From the Proceedings of the 1977 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 15-16, 1977, Las Vegas, Nevada / Hydrologic information is needed to understand and control water pollution from semiarid rangelands. However, the hydrologic systems under any given conditions must be understood and the effects of various land uses predicted. Based on the concept of partial area response, a runoff tracer study was conducted on two small watersheds. The watersheds were partitioned into four geomorphic subzones or hydrologic response units. Each of the four zones on both watersheds was treated with about 1 kg/ha of an individual water soluble herbicide. Runoff volumes and sources estimated using the tracers were consistent with results from simulation studies. Also, the principle of corresponding runoff and pollutant discharge rates was used to develop two methods of runoff hydrograph estimation from each of the geomorphic subzones. Method 1 matched the mean total concentration and total runoff volume. Method 2 matched the instantaneous total concentration and the instantaneous runoff rate from the entire watershed. Results from the two methods suggested that, although they may be equivalent with respect to runoff volume, Method 2 may be more consistent with respect to peak discharge.

From the Proceedings of the 1977 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 15-16, 1977, Las Vegas, Nevada / Extensive disturbances are expected during the remainder of this century due to strip mining in the semi-arid West. Reclamation and revegetation of these disturbed areas is a slow process, primarily due to dry and harsh climatic conditions. Erosion and sediment losses are high. Monitoring of the soil erosion process is a crucial step in planning for a long lasting and stable rehabilitation of these disturbed areas. Erosion plots have been laid out to collect data for the Universal Soil Loss Equation for estimating soil loss from recontoured coal mine spoils. Effectiveness of different cultural and mechanical treatments for erosion control is also being evaluated. Since large-scale coal mining operation has just begun on the Black Mesa, preliminary data could be very effective and useful in Watershed Management planning.

The purpose of this study is to determine if Low Impact Development (LID) can effectively mitigate flooding under projected climate scenarios. LID relies on runoff management measures that seek to control rainwater volume at the source by reducing imperviousness and retaining, infiltrating and reusing rainwater. An event-driven hydrologic/hydraulic model was developed to simulate how climate change, land use and LID scenarios may affect runoff response in the Bowker Creek watershed, a 10km2 urbanized catchment located in the area of greater Victoria, British Columbia, Canada. The first part of the study examined flood impacts for the 2050s (2040-2069) following the A2 emissions scenario. For the 24-hour, 25-year local design storm, results show that projected changes in rainfall intensity may increase flood extents by 21% to 50%. When combined with continued urbanization flood extents may increase by 50% to 72%. The second part of the study identified potential locations for three LID treatments (green roofs, rain gardens and top soil amendments) and simulated their effect on peak in-stream flow rates and flood volumes. Results indicate that full implementation of modeled LID treatments can alleviate the additional flooding that is associated with the median climate change projection for the 5-year, 10-year and 25-year rainfall events. For the projected 100-year event, the volume of overland flood flows is expected to increase by 1%. This compares favourably to the estimated 29% increase without LID. In term of individual performance, rain gardens had the greatest hydrologic effect during more frequent rainfall events; green roofs had minimal effect on runoff for all modelled events; and top soil amendments had the greatest effect during the heaviest rainfall events. The cumulative performance of LID practices depends on several variables including design specifications, level of implementation, location and site conditions. Antecedent soil moisture has a considerable influence on LID performance. The dynamic nature of soil moisture means that at times LID could meet the mitigation target and at other times it may only partially satisfy it. Future research should run continuous simulations using an appropriately long rainfall record to establish the probabilities of meeting performance requirements. In general, simulations suggest that if future heavy rainfall events follow the median climate change projection, then LID can be used to maintain or reduce flood hazard for rainfall events up to the 25-year return period. This study demonstrates that in a smaller urban watershed, LID can play an important role in reducing the flood impacts associated with climate change. / Graduate

Thesis (M. En.)--Miami University, Institute of Environmental Sciences, 2004. / Title from first page of PDF document. Includes bibliographical references (p. 32-34).

Thesis (Ph. D.)--Miami University, Dept. of Botany, 2004. / Title from second page of PDF document. Includes bibliographical references.

