Progress in gully erosion research: IV International Symposium on Gully Erosion 

Permanent URI for this collection

http://hdl.handle.net/2454/27029

Browse

Browsing Progress in gully erosion research: IV International Symposium on Gully Erosion  by Subject "Ephemeral gullies"

Now showing 1 - 6 of 6
  • Thumbnail Image
    PublicationOpen Access
    AnnAGNPS ephemeral gully erosion simulation technology
    (Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Bingner, R.L.; Theurer, F.D.; Gordon, L.M.; Bennett, S.J.; Parker, C.; Thorne, C.; Alonso, C.V.
    Tillage-induced ephemeral gully erosion has been shown to be a significant and sometimes dominant source of sediment within a watershed. An approach has been developed within AnnAGNPS to assess the impact of conservation practices on ephemeral gully erosion as well as sheet and rill erosion. Conservation management treatments should include targeting practices specific for ephemeral gullies differently than for sheet and rill erosion. Within watersheds, gullies are becoming the dominate source of cropland erosion unless preventative conservation practices are installed.
  • Thumbnail Image
    PublicationOpen Access
    Ephemeral gullies: to till or not to till?
    (Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Gordon, L.M.; Bennett, S.J.; Alonso, C.V.; Bingner, R.L.
    While the perceived magnitude of ephemeral gully erosion may be masked after gullies are repaired, the action of plowing in these channels reduces topsoil thickness and crop productivity over a much wider area than the channel itself. This study demonstrates that filling ephemeral gullies on an annual basis during tillage operations may be more destructive than realized. These results should provide land managers an additional incentive for adopting soil conservation practices such as no-till.
  • Thumbnail Image
    PublicationOpen Access
    Ephemeral gully erosion research: processes and modeling
    (Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Alonso, C.V.
    The USDA Natural Resources Conservation Service (NRCS) defines ephemeral gullies as small channels that can be filled in by normal tillage operations only to reform in the same location by subsequent runoff events. Ephemeral gullies contribute significantly to soil erosion in agricultural fields, and NRCS has consistently identified gully erosion as their number one problem to solve. Moreover, headcut development and migration is closely coupled to the initiation of ephemeral gullies and their extension on hillslopes. Research is needed to further understand the physics of these processes, to derive robust predictive algorithms and methodologies, and to develop reliable control methods.
  • Thumbnail Image
    PublicationOpen Access
    Relation between the location of check dams and adjacent vegetation cover in ephemeral gullies (Southeast Spain)
    (Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Conesa García, C.; Pérez Cutillas, P.; García Lorenzo, R.
    In general, the work carried out on vegetation in the Mediterranean catchments is focused more on the hillside vegetation cover than the riparian. Apart from occasional contributions by Alcaraz et al. (1997), Salinas et al. (2000), Mant (2002), Corbacho et al., (2003), Hooke et al. (2005), little more has been published about the vegetation of ephemeral channels in the Southeast of Spain. Specifically, the gullies create a very dynamic fluvial environment of which its connection with the morphological and hydraulic effects of riparian vegetation has been little studied up until now. The channel stability within these torrential streams depends a great deal on how much it is subject to erosion, as well as the production of sediments from the areas directly related to them (upper channel reaches and adjacent hillslopes). This is of unquestionable interest in channels being corrected by check dams, especially to assess the adequacy of their location (Conesa-García et al., 2007). The current paper adds a straightforward methodology in such a way, which relates the location of check dams to the level of vegetation cover developing in the plots of land surrounding the thalweg. For the purpose of study, two semiarid gullied catchments have been chosen, which have a strong tendency to dry up: the Torrecilla and Cárcavo catchments (Southeast Spain). The catchment of Torrecilla (15.5 km2) shows a “gullied” landscape developed on metamorphic materials (slates, phyllites, schists and quartzites), while the Cárvaco catchment (34.8 km2) is drained by ephemeral channels and gullies that deeply dissect the Miocene marls and Quaternary pediments. The projects of hydrological rectification undertaken are similar in both catchments: 33 and 40 check dam series were respectively built during the 1970´s, most of them with gabions.
  • Thumbnail Image
    PublicationOpen Access
    Some examples of ephemeral gully erosion in an Atlantic area of NW Spain
    (Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Valcárcel, M.; Paz, A.; Vidal, E.
    This study aimed to describe types of ephemeral gullies and to determine their origin, evolution and importance as sediment sources in Galicia (Northwest Spain). Concentrated erosion was surveyed on medium textured soils, developed over basic schist of the Ordenes Complex series (Corunna province, Spain) from 1997 to 2006. The studied region has a humid Atlantic climate with a mean annual rainfall of about 1000-1500 mm. Precipitation distribution is uneven, with a maximum between October and March and a minimum in the summer. The geological materials of the study area consist of basic metamorphic rocks and granite. Gullies formed within the field where runoff starts, gullies collecting the runoff from an upstream area and discontinuity gullies due to abrupt slope changes were identified (Valcárcel, M. et al., 2003). Ephemeral gullies formed by incision along linear elements generally showed large sections in zones with high slope, so that a gradual decrease from the maximun crosssection, both toward the head and downstream, occurred. This variation from head-cut to outlet of the gully may be attributed to the small flow rates at the upstream and saturation of the transport capacity downslope, where sedimentation initiates (Casalí et al, 1999).
  • Thumbnail Image
    PublicationOpen Access
    Waterfall erosion as a main factor in ephemeral gully initiation in a part of Northeastern Iran
    (Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Sadeghi, S.H.R.; Rangavar, A.S.; Bashari, M.; Abbasi, A.A.
    The present study assesses the factors controlling gully formation in a study area located in northeastern Iran. Gully erosion in northeastern Iran is very high because of the high rate of human encroachment and the resulting impacts on soil erosion.