40 research outputs found

    Analysis of urban land use and land cover changes: a case of study in Bahir Dar, Ethiopia

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    Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial TechnologiesThe high rate of urbanization coupled with population growth has caused changes in land use and land cover in Bahir Dar, Ethiopia. Therefore, understanding and quantifying the spatio- temporal dynamics of urban land use and land cover changes and its driving factors is essential to put forward the right policies and monitoring mechanisms on urban growth for decision making. Thus, the objective of this study was to analyze land use and land cover changes in Bahir Dar area, Ethiopia by applying geospatial and land use change modeling tools. In order to achieve this, satellite data of Landsat TM for 1986 and ETM for 2001 and 2010 have been obtained and preprocessed using ArcGIS. The Maximum Liklihood Algorithm of Supervised Classification has been used to generate land use and land cover maps. For the accuracy of classified land use and land cover maps, a confusion matrix was used to derive overall accuracy and results were above the minimum and acceptable threshold level. The generated land cover maps have been run with Land Change Modeler for quantifying land use and land cover changes, to examine land use transitions between land cover classes, to identify gain and losses of built up areas in relation to other land cover classes and to asses spatial trend of built up areas. Finally, Land Change Modeler has been run to model land use and land cover changes in Bahir Dar area and to predict future urban land use changes. To achieve this, four model variables that explain urban growth and six land cover transitions were incorporated in the modeling process. Multi-layer perceptron neural network was used to model the transition potential maps and achieved an accuracy of 61%. This result was acceptable to make actual prediction using Markov chain analysis for year 2010. Validation results showed that the model (Land Change Modeler) had a lower accuracy in simulating changes for the year 2010. Generally, the results of this study have shown that there was an increased expansion of built up areas in the last 25 years from 1.5% in 1986 to 4.1 % in 2001 and 9.4% in 2010 at the expense of agricultural areas. The spatial trend of built up areas also showed that there was a growing trend in the western part of Bahir Dar relative to other directions. Therefore, the findings of this study could provide as decision making for urban planning

    An agent-based approach to model farmers' land use cover change intentions

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    Land Use and Cover Change (LUCC) occurs as a consequence of both natural and human activities, causing impacts on biophysical and agricultural resources. In enlarged urban regions, the major changes are those that occur from agriculture to urban uses. Urban uses compete with rural ones due among others, to population growth and housing demand. This competition and the rapid nature of change can lead to fragmented and scattered land use development generating new challenges, for example, concerning food security, soil and biodiversity preservation, among others. Landowners play a key role in LUCC. In peri-urban contexts, three interrelated key actors are pre-eminent in LUCC complex process: 1) investors or developers, who are waiting to take advantage of urban development to obtain the highest profit margin. They rely on population growth, housing demand and spatial planning strategies; 2) farmers, who are affected by urban development and intend to capitalise on their investment, or farmers who own property for amenity and lifestyle values; 3) and at a broader scale, land use planners/ decision-makers. Farmers’ participation in the real estate market as buyers, sellers or developers and in the land renting market has major implications for LUCC because they have the capacity for financial investment and to control future agricultural land use. Several studies have analysed farmer decision-making processes in peri-urban regions. These studies identified agricultural areas as the most vulnerable to changes, and where farmers are presented with the choice of maintaining their agricultural activities and maximising the production potential of their crops or selling their farmland to land investors. Also, some evaluate the behavioural response of peri-urban farmers to urban development, and income from agricultural production, agritourism, and off-farm employment. Uncertainty about future land profits is a major motivator for decisions to transform farmland into urban development. Thus, LUCC occurs when the value of expected urban development rents exceeds the value of agricultural ones. Some studies have considered two main approaches in analysing farmer decisions: how drivers influence farmer’s decisions; and how their decisions influence LUCC. To analyse farmers’ decisions is to acknowledge the present and future trends and their potential spatial impacts. Simulation models, using cellular automata (CA), artificial neural networks (ANN) or agent-based systems (ABM) are commonly used. This PhD research aims to propose a model to understand the agricultural land-use change in a peri-urban context. We seek to understand how human drivers (e.g., demographic, economic, planning) and biophysical drivers can affect farmer’s intentions regarding the future agricultural land and model those intentions. This study presents an exploratory analysis aimed at understanding the complex dynamics of LUCC based on farmers’ intentions when they are faced with four scenarios with the time horizon of 2025: the A0 scenario – based on current demographic, social and economic trends and investigating what happens if conditions are maintained (BAU); the A1 scenario – based on a regional food security; the A2 scenario – based on climate change; and the B0 scenario – based on farming under urban pressure, and investigating what happens if people start to move to rural areas. These scenarios were selected because of the early urbanisation of the study area, as a consequence of economic, social and demographic development; and because of the interest in preserving and maintaining agriculture as an essential resource. Also, Torres Vedras represents one of the leading suppliers of agricultural goods (mainly fresh fruits, vegetables, and wine) in Portugal. To model LUCC a CA-Markov, an ANN-multilayer perceptron, and an ABM approach were applied. Our results suggest that significant LUCC will occur depending on farmers’ intentions in different scenarios. The highlights are: (1) the highest growth in permanently irrigated land in the A1 scenario; (2) the most significant drop in non-irrigated arable land, and the highest growth in the forest and semi-natural areas in the A2 scenario; and (3) the greatest urban growth was recognised in the B0 scenario. To verify if the fitting simulations performed well, statistical analysis to measure agreement and quantity-allocation disagreements and a participatory workshop with local stakeholders to validate the achieved results were applied. These outcomes could provide decision-makers with the capacity to observe different possible futures in ‘what if’ scenarios, allowing them to anticipate future uncertainties, and consequently allowing them the possibility to choose the more desirable future