Thesis (MA)--Stellenbosch, 2004. / ENGLISH ABSTRACT: South Africa is a semi-arid country with an average annual rainfall of 197mm, in comparison with the international average of 860mm per year, of which the available freshwater sources are currently being utilised virtually completely. The water restrictions in the Western Cape during the summer of 2000/2001 and of 2001/2002 are sufficient evidence of this. This threatening water shortage holds far-reaching consequences for the socio-economic development of the country if an active effort is not made to manage the water resources in a sustainable manner. Starting in the 1990s, the concept of integrated catchment management crCM) began to enjoy widespread attention as a mechanism to manage water resources. However, it was primarily forced, state-initiated projects with little direct community involvement that enjoyed a limited amount of success. This study undertook community-driven, integrated catchment management in a relatively small catchment in the Veldwachters River valley in the Stellenbosch area in the Western Cape in order to investigate the effectiveness thereof as a mechanism for sustainable water resource management. The study firstly places the concept of rCM in perspective, after which the study area is demarcated spatially within the South African and the regional context. Community-based action research as research approach provides the techniques to reconcile and integrate the duality of the rCM process, namely the human and physical elements in a catchment, and to successfully involve the community in the process. The first phase of the study entails the gathering of existing and new information and the definition of the environmental status of the catchment area in a situation analysis, which was presented to the community as an information document to initiate public participation. During the second phase, a community partnership was established by means of introductory interviews, correspondence, focus group meetings and public forums. The third and executive phase was characterised by the mobilisation of the community partnership in the execution of strategic planning procedures, such as the formulation of a catchment vision, prioritisation of relevant catchment management issues, the statement of the management objectives and the formulation and implementation of action plans for the management of various issues in the catchment. The conclusion drawn after a thorough evaluation of the course of the study is that the implementation of community-driven integrated catchment management can be successful ina smaller catchment. A few crucial requirements need to be taken into consideration in future applications elsewhere, namely: • That the study area must have a small enough area so that all stakeholders can be involved relatively easily and for a catchment identity and "ownership" of the process to be able to develop; • That the process must initially be facilitated externally until a community partnership has been established and a management committee has been elected, after which the facilitation and management of the process must be handed to the community so that it can finally become completely community driven; • That socio-econornic issues initially will receive more attention than the natural environment, but that these issues need to be utilised to establish the ICM process, after which the natural environment naturally will receive greater priority; and • That the researcher must remain patient, particularly during the second and third phases of the process, as public participation and particularly the establishment of a community-driven process can be slow and exhausting. This case study emphasises that each application of ICM will be unique because the degree of community involvement and the priorities of catchment communities will differ. Communitydriven integrated catchment management is not, under any circumstances, an instant solution for water management and water conservation issues, but it is the only sustainable option. KEY WORDS: catchment management, public/community participation, situation analysis, water resource management, action research. / AFRIKAANSE OPSOMMING: Suid-Afrika is 'n