Decision Analysis and Information
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Item Exploring strategic priorities for regional agricultural research and development investments in southern Africa(Working Paper, 2014) Johnson, Michael E.; Benin, Samuel; You, Liangzhi; Diao, Xinshen; Chilonda, Pius; Kennedy, AdamAn in-depth quantitative analysis is undertaken in this paper to assist the Southern African Development Community (SADC) Secretariat, member countries, and development partners in setting future regional investment priorities for agricultural research and development in the SADC region. A primary goal of this work was to identify a range of agricultural research priorities for achieving sector productivity and overall economic growth in southern Africa, at both the country and regional levels. This is accomplished by adopting an integrated modeling framework that combines a disaggregated spatial analytical model with an economywide multimarket model developed specifically for the region.Item Assessment of groundwater availability from recession flows and instream flow requirements of rivers in South Africa(Report, 2015) Ebrahim, Girma Yimer; Villholth, Karen G.Groundwater is an important resource for multiple uses in South Africa. However, setting limits to its sustainable abstraction while assuring basic human needs is a must. Due to prevalent data scarcity related to groundwater replenishment, which is the traditional basis for estimating groundwater availability, the present report presents a novel method for determining allocatable groundwater in quaternary catchment through information on streamflows. Using established methodologies for assessing baseflows, recession flows, and instream ecological flow requirements, the methodology develops a combined stepwise methodology to determine annual groundwater storage volumes in the catchments using linear reservoir theory, essentially linking low flows proportionally to upstream groundwater storages. The approach was trialled for twenty-one perennial and relatively undisturbed quaternary catchments with long-term and good streamflow records. Using the Desktop Reserve Model to estimate instream ecological flow requirements of the streams and equating these with ecological groundwater reserve, excess baseflows were converted into groundwater storages on an annual basis. Results show that groundwater development potential exists in nineteen of the catchments, with upper limits to allocatable groundwater volumes ranging from 0.01 to 1.58 MCM/yr over the catchments. With a secured availability of these volumes 75% of the years, variability between years is assumed to be manageable. A significant (R2 = 0.86) correlation between baseflow index and the drainage time scale for the catchments underscored the physical basis of the methodology and also enables the reduction of the procedure by one step, omitting recession flow analysis. The method serves as an important complementary tool for the assessment of the groundwater part of the Reserve and the groundwater directed measures.Item Handbook of Remote Sensing, Inland Valley Wetland Cultivation and Preservation for Africa’s Green and Blue Revolution Using Multi-Sensor Remote Sensing(Book, 2015) GU, M.K.; Thenkabail, Prasad S.; Irshad, A.M.; Teluguntla, P.; Dheeravath, VenkateswarluItem Assessment of groundwater availability from recession flows and instream flow requirements of rivers in South Africa(Report, 2015) Ebrahim, Girma Yimer; Villholth, Karen G.Groundwater is an important resource for multiple uses in South Africa. However, setting limits to its sustainable abstraction while assuring basic human needs is a must. Due to prevalent data scarcity related to groundwater replenishment, which is the traditional basis for estimating groundwater availability, the present report presents a novel method for determining allocatable groundwater in quaternary catchment through information on streamflows. Using established methodologies for assessing baseflows, recession flows, and instream ecological flow requirements, the methodology develops a combined stepwise methodology to determine annual groundwater storage volumes in the catchments using linear reservoir theory, essentially linking low flows proportionally to upstream groundwater storages. The approach was trialled for twenty-one perennial and relatively undisturbed quaternary catchments with long-term and good streamflow records. Using the Desktop Reserve Model to estimate instream ecological flow requirements of the streams and equating these with ecological groundwater reserve, excess baseflows were converted into groundwater storages on an annual basis. Results show that groundwater development potential exists in nineteen of the catchments, with upper limits to allocatable groundwater volumes ranging from 0.01 to 1.58 MCM/yr over the catchments. With a secured availability of these volumes 75% of the years, variability between years is assumed to be manageable. A significant (R2 = 0.86) correlation between baseflow index and the drainage time scale for the catchments underscored the physical basis of the methodology and also enables the reduction of the procedure by one step, omitting recession flow analysis. The method serves as an important complementary tool for the assessment of the groundwater part of the Reserve and the groundwater directed measures.Item Plant elemental composition and portable X-rayfluore scence (pXRF) spectroscopy:quantification under differentanalytical parameters(Journal Article, 2016-03) Towett, Erick K.; Shepherd, Keith D.; Drake, B. LeeEmergence of portable X-ray fluorescence (pXRF) systems presents new opportunities for rapid, low-cost plant analysis, both as a lab system and in situ system. Numerous studies have extolled the virtues of using pXRF for a wide range of plant applications, however, for many such applications, there is need for further assessment with regards to analytical parameters for plant analysis. While pXRF is a potential powerful research tool for elemental composition analysis, its successful use in plant analysis is made more likely by having an understanding of X-ray physics, calibration process, and ability to test a variety of homogenous and well-characterized materials for developing a matrix-specific calibration. Because potential pXRF users may often underestimate the complexity of proper analysis, this study aims at providing a technical background for plant analysis using pXRF. The focus is on elemental quantification under different analytical parameters and different methods of sample presentation: direct surface contact under vacuum, placement in a sample cup with prolene as a seal, and without the aid of a vacuum. Direct analysis on the surface of a pXRF provided highest sensitivity and accuracy (R2 > 0.90) for light elements (Mg to P). Sulfur, K, and Ca can be reliably measured without the aid of a vacuum (R2 > 0.99, 0.97, and 0.93 respectively), although lower detection limits may be compromised. pXRF instruments provide plant data of sufficient accuracy for many applications and will reduce the overall time and budget compared with the use of conventional techniques. Sensitivity and accuracy are dependent on the instrument's settings, make, and model. © 2015 The Authors. X-Ray Spectrometry published by John Wiley & Sons, Ltd.Item Land health surveillance and response: a framework for evidence-informed land management(Journal Article, 2015-01) Shepherd, Keith D.; Shepherd, G.; Walsh, Markus G.Degradation of land health – the capacity of land, relative to its potential, to sustain delivery of ecosystem services – is recognized as a major global problem in general terms, but remains poorly quantified, resulting in a lack of specific evidence to focus action. Land health surveillance and response is designed to overcome limitations of current assessment approaches. It is modelled on science principles and approaches used in surveillance in the public health sector, which has a long history of evidence-informed policy and practice. Key elements of the science framework are: (i) repeated measurement of land health and associated risk factors using probability based sampling of well defined populations of sample units; (ii) standardized protocols for data collection to enable statistical analysis of patterns, trends, and associations; (iii) case definitions based on specific diagnostic criteria; (iv) rapid low cost screening tests to permit detection of cases and non-cases in large numbers of samples; (v) cost-effectiveness evaluation of interventions based on projected reduction in risks and problem incidence; (vi) design of statistically analysable studies to evaluate interventions in the real-world; (vii) meta-analysis of these data to guide design of public policy and intervention programmes; and (viii) integrating surveillance and the communication and use of results into operational systems as part of regular policy and practice. The scientific rigour of land health surveillance has potential to provide a sound basis for directing and assessing action to combat land degradation. Specialized national surveillance units should be established to harness and realign existing resources to provide integrated national land health systems. An international unit is needed to provide science and technology support to governments and develop standards, whereas an international agency should coordinate land health surveillance globally. Application of the surveillance framework could result in a shift away from a focus on rehabilitation of severely degraded land towards a preventive approach that focuses more on reducing distal risks at national and regional levels.Item A Bayesian network framework for project cost, benefit and risk analysis with an agricultural development case study(Journal Article, 2016-10) Yet, Barbaros; Constantinou, Anthony; Fenton, Norman; Neil, Martin; Luedeling, Eike; Shepherd, Keith D.Successful implementation of major projects requires