Sparse gauge networks in Sub-Saharan Africa (SSA) limit our ability to identify changing precipitation extremes with in situ observations. Given the potential for satellite and satellite-gauge ...precipitation products to help, we investigate how daily gridded gauge and satellite products compare for seven core climate change precipitation indices. According to a new gauge-only product, the Rainfall Estimates on a Gridded Network (REGEN), there were notable changes in SSA precipitation characteristics between 1950 and 2013 in well-gauged areas. We examine these trends and how these vary for wet, intermediate, and dry areas. For a 31 year period of overlap, we compare REGEN data, other gridded products and three satellite products. Then for 1998-2013, we compare a set of 12 satellite products. Finally, we compare spatial patterns of 1983-2013 trends across all of SSA. Robust 1950-2013 trends indicate that in well-gauged areas extreme events became wetter, particularly in wet areas. Annual totals decreased due to fewer rain days. Between 1983 and 2013 there were positive trends in average precipitation intensity and annual maximum 1 d totals. These trends only represent 15% of SSA, however, and only one tenth of the main wet areas. Unfortunately, gauge and satellite products do not provide consensus for wet area trends. A promising result for identifying regional changes is that numerous satellite products do well at interannual variations in precipitation totals and number of rain days, even as well as some gauge-only products. Products are less accurate for dry spell length and average intensity and least accurate for annual maximum 1 d totals. Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis (3B42-V7) and Climate Hazards center Infrared Precipitation with Stations (CHIRPS v2.0) ranked highest for multiple indices. Several products have seemingly unrealistic trends outside of the well-gauged areas that may be due to influence of non-stationary systematic biases. Social media abstract. Sparse data show increasing Africa rainfall extremes and satellite products fill some missing pieces.
On handling urban informality in southern africa Kamete, Amin Y.
Geografiska annaler. Series B, Human Geography/Geografiska annaler. Series B. Human geography,
March 2013, Letnik:
95, Številka:
1
Journal Article
Recenzirano
Odprti dostop
In this article I reconsider the handling of urban informality by urban planning and management systems in southern Africa. I argue that authorities have a fetish about formality and that this is ...fuelled by an obsession with urban modernity. I stress that the desired city, largely inspired by Western notions of modernity, has not been and cannot be realized. Using illustrative cases of top-down interventions, I highlight and interrogate three strategies that authorities have deployed to handle informality in an effort to create or defend the modern city. I suggest that the fetish is built upon a desire for an urban modernity based on a concept of formal order that the authorities believe cannot coexist with the "disorder" and spatial "unruliness" of informality. I question the authorities' conviction that informality is an abomination that needs to be "converted", dislocated or annihilated. I conclude that the very configuration of urban governance and socio-economic systems in the region, like the rest of sub-Saharan Africa, renders informality inevitable and its eradication impossible.
flavonoidVernonia amygdalina Del) adalah salah satu tanaman obat yang berasal dari Afrika yang menyebar sampai ke Asia, termasuk Indonesia. Vernonia amygdalina Del dikenal dengan nama lokal tanaman ...Afrika. Tanaman ini secara tradisional telah dimanfaatkan sebagai obat diabetes, demam, hipertensi dan asam urat. Tujuan penelian ini adalah menentukan kadar flavonoid total ekstrak daun, kulit batang dan kayu batang tanaman Afrika. Masing-masing sampel (daun, kulit batang dan batang Afrika) diekstraksi kemudian ditentukan kandungan flavonoid totalnya. Berdasarkan hasil penentuan kadar flavonoid dari ekstrak daun, kulit batang dan batang Afrika diketahui bahwa ekstrak batang memiliki kadar flavonoid total yang paling banyak sebesar 418,15 mg QE/g ekstrak.
