Browsing by Author "Sumari, Neema S."
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Item Fuzzy AutoEncode Based Cloud Detection for Remote Sensing Imagery(2017-03-26) Shao, Zhenfeng; Deng, Juan; Wang, Lei; Fan, Yewen; Sumari, Neema S.; Cheng, QiminCloud detection of remote sensing imagery is quite challenging due to the influence of complicated underlying surfaces and the variety of cloud types. Currently, most of the methods mainly rely on prior knowledge to extract features artificially for cloud detection. However, these features may not be able to accurately represent the cloud characteristics under complex environment. In this paper, we adopt an innovative model named Fuzzy Autoencode Model (FAEM) to integrate the feature learning ability of stacked autoencode networks and the detection ability of fuzzy function for highly accurate cloud detection on remote sensing imagery. Our proposed method begins by selecting and fusing spectral, texture, and structure information. Thereafter, the proposed technique established a FAEM to learn the deep discriminative features from a great deal of selected information. Finally, the learned features are mapped to the corresponding cloud density map with a fuzzy function. To demonstrate the effectiveness of the proposed method, 172 Landsat ETM+ images and 25 GF-1 images with different spatial resolutions are used in this paper. For the convenience of accuracy assessment, ground truth data are manually outlined. Results show that the average RER (ratio of right rate and error rate) on Landsat images is greater than 29, while the average RER of Support Vector Machine (SVM) is 21.8 and Random Forest (RF) is 23. The results on GF-1 images exhibit similar performance as Landsat images with the average RER of 25.9, which is much higher than the results of SVM and RF. Compared to traditional methods, our technique has attained higher average cloud detection accuracy for either different spatial resolutions or various land surfaces.Item A Geospatial Approach to Sustainable Urban Planning: Lessons for Morogoro Municipal Council, Tanzania(Sustainability, 2019-11-19) Sumari, Neema S.; Xu, Gang; Ujoh, Fanan; Korah, Prosper I.; Ebohon, Obas J.; Lyimo, Neema NSustainable urban planning is essential in mediating the natural and built environments globally, yet, there is little progress as regards its attainment in developing countries. Rapid and unplanned urbanization continue to threaten the sustainability of many cities in Africa. By selecting Morogoro Municipal Council (MMC) in Tanzania as an example, this study applied well-known remote sensing techniques to understand the dynamics of urban growth and the implications for sustainable urban planning. The study analyzes spatio-temporal characteristics for eighteen years (2000–2018) based on urban land density using gradient and grid-based analysis to further examine land use and urban land density nexus. The results indicate declining urban land densities with distance to the city center, indicating a less compact and fragmented development at the urban fringes; and northward development with limited development to the south of MCC. The knowledge and understanding of the patterns of spatio-temporal conditions, land use planning, and management interventions in MMC are necessary for addressing the inadequacies associated with rapid urbanization within the study area. On this basis, we propose a shift from the modernist to the communicative planning strategy that strongly integrates the urban social, economic, and environmental imperatives, while being adaptable to evolving realities. This plan should also aim to curtail urban sprawl and create a viable city system and economically prosperous city structure for MMC.Item Geospatial Distribution and Accessibility of Primary and Secondary Schools: A case of Abbottabad City, Pakistan(Proceedings of the International Cartographic Association, 2019-07-27) Sumari, Neema S.; Tanveer, Hashir; Shao, Zhenfeng; Kira, Ernest SimonQuality education in isolated areas is a major issue in developing countries like Pakistan, as access to formal education is linked to improved life prospects for rural students. Among the factors for education, accessibility is school availability within a minimum spatial distance. The spatial distribution of schools is generally uneven in most of the cities of Northern Pakistan, thus limiting access to formal education at the primary and secondary level. This paper analyzes the spatial distribution of the primary and secondary schools found in the hilly terrain of Abbottabad city. Results show an uneven scattered pattern of schools and decreasing accessibility with longer travel times, at higher costs. Cost-weighted distance showed that this spatial distribution extends the travel distance by more than 5km for secondary school students living in the city. However, spatial restructuring and reorganization of schools in the study area would enhance student access to school facilities.Item On the absurdity of rapid urbanization: Spatio-temporal analysis of land-use changes in Morogoro, Tanzania(Cities, 2020-07-07) Sumari, Neema S.; Cobbinah, Patrick Brandful; Ujoh, Fanan; Xu, GangThis study questions the frequent overemphasis on population growth aspects of African urbanization with little consideration of the spatial extent by analyzing the influence of population growth on the spatial expansion of the Morogoro urban municipality (MUM) in Tanzania between 2000 and 2016. Shannon's Entropy, a random forest supervised classifier, and spatial analysis were adopted to analyze Multi-temporal Landsat images obtained through the Google Earth Engine platform to quantify the spatial and temporal distribution and pattern of land-use change. Findings from this research show that Shannon's entropy values for MUM increased from 0.522 in 2000, to 0.761 in 2007, and to 0.901 in 2016 with the urban land cover recording a considerable and consistent increase. Similarly, the municipality's annual rate of change in population decreased from 4.17% in 1967 to 3.81% in 2016, and is estimated to rise to 4.54% by 2030 with a corresponding population of 25,262 in 1967 and 622,000 in 2016. From the results, the rate of population growth is not commensurate with the rate of spatial expansion, as the spatial extent is more than twice the population growth. An important contribution from this research relates to the limited attention to the faster rate of urban expansion compared to population growth in African cities; a situation that is inconsistent with sustainable and resilient urban futures. It is recommended that municipal authorities should consider initiatives (e.g., environmental planning models) to reverse the current trend of urban growth in order