careful management of uncertainty and risk. Yet such uncertainty is rarely effectively calculated when analysing project costs and benefits. This paper presents a Bayesian Network (BN) modelling framework to calculate the costs, benefits, and return on investment of a project over a specified time period, allowing for changing circumstances and trade-offs. The framework uses hybrid and dynamic BNs containing both discrete and continuous variables over multiple time stages. The BN framework calculates costs and benefits based on multiple causal factors including the effects of individual risk factors, budget deficits, and time value discounting, taking account of the parameter uncertainty of all continuous variables. The framework can serve as the basis for various project management assessments and is illustrated using a case study of an agricultural development project.Item Enhancing soil and landscape quality in smallholder grazing systems(Book Chapter, 2014-11-24) Steiner, J.L.; Franzluebbers, A.J; Neely, Constance; Ellis, T.; Aynekulu, ErmiasItem Improving the Availability of Quality Planting Materials Through Community-Based Seed and Seedling Systems: The Case of Rural Resource Centres in Cameroon.(Book Chapter, 2014) Takoutsing, B.; Degrande, A.; Tchoundjeu, Z.; Asaah, E.; Tsobeng, A.Item Vegetative propagation of Garcinia lucida Vesque (Clusiaceae) using leafy stem cuttings and grafting.(Journal Article, 2014) Takoutsing, B.; Tsobeng, A.; Tchoundjeu, Z.; Degrande, A.; Asaah, A.Item Scaling-up Sustainable Land Management Practices through the Concept of the Rural Resource Centre: Reconciling Farmers' Interests with Research Agendas(Journal Article, 2014-10-20) Takoutsing, B.; Tchoundjeu, Z.; Degrande, A.; Asaah, E.; Tsobeng, A.Item Soil fertility management(Book Chapter, 2014) Kimaro, Anthony A.; Birhane, E.; Mowo, J.; Betemariam, E.; Mpanda, Mathew; Hadgu, K.M.Item Impacts of water and soil conservation strategies on households’ food security in North West of Benin.(Journal Article, 2014) Egah, Janvier; Baco Mohamed Nasser; Akponikpè, Pierre B.I.; Djenontin, André Jonas; Moutouama Fidèle T.; Tossou, Rigobert C.; Fatondji, Dougbedji; Koala, Saidou; Assogba, Perceval; Kimaro, Anthony A.; Sokpon NestorItem Carbon stock in planted woodlots at Kongowe, Kibaha, Tanzania(Book Chapter, 2014) Kimaro, Anthony A.; Novak, K.D.; Shemdoe, R.S.; Chamshama, S. A.O.Item Development of a global inundation map at high spatial resolution from topographic downscaling of coarse-scale remote sensing data(Journal Article, 2015-03) Fluet-Chouinard, E.; Lehner, B.; Rebelo, Lisa-Maria; Papa, F.; Hamilton, S.K.Large-scale estimates of the area of terrestrial surface waters have greatly improved over time, in particular through the development of multi-satellite methodologies, but the generally coarse spatial resolution (tens of kms) of global observations is still inadequate for many ecological applications. The goal of this study is to introduce a new, globally applicable downscaling method and to demonstrate its applicability to derive fine resolution results from coarse global inundation estimates. The downscaling procedure predicts the location of surface water cover with an inundation probability map that was generated by bagged decision trees using globally available topographic and hydrographic information from the SRTM-derived HydroSHEDS database and trained on the wetland extent of the GLC2000 global land cover map. We applied the downscaling technique to the Global Inundation Extent from Multi-Satellites (GIEMS) dataset to produce a new high-resolution inundation map at a pixel size of 15 arc-seconds, termed GIEMS-D15. GIEMS-D15 represents three states of land surface inundation extents: mean annual minimum (total area, 6.5 × 106 km2 ), mean annual maximum (12.1 × 106 km2 ), and long-term maximum ( 17.3 × 106 km2 ); the latter depicts the largest surface water area of any global map to date. While the accuracy of GIEMS-D15 reflects distribution errors introduced by the downscaling process as well as errors from the original satellite estimates, overall accuracy is good yet spatially variable. A comparison against regional wetland cover maps generated by independent observations shows that the results adequately represent large floodplains and wetlands. GIEMS-D15 offers a higher resolution delineation of inundated areas than previously available for the assessment of global freshwater resources and the study of large floodplain and wetland ecosystems. The technique of applying inundation probabilities also allows for coupling with coarse-scale hydro-climatological model simulations.Item Capacity strengthening strategy through capacity needs assessment for country level strategic analysis and knowledge support system (SAKSS). Zambia(Report, 2014) Musonda, D.; Mavroeidi, V.; Tembo, S.; Matchaya, Greenwell C.; Nhlengethwa, Sibusiso; Chikwenya, N.; Sikombe, D.; Chilonda, PiusItem A global spectral library to characterize the world’s soil(Journal Article, 