semi-ariede land met 'n gemiddelde reenvalsyfer van 497mm per jaar teenoor die wereldgemiddelde van 860mm per jaar, waarvan beskikbare varswaterbronne tans byna ten volle benut word. Die waterbeperkings in die Wes-Kaap gedurende die somers van 2000/2001 en 200112002 is afdoende bewys hiervan. Hierdie dreigende watemood hou verreikende gevolge vir die sosio-ekonomiese ontwikkeling van die land in, indien daar nie 'n daadwerklike poging aangewend gaan word om die waterhulpbronne volhoubaar te bestuur nie. Sedert die negentigerjare het die konsep van geintegreerde opvanggebiedbestuur (GOGB) as waterhulpbronbestuursmeganisme wye belangstelling begin geniet. Dit was hoofsaaklik afgedwonge, staatsgeinisieerde projekte met min direkte gemeenskapsbetrokkenheid wat beperkte sukses gehad het. Hierdie studie het 'n gemeenskapsgedrewe geintegreerde opvanggebiedbestuur op 'n relatief klein opvanggebied in die Veldwachtersrivier vallei in die Stellenbosch omgewing in die Wes-Kaap ondemeem, ten einde die effektiwiteit daarvan as 'n volhoubare waterhulpbron-bestuursmeganisme te ondersoek. Die studie plaas eerstens die konsep van GOGB in perspektief, waama die studiegebied ruimtelik binne die Suid-Afrikaanse en streekskonteks afgebaken word. Gemeenskapsgebaseerde aksienavorsing as navorsingsbenadering verskaf die tegnieke om die tweeledigheid van die GOGB proses, naamlik menslike en fisiese elemente in 'n opvanggebied, te verso en en te integreer en om die gemeenskap suksesvol by die proses te betrek. Die eerste fase van die studie behels die insameling van bestaande en nuwe inligting en die ornskrywing van die omgewingstatus van die opvanggebied in 'n situasie-analise, wat as inligtingsdokurnent aan die gemeenskap voorgele word om publieke deelname te inisieer. Gedurende die tweede fase is 'n gemeenskapsvennootskap gevestig met behulp van inleidende onderhoude, korrespondensie, fokusgroepbyeenkomste en pub Iieke forums. Die derde en uitvoerende lase is gekenmerk deur die mobilisering van die gemeenskapsvennootskap m die uitvoering van strategiese beplanningsprosedures soos die formulering van 'n opvanggebiedvisie, prioritisering van tersaaklike opvanggebiedkwessies, bestuursdoelwitstelling en die formulering en implementering van aksieplanne vir die bestuur van verskeie kwessies in die opvanggebied. Die gevolgtrekking na die noukeurige evaluering van die verloop van hierdie studie, is dat die implementering van gemeenskapsgedrewe gemtegreerde opvanggebiedbestuur in 'n kleiner opvanggebied wel suksesvol kan wees. 'n Paar beslissende vereistes moet met toekomstige toepassings elders in ag geneem word, naamIik: • Dat die studiegebied oppervlakgewys klein genoeg moet wees sodat alle rolspelers relatief maklik betrek kan word en 'n opvanggebied-identiteit en "eienaarskap" van die proses kan ontwikkel; • Die proses moet aanvanklik ekstem fasiliteer word, totdat 'n gemeenskapsvennootskap gevestig is en 'n bestuurskomitee verkies is, waama die fasilitering en bestuur van die proses aan die gemeenskap oorgegee moet word om uiteindelik ten volle gemeenskapsgedrewe te word; • Dat sosio-ekonomiese kwessies aanvanklik aandag b6 die natuurlike omgewing sal geniet, maar dat hierdie kwessies benut moet word om die GOGB proses te vestig, waama die natuurlike omgewing vanselfsprekend hoer prioriteit sal geniet; en • Dat die navorser veral gedurende die tweede en derde fases van die proses geduld moet behou, omdat publieke deelname en veral die vestiging van 'n gemeenskapsgedrewe proses, tydsaam en vermoeiend kan wees. Hierdie gevallestudie beklemtoon dat elke toepassing van GOGB uniek sal wees omdat die mate van gemeenskapsdeelname en -prioriteite tussen opvanggebiedgemeenskappe sal verskil. Gemeenskapsgedrewe gemtegreerde opvanggebiedbestuur is onder geen ornstandighede 'n kitsoplossing vir waterbestuur en -bewaring nie, maar dit is die enigste volhoubare opsie. SLEUTEL WOORDE: opvanggebiedbestuur, publieke/gemeenskapsdeelname, situasie-analise, waterhulpbronbestuur, aksienavorsing

