Browsing Okavango Research Institute (ORI) by Title
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Mantlana, K.; Veenendaal, E.; Arneth, A.; Grispen, V.; Bonyongo, C.; Heitkonig, I.; Lloyd, J. (Blackwell, www.blackwell.co.uk, August NaN, 2009)[more][less]
Abstract: C4 savanna grass species, Digitaria eriantha, Eragrostis lehmanniana and Panicum repens, were grown under optimum growth conditions with the aim of characterizing their above- and below-ground biomass allocation and the response of their gas exchange to changes in light intensity, CO2 concentration and leaf-to-air vapour pressure deficit gradient (Dl). Digitaria eriantha showed the largest above- and below-ground biomass, high efficiency in carbon gain under light-limiting conditions, high water use efficiency (WUE) and strong stomatal sensitivity to Dl (P = 0.002; r2 = 0.5). Panicum repens had a high aboveground biomass and attained high light saturated photosynthetic rates (Asat, 47 μmol m−2 s−1), stomatal conductance, (gsat, 0.25 mol m−2 s−1) at relatively high WUE. Eragrostis lehmanniana had almost half the biomass of other species, and had similar Asat and gsat but were attained at lower WUE than the other species. This species also showed the weakest stomatal response to Dl (P = 0.19, r2 = 0. 1). The potential ecological significance of the contrasting patterns of biomass allocation and variations in gas exchange parameters among the species are discussed. Description: Some mathematical formulas in the title and abstract may not appear as they are in the original article URI: http://hdl.handle.net/10311/872 Files in this item: 1
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Mataka, L.M.; Sajidu, S.M.I.; Masamba, W.R.L.; Mwatseteza, J.F. (Academic Journals: http://www.academicjournals.org/, May NaN, 2010)[more][less]
Abstract: There is a widespread recognition that the presence of heavy metals such as cadmium in water is hazardous to the environment and human health and their discharge into surface waters is of great concern worldwide. The use of natural coagulants such as Moringa for heavy metal removal from water replacing expensive imported synthetic coagulants is particularly appropriate for agro-based developing countries such as Malawi. This study was aimed at investigating the potential of Moringa stenopetala and Moringa oleifera in the removal of cadmium(II) ions from water. The potential of Mstenopetala for cadmium removal was investigated by means of jar test beakers. With an initial cadmium concentration of 7 mg/l,M. stenopetala seed powder, at a dose of 2.50 g/100 ml, reduced the concentration of cadmium by 53.8%. Comparison of removal capacities between M. stenopetala and Moleifera indicated that M. stenopetala was more effective than M. oleifera in removing cadmium from water (p < 0.05). Increasing initial cadmium concentration, agitation time and ionic strength reduced cadmium removal. Equilibrium sorption was attained at pH 5 where maximum cadmium removals were 82.7 and 70.7% using M. stenopetala and M. oleifera respectively. There was a reduction in cadmium removal between 0 to 60°C for M. stenopetala and 0 - 40°C for M. oleifera before increasing with subsequent temperature increases. It was also shown that cadmium sorption at 30°C and pH 3 for the M. oleifera could best be modelled by the Freundlich isotherm whereas the Langmuir model is slightly better than the Freundlich isotherm in the case of the M. Stenopetala. The energies of adsorption from Dubinin-Radushkevich models have indicated that cadmium removal using both powders is based on physisorption. The results indicate that M. stenopetala and M. oleifera have potential in cadmium remediation of polluted waters. URI: http://hdl.handle.net/10311/786 Files in this item: 1
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Gobagoba, L.; Meyer, T.; Ringrose, S.; Kampunzu, A.B.; Coetzee, S. (Botswana Society, NaN, 2005)[more][less]
Abstract: Calcrete deposits of the Qangwa area, northwestern Botswana are evaluated on the basis of satellite imagery and sedimentological analysis. Enhanced Thematic Mapper imagery interpretation combined with field evidence has led to identification of the calcrete. This project aims at making a detailed surficial geology map accompanied by a report as a step in expanding the knowledge of calcretes. It also attempts to develop an understanding of the relationship in the timing of the late Quaternary wetter and drier phases. A digital map using GIS and remote sensing applications was developed from both analysed data and fieldwork. Data analysis revealed five types of calcretes and a calcareous soil. Hardpan calcrete along with brecciated and conglomeratic calcrete dominate the interfluves and are believed to predate the formation of nodular and honeycomb calcrete which occupy the valleys. The older hardpan associated types may have developed following regional wet/warm periods the last of which has been dated elsewhere as occurring c. 120,000. The younger valley calcretes show different mechanisms of formation, and are believed to have been developed following incision and palaeo-lake establishment, c. 25,000 years ago. URI: http://hdl.handle.net/10311/943 Files in this item: 1
