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Data Origin Dr Nick Riversmore in 2007 using MARXAN

Consistency: The dataset was developed using a number of datasets. The technical document which will become available soon lists these datasets and the procedure.

The KwaZulu-Natal Freshwater Systematic Conservation Plan was derived using generic conservation planning software (MARXAN). A two-step, hierarchical process was followed to capture catchment- and local-scale freshwater dynamics, where priority primary catchments were first identified, and then used in a second level for selecting priority sub-catchments, which served as planning units at a finer scale.

Quantitative targets were set for defined freshwater biodiversity features, where primary catchment targets were based on the number of catchment types, river targets were based on total length of each river type, wetland targets were based on the total area of different wetland types, and species targets were set according to the total number of planning units containing lotic- and lentic-associated species.

Selection of priority planning units at both levels was manipulated using modified area-weighted costs. Costs were modified using discounts and penalties, which included, inter alia, the presence of priority estuaries and free-flowing rivers, planning units falling within priority primary catchments, planning units identified as important in an existing terrestrial conservation plan for KwaZulu Natal, and the degree of catchment degradation. Upstream-downstream connectivity was achieved using boundary length costs for adjoining sub-catchments associated

with main rivers and wetlands, and enhanced by setting high targets for sub-catchments through which diadromous eels (Anguilla mossambica) must migrate to reach upper river reaches. Ecological processes were incorporated, as far as possible, by discounting planning units important for surface and groundwater yield.

Recommended Citation

EKZNW (2007) Freshwater Systematic Conservation Plan: Best Selected Surface (Marxan).

Unpublished GIS Coverage [Freshwater_cons_plan_2007], Biodiversity Conservation PlanningDivision, Ezemvelo KZN Wildlife, P. O. Box 13053, Cascades, Pietermaritzburg, 3202.

THE FOLLOWING FILES ARE PRESENT WITHIN THIS ZIP FILE:

1) PLANNING UNITS:

This is the freahwater planning unit surface for the 2007 Freshwater Systematic Conservation Plan (FSCP) run by Dr. Nick Riversmore in 2007 using MARXAN. Within the attribute table, the field {status} highlights the status of the planning units relative to their conservation importance.

2) LinkTable_abundance_for export:

Link this table using the field {Unit_id} to the planning unit layer - use the field of the same name. When you query the planning unit layer, look for all the features with a value >0. This indicates a presence of the feature within the planning unit in question.

3) LinkTable_feature_list_for export:

Use this to determine the names of the features as shown in the [LinkTable_abundance_for export] above. Due to heading length limitations, the codes {value_1; Value_2 etc} had to be used instead of the actual feature name.

4) Description of River type names:

This gives a brief description of the river codes as displayed in [LinkTable_abundance_for

export].

IMPORTANT NOTICES:

Please note, however, that this product is currently under revision, and a new updated version that will replace this version will soon be available. This zip was put together on 08 March 2010.

SANS 1878

FGDC-STD-001-1998