Identifying Key Watershed Characteristics That Affect the Biological Integrity of Streams in the Han River Watershed, Korea

Abstract

Understanding the complex human and natural processes that occur in watersheds and stream ecosystems is critical for decision makers and planners to ensure healthy stream ecosystems. This study aims to characterize the Han River watershed in Korea and extract key relationships among watershed attributes and biological indicators of streams using principal component analysis (PCA) and self-organizing maps (SOM). This study integrated watershed attributes and biological indicators of streams to delineate the watershed and stream biological status. Results from PCA strongly suggested that the proportions of watershed and riparian land use are key factors that explain the total variance in the datasets. Forest land in the watershed appeared to be the most significant factor. Furthermore, SOM planes showed that the biological indicators of streams have strong positive relationships with forest land, well-drained soil, and slope, whereas they have inverse relationships with urban areas, agricultural areas, and poorly drained soil. Hierarchical clustering classified the watersheds into three clusters, exclusively located in the study areas depending on the degree of forest, urban, and agricultural areas. The findings of this study suggest that different management strategies should be established depending on the characteristics of a cluster to improve the biological condition of streams.

Quantitative Morphology of Polder Landscape Based on SOM Identification Model: Case Study of Typical Polders in the South of Yangtze River

“…When it comes to comprehensive evaluation, SOM is frequently used to analyze multifactor datasets and solve complex classification problems, such as a comprehensive analysis of tourist motivation and behavior in protected areas [ 38 ]. SOM can also be used to investigate relationships between research elements, such as correlations between river ecological indicators [ 39 ], pattern associations between different environmental conditions and physiological responses [ 40 ], and links between residents' lifestyles and their choice of residence within the city [ 41 ]. Using SOM to create a parametric building model can optimize the architectural design scheme [ 42 ].…”

Assessment of Spatiotemporal Variations in the Water Quality of the Han River Basin, South Korea, Using Multivariate Statistical and APCS-MLR Modeling Techniques

“…The HRB (126 • 24 -129 • 02 E, 36 • 30 -38 • 55 N) is the largest basin in Korea with an area of 26.219 km 2 , accounting for approximately 27% of the entire country area [31,37]. The Han River is approximately 494 km long, and consists of 920 rivers and streams, including 19 national rivers and streams and 901 local rivers and streams [38]. The average annual precipitation in the HRB is approximately 1300 mm, and the basin witnesses a monsoon climate, with approximately 70% of the precipitation concentrated in summer (July-September) [31].…”

“…Regarding the water use status in the HRB, domestic purposes represent the largest proportion (46.6%), followed by agricultural purposes (38.5%), and industrial purposes (14.9%) [42]. The land use status in the HRB comprises forests (68.9%), farmlands (14.9%), cities (8.3%), and other areas (7.9%) [38]. In this study, Yeongwol 2 (S-1), Chungju Dam (S-2), Dal Stream 4 (S-3), Seom River 4-1 (S-4), Gang Stream (S-5), Gangsang (S-6), Soyang River (S-7), Uiam Dam (S-8), Sambong-ri (S-9), Kyeongan Stream (S-10), Paldang Dam (S-11), Noryangjin (S-12), Gayang (S-13), and Imjin River (S-14) were selected as main water quality monitoring sites in the Han River water quality monitoring network operated by the Ministry of Environment (MOE) (Figure 1).…”

Correlation Analysis between Hydrologic Flow Metrics and Benthic Macroinvertebrates Index (BMI) in the Han River Basin, South Korea

“…They suggested that the aquatic ecosystem be investigated using data such as flow rate and river depth. Park et al [19] characterized the Han River watershed in Korea and extracted key relationships among the watershed attributes and biological indicators of the streams. They used biological indicators of the streams to determine the biological status of the watershed and stream.…”

“…They used biological indicators of the streams to determine the biological status of the watershed and stream. Park et al [19] analyzed the correlation between river morphological factors and water quality factors. Woo et al [20] conducted a study on whether the flow affects water quality and aquatic health by simulating the flow using SWAT.…”