Remote sensing-based fire frequency mapping in a savannah rangeland

Burnt area mapping and fire frequency analysis were carried out in Hwange National Park, Zimbabwe. Hwange National Park typifies a savannah ecosystem which is semi-arid and fire-prone. This paper presents a geospatial analysis to quantify the spatial distribution and fire frequency from 2000 to 2006. Moderate Resolution Imaging Spectroradiometer (MODIS) images from 2000 to 2006 were obtained and classified for burnt area mapping. Linear pixel unmixing was used for image classification and subsequent mapping of burnt areas. The results showed that it was feasible to have discrimination of burnt areas and ‘un-burnt’ areas as well as generating a six year fire frequency map of the study area. Accuracy assessment of the classified images was carried out using field obtained information on fire occurrence to validate the classification results. An error matrix quantified accuracy of classified maps through producer's accuracy, user's accuracy and overall accuracy. High overall accuracy rates of appromately 96%, in turne, justify use of linear pixel unmixing in identifying and mapping burnt areas. Thus pixel unmixing offers a viable mapping tool for fire monitoring and management in protected areas

Contribution of rainwater harvesting technologies to rural livelihoods in Zimbabwe: The case of Ngundu ward in Chivi District

Water has long been regarded as the main limiting resource for crop production in the drought-prone region of sub-Saharan Africa in which Zimbabwe is located. However, the introduction of novel agricultural technologies such as rain-water harvesting (RWH) is seeking to mitigate the effects of these perennial droughts. The successful adoption of such technologies has the potential to alleviate problems faced by resource-poor ‘subsistence\' farmers. Thus this paper examines the contribution of RWH technologies to rural livelihoods in Zimbabwe and consequently to the sustainability of agriculture and rural livelihoods thereof. The methods employed included a questionnaire survey; key informant interviews and field observations. Benefits of RWH technologies found include an increase in agricultural productivity, enhancing household food security and raising of incomes. The technologies also assisted in improving environmental management through water conservation, reduction of soil erosion and resuscitation of wetlands in the study area. The major constraints facing technology adopters were water distribution problems, labour shortage, water-logging during periods of high rainfall and risk of injury to people and livestock as a result of some of the technologies. However, in an area like Chivi where there are frequent droughts and consequently food shortages among smallholder farmers, the benefits of RWH technology adoption seem to outweigh the costs. It was therefore concluded that RWH technologies are suitable for smallholder farmers in semi-arid areas if they are properly tailored to the conditions of the locality where they are promoted. Water SA Vol.32 (3) 2006: pp.437-44

Use of remote sensing to determine rainwater harvesting sites for piped micro-irrigation schemes in Chimanimani District, Zimbabwe

The eastern highlands of Zimbabwe, particularly Chimanimani District, are endowed with natural water bodies such as springs, pools, wetlands, puddles and river systems, which are potential sources of water for irrigated farming. Despite this, water challenges continue to exist due to rainfall seasonality and lack of suitable water harvesting sites. This calls for solutions to harness water in long-lasting sources to support the piped micro-irrigation schemes. These schemes are pillars in agricultural interventions such as horticulture, livestock farming, fish farming and beekeeping. This study therefore, determined potential rainwater harvesting (RWH) sites in Chimanimani District using geospatial techniques. Water pixels from Landsat 8 images were extracted using the normalised difference moisture index (NDMI) and normalized difference vegetation index (NDVI). Potential RWH sites were classified into land-based zones, wetlands and natural water bodies. Findings show that land-based zones cover 27.53%, wetlands cover 24.65% and water bodies cover 6.11% of the district. The study also indicates that integrating geographic information systems with remote-sensing tools is a useful approach in identifying RWH sites. Thus, this study provided a spatially explicit approach and presents a suitability map for RWH in Chimanimani District

The revitalisation of planning education in Africa: a review of planning education at the Catholic University in Beira, Mozambique

