EIA and heritage impact assessment diverge along the Great Wall. Fieldwork at five sites yields a dual-track interface, a judicial EIA-HIA bridge and a checklist for linear World Heritage.
Impact assessment (IA) of linear composite heritage runs on separate tracks: Environmental Impact Assessment (EIA) and Heritage/Cultural Impact Assessment (HIA/HCIA). Along corridors crossing administrative and ecological boundaries, baselines diverge, values misalign and approval interfaces are absent. The Great Wall, notably its Beijing-Tianjin-Hebei section, is a critical case. Fieldwork at Laolongtou, Banchangyu, Panjiakou, Huangyaguan and Jiankou-Mutianyu shows how bifurcated IA fails under contrasting natural media and intervention intensities, and what legal interfaces can restore synergy.
The sites form two gradients. The natural-media gradient (salt erosion, root bioerosion, inundation, freeze-thaw, scenic pressure) exposes incompatible indicators, thresholds and sequencing. The intervention gradient is anchored at Jiankou: roots fracture masonry on steep terrain; trampling paths cause impact without IA baseline, enforcement vacant; minimum-intervention conservation collides with loose-masonry safety hazards. Mutianyu's paving compresses authenticity. IA thus emerges as a governance device.
The study proposes a Dual-Track IA Interface: EIA at corridor scale with ecological integrity as baseline, HIA at node scale with Outstanding Universal Value and authenticity, linked by an Impact Overlap Matrix. The Shanhaiguan Great Wall Cultural Protection People's Tribunal, hearing ecological and relic cases, is analysed as a judicial EIA-HIA interface. Qinhuangdao and Jiankou practices yield a transferable Culture-Nature Synergized IA Checklist for other linear heritage.
Cao Huijie, Director and Managing Partner of Grandall Law Firm (Tianjin), has nearly 20 years' experience advising central SOEs on legal counsel, M&A, corporate governance and compliance.