    Climate Change and Environmental Sustainability-Volume 4

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    Anthropogenic activities are significant drivers of climate change and environmental degradation. Such activities are particularly influential in the context of the land system that is an important medium connecting earth surface, atmospheric dynamics, ecological systems, and human activities. Assessment of land use land cover changes and associated environmental, economic, and social consequences is essential to provide references for enhancing climate resilience and improving environmental sustainability. On the one hand, this book touches on various environmental topics, including soil erosion, crop yield, bioclimatic variation, carbon emission, natural vegetation dynamics, ecosystem and biodiversity degradation, and habitat quality caused by both climate change and earth surface modifications. On the other hand, it explores a series of socioeconomic facts, such as education equity, population migration, economic growth, sustainable development, and urban structure transformation, along with urbanization. The results of this book are of significance in terms of revealing the impact of land use land cover changes and generating policy recommendations for land management. More broadly, this book is important for understanding the interrelationships among life on land, good health and wellbeing, quality education, climate actions, economic growth, sustainable cities and communities, and responsible consumption and production according to the United Nations Sustainable Development Goals. We expect the book to benefit decision makers, practitioners, and researchers in different fields, such as climate governance, crop science and agricultural engineering, forest ecosystem, land management, urban planning and design, urban governance, and institutional operation.Prof. Bao-Jie He acknowledges the Project NO. 2021CDJQY-004 supported by the Fundamental Research Funds for the Central Universities and the Project NO. 2022ZA01 supported by the State Key Laboratory of Subtropical Building Science, South China University of Technology, China. We appreciate the assistance of Mr. Lifeng Xiong, Mr. Wei Wang, Ms. Xueke Chen, and Ms. Anxian Chen at School of Architecture and Urban Planning, Chongqing University, China

    Assessment of soil erosion based on clustered geoinformatics approaches: a case study of Tyume River Catchment, Eastern Cape, South Africa

