459 research outputs found

    Possible Effects of Seasonal Fires on Drought Across the Northern Sub-Saharan African Region

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    Recent satellite-based studies have revealed that the northern sub-Saharan African (NSSA) region has one of the highest biomass-burning rates per unit land area among all regions of the world. Because of the high concentration and frequency of fires in this region, with the associated abundance of heat release and gaseous and particulate smoke emissions, biomass-burning activity is believed to be a major driver of the regional carbon, energy, and water cycles. We acknowledge that the rainy season in the NSSA region is from April to September while biomass burning occurs mainly during the dry season (October to March). Nevertheless, these two phenomena are indirectly coupled to each other through a chain of complex processes and conditions, including land-cover and surface-albedo changes, the carbon cycle, evapotranspiration, drought, desertification, surface water runoff, ground water recharge, and variability in atmospheric composition, heating rates, and circulation. In this presentation, we will examine the theoretical linkages between these processes, discuss the preliminary results based on satellite data analysis, and provide an overview of plans for more integrated research to be conducted over the next few years

    Coherent Evaluation of Aerosol Data Products from Multiple Satellite Sensors

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    Aerosol retrieval from satellite has practically become routine, especially during the last decade. However, there is often disagreement between similar aerosol parameters retrieved from different sensors, thereby leaving users confused as to which sensors to trust for answering important science questions about the distribution, properties, and impacts of aerosols. As long as there is no consensus, and the inconsistencies are not well characterized and understood, there will be no way of developing reliable model inputs and climate data records from satellite aerosol measurements. Fortunately, the Aerosol Robotic Network (AERONET) is providing well-calibrated globally representative ground-based aerosol measurements corresponding to the satellite-retrieved products. Through a recently developed web-based Multi-sensor Aerosol Products Sampling System (MAPSS), we are utilizing the advantages offered by collocated AERONET and satellite products to characterize and evaluate aerosol retrieval from multiple sensors. Indeed, MAPSS and its companion statistical tool AeroStat are facilitating detailed comparative uncertainty analysis of satellite aerosol measurements from Terra-MODIS, Aqua-MODIS, Terra-MISR, Aura-OMI, Parasol-POLDER, and Calipso-CALIOP. In this presentation, we will describe the strategy of the MAPSS system, its potential advantages for the aerosol community, and the preliminary results of an integrated comparative uncertainly analysis of aerosol products from multiple satellite sensors

    The Distributional Impact of Healthcare Financing in Nigeria: A Case Study of Enugu State

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    The deregulation of healthcare financing and supply in Nigeria has shifted the healthcare system towards competitive market ideals. Households' decision to utilize healthcare is identical with healthcare financing. This financing arrangement has potentials for income redistribution in a society with already high levels of inequality in resource redistribution. This study attempts to examine the extent to which this system of healthcare financing leads to catastrophic expenditures, defined as a threshold percentage of a household's income, and the extend of impoverishment arising from healthcare spending. It also uses the Aronson, Johnson, and Lambert (1994) decomposition framework to analyze redistributive effects in terms of vertical and horizontal inequities, as well as re-ranking effect. The study finds that healthcare spending engenders high incidence of catastrophic spending and impoverishment in the population. It also finds that healthcare spending is pro-rich in its redistributive effect, with significant vertical and horizontal inequities as well as reranking inherent in the system. The paper suggests policy reforms that separate healthcare utilization from healthcare financing if the poor are to have access to healthcare services.Redistributive effects, Healthcare financing, Catastrophic financing, Impoverishing effects, Equity, Nigeria

    Contingent Valuation in Community-Based Project Planning: The Case of Lake Bamendjim Fishery Restocking in Cameroon

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    The study examined the usefulness and relevance of the contingent valuation method (CVM) in community-based (CB) project planning and implementation. To elicit willingness to pay (WTP) values for the restocking of Lake Bamendjim with Tilapia nilotica and Heterotis niloticus fish species, the study used pre-tested questionnaires interviewer-administered to 1,000 randomly selected households in the Bambalang Region of Cameroon.The datawere elicitedwith the conventional referendumdesign and analysed using a referendum model. Empirical findings indicated that about 85% of the sampled households were willing to pay about CFAF1,054 (US$2.1) for the restocking project. This amount was found to be significantly related to the starting price used in the referendum design, household income, the gender of the respondent, the age of the respondent, household poverty status, and previous participation of a household in a community development project.The findings prompted the following recommendations. Firstly, in order to reduce community burden due to cash constraints, it is advisable for the mean estimate obtained for the scheme to be split into four instalments over a year. Secondly, since the success of the scheme largely depends on the governing roles of the scheme, it is further advisable for the community to allowthemanagement of the scheme to be handled by the elderly community members. Finally, it will be important during the financing of the scheme, to levy wealthier household heads an amount sufficient to subsidize poorer household heads who cannot afford to pay the threshold price.