Planning education at the Catholic University of Mozambique consists of undergraduate and post graduate programmes. These programmes aim to provide an overall understanding of the human-environment nexus by addressing physical, economic and human development needs as well as proposing appropriate and effective planning for different regions. The programmes are also part of the institution‟s way of complementing government efforts of decentralization by building the requisite manpower targeted for policy implementation. Of the post-graduate studies, the MSc in Regional Development Planning was introduced in February 2008 while the MSc in Geographic Information Systems (GIS) began in March 2009. In March 2010, the University will introduce a BSc Honours in Regional, District and Town Planning programme. The need to focus education towards development and planning was necessitated by the government's emphasis on decentralisation in planning and management of districts and noted uneven regional development between the north and south of the country. This noted uneven development then entailed the need for capacity building in the planning profession. This paper gives an overview of planning programmes at the Catholic University of Mozambique, Beira. It outlines economic, socio-political and physical environment within which programmes are offered in Mozambique as well as Beira City. Major challenges faced in delivering these programmes are highlighted. It concludes by outlining how regional development and planning programmes in the 21st Century are designed to equip graduates for employment in development oriented research, planning, education and management in both public and private sectors where they can contribute meaningfully to sustainable regional development

The application of geographic information systems (GIS) in the analysis of nutrient loadings from an agro-rural catchment

A large amount of data is usually generated during environmental monitoring programmes. The data need to be transformed into useful information that can be used for interpretation and analysis of problems. This paper outlines the feasibility of using geographic information system (GIS) techniques in the analysis of catchment nutrient yields with the aim of providing a knowledge base for effective decision-making. In this case the spatial and temporal distributions of the nutrient yields in the catchment were analysed. Interpolation with the GIS packages (Arc View Version 3.1 and Arc View Spatial Analyst) enabled the estimation of yields in areas without actual measurement thereof. (WaterSA: 2003 29(2): 189-194

Use of remote sensing to determine rainwater harvesting sites for piped micro-irrigation schemes in Chimanimani District, Zimbabwe

The eastern highlands of Zimbabwe, particularly Chimanimani District, are endowed with natural water bodies such as springs, pools, wetlands, puddles and river systems, which are potential sources of water for irrigated farming. Despite this, water challenges continue to exist due to rainfall seasonality and lack of suitable water harvesting sites. This calls for solutions to harness water in long-lasting sources to support the piped micro-irrigation schemes. These schemes are pillars in agricultural interventions such as horticulture, livestock farming, fish farming and beekeeping. This study therefore, determined potential rainwater harvesting (RWH) sites in Chimanimani District using geospatial techniques. Water pixels from Landsat 8 images were extracted using the normalised difference moisture index (NDMI) and normalized difference vegetation index (NDVI). Potential RWH sites were classified into land-based zones, wetlands and natural water bodies. Findings show that land-based zones cover 27.53%, wetlands cover 24.65% and water bodies cover 6.11% of the district. The study also indicates that integrating geographic information systems with remote-sensing tools is a useful approach in identifying RWH sites. Thus, this study provided a spatially explicit approach and presents a suitability map for RWH in Chimanimani District

Spatial scale impact on daily surface water and sediment fluxes in Thukela river, South Africa

International audienc

Improving the understanding of rainfall distribution and characterisation in the Cathedral Peak catchments using a geo-statistical technique

The characterisation of rainfall variability, spatially and temporally, is essential for hydrological and ecological analyses. Inherently, this variability is distinctly more obvious in mountainous areas compared to lowlands. The objective of this study was to ascertain if the use of the regression-Kriging technique would provide improved estimates and understanding of the rainfall distribution across the Cathedral Peak catchments in the Drakensberg escarpment region, South Africa. Findings showed longitude and altitude to be the overall best predictors of the distribution of rainfall for the annual period, wet season and dry season, with longitude explaining 72% and altitude explaining 26% of the rainfall variability for mean annual precipitation, 73% and 26% for the wet season and 50% and 22% for the dry season, respectively. The combination of both longitude and altitude showed a larger coefficient of determination, of 0.73, 0.74 and 0.51, for the annual, wet season and dry season, respectively. Long-term mean annual rainfall patterns showed an overall strong directional distribution from west to east with a distinct pattern observed during the dry season. It was concluded that regression-Kriging is a useful alternative method for characterising rainfall distribution as well as prediction errors for mountainous areas