Submitted by Milena Rubi (milenarubi@ufscar.br) on 2017-08-08T17:21:17Z No. of bitstreams: 1 LEAL_Mariana_2016.pdf: 33531179 bytes, checksum: 79338822f2cee7514132a1426bb9d6ee (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-08-08T17:21:25Z (GMT) No. of bitstreams: 1 LEAL_Mariana_2016.pdf: 33531179 bytes, checksum: 79338822f2cee7514132a1426bb9d6ee (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-08-08T17:21:31Z (GMT) No. of bitstreams: 1 LEAL_Mariana_2016.pdf: 33531179 bytes, checksum: 79338822f2cee7514132a1426bb9d6ee (MD5) / Made available in DSpace on 2017-08-08T17:21:37Z (GMT). No. of bitstreams: 1 LEAL_Mariana_2016.pdf: 33531179 bytes, checksum: 79338822f2cee7514132a1426bb9d6ee (MD5) Previous issue date: 2016-04-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Water is one of the most abundant natural resources on the planet, but at the same time is becoming scarce in both quantity and quality in many regions, causing numerous conflicts. The watershed must be a permeable environment, where water infiltrates the soil and reaches the water table and then can be distributed abundant and continuously. Knowledge of the physical and biological characteristics of the basin influencing the handling and consequently the production of water. This study aimed to characterize the Itanguá watershed to support the management of the National Capão Bonito Forest, SP for conservation of water. This dissertation was divided into chapters: chapter 1 contextualized the issues relevant to this study, in the form of bibliographic review, chapter 2 discussed the hydro-environmental characterization of the basin, chapter 3 identified the vulnerability of Itangua watershed to the floods and the areas to be reforested in the permanent preservation areas, chapter 4 identified the priority areas for soil and water conservation and chapter 5 provides a general conclusion. The first results indicated that 60% of the sources analyzed in situ, were characterized as point while the others were diffuse and according to macroscopic evaluation, 13% of the sources were considered with great, 80% good and 7% with reasonable conservation state. The main negative environmental impacts observed were the presence of both exotic species such as: Boar (Sus scrofa) and Pinus spp. and the absence of native vegetation in the area of permanent preservation. The morphometric analysis showed that the Itanguá watershed is an important site for the conservation of water resources by having more elongated and low tendency to form flooding. Were also found nine different priorities classes of soil conservation practices implementation and six classes for forest restoration in permanent preservation area of waterways. The results provided a characterization of the basin Itanguá and important information, since they contribute to the Flona the management plan of Capão Bonito. All methods used in the study were satisfactory to achieve the proposed purpose. / A água é um dos recursos naturais mais abundantes no planeta, mas que ao mesmo tempo está se tornando escasso tanto em quantidade como em qualidade em diversas regiões, ocasionando inúmeros conflitos. A bacia hidrográfica deve ser um ambiente permeável, onde a água infiltra no solo e alcança o lençol freático para depois ser distribuída de maneira abundante e contínua. O conhecimento das características físicas e biológicas da bacia influencia no manejo e, consequentemente, na produção de água. Desta forma, este trabalho teve por objetivo a caracterização da bacia do Itanguá como suporte à gestão da Floresta Nacional de Capão Bonito, SP, visando à conservação da água. Essa dissertação foi dividida em capítulos, sendo que o capítulo 1 contextualizou os temas pertinentes à realização desse estudo, na forma de revisão bibliográfica, o capítulo 2 abordou a caracterização hidroambiental da bacia, o capítulo 3 avaliou a vulnerabilidade da bacia a enchentes e as áreas que necessitam ser reflorestadas, o capítulo 4 identificou as áreas prioritárias à conservação de solo e água e o capítulo 5 apresentou uma conclusão geral. Os primeiros resultados indicaram que 60% das nascentes analisadas in loco, foram caracterizadas como pontuais enquanto que as demais foram difusas e de acordo com a avaliação macroscópica, 13% das nascentes foram consideradas com ótimo, 80% com bom e 7% com razoável estado de conservação. Os principais impactos ambientais negativos observados foram a presença de espécies exóticas tanto animal