 227–240 Available online 25 May 2017 0341-8162/ © 2017 Elsevier B.V. All rights reserved. MARK