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uMzimkhulu Catchment Study

The umzumkhulu catchment assessment was a project commissioned by the department of Water Affairs (DWA) to undertake a full hydrological study of the uMzimkhulu river catchment. As part of this process the full project took modelled current and planned water usage as well as identifying current and potential commercial timber in the area.

Quartex was involved in the project to provide GIS support and analysis and hysrological support. As part of this process we undertook the following key components of the project:

Identification of current landuse:

Utilising existing aerial photography and 2007 landuse, we were able to verify and enhance the 2007 landuse dataset to provide a comprehensive dataset of current landuse in the catchment. This provided the main input into the hydrological modelling. As part of this excercise all river courses (4 levels) and the quaternary boundary were digitised based upon the aerial photography. Additionally, all farm dams and wetlands were also digitised.

landuse

Agricultural Utilisation:

Study of agricultural utilisation of water based upon WARMs data and onsite survey. as part of this process an agricultural crop demand was determined and presented at a quaternary catchment level

Timber Potential:

A timber potential study was undertaken to determine areas suitable for timber. A "negative mapping" exercise was undertaken to elimnate the unsuitable areas and to identify identify "positive window areas" for further investigation. These -unsuitable areas are associated with unsuitable conditions, and termed "exclusion criteria". Exclusion criteria included:

certain landuse classes
EKZNW - Environmentally sensitive areas (minset)
Slope
Mean Annual Precipitation
Agricultural Bio-Resource units (unsuitable soil types)

Based upon this, suitable areas were then divided into:

High suitability
Medium
Low
Not Suitable

Forpot

10 November 2010
Andrew