2016-04) Viscarra Rossel, Raphael A.; Behrens, T; Ben-Dor, E.; Brown, D.J.; Demattê, JAM; Shepherd, Keith D.; Shi, Z; Stenberg, B; Stevens, A; Adamchuk, V; Aïchik, H; Barthèsl, BG; Bartholomeus, H.M.; Bayer, AD; Bernoux, Martial; Böttchero, K; Brodský, L; Du, CW; Chappell, A; Fouad, Y; Genot, V; Gómez, C.; Grunwald, S.; Gubler, A; Hedley, CB; Knadel, M; Morrás, HJM; Nocita, M; Ramírez Lopez, L.; Roudier, P.; Rufasto Campos, EM; Sanborn, P; Sellitto, VM; Sudduth, KA; Rawlins, BG; Walter, C; Winowiecki, Leigh Ann; Hong, SY; Ji, WSoil provides ecosystem services, supports human health and habitation, stores carbon and regulates emissions of greenhouse gases. Unprecedented pressures on soil from degradation and urbanization are threatening agro-ecological balances and food security. It is important that we learn more about soil to sustainably manage and preserve it for future generations. To this end, we developed and analyzed a global soil visible–near infrared (vis–NIR) spectral library. It is currently the largest and most diverse database of its kind. We show that the information encoded in the spectra can describe soil composition and be associated to land cover and its global geographic distribution, which acts as a surrogate for global climate variability. We also show the usefulness of the global spectra for predicting soil attributes such as soil organic and inorganic carbon, clay, silt, sand and iron contents, cation exchange capacity, and pH. Using wavelets to treat the spectra, which were recorded in different laboratories using different spectrometers and methods, helped to improve the spectroscopic modelling. We found that modelling a diverse set of spectra with a machine learning algorithm can find the local relationships in the data to produce accurate predictions of soil properties. The spectroscopic models that we derived are parsimonious and robust, and using them we derived a harmonized global soil attribute dataset, which might serve to facilitate research on soil at the global scale. This spectroscopic approach should help to deal with the shortage of data on soil to better understand it and to meet the growing demand for information to assess and monitor soil at scales ranging from regional to global. New contributions to the library are encouraged so that this work and our collaboration might progress to develop a dynamic and easily updatable database with better global coverage. We hope that this work will reinvigorate our community's discussion towards larger, more coordinated collaborations. We also hope that use of the database will deepen our understanding of soil so that we might sustainably manage it and extend the research outcomes of the soil, earth and environmental sciences towards applications that we have not yet dreamed of.Item Understanding of the current practices, challenges and opportunities of the green economy in Limpopo Province [South Africa](Journal Article, 2015) Nhemachena, Charles; Jonas, S.; Karuaihe, S.The paper investigates the current practices of the green economy, and challenges and opportunities in the Limpopo Province of South Africa. The paper is based on a baseline study designed to gather data from key informants in Limpopo provincial, district and local municipalities. Twenty-three key informants in the province were interviewed. Primary data collected from key informants was supplemented by secondary data from document reviews. Descriptive statistics were used to analyse data on the current practices of green economy, and challenges and opportunities in the province. Findings from the study suggest that there is generally significant awareness of the green economy concept across the provincial district and local municipalities in Limpopo Province. However, there are gaps in terms of information gathering, storage and sharing on green economy activities in the district municipalities, provincial and national departments. The main barriers constraining the implementation of green economy initiatives in the municipalities include lack of information; shortage of workers with full knowledge on green economy; shortage of training programmes on green economy; and costs of implementation. The main recommendations from this research include the need to improve awareness of green economy activities across all levels in the province, especially with communities’ need for evidence-based research to demonstrate the potential of green economy activities that can contribute to job creation and poverty reduction; and training of officials on how the green economy can contribute to addressing developmental challenges such as service delivery, job creation, local economic development and poverty reduction.Item Trends in public agricultural spending in Swaziland(Brief, 2014) Nhlengethwa, S.B.; Matchaya, Greenwell C.; Musaba, Emmanuel; Chilonda, PiusItem Development goals should enable decision-making.(Journal Article, 2015) Shepherd, Keith D.; Hubbard, D.; Fenton, N.; Claxton, K.; Luedeling, Eike; Leeuw, Jan de