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    This research centres on the holistic assessments of spatial and temporal dimensions of soil erosion zones based on the parameters of geomorphometry, hydro-statistics, and land use/cover dynamics. The study used a case study approach based on a clustered framework model of soil erosion parameters in the Tyume River basin in Eastern Cape, South Africa. The methods adopted for the investigation are, namely; non-parametric time-series assessment of streamflow dataset, semidecadal assessment of land use/cover (LU/C) dynamics, geospatial analysis of geomorphometric variables, vulnerability analysis of soil erosion zones, regression analysis of determination coefficient, and Receiver Operating Characteristic Curve (ROC). The delineation of soil erosion zones was based on the integrated analysis of the parameters of geomorphometry, geology, hydrology, and land use/ cover. The result of the hydro-statistical analysis of the Tyume River reports a major decline in the inter-annual regime frequency of storm flow based on the Mann- Kendall (MK) test and Sen’s slope assessment in 1992 (p-value = 0.031), 1997 (p-value = 0.045), 2003 (p-value = 0.021), 2008 (p-value = 0.003), and 2016 (p-value = 0.002). The MK test depicted a recurrence of peak streamflow acceleration in every three years based on low-flow and highflow transition. The sensitivity of LU/C to temporal dynamics of streamflow trends shown by the coefficient of correlation of trends of the LU/C water bodies with streamflow semi-decadal acceleration indicates a moderately relevant relationship, R = 0.76. The temporal analysis of LU/C and hydro-statistical analysis shows that the Tyume basin was highly vulnerable to soil erosion by water in 1999, 2009, and 2019. The vulnerability of the Tyume River basin in 2019 is exceptional and this is due to the conversion of forested area (woodland) into a built-up environment and farmland, with a high vulnerability in 2019 due to the slump in the rate of change of woodland and precipitation, and the increase in the rate of built-up and agricultural activities. The soil erosion vulnerability mapping divides the river basin into the critical high, high, moderate, low, nonvulnerable zones that cover 40 km2, 135 km2, 209 km2, and 186 km2 respectively. Regression analysis shows that the areas of soil erosion in the Tyume basin are moderately represented by the model (R2 = 56) while the model performance assessment based on success rate and prediction rate estimation from the area under the ROC curve shows that the model is good, Area Under Curve of the ROC = 0.899, and 0.897. The analysis suggests that soil erosion is driven by the impact of land use/land cover change, particularly in areas of high drainage density. Significantly, high vegetation density played a vital role in lowering high-flow on the hill-slope and low topographic wetness area as well as in areas with erodible geologic properties. The study, therefore, recommends the advocacy of crop rotation method of agricultural practice in the highly critical areas of soil erosion and recommends the development of riparian forests around the Tyume River. The study provides important information for environmental stakeholders on degradable areas which may require the urgent implementation of sustainable development measures.Thesis (MPhil) -- Faculty of Science and Agriculture, 202

    Assessment of soil erosion based on clustered geoinformatics approaches: a case study of Tyume River Catchment, Eastern Cape, South Africa

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    This research centres on the holistic assessments of spatial and temporal dimensions of soil erosion zones based on the parameters of geomorphometry, hydro-statistics, and land use/cover dynamics. The study used a case study approach based on a clustered framework model of soil erosion parameters in the Tyume River basin in Eastern Cape, South Africa. The methods adopted for the investigation are, namely; non-parametric time-series assessment of streamflow dataset, semidecadal assessment of land use/cover (LU/C) dynamics, geospatial analysis of geomorphometric variables, vulnerability analysis of soil erosion zones, regression analysis of determination coefficient, and Receiver Operating Characteristic Curve (ROC). The delineation of soil erosion zones was based on the integrated analysis of the parameters of geomorphometry, geology, hydrology, and land use/ cover. The result of the hydro-statistical analysis of the Tyume River reports a major decline in the inter-annual regime frequency of storm flow based on the Mann- Kendall (MK) test and Sen’s slope assessment in 1992 (p-value = 0.031), 1997 (p-value = 0.045), 2003 (p-value = 0.021), 2008 (p-value = 0.003), and 2016 (p-value = 0.002). The MK test depicted a recurrence of peak streamflow acceleration in every three years based on low-flow and highflow transition. The sensitivity of LU/C to temporal dynamics of streamflow trends shown by the coefficient of correlation of trends of the LU/C water bodies with streamflow semi-decadal acceleration indicates a moderately relevant relationship, R = 0.76. The temporal analysis of LU/C and hydro-statistical analysis shows that the Tyume basin was highly vulnerable to soil erosion by water in 1999, 2009, and 2019. The vulnerability of the Tyume River basin in 2019 is exceptional and this is due to the conversion of forested area (woodland) into a built-up environment and farmland, with a high vulnerability in 2019 due to the slump in the rate of change of woodland and precipitation, and the increase in the rate of built-up and agricultural activities. The soil erosion vulnerability mapping divides the river basin into the critical high, high, moderate, low, nonvulnerable zones that cover 40 km2, 135 km2, 209 km2, and 186 km2 respectively. Regression analysis shows that the areas of soil erosion in the Tyume basin are moderately represented by the model (R2 = 56) while the model performance assessment based on success rate and prediction rate estimation from the area under the ROC curve shows that the model is good, Area Under Curve of the ROC = 0.899, and 0.897. The analysis suggests that soil erosion is driven by the impact of land use/land cover change, particularly in areas of high drainage density. Significantly, high vegetation density played a vital role in lowering high-flow on the hill-slope and low topographic wetness area as well as in areas with erodible geologic properties. The study, therefore, recommends the advocacy of crop rotation method of agricultural practice in the highly critical areas of soil erosion and recommends the development of riparian forests around the Tyume River. The study provides important information for environmental stakeholders on degradable areas which may require the urgent implementation of sustainable development measures.Thesis (MPhil) -- Faculty of Science and Agriculture, 202