Gobagoba 2005 calcrete mapping.pdf (2.409Mb) -
Mbaiwa, J.E. (Elsevier, www.elsevier.com, NaN, 2004)[more][less]
Abstract: This paper reviews available literature concerning water resources use in the Okavango River Basin (ORB). It describes a number of common arguments regarding possibilities for the emergence of violent conflict in and among Basin states, particularly those states party to the Okavango River Basin Commission (Okacom)—Angola, Botswana and Namibia. The paper presents data concerning present and future water demands and examines a number of formal, institutional steps taken by global and regional actors to facilitate sustainable development, natural resources management and peaceful cooperation in the Basin. Contrary to trends in much of the literature, the paper suggests that there is great scope for enhanced inter-state cooperation in the Basin. It argues that to achieve sustainable utilisation of water resources and avoid violent conflict in the ORB, an integrated management plan for the entire basin needs to be developed. In addition, each basin member-state should observe international and regional conventions and treaties governing the use of water resources when designing national water development projects that require the use of water from the ORB. URI: http://hdl.handle.net/10311/934 Files in this item: 1
Mbaiwa Causes and Solutions.pdf (1.775Mb) -
Swatuk, L.A.; Kgomotso, P.K. (Elsevier, www.elsevier.com/locate/pce, NaN, 2007)[more][less]
Abstract: Supplying adequate water and sanitation facilities to small, scattered rural communities and/or large, fast growing settlements in remote areas is a challenge not easily met anywhere in the world. This article focuses on just such a challenge in the remote, rural area of Ngamiland District in north-western Botswana. Drawing on a combination of critical analysis of government and secondary data, participant observation, and key stakeholder interviews conducted over the period 2004–2006, the article shows that despite a good aggregate record of supplying water and sanitation throughout the country, there are abiding, often serious, problems with supply in remote areas. The research reveals that due to a combination of limited human and financial resource capacity, government policy that deliberately under-serves remote areas in order to encourage resettlement, and complacence among key decision-takers, supply problems go unresolved. The article suggests four key interventions as possible ways forward: using the Okavango Delta Management Plan (ODMP) process as a guiding framework for institutional reform; linking research directly to human resource capacity development; treating water as both a social and an economic good; and soliciting an IWRM ‘champion’ to drive the political process. URI: http://hdl.handle.net/10311/501 Files in this item: 1
Swatuk2007WATERSUPPLY.pdf (1.584Mb) -
Mbaiwa, J.E. (Elsevier, September 5, 2010)[more][less]
Abstract: The Community-Based Natural Resource Management (CBNRM) program in Botswana aims at achieving conservation and rural development. In the Okavango Delta, some communities are involved in tourism through CBNRM to improve their livelihoods. However, research has not adequately analyzed changes caused by CBNRM on traditional livelihood activities and lifestyles. This study, therefore, uses modernization theory to analyze changes on traditional livelihood activities and lifestyles caused by CBNRM at Sankoyo, Mababe and Khwai villages in the Okavango Delta. Using primary and secondary data sources, results indicate that CBNRM is causing a decline in traditional livelihood activities like subsistence hunting, gathering, crop and livestock farming. As a result, a modern cash economy has emerged. New livelihood activities done by communities include: employment in CBNRM projects, the sale of crafts to tourists and thatching grass to tourism lodges. Income derived from CBNRM affords households to build modern houses, buy foreign foods and household equipment like: four-burner gas stoves, kitchen utensils, and satellite televisions. Conversely, this causes a decline in the consumption of traditional foods and the use of huts and household utensils. CBNRM is thus a modernization tool since it is causing a transformation of traditional livelihood activities and lifestyles. However, even though changes in livelihood activities and lifestyles may be an indication of the dynamism of culture in study villages, sudden change and modernization may increase livelihood insecurity. As such, tourism planning should ensure that modernization is sensitive to traditional economic systems and the need for rural livelihood sustainability. URI: http://hdl.handle.net/10311/805 Files in this item: 1
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Characterization of arsenic occurrence in the water and sediments of the Okavango Delta, NW BotswanaHuntsman-Mapila, P.; Mapila, T.; Letshwenyo, M.; Wolski, P.; Hemond, C. (Elsevier Science B.V. Amsterdam; http://www.elsevier.com/wps/find/journaldescription.cws_home/768/description#description, NaN, 2006)[more][less]