    Detailed Evaluation of MODIS Fire Radiative Power Measurements

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    Satellite remote sensing is providing us tremendous opportunities to measure the fire radiative energy (FRE) release rate or power (FRP) from open biomass burning, which affects many vegetated regions of the world on a seasonal basis. Knowledge of the biomass burning characteristics and emission source strengths of different (particulate and gaseous) smoke constituents is one of the principal ingredients upon which the assessment, modeling, and forecasting of their distribution and impacts depend. This knowledge can be gained through accurate measurement of FRP, which has been shown to have a direct relationship with the rates of biomass consumption and emissions of major smoke constituents. Over the last decade or so, FRP has been routinely measured from space by both the MODIS sensors aboard the polar orbiting Terra and Aqua satellites, and the SEVIRI sensor aboard the Meteosat Second Generation (MSG) geostationary satellite. During the last few years, FRP has been gaining recognition as an important parameter for facilitating the development of various scientific studies relating to the quantitative characterization of biomass burning and their emissions. Therefore, we are conducting a detailed analysis of the FRP products from MODIS to characterize the uncertainties associated with them, such as those due to the MODIS bow-tie effects and other factors, in order to establish their error budget for use in scientific research and applications. In this presentation, we will show preliminary results of the MODIS FRP data analysis, including comparisons with airborne measurements

    Assessment of the Vulnerability of Water Resources to Seasonal Fires Across the Northern Sub-Saharan African Region

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    The northern sub-Saharan African (NSSA) region, extending from the southern fringes of the Sahara to the Equator, and stretching west to east from the Atlantic to the Indian ocean coasts, plays a prominent role in the distribution of Saharan dust and other airborne matter around the region and to other parts of the world, the genesis of global atmospheric circulation, and the birth of such major (and often catastrophic) events as hurricanes. Therefore, this NSSA region represents a critical variable in the global climate change equation. Recent satellite-based studies have revealed that the NSSA region has one of the highest biomass-burning rates per unit land area among all regions of the world. Because of the high concentration and frequency of fires in this region, with the associated abundance of heat release and gaseous and particulate smoke emissions, biomass-burning activity is believed to be a major driver of the regional carbon, energy, and water cycles. We acknowledge that the rainy season in the NSSA region is from April to September while biomass burning occurs mainly during the dry season (October to March). Nevertheless, these two phenomena are indirectly coupled to each other through a chain of complex processes and conditions, including land-cover and surface-albedo changes, the carbon cycle, evapotranspiration, drought, desertification, surface water runoff, ground water recharge, and variability in atmospheric composition, heating rates, and circulation. In this presentation, we will examine the theoretical linkages between these processes, discuss the preliminary results based on satellite data analysis, and provide an overview of plans for more integrated research to be conducted over the next few years

    Researching the Link Between Biomass Burning and Drought Across the Northern Sub-Saharan African Savanna/Sahel Belt

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    The northern sub-Saharan African (NSSA) region, bounded by the Sahara, Equator, and the West and East African coastlines, is subjected to intense biomass burning every year during the dry season. This is believed to be one of the drivers of the regional carbon and energy cycles, with serious implications for the water cycle anomalies that probably contribute to drought and desertification. In this presentation, we will discuss a new multi-disciplinary research in the NSSA region, review progress, evaluate preliminary results, and interact with the research and user communities to examine how best to coordinate with other research activities in order to address related environmental issues most effectively

    Are malaria treatment expenditures catastrophic to different socio-economic and geographic groups and how do they cope with payment? A study in southeast Nigeria.