como vegetal: Javali (Sus scrofa) e Pinus spp. e a ausência de vegetação nativa na área de preservação permanente dos cursos d’água. A análise morfométrica apontou que a bacia do Itanguá é um local importante para a conservação dos recursos hídricos por apresentar forma mais alongada e baixa tendência a enchentes e ao partir da análise do uso e cobertura da terra foi possível identificar quais os locais que precisam ser reflorestados na área de preservação permanente. Foram ainda encontradas nove diferentes classes de prioridades para a implantação de práticas conservacionistas de solo e seis classes para a restauração florestal na área de preservação permanente dos cursos d’água. Os resultados obtidos proporcionaram a caracterização da bacia do Itanguá e a obtenção de importantes informações, uma vez que contribuem com o Plano de Manejo da Flona de Capão Bonito. Todas as metodologias utilizadas no trabalho foram satisfatórias para alcançar os objetivos propostos.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-30T20:23:27Z No. of bitstreams: 1 ESTANLEY PIRES RIBEIRO - DISSERTAÇÃO PPGSA ACADÊMICO 2017..pdf: 5679917 bytes, checksum: cb0dfa1e581ddb4672005a2fdd97e39e (MD5) / Made available in DSpace on 2018-04-30T20:23:27Z (GMT). No. of bitstreams: 1 ESTANLEY PIRES RIBEIRO - DISSERTAÇÃO PPGSA ACADÊMICO 2017..pdf: 5679917 bytes, checksum: cb0dfa1e581ddb4672005a2fdd97e39e (MD5) Previous issue date: 2017 / Neste estudo teve-se como objetivo geral avaliar os impactos ambientais adversos ocasionados pelas ações antrópicas na microbacia do Açude Epitácio pessoa, bem como propor medidas de controle ambiental. O banco de dados montado contou com dados referentes aos impactos ambientais do meio físico, biótico e antrópico em maior ocorrência e de forma mais significativa. Inicialmente, realizou-se um check list dos impactos ambientais presentes na microbacia, posteriormente, foram analisados por meio da metodologia Pressão-Estado-Impacto-Resposta, possibilitando diagnosticar a qualidade ambiental da microbacia, bem com as respostas ou ausência delas para cada tipo de impacto ao meio ambiente. Também foram obtidas informações por meio de entrevistas informais com a população local e registros fotográficos. Os resultados revelaram que são inúmeros os impactos ambientais no meio físico, biótico e antrópico na microbacia atualmente e que em sua maioria não apresentam resposta para sua eliminação ou mitigação. Concluiu-se assim que, apesar da microbacia apresentar uma relevante importância socioeconômica para o Estado da Paraíba, a mesma encontra-se submetida a uma contínua e gradativa deterioração das condições ambientais, comprometendo a sua qualidade ambiental, evidenciando também a necessidade de intervenções mais efetivas por parte do poder público, representado pelos dos órgãos responsáveis. / In this study, the general objective was to evaluate the environmental impacts caused by the anthropic actions in the Epitacio person's watershed, as well as to propose environmental control measures. The assembled database included data related to the environmental impacts of the physical, biotic and anthropic environments in greater occurrence and in a more significant way. Initially, a check list of the environmental impacts present in the microbasin was carried out. Later, they were analyzed through the Pressure-State-Impact-Response methodology, making it possible to diagnose the environmental quality of the microbasin, as well as the responses or absence of them for each type of Impact on the environment. Information was also obtained through informal interviews with the local population and photographic records. The results revealed that there are innumerous environmental impacts in the physical, biotic and anthropic environments in the microbasin today and that, for the most part, have no response to their elimination or mitigation. It was concluded that, although the microbasin presents a relevant socioeconomic importance for the State of Paraíba, it is subject to a continuous and gradual deterioration of the environmental conditions, compromising its environmental quality, evidencing also the need for more effective interventions By the public authority, represented by those responsible.