Abstract: Detailed chemical analyses were performed on surface water, groundwater and sediment samples collected from the Okavango Delta between February and November 2003 in order to examine the distribution and geochemistry of naturally occurring As in the area. Surface water in the Okavango Delta, which is neutral to slightly acidic and has high dissolved organic C (DOC), was found to be slightly enriched in As when compared to a global value for stream water. Of the 20 new borehole analyses from this project, six were found to have values exceeding 10 ug/L. the current World Health Organization provisional guideline value for As. The results from field speciation indicate that As(III) is slightly more predominant than As(V). There is a positive correlation between As and pH and between As and DOC in the groundwater samples. For the sediment samples, there is a positive correlation between As and Co. As and Fe. As and loss on ignition (LOI) and between As and the percent fines in the sample. Reductive dissolution of oxides and hydroxides in the sediments with organic C as an electron acceptor is the likely mechanism for the release of As from the sediments into the groundwater. URI: http://hdl.handle.net/10311/135 Files in this item: 2
huntsman-mapila_app_geochem.pdf (3.170Mb)license.txt (1.998Kb) -
Magole, I. (Routledge, December 14, 2009)[more][less]
Abstract: The contestation for common pool resources in Botswana pits powerful institutions such as national governments and international organisations against powerless local communities who continue to rely heavily on these resources despite all attempts to dislodge them. This paper explores how common pool resource management has shifted from locally based and peoplecentred endogenous resource management to state-defined and controlled forms. This shift has marginalised San communities, who have historically relied on their commons for survival. The paper is informed by case studies of two San villages in Ngamiland District in northwestern Botswana, Mababe and Phuduhudu, both situated adjacent to national parks. The government and donor agencies introduced community-based natural resource management with the promise of reversing the loss of the commons for such groups as the San; however, the evidence on the ground suggests the promise has not been translated into practice. URI: http://hdl.handle.net/10311/793 Files in this item: 1
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Thakadu, T.; Irani, T.; Telg, R. (Taylor & Francis, February 18, 2011)[more][less]
Abstract: An effective response to global environmental challenges requires analysis of communication patterns, processes and approaches. In addition, improving communication through emerging information and communication technologies (ICT) also must be explored. Understanding recipients’ perception of the innovations used in information diffusion is also necessary. This study, using a sample of 120 subjects, examined attitudes of leaders of community-based natural resources organizations toward two approaches used in public instructional communication in the Okavango Delta, Botswana. The quasi-experimental study also explored the effect of demographic variables on subjects’ attitudes. The results demonstrated more favorable attitudes toward the visualized method than the traditional verbal method, suggesting subjects’ preference and acceptance for the visualized public instructional communication approaches. Results also indicated a differential effect of age on attitude toward methods of communication. The results of the study highlight the importance for practitioners to use integrated communication approaches in the public sphere. Suggestions for future research are offered. URI: http://hdl.handle.net/10311/769 Files in this item: 1
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Swatuk, L.A.; Motsholapheko, M. (Elsevier, www.elsevier.com/locate/pce, NaN, 2008)[more][less]
Abstract: The Boteti River is an ephemeral outflow of the Okavango River. It lies in the north-western part of Botswana where about 25,000 people reside across a number of widely scattered villages and informal settlements. The river, with its seasonal streams and pans, is vital to the livelihoods of these people, their livestock, and the wildlife that share this physical space. A combination of factors has led to widespread degradation of the physical resource base – both in the river bed itself and in the wider environment. As part of its outreach role, the Harry Oppeheimer Okavango Research Centre has undertaken a multi-year project along the Boteti River to assist people there with the rehabilitation of their resource base. The globally influential concept of integrated water resources management (IWRM) provides the analytical framework, in particular its emphasis on dialogue and stakeholder participation. The project has three primary aspects: facilitation of a dialogue platform; action-research; outreach and information dissemination. After two years of implementation, the project has collected a good deal of data and established a River Basin Forum with a common vision. However, the project continues to face difficulties in implementation: participation is limited; myths regarding resource degradation are difficult to dispel; meaningful communication among differently empowered actors is hard to achieve; and there are numerous human, financial and technological limitations. The primary researchers continue to alter their methods in the hope of achieving a functioning River Basin Committee (RBC), but observe that the globalized ideals of IWRM are, in this particular case at least, of limited use when attempting to alter localized management practices in basins with deeply embedded social and cultural practices. URI: http://hdl.handle.net/10311/504 Files in this item: 1
