Dynamics of Land Use and Land Cover Changes in Harare, Zimbabwe: A Case Study on the Linkage between Drivers and the Axis of Urban Expansion

With increasing population growth, the Harare Metropolitan Province has experienced accelerated land use and land cover (LULC) changes, influencing the city’s growth. This study aims to assess spatiotemporal urban LULC changes, the axis, and patterns of growth as well as drivers influencing urban growth over the past three decades in the Harare Metropolitan Province. The analysis was based on remotely sensed Landsat Thematic Mapper and Operational Land Imager data from 1984–2018, GIS application, and binary logistic regression. Supervised image classification using support vector machines was performed on Landsat 5 TM and Landsat 8 OLI data combined with the soil adjusted vegetation index, enhanced built-up and bareness index and modified difference water index. Statistical modelling was performed using binary logistic regression to identify the influence of the slope and the distance proximity characters as independent variables on urban growth. The overall mapping accuracy for all time periods was over 85%. Built-up areas extended from 279.5 km2 (1984) to 445 km2 (2018) with high-density residential areas growing dramatically from 51.2 km2 (1984) to 218.4 km2 (2018). The results suggest that urban growth was influenced mainly by the presence and density of road networks

Central Places and Their Environment – Preliminary Results from the Research Group

The projects of the Research Group »Central Places and Their Environment« involved investigations of individual sites having the character of central places or of limited regions within which networks of settlements were present. Cities, seats of power, and sacred sites are investigated in terms of their significance for and shaping influence on surrounding regions. These themes are explored through direct collaborations between scientists from the archaeological and earth sciences respectively. The focus of our investigations is the network of relations between central sites or settlements in spaces of limited extension and their surroundings. This involves reconstructing the development of the respective central site and of the historical landscape, as well as of various site factors, and analyzing the structure of relationships with the surrounding territory and the connecting region. The types of influence exerted by such central places on the surrounding space are compared in terms of various cultures, regions, and societal systems. The focal areas of investigation are the Mediterranean region, the Black Sea area, Central Asia, and the Middle East. Studies include central places for which adequate historical sources are available, but also sites from preliterate epochs

a Review

The ancient and now abandoned settlement of Naga, had its heyday around 2000 years ago, located in the hinterland of a Nile tributary. Here we present 15 new OSL-dates and four new radiocarbon-ages. Data show that fundamental environmental changes did not take place in the investigation area at least during the past 2000 years; nevertheless, subsystems may have varied significantly

Linking Land Tenure and Integrated Watershed Management - A Review

Land tenure is given attention in the general discussions on conservation and management of natural resources, but the necessary holistic approach to understand the linkages is less considered. Thus, we considered a watershed as a unit of reference and Integrated Watershed Management as a holistic land and water resources management approach with various roles and touchpoints with land tenure issues. To examine the role of land tenure on the management of natural resources in watersheds, we reviewed and compiled literature that captures watershed issues, integrating aspects of land tenure, and aiming to identify the key land tenure roles, dynamics, and its influences on integrated watershed management. Land tenure is observed playing various roles in watersheds and, thus, also on integrated watershed management as an approach—as a driver of change, influence for investment decisions, an incentive for adoption of practices, and leading to sustainability. Land tenure dynamics range from land tenure security, land tenure forms, land access and acquisition modalities, and how these aspects of land tenure relate with integrated watershed management

Towards Legislation Responsive to Integrated Watershed Management Approaches and Land Tenure

Land tenure affects integrated watershed management approaches in various ways, such as influencing land use and investment in sustainability practices and decisions. However, some land tenure and integrated watershed management relations need more examination, including how the prevailing relevant legislation responds and the needed course of action. In this paper, we provide relevant evidence to support a shift to responsive actions and legislation through (a) examining land tenure scenarios affecting integrated watershed management, including the public–private land tenure co-existence from a watershed perspective; (b) the responsiveness of the prevailing relevant legislation to integrated watershed management and the land tenure scenarios and (c) identifying legislative remedies recommendable for responsiveness. We use qualitative methods to review secondary data sources, including four legislations, and complement them with field survey data. Field experiences are from three sub-catchments in the Lake Victoria basin, each representing a different land tenure system, as case studies. Land tenure links with integrated watershed management in various ways, such as influencing land use decisions. However, underscoring the relationship from the private and public land tenure perspective also indicates a complex and tense spatial relationship. As such, it likely limits adopting sustainable land use and management practices in watersheds as a case. Regardless, the perceptions from the study area indicate the land tenure systems and forms enabling sustainable choices and decisions, despite limitations such as tenure insecurity. The disconnect between integrated watershed management aspirations of ensuring sustainability, the land tenure abilities and the subsequent human practices is mainly institutional, with the relevant legislation indicating a low to moderate level of responsiveness to integrated watershed management approaches and land tenure, thus, abating effectiveness. Therefore, we suggest a shift towards responsive programming and legislation and the adoption of model legislation to support responsiveness replication. We also recommend further studies to assess the legal gaps and feasibility thereof

Integrated Water Resources Management Approaches to Improve Water Resources Governance