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    OBJECTIVES: To determine the inequities in the household income depletion resulting from malaria treatment expenditures, the sacrifice of basic household needs (catastrophe) and the differences in payment strategies among different socio-economic and geographic groups in southeast Nigeria. METHODS: Data were gathered through pre-tested, structured questionnaires from a random sample of 2 250 householders in rural and urban parts of southeast Nigeria. The level of catastrophic malaria treatment expenditure was computed as the percentage of average monthly malaria treatment expenditure divided by the average monthly non-food household expenditure, using a threshold of 5%. Socio-economic inequity was established using a socio-economic status (SES) index, while a rural-urban comparison examined geographic disparities. RESULTS: The average cost to treat a case of malaria was 796.5 Naira (6.64)foradultsand789.0Naira(6.64) for adults and 789.0 Naira (6.58) for children. The monthly malaria treatment expenditure as a proportion of monthly household non-food expenditure was 7.8%, 8.5%, 5.5% and 3.9% for the most poor, very poor, poor and least poor SES groups respectively. Malaria treatment accounted for 7.1% and 5.0% of non-food expenditures for rural and urban dwellers, respectively. More than 95% of the people financed their treatment through out-of-pocket payment (OOP), with no SES and rural-urban variance, as opposed to insurance payment mechanisms and fee exemptions. CONCLUSION: There were socio-economic and geographic inequities in the financial burden resulting from malaria treatment. The treatment expenditure depleted more of the aggregate income of the two worse-off SES (Q1 and Q2) and of the rural dwellers. Government and donor agencies should institute the abolition of user fees for malaria, the transition from OOP to pre-payment mechanisms and the improvement of physical access to appropriate malaria treatment services, as well as subsidies and deferrals in order to engender financial risk protection from malaria treatment

    Multi-Satellite Synergy for Aerosol Analysis in the Asian Monsoon Region

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    Atmospheric aerosols represent one of the greatest uncertainties in environmental and climate research, particularly in tropical monsoon regions such as the Southeast Asian regions, where significant contributions from a variety of aerosol sources and types is complicated by unstable atmospheric dynamics. Although aerosols are now routinely retrieved from multiple satellite Sensors, in trying to answer important science questions about aerosol distribution, properties, and impacts, researchers often rely on retrievals from only one or two sensors, thereby running the risk of incurring biases due to sensor/algorithm peculiarities. We are conducting detailed studies of aerosol retrieval uncertainties from various satellite sensors (including Terra-/ Aqua-MODIS, Terra-MISR, Aura-OMI, Parasol-POLDER, SeaWiFS, and Calipso-CALIOP), based on the collocation of these data products over AERONET and other important ground stations, within the online Multi-sensor Aerosol Products Sampling System (MAPSS) framework that was developed recently. Such analyses are aimed at developing a synthesis of results that can be utilized in building reliable unified aerosol information and climate data records from multiple satellite measurements. In this presentation, we will show preliminary results of. an integrated comparative uncertainly analysis of aerosol products from multiple satellite sensors, particularly focused on the Asian Monsoon region, along with some comparisons from the African Monsoon region

    Quantitative Evaluation of MODIS Fire Radiative Power Measurement for Global Smoke Emissions Assessment

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    Satellite remote sensing is providing us tremendous opportunities to measure the fire radiative energy (FRE) release rate or power (FRP) from open biomass burning, which affects many vegetated regions of the world on a seasonal basis. Knowledge of the biomass burning characteristics and emission source strengths of different (particulate and gaseous) smoke constituents is one of the principal ingredients upon which the assessment, modeling, and forecasting of their distribution and impacts depend. This knowledge can be gained through accurate measurement of FRP, which has been shown to have a direct relationship with the rates of biomass consumption and emissions of major smoke constituents. Over the last decade or so, FRP has been routinely measured from space by both the MODIS sensors aboard the polar orbiting Terra and Aqua satellites, and the SEVIRI sensor aboard the Meteosat Second Generation (MSG) geostationary satellite. During the last few years, FRP has steadily gained increasing recognition as an important parameter for facilitating the development of various scientific studies and applications relating to the quantitative characterization of biomass burning and their emissions. To establish the scientific integrity of the FRP as a stable quantity that can be measured consistently across a variety of sensors and platforms, with the potential of being utilized to develop a unified long-term climate data record of fire activity and impacts, it needs to be thoroughly evaluated, calibrated, and validated. Therefore, we are conducting a detailed analysis of the FRP products from MODIS to evaluate the uncertainties associated with them, such as those due to the effects of satellite variable observation geometry and other factors, in order to establish their error budget for use in diverse scientific research and applications. In this presentation, we will show recent results of the MODIS FRP uncertainty analysis and error mitigation solutions, and demonstrate their implications for biomass burning emissions assessment
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