Motsholapheko2008IntegratedWater.pdf (1.154Mb) -
Toteng, E.N.; Mbaiwa, J.E.; Moswete, N.N. (Botswana Society, NaN, 2005)[more][less]
Abstract: This paper is derived from a broader study that examined community attitudes and perceptions towards ecological issues in Maun and Gaborone to determine how these could be harnessed towards ecologically sustainable urban development. The major problem in the two study sites is that there has been rapid urban growth since the 1970s, but very little attention has been devoted to the environmental implications of that growth. The environmental issues on which community attitudes and perceptions were sought included the following: urban water and waste water; urban solid waste management; urban impacts on wildlife; and urban energy conservation and management. These issues were selected on the basis of what the authors were able to obtain socio-ecological data on, given the time and financial constraints of thestudy. The urban ecosystems management model is used as an analytical framework that could be further harnessed by policy and decision-makers to mobilize stakekeholders towards sustainable urban development. A social survey method was used to generate data among heads of households in Maun and Gaborone. It was found that most ordinary members of the community were not involved by government authorities in decision-making affecting natural resource use and environmental issues. However and in general, the communities had positive attitudes and perceptions towards environmental issues. The major draw-back is that these communities are generally not consulted by state agencies in decision-making processes affecting their environment. It is concluded that this is inimical to ecological urban development. URI: http://hdl.handle.net/10311/945 Files in this item: 1
Toteng 2005 Community.pdf (2.443Mb) -
Kgathi, D.L.; Ngwenya, B.N. (Botswana Society, http://www.botsoc.org.bw, NaN, 2005)[more][less]
Abstract: This paper examines the impact of Community-Based Natural Resource Management (CBNRM) in Ngamiland over the past ten years. It shows that CBNRM has made some strides in strengthening and creating new organisations/ institutions, empowering local communities, creating social networks and improving the institutional capacity of community trusts. Communities receive benefits from employment opportunities, social infrastructure, provision of transport, and assistance on meeting the costs of funerals. However, the contribution of most of the benefits to livelihood diversification is limited as they mainly accrue to the communities rather than individuals. The programme faces many challenges, such as limited institutional capacity for running organizations, insecurity of tenure, stakeholder conflicts, mismanagement of funds, and problems of how to use and equitably distribute the financial benefits to individual households. URI: http://hdl.handle.net/10311/965 Files in this item: 1
Kgathi2005 CBNRM.pdf (2.852Mb) -
Sebele, L.S. (Elsevier, www.elsevier.com/locate/tourman, NaN, 2010)[more][less]
Abstract: The impact of Community-Based Natural Resource Management (CBNRM) is seen by many as a ‘win-win’ situation with reference to natural resources conservation and the improvement of local communities’ livelihoods. However, community engagements in CBNRM and tourism have elicited many views as far as natural resources utilization is concerned. Some affirm the importance of CBNRM; others question it, while others call for its improvement. The premise of this study is to investigate the benefits and challenges of community-based tourism in one community of Botswana. Results show that although some benefits have been identified, there remain many challenges for the Khama Rhino Sanctuary Trust (KRST). It is evident that for community-based tourism to bring more benefits for locals, more interaction is needed between them and the Trust management. Increased local involvement and participation will help to ensure that people are empowered and the conservation of natural resources takes place. This paper asserts that community-based ventures, if properly run and managed, can promote the conservation of natural resources and increase local benefits through participation in tourism activities. Description: Case Study URI: http://hdl.handle.net/10311/503 Files in this item: 1
Sebele2010TourismVentures.pdf (1.383Mb) -
Mmopelwa, G.; Ngwenya, B.N. (Academic Journals, December 4, 2010)[more][less]
