6 - Nzhelele Catchment Basin – Ecosystem Services and Land Use

This was personally one of the most interesting projects I have ever worked on. The planning for the Makhado Mine for Coal of Africa required a review of the Vhembe Biosphere reserve as well as the Nzhelele catchment basin and their ecosystem services. This review of all the mapped information was placed on a map composition in a sequence that would follow a thin red line of logic in one single map poster. It will require some detailed study by zooming in on each of the maps on the poster but will reveal the vast amount of information these maps contain. (see the download link at the end of this article for the full size version)

From the left of the map upwards, over the top, and down the right side of the poster you will find the maps of the individual ESS services. The final map with the total ESS value is found at the bottom right.

The Ecosystem Service logic is based on the four ESS categories and is placed at the bottom of the map. These categories form the bases of the evaluation and are grouped in Provisioning, Regulating, Supporting and Cultural services.

The Soutpansberg Mountain Range, consisting mainly of quartzite, dips away in three ridges towards the north, making up the southern of half of the catchment. The northern half consists of Karoo sediments and granite to the north of the mountain all the way up to the Limpopo River.

Coal deposits are found in the Karoo sediments on the north of the mountain. This is where most of the mining applications are found and the geologic formation is indicated in orange on the mineral value map.

From the catchment basin and runoff map its clear that 50% of the runoff is derived from only one of the quaternary catchments, A80A. This catchment is on the southern side of the catchment but with the highest elevation. This small catchment provides half of the ESS provisioning value and this is the most limiting of all the ESS services.

Due to the policy of separate development, intensive farmland is found north of the mountain along the Nzelele River and the community settlements are found on the mountain adjacent to the river and its irrigation itself. This is probably one of the few instances where the communities received the land with the highest potential for agriculture and also for ESS values delivering to the people surrounding the mountain.

The Nzhelele Dam supplies water for formal agriculture while also meeting the demand from mine. The urbanization and rural agriculture is found within the high rainfall catchments upstream of the dam where the environmental impact is increasingly high and unorganized land use is reducing the ESS values.

The land uses with the highest impact are those related to the exotic plantations. These forests are all planted many years ago in high rainfall catchments and have a dramatic effect on the runoff from these quaternaries.

Culturally these quartzite mountains and its indigenous forests are of high value to the local communities and hold memories of the past where the indigenous forest and dramatic cliff faces of quartzite provides many tales and legends of yesterday.

The one important observation is that the mineral value and the natural capital or ESS values are found separate from each other and no conflict itself exists.

There is not sufficient water in the catchments of the Nzhelele River and with the increase demand from urbanization in the upper catchment; innovative means of managing the ESS has to be found. One of the obvious ones is to review the land use in the upper catchments and plan for its restricted distribution as well as the spread of exotic species outwards from the forest.

The major proposal from this study was to improve the distribution of water from the mountain catchments through a management plan for the mountain region based on its ESS values.

All of the information was placed in a GIS database and ArcInfo was used to create the separate maps and the poster.

If you would like a copy of the individual maps it could be send to you electronically.

Click Here For the High Resolution Map (7mb)