Jurnal Pengelolaan Sumberdaya Alam dan Lingkungan (Journal of Natural Resources and Environmental Management)
Vol 16 No 5 (2026): Jurnal Pengelolaan Sumberdaya Alam dan Lingkungan (JPSL)

Comparative Delineation Methods and Ecological Quality Assessment of Riparian Zones in the Downstream Ayung River, Bali

I Kade Alfian Kusuma Wirayuda (Department of Aquatic Resources Management, Faculty of Marine Science and Fisheries, Udayana University)
I Putu Gede Eka Handrayana Putra (Department of Aquatic Resources Management, Faculty of Marine Science and Fisheries, Udayana University)
Pratama Made Dendy (Department of Aquaculture, Faculty of Marine Science and Fisheries, Udayana University)
Moh Saifulloh (Department of Marine Sciences, Faculty of Marine Science and Fisheries, Udayana University)



Article Info

Publish Date
22 Sep 2026

Abstract

Riparian zones are transitional areas between aquatic and terrestrial ecosystems. They play a very important ecological role in both ecosystems. The accuracy of ecological assessments of riparian zones fundamentally depends on how riparian boundaries are delineated. Current policies rely on strict, fixed buffer zones, which lead to generalization. This study evaluates how boundary sensitivity affects the Riparian Strip Quality Index (RSQI). This study compares three delineation methods (Upland Terrace, Fixed-width buffer, and slope-based) in the downstream Ayung River, Bali. Statistical analysis indicated that the delineation method affected the ecological assessment outcomes (η² = 0.49). The fixed-width buffer delineation method tends to underestimate riparian quality by including non-contributing built-up areas (27.23%). In contrast, the Upland Terrace method shows more ecologically representative results and has no significant score difference with slope-based delineation (Wilcoxon Z = -0.75). RSQI evaluations showed significant spatial variability. It also indicated local degradation in urbanized segments (RSQI dropping to 50.09–59.77 in Segments 1 and5), and pristine environmental quality where segments are dominated by natural vegetation (RSQI = 94.41 in Segment 9). These findings show the disadvantages of current regulations that use a generalized delineation method. To improve urban river management, policymakers need to consider a transition to geomorphology-based boundary delineations and carry out targetedrestoration in degraded areas.

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Journal Info

Abbrev

jpsl

Publisher

Subject

Agriculture, Biological Sciences & Forestry Earth & Planetary Sciences Environmental Science

Description

JPSL publishes articles in fields: Environmental Policy and Management, Disaster Mitigation, Regional Planning, Land Resources Evaluation, Hidrology, Systems Modelling and Sciences, Water Pollution, Air Pollution, Environmental Technology, Ecotourism, Biodiversity, Environmental Economics, Public ...