The water crisis can alternatively be called a governance crisis. Thus, the demand for good water governance to ensure effective water resources management and to attain specific water goals is growing. Many countries subscribe to the Integrated Water Resources Management (IWRM) approach to achieve this goal. The Integrated Water Resources Management approach aims to ensure a process that promotes the coordinated development and management of water, land, and related resources in a drainage basin to maximise economic and social welfare equitably without compromising the sustainability of vital ecosystems. The design of the Integrated Water Resources Management approach, including its pillars and principles, aspires to good water governance and effective resource management. However, empirical studies examining this hypothesis and analysing the impact of the Integrated Water Resources Management approach on water resources governance are limited, especially in developing countries. Therefore, we characterised and compared the water resources governance aspects of two catchments in Uganda’s Lake Albert basin. One of the catchments was exposed to integrated water resources management projects, while the other had no exposure to integrated water resources management projects. Some of the factors that supported the comparability of the two sites included spatial proximity linking into a related hydrological and social-economic setup, common water needs and belonging to the same water administration zone. Comparing both areas led us to analyse whether there was a difference in water resources governance actions, as well as in the quality of water resources governance, under the same overall water management and administrative zone. The data were based on field surveys using questionnaires and information guides in both catchments. The results show that the performance of water resources governance is markedly better in the catchment with Integrated Water Resources Management practices than the base catchment unaffected by these practices. Key themes examined include water resources governance styles, water resources governance systems presence, functionality, the performance of good governance principles, and water resources management effectiveness. The findings contribute to the aspirations for the promotion of integrated water management approaches for improved water resources governance, and the concept that the effectiveness of water resources management measures depends on governance effectiveness. Water governance is significant, as it spells out the power, rights, decisions, and priorities relating to given water resources and communities

Geoarchaeology – A New Discipline?

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Land Use Changes and Their Perception in the Hinterland of Barranquilla, Colombian Caribbean

The coastal strip of the western peri-urban area of Barranquilla in the Atlántico Department (Colombia) is experiencing changes in human-environment interactions through infrastructure, residential, and tourism projects in a vulnerable landscape. In the hilly area, fragments of biodiverse tropical dry forest still exist in various states of conservation and degradation. To understand the interrelated social, economic, and ecological transformations in the area, we analyzed land use change on the local scale including the local community’s perception, because the local community is a key actor for sustainable land use. For the analysis of the interrelated social, economic, and ecological processes, we combined visual interpretation of high-resolution satellite imagery, on-site field land use mapping, and a spatial statistical analysis of the distribution of land use classes with in-depth interviews and a participatory GIS workshop, thus benefitting from the complementary methodological strengths of these approaches. The case study is the rural community of El Morro, which exhibits the typical social, economic, and ecological changes of the coastal strip of the western peri-urban area of Barranquilla. The local community perceives a continuous loss of forest area, but observations from on-site field mapping cannot confirm this linear trend. We observed a gradual replacement of traditional land uses such as smallholder agriculture, charcoal production, and cattle breeding by services for tourism, gated community projects for urban dwellers, and infrastructure projects; these spatial developments have several characteristics of rural gentrification. We conclude that the drivers of environmental degradation have changed and the degradation increased. The development projects of external companies have been rejected by the local community and have induced environmental consciousness among community members. Thus, the local community has become an advocate for sustainable land use in the study area

Predicting the Impact of Future Land Use and Climate Change on Potential Soil Erosion Risk in an Urban District of the Harare Metropolitan Province, Zimbabwe

Monitoring urban area expansion through multispectral remotely sensed data and other geomatics techniques is fundamental for sustainable urban planning. Forecasting of future land use land cover (LULC) change for the years 2034 and 2050 was performed using the Cellular Automata Markov model for the current fast-growing Epworth district of the Harare Metropolitan Province, Zimbabwe. The stochastic CA–Markov modelling procedure validation yielded kappa statistics above 80%, ascertaining good agreement. The spatial distribution of the LULC classes CBD/Industrial area, water and irrigated croplands as projected for 2034 and 2050 show slight notable changes. For projected scenarios in 2034 and 2050, low–medium-density residential areas are predicted to increase from 11.1 km2 to 12.3 km2 between 2018 and 2050. Similarly, high-density residential areas are predicted to increase from 18.6 km2 to 22.4 km2 between 2018 and 2050. Assessment of the effects of future climate change on potential soil erosion risk for Epworth district were undertaken by applying the representative concentration pathways (RCP4.5 and RCP8.5) climate scenarios, and model ensemble averages from multiple general circulation models (GCMs) were used to derive the rainfall erosivity factor for the RUSLE model. Average soil loss rates for both climate scenarios, RCP4.5 and RCP8.5, were predicted to be high in 2034 due to the large spatial area extent of croplands and disturbed green spaces exposed to soil erosion processes, therefore increasing potential soil erosion risk, with RCP4.5 having more impact than RCP8.5 due to a higher applied rainfall erosivity. For 2050, the predicted wide area average soil loss rates declined for both climate scenarios RCP4.5 and RCP8.5, following the predicted decline in rainfall erosivity and vulnerable areas that are erodible. Overall, high potential soil erosion risk was predicted along the flanks of the drainage network for both RCP4.5 and RCP8.5 climate scenarios in 2050

Ancient Water Harvesting Methods in the Drylands of the Mediterranean and Western Asia

Water harvesting methods were a vital part of the water supply system of many ancient settlements in the drylands of the Mediterranean region andWestern Asia. Various water harvesting techniques evolved during the Bronze Age or earlier, and some of these remain in use even today. Based on literature we give a brief overview and present a tentative classification of these water harvesting methods and present the basic concepts behind these techniques supplemented with references to archaeological case studies