Abstract: The Okavango Delta is the largest multi-species and multi-gear fishery in Botswana. However, there is lack of an understanding of the nature of fish market in the Delta. The objectives of the survey were (1) to identify and describe the socio economic profile of the fishers in the fishing market, (2) to describe the operations of the market and (3) to identify market constraints of fishing. A structured questionnaire was used to collect data from fishers in four study sites in the Delta. The study revealed that fishing market in the Okavango Delta is very ‘informal’ in nature, with almost no intermediaries, and catering only for the local population. Lack of preservation facilities, transport, low levels of skills and lack of access to credit are the various constraints facing fishers. URI: http://hdl.handle.net/10311/739 Files in this item: 1
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Huntsman-Mapila, P.; Kampunzu, A.B.; Vink, B.; Ringrose, S. (Elsevier; http://www.elsevier.com/wps/find/journaldescription.cws_home/503361/description#description, NaN, 2005)[more][less]
Abstract: [Please note that chemical formulae do not display properly]:The siliciclastic sediments of the Okavango inland Delta of northwest Botswana have a modal composition of quartz arenites and result from a complex history, including transport by river and deposition in a nascent rift basin located in a desert environment with input of aeolian sands. The geochemical composition of sediments from the Okavango Delta was determined in order to constrain the role of weathering at the source and the composition of the source rocks. The chemical analyses and the interelement ratios show a broad compositional range usually encompassing the PAAS composition. The chemical index of alteration (CIA) values and the A-CN-K diagram define an evolution trend which can be interpreted using a mixing model involving a strongly weathered component which corresponds to the sedimentary fraction transported by the Okavango River and a relatively immature component which corresponds to the aeolian sand component of the Okavango sediments. Field geological data supported by geochemical ratios involving elements with affinity for mafic-ultramafic and felsic rocks such as Th/Cr, Th/Sc, La/Sc, La/Co and Eu/Eu* support a source area including mafic-ultramafic and felsic rocks, with or without intermediate rocks. The relationships between certain elements (Cr-Ni, Na2O-Al2O3, K2O- Al2O3) refine the interpretation by pointing to the existence of at least three source rock end-members, including a felsic rock source and pyroxene-rich and olivine-rich mafic-ultramafic source rocks. Proterozoic granitoid-gabbro and related volcanic and ortho-metamorphic rock complexes exposed in NW Botswana and adjacent Angola and Namibia are the source rocks of the sediment component which was mixed with aeolian sand and interacted with a variable proportion of diagenetic carbonates to produce the Okavango sediments. Description: This paper was a contribution to the SAFARI 2000 Research Project. URI: http://hdl.handle.net/10311/153 Files in this item: 2
huntsman_mapila_sedgeo.pdf (6.089Mb)license.txt (1.998Kb) -
Daka, P.S.; Obuseng, V.C.; Torto, N.; Huntsman-Mapila, P. (South African Water Research Commission http://www.wrc.org.za, NaN, 2006)[more][less]
Abstract: Deltamethrin concentrations were determined in 35 sediment samples collected from three different habitats: channel, lagoon and pool sites from Xakanaxa in the Okavango Delta, NW Botswana. The samples were Soxhlet-extracted in acetone to extract deltamethrin residues and subsequently cleaned-up with silica gel 60. The final determination was carried out with a gas chromatograph equipped with an electron capture detector (GC-ECD). The sample work-up and determination gave deltamethrin recoveries of 54 to 97%, and detection limits of 0.004 mg/kg dw. The concentration of deltamethrin residues in the sediment samples collected from the three sprayed areas in the Okavango delta ranged between 0.013 and 0.291 mg/kg dw, with the highest concentrations observed in samples obtained from the pool sites. Analysis of samples for organic matter content showed percentage total organic carbon (% TOC) ranging between 0.19% and 8.21%, with samples collected from the pool having the highest total organic carbon. The concentrations of deltamethrin residues and the % TOC in sediment samples showed a similar trend with the highest levels recorded in the pool samples. These data confirmed that a simple method based on GC-ECD, after Soxhlet extraction, was robust enough to enable quantification of deltamethrin in the sediments, because comparable results were obtained with a more sophisticated system consisting of a GC coupled to a mass spectrometer with a time of flight (TOF) analyser. URI: http://hdl.handle.net/10311/650 Files in this item: 1
Daka_WSA_2006.pdf (1.231Mb) -
Magole, L.I.; Gojamang, O. (Botswana Society, NaN, 2005)[more][less]