    Modelling basin-scale sediment dynamics in the Petit lac d'Annecy catchment, France

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    This research describes the testing, development and application of an established hydro-geomorphic numerical model (CAESAR) over different time scales (170-2000 years) to simulate at hourly time resolution, the changes in the hydrological and sediment regime of the Petit lac d’Annecy catchment in response to changes in system drivers. Two thousand year long model runs in five different morphological settings were simulated, the results suggest that intrinsic system behaviour such as storage-release, hillslope-channel coupling and supply-capacity relationships may well exert larger controls on sediment discharge patterns over this timescale than climate or land use drivers. Hypothetical scenarios to investigate the geomorphic implications of a snow-free pre-alpine region over the last 2000 years show that there would be around 1.4 times more sediment discharge, with the annual hydrological regime radically altered with increased flooding throughout the year, particularly in winter months and a lack of a sustained discharge peak in the ‘melt’ months. This has implications for the projected environmental changes over the coming decades. The simulated effects of increased precipitation, reduced forest cover and snow-free conditions, in combination, point to increased amounts of coarse sediment discharge within the channels. Broad estimations show that a 20% reduction in forest cover or snow-free conditions can result in an additional 1m of sediment moving through the system and accumulating in the lake with potentially large impacts on flooding, in-channel fauna, benthic-dwelling lake fauna, aquatic macrophysics and water quality and water availability for storage and local power generation

    Land Use Conflict Detection and Multi-Objective Optimization Based on the Productivity, Sustainability, and Livability Perspective

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    Land use affects many aspects of regional sustainable development, so insight into its influence is of great importance for the optimization of national space. The book mainly focuses on functional classification, spatial conflict detection, and spatial development pattern optimization based on productivity, sustainability, and livability perspectives, presenting a relevant opportunity for all scholars to share their knowledge from the multidisciplinary community across the world that includes landscape ecologists, social scientists, and geographers. The book is systematically organized into the optimization theory, methods, and practices for PLES (production–living–ecological space) around territorial spatial planning, with the overall planning of PLES as the goal and the promotion of ecological civilization construction as the starting point. Through this, the competition and synergistic interactions and positive feedback mechanisms between population, resources, ecology, environment, and economic and social development in the PLES system were revealed, and the nonlinear dynamic effects among subsystems and elements in the system identified. In addition, a series of optimization approaches for PLES is proposed

    Sustainable Use of Soils and Water: The Role of Environmental Land Use Conflicts

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    This book on the sustainable use of soils and water addressed a variety of issues related to the utopian desire for environmental sustainability and the deviations from this scene observed in the real world. Competing interests for land are frequently a factor in land degradation, especially where the adopted land uses do not conform with the land capability (the natural use of soil). The concerns of researchers about these matters are presented in the articles comprising this Special Issue book. Various approaches were used to assess the (im)balance between economic profit and environmental conservation in various regions, in addition to potential routes to bring landscapes back to a sustainable status being disclosed

    Forest landscapes and global change. New frontiers in management, conservation and restoration. Proceedings of the IUFRO Landscape Ecology Working Group International Conference

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    This volume contains the contributions of numerous participants at the IUFRO Landscape Ecology Working Group International Conference, which took place in Bragança, Portugal, from 21 to 24 of September 2010. The conference was dedicated to the theme Forest Landscapes and Global Change - New Frontiers in Management, Conservation and Restoration. The 128 papers included in this book follow the structure and topics of the conference. Sections 1 to 8 include papers relative to presentations in 18 thematic oral and two poster sessions. Section 9 is devoted to a wide-range of landscape ecology fields covered in the 12 symposia of the conference. The Proceedings of the IUFRO Landscape Ecology Working Group International Conference register the growth of scientific interest in forest landscape patterns and processes, and the recognition of the role of landscape ecology in the advancement of science and management, particularly within the context of emerging physical, social and political drivers of change, which influence forest systems and the services they provide. We believe that these papers, together with the presentations and debate which took place during the IUFRO Landscape Ecology Working Group International Conference – Bragança 2010, will definitively contribute to the advancement of landscape ecology and science in general. For their additional effort and commitment, we thank all the participants in the conference for leaving this record of their work, thoughts and science
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