The Rimba Raya Biodiversity Reserve REDD Project

In the revised Toolkit, HCV 4.2 areas are defined as areas withestimated soil Erosion Risk Potential of > 180 t/ha/yr. Theprocedure recommended for evaluating HCV 4.2 is asimplification of the Universal Soil Loss Evaluation (USLE), whereland cover types and soil management are ignored (i.e., a worst-­casescenario). An indicative map of HCV 4.2 areas forKalimantan prepared by Tropenbos is provided with the revisedToolkit as a Digital Annex. According to this map, HCV 4.2 is notpresent in the Project Zone (see Figure 17 below). This findingalso accords well with the occurrence of soil types in the ProjectZone (see Section G 1.1), topography, and inferred erosion risk.Continued degradation of peat swamp forest in the Project Zone,especially in the form of drainage canal construction andconversion to oil palm, will have negative impacts on waterquality through increased sedimentation. This, however, is moreappropriately treated in HCV 4.1, where peat swamp forests havebeen identified as an HCV 4.1 ecosystem vital for watershedprotection and provision of clean water.Figure 17. Erosion Potential in the Project Zone73