INTEGRATED TOPOSEQUENCE ANALYSIS AT THE CONFLUENCE ZONE OF THE RIVER EBONYI HEADWATER CATCHMENT (SOUTH EASTERN NIGERIA)

An integrated survey along a continuum of two representative toposeque nces, crossing fluvial and interfluvial landscapes downstream of the c onfluence of two perennial rivers of the upper reaches of the River Eb onyi catchment resulted in a methodology for characterising toposequen ces and for identifying priorities for land evaluation. The so-called Integrated Toposequence Analysis (ITA) merges conventional biophysical surveying and participatory research techniques along toposequences a nd sets a framework for developing relational databases for land resou rce mapping at village and catchment scale. Relationships between phys iographic position, soil characteristics, vegetation and land use demo nstrate the physical and human influences affecting the current land s tatus along the catenae. Indigenous appraisal of soil characteristics and productivity provides insight in current land use strategies at fa rm level, whereas, analysis from standard biophysical methods demonstr ates the constraints to present land use trends. Results indicate the limited scope for further agricultural intensification on the upland i nterfluve areas with the present farming system practices, and show th e increasing pressure to exploit the fluvial wetlands. (C) 1998 Elsevi er Science B.V. All rights reserved.