Abstract: Despite the existence of a model of the life cycle of tourist destinations (Butler, 1980, adapted by Prossor, 1994), non-beach tourist destinations are seldom subjected to an appraisal of their evolution and an assessment of the developmental stage or phase the particular destination may be in. In this paper we explore the dynamics of tourist visitation to national parks and game reserves in Botswana over a period of ten years (1995-2004. We have used data on tourists collected by the Department of Wildlife and National Parks (DWNP) staff at national park and game reserve gates, which they summarize on a monthly basis and forward to the Parks and Reserves Reservation Office (PARRO). We conclude that the development of tourism in the Chobe National Park and Moremi Game Reserve follow Butler’s model and show signs of stagnation. Based on the findings of the paper, a recommendation to review the Botswana Tourism Master Plan (2000) is suggested in order to align it with realistic tourism trends of the national parks and game reserves. URI: http://hdl.handle.net/10311/939 Files in this item: 1
Magole 2005 Dynamics.pdf (2.198Mb) -
VanderPost, C. (Botswana Society, http://www.botsoc.org.bw, NaN, 2005)[more][less]
Abstract: During the years 1849 to 1900 the first maps of (portions of) the Okavango Delta region in Ngamiland were produced by missionaries, explorers, travellers and adventurers. Considerable progress was made from the first attempt by Livingstone and Oswell in 1849 to the work by Passarge at the turn of the 20th century. There were great improvements in the positional accuracy of Lake Ngami, the initial attraction of the region, and many of the river courses and other features in the Okavango-Ngamiland region, as maps became much more detailed. This paper describes the progress from the first rather inaccurate mapping attempts to the more sophisticated work produced just before the turn of the 20th century when the word ‘Okavango’ actually began to appear on maps. These early mapping efforts laid the foundation for the cartography of the colonial era. URI: http://hdl.handle.net/10311/955 Files in this item: 1
VanderPost 2005 Early maps.pdf (2.241Mb) -
Thakadu, O.T.; Mangadi, K.T.; Bernard, F.E.; Mbaiwa, J.E. (Botswana Society, NaN, 2005)[more][less]
Abstract: This study aimed at assessing the economic contribution of safari hunting to rural livelihoods in the Okavango Delta in Botswana, using Sankuyo village as a case study. This study was carried out between June and July 2004. It employed primary and secondary data sources. Findings indicate that, within the context of Community Based Natural Resources Management (CBNRM), safari hunting has socio-economic benefits accruing to Sankuyo (at household and community level). These benefits include income(coming in the form of cash dividends and through employment) that have been generated, and the development of recreational and household sanitation facilities that has taken place in the village. The study also found that the distribution of safari hunting benefits among Sankuyo households is fairly equitable. Income from safari hunting has also been used to purchase communally owned resources such as vehicles. Because of these benefits, the people of Sankuyo have since developed positive attitudes towards safari hunting. These findings thus suggest that safari hunting is important in improving rural livelihoods in the Okavango Delta while at the same time promoting natural resource conservation. URI: http://hdl.handle.net/10311/944 Files in this item: 1
Thakadu 2005 Economic.pdf (2.744Mb) -
Mladenov, N.; McKnight, D.M.; Wolski, P.; Ramberg, L. (The Society of Wetland Scientists, NaN, 2005)[more][less]
Abstract: In the Okavango Delta in Botswana, dissolved organic matter (DOM) transport is controlled by the slow movement of an annual flood ‘pulse’ across permanently and seasonally flooded wetlands, known respectively as the Permanent Swamp and Seasonal Swamp. We studied temporal and spatial variations in fluorescence index (FI) and specific UV absorbance (SUVA) of DOM to identify DOM sources and fate during the flood. Dissolved organic carbon (DOC) concentrations ranged from 2 to 25 mg C L21 in channels of the Delta, with seasonal floodplains having consistently higher concentrations. Chemical indices, such as DOC concentrations, conductivity, specific UV absorbance (SUVA), fluorescence, total dissolved nitrogen, and chlorophyll a, were analyzed for channel and floodplain sites in the Seasonal Swamp. DOC concentrations increased during the rising limb of the flood in the Seasonal Swamp. SUVA of whole water samples and fluorescence index (FI) of fulvic acids isolated from channel and floodplain sites changed in a manner indicating the release of DOM by leaching of plant litter during the flood. After the flood receded, DOC concentrations and fulvic acid content decreased, and microbially-derived sources of organic matter dominated. Along two river reaches, measuring over 400 km each, variations in DOC concentrations were primarily due to geomorphology, with the effects of the annual flood overprinted atop the spatial controls. Increasing downstream DOC concentrations were found to be a product of inundation of DOC-rich seasonal floodplains and evaporation-enriched waters downstream. Increasing SUVA, dissolved nitrogen, and fulvic acid content, and decreasing FI downstream suggested microbial processing of terrestrial DOM and possible release of nutrients incorporated in the DOM. URI: http://hdl.handle.net/10311/526 Files in this item: 1
Mladenov2005FLOODynamics.pdf (2.529Mb)