Analytic hierarchy process based spatial biodiversity impact assessment model of highway broadening in Sikkim Himalaya

Abstract

Spatial impacts of highway projects on biodiversity of North-Eastern Himalaya remains largely unexplored. Usually a number of ecological criteria are required in biodiversity impact assessment. However, a wide set of such criteria can be overwhelming for the decision-makers to assess the viability of such projects. SBIAM uses landscape metrics and experts’ opinion to create a single composite biodiversity value map. The weighted area loss under various project alternatives estimated from Biodiversity Value Map is compared to identify the most viable alternative. SBIAM uses AHP and curve fitting method in the biodiversity estimation. The study indicates that the highway broadening project in the study area will cause a moderate biodiversity loss. Sensitivity analysis of SBIAM indicates its robustness, and shows that forest patches near the highway are most sensitive to disturbances and patch proximity. SBIAM can be applied in varied spatial scales, terrains and development projects as a decision support tool.

Abbreviations
AHP	=	Analytic Hierarchy Process
BIA	=	Biodiversity Impact Assessment
ICCR	=	Impact Category Change Rate
LM(s)	=	Landscape Metric(s)
MACR	=	Mean Absolute Change Rate
PSI	=	Patch Shape Index
SBIAM	=	Spatial Biodiversity Impact Assessment Model
SESA	=	Spatially Explicit Sensitivity Analysis

Keywords:

• Biodiversity impact assessment
• highway
• mountain
• sensitivity analysis
• spatial analysis

Acknowledgement

We would like to acknowledge the expertise and logistics extended by Sourya Das, Assistant Professor, Mumbai campus, Jamsetji Tata School of Disaster Studies; Sunita Pradhan, Fellow, ATREE, Gangtok Unit; Priyadarshinee Shrestha, Coordinator, WWF, Gangtok Unit; Santanu Gupta, Faculty, SMIT, Majitar; Usha Lachungpa, Retd. Senior Research Officer; C.S. Rao, Chief Conservator of Forest (Territorial); and Hemlata Rai, GIS Engineer, of the DEFWM, Govt. of Sikkim.

Disclosure statement

No potential conflict of interest was reported by the authors.