The recent high profile flooding events – that have occurred in many parts of the world – have drawn attention to the need for new and improved methods for water resources assessment, water management and the modelling of large-scale flooding events. In the case of the Zambezi Basin, a review of the 2000 and 2001 floods identified the need for tools to enable hydrologists to assess and predict daily stream flow and identify the areas that are likely to be affected by flooding. As a way to address the problem, a methodology was set up to derive catchment soil moisture statistics from Earth Observation (EO) data and to study the improvements brought about by an assimilation of this information into hydrological models for improving reservoir management in a data scarce environment. Rainfall data were obtained from the FEWSNet Web site and computed by the National Oceanic and Atmospheric Administration Climatic Prediction Center (NOAA/CPC). These datasets were processed and used to monitor rainfall variability and subsequently fed into a hydrological model to predict the daily flows for the Zambezi River Basin. The hydrological model used was the Geospatial Stream Flow Model (GeoSFM), developed by the United States Geological Survey (USGS). GeoSFM is a spatially semi-distributed physically-based hydrological model, parameterised using spatially distributed topographic data, soil characteristics and land cover data sets available globally from both Remote Sensing and in situ sources. The Satellite rainfall data were validated against data from twenty (20) rainfall gauges located on the Lower Zambezi. However, at several rain gauge stations (especially those with complex topography, which tended to experience high rainfall spatial variability), there was no direct correlation between the satellite estimates and the ground data as recorded in daily time steps. The model was calibrated for seven gauging stations. The calibrated model performed quite well at seven selected locations (R2=0.66 to 0.90, CE=0.51 to 0.88, RSR=0.35 to 0.69, PBIAS=−4.5 to 7.5). The observed data were obtained from the National Water Agencies of the riparian countries. After GeoSFM calibration, the model generated an integration of the flows into a reservoir and hydropower model to optimise the operation of Kariba and Cahora Bassa dams. The Kariba and Cahora Bassa dams were selected because this study considers these two dams as the major infrastructures for controlling and alleviating floods in the Zambezi River Basin. Other dams (such as the Kafue and Itezhi-Thezi) were recognised in terms of their importance but including them was beyond the scope of this study because of financial and time constraints. The licence of the reservoir model was limited to one year for the same reason. The reservoir model used was the MIKE BASIN, a professional engineering software package and quasi-steady-state mass balance modelling tool for integrated river basin and management, developed by the Denmark Hydraulic Institute (DHI) in 2003. The model was parameterised by the geometry of the reservoir basin (level, area, volume relationships) and by the discharge-level (Q-h) relationship of the dam spillways. The integrated modelling system simulated the daily flow variation for all Zambezi River sub-basins between 1998 and 2008 and validated between 2009 and 2011. The resulting streamflows have been expressed in terms of hydrograph comparisons between simulated and observed flow values at the four gauging stations located downstream of Cahora Bassa dam. The integrated model performed well, between observed and forecast streamflows, at four selected gauging stations (R2=0.53 to 0.90, CE=0.50 to 0.80, RSR=0.49 to 0.69, PBIAS=−2.10 to 4.8). From the results of integrated modelling, it was observed that both Kariba and Cahora Bassa are currently being operated based on the maximum rule curve and both remain focused on maximising hydropower production and ensuring dam safety rather than other potential influences by the Zambezi River (such as flood control downstream – where the communities are located – and environmental issues). In addition, the flood mapping analysis demonstrated that the Cahora Bassa dam plays an important part in flood mitigation downstream of the dams. In the absence of optimisation of flow releases from both the Kariba and Cahora Bassa dams, in additional to the contribution of any other tributaries located downstream of the dams, the impact of flooding can be severe. As such, this study has developed new approaches for flood monitoring downstream of the Zambezi Basin, through the application of an integrated modelling system. The modelling system consists of: predicting daily streamflow (using the calibrated GeoSFM), then feeding the predicted streamflow into MIKE BASIN (for checking the operating rules) and to optimise the releases. Therefore, before releases are made, the flood maps can be used as a decision-making tool to both assess the impact of each level of release downstream and to identify the communities likely to be affected by the flood – this ensures that the necessary warnings can be issued before flooding occurs. Finally an integrated flood management tool was proposed – to host the results produced by the integrated system – which would then be accessible for assessment by the different users. These results were expressed in terms of water level (m). Four discharge-level (Q-h) relationships were developed for converting the simulated flow into water level at four selected sites downstream of Cahora Bassa dam – namely: Cahora Bassa dam site, Tete (E-320), Caia (E-291) and Marromeu (E-285). However, the uncertainties in these predictions suggested that improved monitoring systems may be achieved if data access at appropriate scale and quality was improved.

