Evaluation of Different Digital Elevation Models (DEMs) for Geospatial Applications: A Case Study of Ibadan, Nigeria

Context and background In Ethiopia, farmers do not have individual property rights to the land they occupy and cultivate since the 1995 Federal Democratic Republic of Ethiopia (FDRE) constitution clearly states that land belongs to the state and the peoples of Ethiopia. To address concerns about the insecure tenure of farmers that could result from the absence of enduring private ownership of land, to eliminate land disputes, to promote sustainable use of land resources, and to support long-term land-related investments, such as soil conservation measures, the Ethiopian government introduced a land registration and certification program in 1998. In addition, cities and towns are also rapidly expanding horizontally, encroaching on fertile agricultural land, which could reverse the land tenure security expected from the land certification program. Goal and Objectives: This study aims to examine the effect of Ethiopia's land certification program on the soil conservation practices of rural and peri-urban farming households in the Tigray region of Ethiopia. Methodology: The study employs descriptive statistics and a binary logistic regression model to empirically assess the effect of the Ethiopian land certification program on investment in soil conservation practices. Results: Context and background Digital elevation models (DEMs) are essential tools for a wide range of scientific and geospatial applications, providing critical data for elevation and terrain analysis. While remote sensing DEMs have gained popularity due to their extensive spatial coverage and detailed spectral characteristics, assessing their accuracy is crucial for ensuring the reliability of the information they provide. Goal and Objectives: This study aims to evaluate the accuracy and performance of various Digital Elevation Models (DEMs) for geospatial applications in Ibadan, Nigeria. The specific objectives are to assess the DEMs' accuracy using GPS point survey data and to identify the most suitable DEM for reliable topographic representation in the study area. Methodology: Seven DEMs were evaluated: Shuttle Radar Topography Mission with 30 m and 90 m resolution (SRTM30 and SRTM90), NASADEM with 30 m resolution, Copernicus DEM with 30 m and 90 m resolution (COP30 and COP90), Advanced Land Observing Satellite World 3D with 30 m resolution (AW3D30), and ALOS PALSAR with 12.5 m resolution. The DEMs' accuracy was assessed using mean error (ME), mean absolute error (MAE), standard deviation