In the past decade, palm oil has risen to become the most produced and consumed vegetable oil in the world. Growth of commercial plantations in Southeast Asia and recent expansions in West Africa and ...Latin America have led to a growing call for the sustainable production of palm oil, driven to a large extent by concerns over the associated impacts of deforestation and biodiversity losses. This study investigates the academic response to the calls for the sustainable production of palm oil by identifying and analysing Thomson Reuters Institute for Scientific Information indexed palm oil sustainability related publications from 2004 to 2013. The results show that the total number of publications has increased exponentially from 11 in 2004 to 713 by 2013. However, this growth is shown to be carried mainly by research within technical aspects of palm oil residue use; publications in the categories of land use & land use change, biodiversity and socio-economic aspects have increased, but the growth has been markedly slower. It is thus argued that there is currently an imbalance in research strategies since the focus towards technical topics is at odds with the major sustainability issues raised about palm oil production. To address the current imbalance in palm oil research, this study proposes a holistic framework for palm oil sustainability research with the aim of achieving multidisciplinary studies and emphasizing collaboration between industry and academia. Research sponsors and public bodies in charge of science, social science and technology research frameworks will thus benefit from improved understanding of where research and development resources can be allocated to facilitate the transition towards improved sustainability.
•Substantial increases are seen in ISI publications on palm oil sustainability.•Residue technology and use is the most published sustainability category.•Most sustainability categories are still under-researched.•There is a need for an increased multidisciplinary research approach.•Universities act as ‘anchor-institutions’ for sustainable development strategies.
Despite its central importance to global family planning, the “unmet need for contraception” metric is frequently misinterpreted. Often conflated with a lack of access, misinterpretation of what ...unmet need means and how it is measured has important implications for family planning programs. We review previous examinations of unmet need, with a focus on the roles of access and demand for contraception, as well as the role of population control in shaping the indicator's priorities. We suggest that disaggregating unmet need into “demand‐side unmet need” (stemming from lack of demand) and “supply‐side unmet need” (stemming from lack of access) could allow current data to be leveraged into a more person‐centered understanding of contraceptive need. We use Demographic and Health Survey data from seven sub‐Saharan African countries to generate a proof‐of‐concept, dividing women into unmet need categories based on reason for contraceptive nonuse. We perform sensitivity analyses with varying conceptions of access and disaggregate by education and marital status. We find that demand‐side unmet need far exceeds supply‐side unmet need in all scenarios. Focusing on supply‐side rather than overall unmet need is an imperfect but productive step toward person‐centered measurement, while more sweeping changes to family planning measurement are still required.
Energy poverty in developing regions is a major global concern, with the rural areas of South Asia, South-East Asia and Sub-Saharan Africa being the most affected. The major residential energy ...consumption in these regions is for cooking and lighting, which is basically covered with traditional biomass and fossil fuels. This situation acts as a development barrier, while implying stress on resources and the environment. Solar home systems (SHS) can play an important role in overcoming this problem. Recent technological advances and cost reductions in lithium-ion batteries favour their use in such application. Domestic electric devices with outstanding energy efficiency are becoming the standard around the globe. This paper focuses on exploiting these innovations to provide a solution for domestic energy poverty in developing regions. The layout of a SHS that integrates a lithium-ion battery-pack and is complemented with LED lamps and an energy efficient multicooker is presented. The paper assesses the SHS in contrast with existing practices under domestic energy poverty, with consideration of the learning curve. It is concluded that the cost of energy of the SHS is slightly cheaper than the business as usual case on the short term, and notably cheaper on the longer run. Furthermore, a financing scheme is proposed to overcome implementation barriers. Government support is considered, and quantified based on the SHS carbon abatement and saved fossil fuel subsidies. A substantial share of the initial investment can be covered under such scheme. This case study allows to draw general conclusions on the potential of SHS as a solution for domestic energy poverty in developing regions, on the financing gaps that hamper implementation and eventually on the required actions to overcome these.
•The state of the art of domestic energy poverty in developing regions is summarized.•A solar home system with lithium-ion battery is proposed as a solution.•The solar home system is assessed in contrast with current practices under energy poverty.•The solar home system is more cost effective and has an incremental cost advantage over time.•A financing scheme is suggested to overcome implementation barriers.
•The role of sustainability-oriented standards in global food markets is growing.•We analyze impacts of Fairtrade, Organic, and UTZ standards on coffee farmers in Uganda.•We use survey data and ...propensity score matching with multiple treatments.•Fairtrade increases living standards by 30% and reduces the prevalence and depth of poverty.•For the other two standards, no significant impacts are found.
