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The hydrological impacts and sustainability of wetland drainage cultivation in Illubabor, Ethiopia
Author(s) -
Dixon A. B.
Publication year - 2002
Publication title -
land degradation and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.403
H-Index - 81
eISSN - 1099-145X
pISSN - 1085-3278
DOI - 10.1002/ldr.479
Subject(s) - wetland , sustainability , drainage , environmental science , agriculture , groundwater , water resource management , hydrology (agriculture) , geography , agroforestry , ecology , geology , geotechnical engineering , archaeology , biology
Wetlands are critical resources in the highlands of southwest Ethiopia, where they perform numerous environmental functions and provide a range of benefits for local communities. In recent years, however, an increase in the drainage and cultivation of these areas and reports of wetland degradation have raised concerns over the sustainability of wetland agriculture. This paper presents the results of a study in which groundwater levels were monitored in a series of wetlands undergoing different stages of drainage and cultivation, to establish the hydrological changes taking place as a consequence. The results suggest that drainage and cultivation induce extreme spatial and temporal variations in the wetland watertable. This is linked in part to structural and chemical changes in the wetland soil which affect hydraulic conductivity. Statistical analysis of this variability revealed the existence of wetland subunits, exhibiting specific hydrological behaviour, which may reflect the influence of current and past land use. Although degradation of these wetlands does occur, many wetland users are aware of their impacts and have developed practices which, in most cases, prevent overdrainage to the extent that the wetlands cannot support agriculture. In this respect, it is argued that wetland use remains hydrologically sustainable, although this ultimately rests upon the ability of communities to continue to develop and apply their indigenous wetland management practices under rapidly changing environmental, socio‐economic and political conditions. Copyright © 2002 John Wiley & Sons, Ltd.