 | The long-term impact of acacia mearnsii trees on evaporation, streamflow and groundwater resources |
| Expanded Title: | The Two Streams catchment experiments have been used over the last nine years to study the impact of trees on hydrological processes. Burger (1999), for example, estimated total evaporation using the Bowen ratio energy balance method and showed that annual total evaporation exceeded annual rainfall when measured over Acacia mearnsii at Two Streams during the exponential growth phase. This suggested that either the instruments used were providing incorrect results, or that tree roots were accessing groundwater and depleting soil water reserves from within the deep soil profile. Everson et al. (2008) showed the significant impact that riparian zone management can have on the hydrology of the catchment.
Currently the regulation of water use by forestry is based on estimates of plantation water use of over entire rotations at quaternary catchment scale (Gush et al., 2002), which are average values that are not site or age specific. In addition the model used did not account for soil water depletion at depths greater than 1.2 m. Gush et al. (2002) concluded that our understanding of the hydrological processes with regard to the water use of trees from deep soil profiles was inadequate. These experiments provided a good opportunity for studies to extend our understanding of some of the hydrological processes associated with afforestation such as low flows and deeper soil water dynamics. |
| Date Published: | 27/11/2011 |
| Document Type: | Research Report |
| Document Subjects: | Water Resource Management/IWRM - Catchment Management |
| Document Keywords: | Hydrology |
| Document Format: | Report |
| Document File Type: | pdf |
| Research Report Type: | Technical |
| WRC Report No: | TT 505/11 |
| ISBN No: | 978-1-4312-0020-3 |
| Authors: | Clulow AD; Everson CS; Gush MB |
| Project No: | K5/1682 |
| Originator: | WRC |
| Organizations: | School of Bioresources Engineering and Environmental Hydrology. Univesrity of KwaZulu-Natal; CSIR Natural Resources and the Environment. |
| Document Size: | 5 538 KB |
| Attachments: | EXECUTIVE SUMMARY for TT 505.pdf
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