Keywords
wetlands, catchments, remote sensing, swat
Start Date
1-7-2008 12:00 AM
Abstract
Many wetlands are dependent on river basin processes, and at the same time, scientists have recognised the important role of wetlands in the river basin: they are important zones for groundwater recharge, they temper high flows and are therefore very important to limit flooding. By purifying the water, wetlands also play a very important role for water quality. However, the underlying processes are often not very well known or are poorly quantified. This is especially true for many wetland rich basins in Africa that are poorly gauged or even ungauged. In this study we analyse to what extend remote sensing data can be of use to analyse and model ungauged or poorly gauged wetland rich river basins, taking the Kagera river basin as a case study by using existing maps with information on the basis of soil water of the toplayer, evapotranspiration maps, DEM and land use maps and satellite born rainfall estimates. A river basin model is built using the “Soil and Water Assessment Tool”. The freely available GIS maps for DEM, Soil Maps and land use maps are very useful for setting up catchment models but they are not very helpful for wetland characterisation. The satellite rainfall data are still not well replacing ground data to model the rainfall-runoff processes. The generated maps for daily soil water values are promising to derive information on the dynamics of remote riverine wetlands. With this information, a better integration of wetland and catchment models should be obtained.
Understanding riverine wetland-catchment processes using remote sensing data and modelling
Many wetlands are dependent on river basin processes, and at the same time, scientists have recognised the important role of wetlands in the river basin: they are important zones for groundwater recharge, they temper high flows and are therefore very important to limit flooding. By purifying the water, wetlands also play a very important role for water quality. However, the underlying processes are often not very well known or are poorly quantified. This is especially true for many wetland rich basins in Africa that are poorly gauged or even ungauged. In this study we analyse to what extend remote sensing data can be of use to analyse and model ungauged or poorly gauged wetland rich river basins, taking the Kagera river basin as a case study by using existing maps with information on the basis of soil water of the toplayer, evapotranspiration maps, DEM and land use maps and satellite born rainfall estimates. A river basin model is built using the “Soil and Water Assessment Tool”. The freely available GIS maps for DEM, Soil Maps and land use maps are very useful for setting up catchment models but they are not very helpful for wetland characterisation. The satellite rainfall data are still not well replacing ground data to model the rainfall-runoff processes. The generated maps for daily soil water values are promising to derive information on the dynamics of remote riverine wetlands. With this information, a better integration of wetland and catchment models should be obtained.
