Search for dissertations about: "Sahel"

Showing result 16 - 20 of 21 swedish dissertations containing the word Sahel.

  2. 16. Computationally efficient methods in spatial statistics : Applications in environmental modeling

    Author : David Bolin; Matematisk statistik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : In this thesis, computationally efficient statistical models for large spatial environmental data sets are constructed. In the first part of the thesis, a method for estimating spatially dependent temporal trends is developed. A space-varying regression model, where the regression coefficients for the spatial locations are dependent, is used. READ MORE

  4. 17. Models and Methods for Random Fields in Spatial Statistics with Computational Efficiency from Markov Properties

    Author : David Bolin; Matematisk statistik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; random fields; Gaussian Markov random fields; Matérn covariances; stochastic partial differential equations; Computational efficiency;

    Abstract : The focus of this work is on the development of new random field models and methods suitable for the analysis of large environmental data sets. A large part is devoted to a number of extensions to the newly proposed Stochastic Partial Differential Equation (SPDE) approach for representing Gaussian fields using Gaussian Markov Random Fields (GMRFs). READ MORE

  5. 18. Food security in a changing climate : The role of cropland intensification and land acquisitions across Africa

    Author : Altaaf Mechiche-Alami; Institutionen för naturgeografi och ekosystemvetenskap; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Agriculture; land grabbing; sustainability science; Network Analysis; Earth observation; Crop model;

    Abstract : Food security is one of the world’s greatest challenges. The current food system shows an entanglement across the globe which means that local farmers reliant on subsistence agriculture no longer operate in isolation of larger-scale processes within the global economy or the changing biophysical system of the planet. READ MORE

  6. 19. Demographic History and Adaptation in African Populations

    Author : Mário Vicente; Carina Schlebusch; Mattias Jakobsson; Lluis Quintana-Murci; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; African demography; human evolutionary genetics; population structure; population admixture; genetic adaptation;

    Abstract : Africa is the continent where modern humans originated and yet, African demographic history remains largely unknown. Through analyzing the genetic composition of extant and extinct individuals, it is possible to reveal signals of past demographic history and adaptation. READ MORE

  7. 20. Primary Production in African Drylands : Quantifying Supply and Demand Using Earth Observation and Socio-ecological Data

    Author : Abdulhakim Abdi; Institutionen för naturgeografi och ekosystemvetenskap; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Net primary production; Africa; Drylands; Coupled human and natural systems; Human-Environment Relations; Food security; Earth observation; Remote Sensing;

    Abstract : The human-environment connection in the mostly rural drylands of sub-Saharan Africa forms a complex, interlinked system that provides ecosystem services. This system is susceptible to climatic variability that impacts the supply of its products, and high population growth, which impacts the demand for these products. READ MORE