The road to food security : evaluating and improving open-access road data in Tanzania with satellite imagery
(2018) In Student thesis series INES NGEM01 20181Dept of Physical Geography and Ecosystem Science
- Abstract (Swedish)
- Metoderna som används för att göra den globala livsmedelsförsörjningen tryggare har bytt fokus från själva produktionen av jordbruksgrödor till att öka människors tillgänglighet till marknader. Analyser visar att det finns ett samband mellan inkomst, avlägsenhet, och hur stor andel av god jordbruksmark faktiskt används för jordbruk.
För att beräkna tillgänglighet krävs fullständig, uppdaterad, och pålitlig vägdata; men sådan data saknas ofta i många länder. Trots detta kan öppen tillgång vägdatabaser, till exempel OpenStreetMap (OSM) och den Global Road Open Access Dataset (gROADS), används som alternativa datakällor eftersom de erbjuder en omfattande global täckning och kan laddas ner helt kostnadsfritt. Däremot har dess kvalité... (More) - Metoderna som används för att göra den globala livsmedelsförsörjningen tryggare har bytt fokus från själva produktionen av jordbruksgrödor till att öka människors tillgänglighet till marknader. Analyser visar att det finns ett samband mellan inkomst, avlägsenhet, och hur stor andel av god jordbruksmark faktiskt används för jordbruk.
För att beräkna tillgänglighet krävs fullständig, uppdaterad, och pålitlig vägdata; men sådan data saknas ofta i många länder. Trots detta kan öppen tillgång vägdatabaser, till exempel OpenStreetMap (OSM) och den Global Road Open Access Dataset (gROADS), används som alternativa datakällor eftersom de erbjuder en omfattande global täckning och kan laddas ner helt kostnadsfritt. Däremot har dess kvalité ifrågasatts eftersom vägdata samlas in i databaserna genom crowdsourcing, vilket påverkar rumslig noggrannhet och fullständighet på olika sätt i olika delar av världen beroende på vem som hade samlat in data och hur den hade samlats in.
Det här examensarbetet syftar till att utvärdera dessa befintliga öppen tillgång vägdatabaser samt försöka extrahera ett mer omfattande vägnät ur öppen tillgång Google Earth och Sentinel-2 satellitbilder där befintliga vägdatabaser har brister. Tanzania har valts ut som testområde därför att landet har en otrygg livsmedelsförsörjning trots att andelen jordbruksmark i landet räcker till att tillgodose befolkningens livsmedelsbehov. Resultaten visar att OSM-vägdatabasen har en god geografisk noggrannhet och fullständighet fastän några mindre vägar saknas, medan gROADS-vägdatabasen är olämplig för småskaliga analyser där hög geografisk noggrannhet krävs. De visar även att det är möjligt att extrahera ett vägnät som består av små grusvägar ur Google Earth:s satellitbilder med hög rumslig upplösning, dock metoden som har använts på de Sentinel-2 satellitbilderna misslyckades. (Less) - Abstract
- Contemporary approaches to improving food security amongst the world’s vulnerable populations have shifted from attempts to improve crop yield to improving accessibility to markets. Analyses show that there is a correlation between income, distance from cities, and the ratio of potential agricultural production to realised agricultural production.
Complete, up-to-date, and reliable road network data are essential to quantify accessibility. However, official road network data published by the relevant governing bodies is unavailable in many parts of the world. Thus, open-access datasets such as OpenStreetMap (OSM) and the Global Road Open Access Dataset (gROADS) have been used as alternatives due to their global coverage and... (More) - Contemporary approaches to improving food security amongst the world’s vulnerable populations have shifted from attempts to improve crop yield to improving accessibility to markets. Analyses show that there is a correlation between income, distance from cities, and the ratio of potential agricultural production to realised agricultural production.
Complete, up-to-date, and reliable road network data are essential to quantify accessibility. However, official road network data published by the relevant governing bodies is unavailable in many parts of the world. Thus, open-access datasets such as OpenStreetMap (OSM) and the Global Road Open Access Dataset (gROADS) have been used as alternatives due to their global coverage and easy-of-access. Nevertheless, the crowd-sourced nature of these datasets means that the spatial accuracy and extent of these datasets varies on both local and global scales.
This thesis project includes an evaluation of the existing open-access road network datasets and examines the possibility of extracting road network data from open-access Google Earth and Sentinel-2 satellite imagery where the existing data is lacking. Tanzania serves as the study area for this thesis project due to its comparability with other sub-Saharan African countries suffering from crop deficits and food insecurity despite good agricultural potential. The results show that the OSM data are in general quite accurate and provide a good coverage with some missing road segments, while the gROADS data are insufficient for analyses at local scales or those which require high spatial accuracy. The results also show that road networks featuring narrow unpaved roads can be successfully extracted from high resolution Google Earth imagery, though further refinements are necessary to reduce noise. The method applied to the Sentinel-2 imagery proved unsuccessful in this particular study. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8955024
- author
- Ragosnig, Corey Nicholas LU
- supervisor
-
- Ola Hall LU
- organization
- alternative title
- På väg mot en trygg livsmedelsförsörjning : en utvärdering och förbättring av öppen tillgång vägdatabaser i Tanzania med satellitbilder
- course
- NGEM01 20181
- year
- 2018
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Physical Geography and Ecosystem Analysis, Human Geography, Remote Sensing, Road Extraction, Food Security, Open-Access Data
- publication/series
- Student thesis series INES
- report number
- 460
- language
- English
- id
- 8955024
- date added to LUP
- 2018-07-16 11:40:12
- date last changed
- 2018-07-16 11:40:12
@misc{8955024,
abstract = {{Contemporary approaches to improving food security amongst the world’s vulnerable populations have shifted from attempts to improve crop yield to improving accessibility to markets. Analyses show that there is a correlation between income, distance from cities, and the ratio of potential agricultural production to realised agricultural production.
Complete, up-to-date, and reliable road network data are essential to quantify accessibility. However, official road network data published by the relevant governing bodies is unavailable in many parts of the world. Thus, open-access datasets such as OpenStreetMap (OSM) and the Global Road Open Access Dataset (gROADS) have been used as alternatives due to their global coverage and easy-of-access. Nevertheless, the crowd-sourced nature of these datasets means that the spatial accuracy and extent of these datasets varies on both local and global scales.
This thesis project includes an evaluation of the existing open-access road network datasets and examines the possibility of extracting road network data from open-access Google Earth and Sentinel-2 satellite imagery where the existing data is lacking. Tanzania serves as the study area for this thesis project due to its comparability with other sub-Saharan African countries suffering from crop deficits and food insecurity despite good agricultural potential. The results show that the OSM data are in general quite accurate and provide a good coverage with some missing road segments, while the gROADS data are insufficient for analyses at local scales or those which require high spatial accuracy. The results also show that road networks featuring narrow unpaved roads can be successfully extracted from high resolution Google Earth imagery, though further refinements are necessary to reduce noise. The method applied to the Sentinel-2 imagery proved unsuccessful in this particular study.}},
author = {{Ragosnig, Corey Nicholas}},
language = {{eng}},
note = {{Student Paper}},
series = {{Student thesis series INES}},
title = {{The road to food security : evaluating and improving open-access road data in Tanzania with satellite imagery}},
year = {{2018}},
}