Environmentally conscious least cost multi-criteria decision making for modeling railway network for Eritrea

Authors: MENGESTE, MICHAEL - Chicago State University; GALA, TEKLEAB - Chicago State University; Birru, Girma

Submitted to: International Journal of Sustainable Development and Planning
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2021
Publication Date: 6/22/2021
Citation: Mengeste, M., Gala, T., Birru, G.A. 2021. Environmentally conscious least cost multi-criteria decision making for modeling railway network for Eritrea. International Journal of Sustainable Development and Planning. 16(3):427-436. https://doi.org/10.18280/ijsdp.160303.
DOI: https://doi.org/10.18280/ijsdp.160303

Interpretive Summary: This study has found topographic characteristics, LULC data, and source and destination nodes as physical, environmental, and social input parameters necessary for modeling the least-cost railway network. Accordingly, 5 major land major LULC classes were found, where the majority of which is Agricultural lands (i.e., 46%) followed by Steppe (i.e., 43%). The remaining LULC types expand only on 11% of the study area, indicating their lesser influences in the modeling. Additionally, topographically, the study area mainly consists of level to gently rolling landscape (i.e., 64%) and only 20% is hilly or very hilly topography to pose difficult terrain for routing for railway lines. The least-cost multi-criteria decision support applied for designing and planning a railway network modeled seven major routes. The four routes run North-to-South (i.e., Metera, Highland, Gash Barka, and Western lines), while three run East-to-West (i.e., Senhit, Central, and Belt lines). In general, the modeled railway network system covers the overall distance of 1, 610 km, which the capacity of serving five of the six administrative regions of constituting 93% of the nearly 5.8 million Eritrean population. It also connects 24 major urban centers and settlement areas with an estimated 1,658,749 population; approximately 70% of the 2,370,492 Eritrea’s urbanites. These findings are significant to revitalize Eritrea’s railway transportation service decimated over a century ago. It would provide alternative or additional transportation services (i.e., passengers and freights) to Eritrea’s current road, air, and sea transportations; thereby reducing environmental pollution, traffic congestion, and travel time. It also creates opportunities for the agriculture sector generating new internal economic ventures and international trading prospects. The international connection to neighboring countries would identify a tremendous market opportunity that could be involving approximately 160 million people in the horn of Africa. The railway's service is also significant in boosting Eritrean and the broader East African tourism industry, by leveraging the beauty of the landscapes, the region’s socio-cultural and historical richness, and diversity, and the hospitality of the indigenous communities. Finally, it is a gateway to the Ethiopia tourism attractions (i.e., Semien Mountains, Axum 4th century A.D. kingdoms and villages, Gonder city and its medieval era civilizations (cathedrals, castles, palaces), and other rare and distinctive UNESCO World Heritage sites. Although significant, the research has the following limitations. Firstly, even though the model used the concept of multi-criteria railway route planning network routing, it only accounted, settlement, elevation, and land cover land use data. Much better modeling outcome can be achieved if more criteria such as but not limited to, logistical, economic, and cultural are also considered in future research. These criteria are not currently available for Eritrea. Secondly, the modeling was conducted by simply connecting every major city in the study area, into source-destination nodes' shortest path line segment. Better alternative routing could be modeled through systematic iterative additions or eliminations by computing the shortest path between all pair of nodes, thereby in effect, fewer nodes of relatively shortened segments are developed. Thirdly, routing algorithms are changing in recent years. Advances in these algorithms have brought about methods performing the modeling faster and efficiently than Dijkstra’s algorithm used in the Least Cost Paths modeling adopted in this study. Availability of the various routing algorithms and the advances in the field is the indication that there hasn’t been a single best routing algorithm hitherto. Future research exploring and exploiting alternative and advance

Technical Abstract: Sustainable socio-economic and environmental benefits can be obtained through a proper development of railway transportation. Nonetheless, in Eritrea, a country that once had a vibrant railway system, currently it is nonfunctional. There are also ambitious sectoral investments in neighboring Ethiopia and Sudan, pressing Eritrea to revitalize its decimated railway transportation system. Therefore, this study used population settlement pattern, environmental and physical criteria as inputs to a least cost multi-criteria decision-making algorithm, for modeling the railway network for Eritrea. Accordingly, seven railway routes, 4 routes running in the north-to-south direction, and 3 routes running in the east-to-west direction, covering a total of 1, 610 km distance were modeled. This railway network will give services to 5 out of 6 Eritrean’s administrative regions, where 93% of the estimated 5.8 million people reside. Additionally, it will service the 21 urban centers, where an estimated population of 1,658,749 live; approximately 70% of Eritrea’s urban population; while also boosting regional integration, peace, and development thereof, in an otherwise conflict-ravaged geographical region. Thus, the least-cost multi-criteria decision support was found to be effective in designing the railway network with minimal impact on the environment.