1,721,057 research outputs found
Creating a national, accurate digital surface model for use in small-scale inter-visibility assessments
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Detailed statistics of W/S-scores by census round for 'A Global Perspective on Drinking-water and Sanitation Classification: An Evaluation of Census Content'
No full textThis is 'S2 Appendix.' as the supporting information for 'A Global Perspective on Drinking-water and Sanitation Classification: An Evaluation of Census Content'</span
An investigation of land cover change in Mafungabusi Forest, Zimbabwe, using GIS and participatory mapping
No full textThis paper investigates the processes governing land cover change in and around the Mafungabusi Forest Reserve in Zimbabwe. Land cover change was analysed using aerial photography from 1976-1996 within a Geographic Information System (GIS). Perceived change and its causes were investigated through governmental data sources, participatory mapping and interviews with the local community and forest guards. It is found that whilst forest cover within the forest reserve has remained stable, there has been a steady decline in forest cover outside the forest reserve's boundaries
Written evidence: appendix 40: memorandum from Dr Stephen W Grundy, and Dr James A Wright, University of Bristol
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Rural:urban inequalities in post 2015 targets and indicators for drinking-water
No full textDisparities in access to drinking water between rural and urban areas are pronounced. Although use of improvedsources has increased more rapidly in rural areas, rising from 62% in 1990 to 81% in 2011, the proportion of therural population using an improved water source remains substantially lower than in urban areas. Inequalities incoverage are compounded by disparities in other aspects of water service. Not all improved sources are safe andevidence from a systematic review demonstrates that water is more likely to contain detectable fecal indicatorbacteria in rural areas. Piped water on premises is a service enjoyed primarily by those living in urban areas sodifferentiating amongst improved sources would exacerbate rural:urban disparities yet further. We argue that an urban bias may have resulted due to apparent stagnation in urban coverage and the inequity observed between urban and peri-urban areas. The apparent stagnation at around 95% coverage in urban areas stems in part from relative population growth – over the last two decades more people gained access to improved water in urban areas. There are calls for setting higher standards in urban areas which would exacerbate the already extreme rural disadvantage. Instead of setting different targets, health, economic, and human rights perspectives, we suggest that the focus should be kept on achieving universal access to safewater (primarily in rural areas) while monitoring progress towards higher service levels, including greater water safety (both in rural and urban areas and among different economic strata)
Valuing the impacts of climate change on protected areas in Africa
No full textThis study quantifies the economic costs of climate change impacts on protected areas in Africa. Downscaled results from four Global Circulation Models (GCMs) are used to classify different ecosystems in accordance with the Holdridge Life Zone (HLZ) system. A benefits transfer approach is then used to place an economic value on the predicted ecosystem shifts resulting from climate change in protected areas. The results provide approximations for the impacts on biodiversity in Africa under the “business-as-usual” scenario established by the Intergovernmental Panel on Climate Change (IPCC) for the middle and end of the 21st century. The geographical analysis shows that there are twenty HLZs in Africa and all of them are represented in the protected area network. Three of these HLZs do not change in extent as a result of climate change. Assuming initially that the willingness to pay (WTP) values and the preferences for different ecosystem services remain constant, three of the GCM models show an (undiscounted) negative economic impact of climate change for protected areas in Africa for the year 2100. The worst-case damage scenario totals USD 74.5 million by 2100. However, the model for the year 2065 shows a higher undiscounted value than the present. The finding of positive net impacts from warming is consistent with the predictions of other macro models that show potential gains from warming scenarios. <br/
Association of supply type with fecal contamiantion of source water and household stored drinking water in developing countries: a bivariate meta-analysis
No full textBackground: Access to safe drinking water is essential for health. Monitoring access to drinking water focuses on water supply type at the source, but there is limited evidence on whether quality differences at the source persist in water stored in the household.Objectives: To assess the extent of fecal contamination at the source and in household stored water (HSW) and explore the relationship between contamination at each of these sampling points and water supply type.Methods: A bivariate random-effects meta-analysis of 45 studies, identified through a systematic review, that reported either the proportion of samples free of fecal indicator bacteria and/or individual sample bacteria counts for source and HSW, disaggregated by supply type.Results: Water quality deteriorated substantially between source and stored water. Mean percentage of contaminated samples (noncompliance) at the source was 46% (95% CI: 33, 60%) while mean noncompliance in HSW was 75% (95% CI: 64, 84%). Water supply type was significantly associated with noncompliance at the source (p < .001) and in HSW (p = 0.03). Source water (OR = 0.2; 95% CI: 0.1, 0.5) and HSW (OR = 0.3; 95% CI: 0.2, 0.8) from piped supplies had significantly lower odds of contamination when compared to non-piped water, potentially due to residual chlorine.Conclusions: Piped water is less likely to be contaminated compared to other water supply types at both the source and in HSW. A focus on upgrading water services to piped supplies may help improve safety, including for those drinking stored water
Spatial patterns and recent trends in the climate of tropical rainforest regions
No full textWe present an analysis of the mean climate and climatic trends of tropical rainforest regions over the period 1960-1998, with the aid of explicit maps of forest cover and climatological databases. Until the mid-1970s most regions showed little trend in temperature, and the western Amazon experienced a net cooling probably associated with an interdecadal oscillation. Since the mid-1970s, all tropical rainforest regions have experienced a strong warming at a mean rate of 0.26 ± 0.05 °C per decade, in synchrony with a global rise in temperature that has been attributed to the anthropogenic greenhouse effect. Over the study period, precipitation appears to have declined in tropical rainforest regions at a rate of 1.0 ± 0.8% per decade (p < 5%), declining sharply in northern tropical Africa (at 3-4% per decade), declining marginally in tropical Asia and showing no significant trend in Amazonia. There is no evidence so far of a decline in precipitation in eastern Amazonia, a region thought vulnerable to climate-change-induced drying. The strong drying trend in Africa suggests that this should be a priority study region for understanding the impact of drought on tropical rainforests. We develop and use a dry-season index to study variations in the length and intensity of the dry season. Only African and Indian tropical rainforests appear to have seen a significant increase in dry-season intensity. In terms of interannual variability, the El Niño-Southern Oscillation (ENSO) is the primary driver of temperature variations across the tropics and of precipitation fluctuations for large areas of the Americas and southeast Asia. The relation between ENSO and tropical African precipitation appears less direct.<br/
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