Submitted to: International Soil Conservation Organization Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/15/2004
Publication Date: 7/4/2004
Citation: Ritchie, J.C., Finney, V.L., Oster, K.J., Ritchie, C.A. 2004. Floodplain sediment deposition in northern California, USA. In: Proceedings of Conserving Soil and Water for Society: Sharing Solutions,ISCO 2004-13th International Soil Conservation Organisation Conference, July 4-9, Brisbane, Australia. Paper No. 138. 2004 CDROM. Interpretive Summary:
Technical Abstract: Land use changes have occurred in the Stemple Creek watershed in northern California USA that have increased and then decreased the erosion and movement of soil into floodplain, stream channels, and the bay. This study documented sediment deposition rates and patterns in the floodplain of Stemple Creek. Deposition rates ranged from 0.31 to 3.50 cm/y and an average of 1.29 cm/yr for the 1954 to 1964 period and from 0.26 to 1.84 cm/yr for the period from 1964 to 2002 with an average of 0.85cm/yr. Sediment deposition in the floodplain has decreased since the middle 1950's probably related to change from row crop agriculture and grazing. These floodplains are acting as significant sinks for the eroded material moving from the uplands. These floodplains are keeping eroded materials from reaching the stream channels or the bay. Plans need to be developed for these floodplains to insure that they remain a sink and do not become a source for eroded materials as improved management practices on the upland areas reduce sediment input to the floodplain.