African Journal of
Environmental Science and Technology

  • Abbreviation: Afr. J. Environ. Sci. Technol.
  • Language: English
  • ISSN: 1996-0786
  • DOI: 10.5897/AJEST
  • Start Year: 2007
  • Published Articles: 1014

Article in Press

HYDROLOGICAL RESPONSE TO LAND USE AND LAND COVER CHANGES OF RIBB WATERSHED, ETHIOPIA

Solomon Bogale Aynalem

  •  Received: 23 November 2020
  •  Accepted: 16 February 2021
The analysis examined the Covering the surface within the catchment and its effect on the catchment's hydrological responses. The Soil and Water Assessment Tool (SWAT2009) model was wont to investigate the impact of land cover change on hydrological responses of the study area. Sensitivity analysis result shown SCN curve number (CN), Soil Evaporation Compensation Factor (ESCO), Soil Depth (m) (Sol_Z), Threshold water depth within the shallow aquifer for flow (GWQMN), Base flow alpha factor (Alpha_Bf), (REVAPMN) and Soil Available Water Capacity (SOL_AWC) were found the foremost influential parameters affecting flow and USLE equation support practice (USLE_P),Linear parameter for max sediment yield (SPCON), Exponential parameter for max sediment yield in channel sediment routing (SPEXP),Cropping practice factor (USLE_C),channel cover factor (CH_COV1),channel erodiability factor (CH_ERODMO) were the foremost sensitive parameters affecting the sediment yield of sediment catchment respectively. Scenarios were developed to research the effect of the land use/cover changes to the hydrological regime. Base scenario: current land use practices has farmland , grass land, shrub and bush land, forest land, built up area and water body, scenario1: shrub and bush lands completely changed to forest land and scenario2: Grass land changed to farmland . The result for various land use scenarios show that: conversion of shrub land to forest area reduced surface runoff, reduced the quantity of sediment transported out and increase base flow but conversion of grass land in to farmland areas increased surface runoff during wet seasons and reduced base flow during the dry seasons and also because the peak flow increases it's suspected of carrying more sediment.

Keywords: SWAT, LULCC, SUFI-2, Ribb, stream flow, sediment yield, hydrological modeling, water balance, model calibration, validation