Analysing river flow using actual data and hydrological models
Environmental hydrology investigations develop an understanding of the water flows within a study area to facilitate environmental planning and management, and integrate sustainable development planning.
GroundTruth is able to perform detailed to broad scale hydrological simulations which focus around changes and impacts to environmental flows in river systems. Through the use of various models GroundTruth is able to both simulate changes to the water balance and investigate the potential impacts on river ecological processes and water quality.
Physical conceptual models utilised by GroundTruth provide detailed representation of the hydrological cycle including surface runoff, subsurface flows, evapotranspiration, streamflow, etc. With GIS spatial mapping as input, the approach allows detailed simulation and investigation of the impacts of land use change on the volume and timing of river flows. Natural condition, pre-development and post-development scenarios taking account of changes in parameters such as impervious areas, type and extent of vegetation, water extractions and stormflow system or effluent discharges allows investigation of the changes to the volumes and timing of flows.
Hydrological modelling also allows the simulation of flow records for un-gauged rivers, providing data which can feed the investigation of flow requirements, ecological reserve determinations and the dilution of effluent discharges and water pollutants.
Streamflow is a primary hydrological constraint that drives river ecological processes. River ecosystems therefore depend on natural hydrological flow regimes in order to function properly and this largely depends on natural flow variability including extreme conditions such as floods and droughts. The Indicators of Hydrological Alteration (IHA) model developed by Richter et al. (1996) is a particularly useful model for defining a river's natural hydrological signature using a number of hydrological parameters and is capable of determining ecohydrological impacts caused by alterations of flow regimes. GroundTruth has adopted the IHA model to provide an ecological perspective of anthropogenic impacts on river systems.
Catchment Management Plans
A catchment management plan may be a requirement for environmental authorisation of certain projects or may be a mandated requirement of certain public agencies. A catchment management plan takes account of impacts on water resources within the catchment, and details priorities and plans to best manage and mitigate these impacts to achieve certain water quality or quantity goals, while improving aquatic habitat condition and resilience. Catchment management plans may incorporate habitat rehabilitation, infrastructure development, systems innovation and education to improve catchment management and condition. GroundTruth strives to develop innovative, cost-effective and sustainable solutions to catchment management challenges in Africa.
River rehabilitation involves a process of restoring various components of a river reach including hydrology, hydraulics, geomorphology and chemistry as well as biotic composition (e.g. riparian and instream flora and fauna). Rehabilitation is essential in situations where rivers become degraded as a result of activities causing physical disturbance to river form and functionality.