Voluntary standards are gaining in importance in global markets for high-value foods. We analyze and compare impacts of three sustainability-oriented standards – Fairtrade, Organic, and UTZ – on the livelihoods of smallholder coffee farmers in Uganda. Using survey data and propensity score matching with multiple treatments, we find that Fairtrade certification increases household living standards by 30% and reduces the prevalence and depth of poverty. For the other two certification schemes, no significant impacts are found. Several factors that can explain differential impacts are discussed. Overly general statements about the effects of sustainability standards on smallholder livelihoods may be misleading.
Wetlands are valuable ecosystems providing a variety of important ecosystem services such as food supply and flood control. Due to increasing anthropogenic influences and the impact of climate ...change, wetlands are increasingly threatened and degraded. An effective monitoring of wetlands is therefore necessary to preserve and restore these endangered ecosystems. Earth Observation (EO) data offer a great potential to support cost-effective and large-scale monitoring of wetlands. Current state-of-the-art methods for wetland mapping, however, require large training data and manual effort and can therefore only be locally applied. The focus of this study is to evaluate a methodology for large-scale and highly automated wetland mapping based on current EO data streams. For this purpose, an algorithm for water and wetness detection based on multi-temporal optical imagery and topographic data is presented. Suitable spectral indices sensitive to water and wetness were identified using feature selection methods based on mutual information between optical indices and occurrence of water and wetness. In combination with the Topographic Wetness Index (TWI), these were used to derive monthly water and wetness masks using a dynamic thresholding approach. Aggregating all observations corrected for seasonal bias yielded flooding and wetness frequencies and the Water Wetness Presence (or Probability) Index (WWPI) as an indicator for wetland occurrence or a pre-inventory. To demonstrate the applicability of the proposed method, the algorithm is demonstrated at three study sites with different wetland types in Kenya/Uganda, Algeria, and Austria using Sentinel-2 MultiSpectral Instrument (MSI) imagery. For all sites, the overall accuracy was above 92%. User's and producer's accuracies were higher for water (>96%) than for wetness (>75%). Due to the high degree of automation and low processing time, the proposed method is applicable on a large scale and has already been applied during the production of the Copernicus High Resolution Water-Wetness Layer and within the European Space Agency (ESA) project GlobWetland Africa.
•A highly automated algorithm for water and wetness detection is proposed.•Tile-based image thresholding is applied to spectral and topographic indices.•Water is automatically detected with very high accuracy across different regions.•The Water and Wetness Probability Index provides a basic wetland inventory.
We compiled published and newly-obtained data on the directly-measured atmospheric deposition of total phosphorus (TP), filtered total phosphorus (FTP), and inorganic phosphorus (PO4-P) to open land, ...lakes, and marine coasts. The resulting global data base includes data for c. 250 sites, covering the period 1954 to 2012. Most (82%) of the measurement locations are in Europe and North America, with 44 in Africa, Asia, Oceania, and South-Central America. The deposition rates are log-normally distributed, and for the whole data set the geometric mean deposition rates are 0.027, 0.019 and 0.14 g m(-2) a(-1) for TP, FTP and PO4-P respectively. At smaller scales there is little systematic spatial variation, except for high deposition rates at some sites in Germany, likely due to local agricultural sources. In cases for which PO4-P was determined as well as one of the other forms of P, strong parallels between logarithmic values were found. Based on the directly-measured deposition rates to land, and published estimates of P deposition to the oceans, we estimate a total annual transfer of P to and from the atmosphere of 3.7 Tg. However, much of the phosphorus in larger particles (principally primary biological aerosol particles) is probably redeposited near to its origin, so that long-range transport, important for tropical forests, large areas of peatland and the oceans, mainly involves fine dust from deserts and soils, as described by the simulations of Mahowald et al. (Global Biogeochemical Cycles 22, GB4026, 2008). We suggest that local release to the atmosphere and subsequent deposition bring about a pseudo-diffusive redistribution of P in the landscape, with P-poor ecosystems, for example ombrotrophic peatlands and oligotrophic lakes, gaining at the expense of P-rich ones. Simple calculations suggest that atmospheric transport could bring about significant local redistribution of P among terrestrial ecosystems. Although most atmospherically transported P is natural in origin, local transfers from fertilised farmland to P-poor ecosystems may be significant, and this requires further research.
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