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Land Tenure Regimes, Zimbabwe

A Methodology to Study the Impact of Land Tenure Regimes on Degradation of the Save River Catchment in Zimbabwe

Crispen Marunda (2001)

This research analyses the impacts of different tenure regimes on the degradation of the Save River Catchment Area in south eastern Zimbabwe.

Our hypothesis: the tenure system on any part of the catchment affects the quality of the catchment hydrology. The approach recognises the tenurial and ecological basis of human settlement and land use practices; and couples tenure regimes with landscape ecological analyses. Using GIS, hydrological sub-zones are linked to the ecological and demographic factors, and the extent of degradation.

The impacts of spatial heterogeneity, influenced by the tenure regimes, are explained in terms of hydrological parameters – surface run-off, ground water resources, sedimentation – using multiple regression models. Based on principal component analysis, areas are classified by the extent of degradation and those needing priority attention are identified.

SAVE RIVER CATCHMENT AREA (SRCA)

The Save River Catchment Area covers almost 82050 km2 of the total land area of Zimbabwe. It is made up of two major river systems – the Save and Runde rivers – and is typical of a spatial landscape in which socio-economic and environmental activities are degrading the condition of the catchment.


These include: Communal areas (open access and CPRs), large scale commercial farming areas, small scale commercial farming areas, resettlement areas, state lands (woodlands and national parks).The type of regime affects the type of resources available, access rights and ultimately the use patterns (mainly crop production, grazing and woodlands). In the communal areas, access is generally open; the absence of strong institutional frameworks to support CPRs and their low biological capital, has led to high levels of soil erosion, surface runoff, erratic ground water supplies and choking of the river channels.

HYDROLOGICAL SUB-ZONES


Forty hydrological zones form the basic sampling units for the whole catchment area. The zones are spatially integrated with the tenure regimes.

The geology, land use pattern and population densities have an impact on the catchment condition. All possible causative variables will be created from either remotely sensed data or digitised from maps.

Geology

Land use

Wards










Use of GIS will give statistics on the geology, land-use pattern, vegetation, topography and human and livestock population densities for each tenure category by area. Then these will be used to couple the land use model to the hydrological sub-model, thereby linking land use, ecology and the observed hydrology of the catchment.

Hydrology

% of land eroded

RESPONSE VARIABLES

The response variables are hydrological parameters and the percentage of degraded land. For example, run-off is positively related to rainfall (see graphs), and a correlation is assumed between the residual variation – both spatial and temporal – and the tenure regime, land-use patches and ecological mosaics through-out the catchment.

RESULTS

For each tenure category, the following relations will be examined:

1) land use percentage (area) and observed hydrological parameters;
2) the effect of vegetation and soil type on hydrology;
3) the effect of population densities (human and livestock) and poverty status on hydrology and degradation.

The outcome is a spatial quantification of tenure impacts at the catchment level. The relationships can further be modelled to predict the impact of future land use transfers and to come up with “what if” situations. Such scenarios can be used to support research and policies that promote sustainability.

Last Updated: 18 December 2018