Using GIS and Remote Sensing for Assessing Riparian Ecosystems along the Naryn River, Kyrgyzstan.

Abstract

In the extremely continental and semi-arid climate of Kyrgyzstan, the rivers and their floodplains have an enormous importance as a regional hotspot of biodiversity and for the provision of ecosystem services to local people. For a comprehensive assessment of riparian ecosystem services objective and conscientious information about the structure and processes of the natural environment is required. The integration of remote sensing and GIS analysis can provide such information in an efficient way. In this paper, we present a workflow for the derivation of the extent and spatial distribution of floodplain ecosystems along the main streams within the Naryn catchment. Riparian ecosystems are characterized by natural to semi-natural vegetation which is connected to rivers via potential flooding, erosion or deposition of sediment or the recharge of groundwater from the river discharge. To capture this conceptual idea, we combine terrain analysis for deriving areas structurally connected to the river channels with multispectral remote sensing for distinguishing vegetated from non-vegetated areas. Applying this approach to the catchment of the Naryn River, 2369.84 km² of areas connected to the main streams could be identified. From this area, 65.74 % are vegetated, 18.18 % covered with water and 16.08 % are characterized by bare soil. While we could demonstrate the general ability of this approach for delineating riparian ecosystems, further field calibration will be required for testing and enhancing the reliability of the results.