From Fragmented to Polycentric: Social Network Analysis of Transboundary Water Governance Regime Shifts.

Transboundary water governance transitions from centralized to polycentric arrangements present complex institutional challenges requiring systematic analysis. This study applies social network analysis integrated with Pahl-Wostl's governance regime typology to examine cooperation and conflict evolution across Iran's major transboundary river basins, comparing pre-1979 centralized governance with post-1979 institutional arrangements. Results reveal observable structural changes between the two periods. Pre-1979 "Whole Area" cooperation networks showed low density (14.5%) and moderate centralization (26.6%), indicating fragmented structures. Conflict networks were similarly sparse (density 11.7%) and moderately centralized (30.2%), reflecting limited interconnectedness. Post‑1979 analysis demonstrates more interconnected governance; cooperation density rose to 20.9% and centralization increased slightly to 36.5%, with transitivity as supplementary trust indicator rising to 27.9%. Basin-specific changes highlight transitions toward polycentricity. In the Harirud, cooperation density jumped from 13.3% to 53.3% and transitivity from 16.7% to 39.7%, signaling stronger collaborative structures. Conflict density also rose sharply (16.7% to 83.3%), with transitivity increasing from 0% to 50%, though centralization remained stable at 22.2%. The framework demonstrates transferability to other transboundary contexts by systematically identifying governance regime shifts, stakeholder network evolution, and institutional change mechanisms. Findings underscore the importance of network dynamics for enhancing adaptive capacity and conflict resolution in transboundary water management.