In the dominantly small-scale subsistence agricultural system of Ethiopia, where most of the organic inputs are not returned to soil and land is not used based on its best suitability, the contribution of agriculture to climate change mitigation/adaptation through reduction of greenhouse gases emission is undermined. When this low-input agricultural practice is coupled with rugged topography, high population pressure, generally low soil fertility, and looming climate change, ensuring food and nutrition security of society as well as sustainable use of land resources is practically impossible. Under such circumstances, finding alternative land uses, through scientific investigation, that meet the triple mandates of climate-smart agriculture under current and future climate is imperative. In view of this, a study was conducted in Hades Sub-watershed, eastern Ethiopia, to evaluate the carbon stock of major land uses, evaluate suitability of land for rainfed production of sorghum (Sorghum bicolor L.), Maize (Zea mays L.), coffee (Coffea arabica), upland rice (Oryza sativa L.) and finger millet (Eleusine coracana L.), and project biomass production of late-maturing sorghum and maize varieties under changing climate and its contribution to carbon sequestration and reduction of greenhouse gases (GHGs) emission. Soil and vegetation samples were collected following recommended procedures. Secondary data on required crop parameters were collected for model calibration and validation in the biomass projection study made using the AquaCrop v6.0 model. Climate data of the study area was obtained from the National Meteorology Agency of Ethiopia and analyzed following standard procedures. Near-century (NC) (2017-2039) and Mid-century (MC) (2040-2069) climate was projected under two emission scenarios (RCP4.5 and RCP8.5) using four models (CNRM-CERFACS-CNRM-CM5, ICHEC-EC-Earth, MOHC-HadGEM2-ES, and MPI-M-MPI-ESM-LR) and a Multi-model Ensemble. Biomass production projection, for the climate projected under the two emission scenarios using the four models and the ensemble, was made for late-maturing sorghum (Muyira-1) and maize (BH661) varieties. From the projected biomass, organic carbon and its equivalent CO2 were estimated. Furthermore, adaptation measures, involving adjusting planting dates and irrigation, under the changing climate were evaluated for their influence on biomass production under the time slices, RCPs, and models mentioned above. The carbon stock assessment study was conducted on four major land uses (cultivated, grazing, coffee agroforestry, and forest lands) identified in the study area. The land suitability assessment, using the maximum limitation method, study was conducted on four soil mapping units identified in the sub-watershed. Results indicate that total organic carbon stock (soil, litter plus live vegetation) in the sub-watershed ranged from 138.95 ton ha-1 in the crop land to 496.26 ton ha-1 in the natural forest. The soil organic carbon stock was found to be relatively higher than that of the vegetation carbon stock in the natural forest and coffee agroforestry land uses. The results of suitability evaluation revealed that the maximum current and potential (after corrective xix measures are taken) land suitability class for production of late-maturing sorghum (180-240 days cycle), maize (180-210 days crop cycle), finger millet (120 – 150 days cycle) and coffee in the sub-watershed is marginally suitable (S3c). The maximum current and potential land suitability for upland rice (120 days) is not suitable (N2c). The major permanent limiting factor is low mean temperature (14.6 C) of the growing period in the study area as compared to the optimum temperature required for optimum growth of the selected crops. The major soil and landscape limitations include steep slope, poor drainage of low-lying areas, shallow effective root zone in the upper slopes, low organic matter and available P for sorghum and maize, high pH for maize and wetness for coffee. In all the climate models and emission scenarios, minimum and maximum temperature increment is high during June-July-August-September (JJAS) compared with the other seasons. The modest rise in minimum temperature and the slight increment of maximum temperature during the crop growing seasons (February-March-April-May (FMAM) and JJAS will benefit late-maturing sorghum and maize production in the study area. For the same model, the projected biomass yield and organic carbon sequestration of the two crop varieties varied with time slice and the type of emission scenario used. Generally, increasing biomass production and carbon sequestration were projected for Mid-century (MC) than Near-century (NC) for most of the models used. Late planting would increase sorghum biomass yield and the corresponding organic carbon as compared to early planting as projected by most of the models under both RCPs. Most models predicted an increase in maize biomass yield and organic carbon sequestration if supplementary irrigation is used. The results of this study indicate that the current land uses are not enhancing carbon sequestration because of their exploitative nature and the soil/landscape and climate are not optimum for production of the crops studied. The rise in temperature in the coming 50 years is expected to create a more favorable condition for production of late-maturing sorghum and maize varieties. In order to enhance carbon sequestration, soil productivity and crop yield, and reduce greenhouse gas emissions, the current land uses and their management require re-visiting. / College of Agriculture and Environmental Sciences / Ph. D. (Environmental Sciences)