to improve the health, density, sustainability and resilience of the urban environment.Item Pattern analysis of substandard and inadequate distribution of educational resources in urban–rural areas of Abbottabad, Pakistan(GeoJournal, 2019-06-04) Tanveer, Hashir; Balz, Timo; Sumari, Neema S.; Shan, Rafi-usDespite an extensive system of public schools, Abbottabad, Pakistan has a chronically low literacy rate. A factor contributing to these low literacy rates might be a spatial mismatch between public schools and dense settlements in fast-growing urban and semi-urban areas of this municipal region. To test this proposition, the locations of 153 public schools were collected using hand-held GPS devices to create a geo-database, and a road network was created from the open street map and Google imagery. Nearest neighbor, K-function, Spearman’s Rho, and directional analyses were applied to this data to overcome the limitations of sparse geospatial data. A point pattern analysis shows that more than 50% of secondary schools were clustered south of the city while most of the built-up area was in the north. Localizing Geospatial data, spatial restructuring, and reorganization of schools in the study area would support rational planning and enhance student access to school facilities.Item Status of geoinformatics education and training in Sub-Saharan Africa: initiatives taken and challenges(2019-03-11) Sumari, Neema S.; Shao, Zhenfeng; Van Genderen, John L.; Musakwa, Walter; Ujoh, Fanan; Washaya, Prosper; Gumbo, TrynosThis paper presents an update on some of the activities that have taken place since aWorld Bank report; “Guidelines for Education and Training in Environmental Information Systems in Sub-Saharan Africa: Some Key Issues” was published and provides details on the current situation. It shows how organizations such as the African Association on Remote Sensing of Environment, International Society of Photogrammetry and Remote Sensing, European Association of Remote Sensing Companies, Group on Earth Observation, and several others have helped to increase manpower resources in the region and strengthened institutional capacity in the field of geoinformatics, through capacity building, technology transfer, international cooperation and the provision of internal African resources. After reviewing what has happened in the field of geoinformatics education and training, we focused on current initiatives taken and challenges in five Sub-Saharan countries: Ethiopia, Nigeria, South Africa, Tanzania, and Zimbabwe. We reviewed GIS education and training in the private sector, government, information communications technology in higher education institutions, GIS application areas and challenges facing GIS education and training. Findings show that; change should involve education stakeholders in all levels of education and curriculum quality, regional and international cooperation through exchange programs, should be a priority for Sub-Saharan Africa countries.Item Urban expansion and form changes across African cities with a global outlook: Spatiotemporal analysis of urban land densities(Journal of Cleaner Production, 2019-03-27) Xu, Gang; Dong, Ting; Cobbinah, Patrick Brandful; Jiao, Limin; Sumari, Neema S.; Chai, Baohui; Liu, YaolinAfrica has been experiencing rapid urbanization, yet limited studies have systematically investigated urban growth dynamics across African cities. Using 25 cities as cases, we quantified urban growth and form changes in Africa via spatiotemporal analysis of urban land densities in concentric rings over three time points (1990, 2000, and 2014). The results show that African cities have rapidly grown both in population and built-up areas, which increased by about 4% and more than 5% per annum, respectively. Urban land density (defined as the proportion of the built-up area to the buildable area) in each concentric ring decreases from the city center to the urban periphery with diverse patterns among cities. Comparatively, small cities have a lower urban land density and a more dispersed urban form than medium-sized and large cities in Africa. The international comparisons between cities with over one million population in Africa, Asia (e.g., China and India), Europe, and North America (i.e., the United States) reveal that African cities have a relatively less compact urban form. Implications of these findings for the future of African cities are further proffered.Item Urban sprawl and its impact on sustainable urban development: a combination of remote sensing and social media data(Geo-spatial Information Science, 2020-07-28) Shao, Zhenfeng; Sumari, Neema S.; Portnov, Aleksei; Ujoh, Fanan; Musakwa, Walter; Mandela, Paulo J.Urbanization is one of the most impactful human activities across the world today affecting the quality of urban life and its sustainable development. Urbanization in Africa is occurring at an unprecedented rate and it threatens the attainment of Sustainable Development Goals (SDGs). Urban sprawl has resulted in unsustainable urban development patterns from social, environmental, and economic perspectives. This study is among the first examples of research in Africa to combine remote sensing data with social media data to determine urban sprawl from 2011 to 2017 in Morogoro urban municipality, Tanzania. Random Forest (RF) method was applied to accomplish imagery classification and location-based social media (Twitter usage) data were obtained through a Twitter Application Programming Interface (API). Morogoro urban municipality was classified into built-up, vegetation, agriculture, and water land cover classes while the classification results were validated by the generation of 480 random points. Using the Kernel function, the study measured the location of Twitter users within a 1 km buffer from the center of the city. The results indicate that, expansion of the city (built-up land use), which is primarily driven by population expansion, has negative impacts on ecosystem services because pristine grasslands and forests which provide essential ecosystem services such as carbon sequestration and support for biodiversity have been replaced by built-up land cover. In addition, social media usage data suggest that there is the concentration of Twitter usage within the city center while Twitter usage declines away from the city center with significant spatial and numerical increase in Twitter usage in the study area. The outcome of the study suggests that the combination of remote sensing, social sensing, and population data were useful as a proxy/inference for interpreting urban sprawl and status of access to urban services and infrastructure in Morogoro, and Africa city where data for urban planning is often unavailable, inaccurate, or stale.