Development of Habitat-riparian Quality Indexing System as a Tool of Stream Health Assessment: Case Study in the Nakdong River Basin

Abstract

The major focus of this study is to evaluate a newly developed stream naturalness index system ‘Habitat-riparian Indexing System (HIS).’ There have been many studies that have assessed stream naturalness in order to provide information required for restoration. The results of these studies were enough for the purpose of the studies;however, the methodologies were limited especially with respect to rapid measurement and the representation of ecological habitats. Therefore, we derived crucial variables from a popularly utilized method and merged them with other criteria obtained from overseas approaches, resulting in the development of the HIS method. The stability of HIS was evaluated by comparing the results with the Stream Naturalness Index (SNI) of Cho (1997). We monitored 100 stream sites in the Nakdong River system using the two different methods for two sampling periods (spring and autumn), and the results were compared using statistical analyses. The determination coefficients between the index values from two methods were c.a. 0.6 for both seasons, and statistics revealed that HIS had a relatively higher stability, providing index values for stream environments. The results of this work suggest a possibility of the utility of HIS for other stream habitats.