Hydrological and Erosion Processes in the Ethiopian Highlands PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Hydrological and Erosion Processes in the Ethiopian Highlands PDF full book. Access full book title Hydrological and Erosion Processes in the Ethiopian Highlands by Haimanote Kebede Bayabil. Download full books in PDF and EPUB format.
Author: Haimanote Kebede Bayabil Publisher: ISBN: Category : Languages : en Pages : 296
Book Description
With the objective to ameliorate the impact of recurrent drought and severe erosion, nonindigenous soil and water conservation structures are ubiquitous in the Ethiopian highlands. Nevertheless, erosion and drought remain critical problems in the sub-humid and humid highlands. The less than optimum performance of the non-indigenous practice is caused in part by not taking the varying landscape and climate conditions into account that determine the spatial pattern of runoff and erosion and thereby the performance of soil and water conservation practices. This dissertation research was conducted with the objectives of understanding runoff generation processes and spatial and temporal runoff and erosion patterns at different (plot and watershed) scales. In addition, we investigated the potential of biochar, charcoal, and deep-rooted crops to improve soil hydraulic properties and greenhouse gas emissions. Field and laboratory experiments were conducted in the 113 ha Anjeni watershed during the 2012 and 2013 rainy monsoon phases. Field infiltration tests were conducted and soil samples were analyzed for selected soil parameters. Soil column experiments were conducted to assess the effects of biochar and charcoal amendments on moisture retention and permeability of soils. Runoff and erosion rates were measured from 24 runoff-erosion plots and at watershed outlet. In addition, gas samples were collected using static chambers and analyzed for nitrous oxide and methane emissions. Results showed that while poor soil conditions (acidic, high clay and low organic matter content) are common, saturation excess runoff was the dominant runoff mechanism. Rainfall intensity would exceed median infiltration rate only 21% of the time. Soil degradation level and tillage significantly affected runoff. Sediment concentration and yield increased with greater plot length from 3 m to 15 m, but decreased at a plot length of 30 m. Sediment rating coefficients were also affected by plot size and with the progression of the rainy monsoon phase. Wood charcoal improved permeability of soils near saturation (10 and 30 kPa). However, effect of charcoal on runoff and erosion at plot level was not significant. Significant differences were observed between seasonal nitrous oxide emissions, with greater fluxes observed during the end of the rainy monsoon phase. Overall findings of this dissertation research imply that hillslope runoff and erosion rates are greatly variable both spatially and temporally. Taking the spatial pattern and mechanisms of runoff generation into account is of paramount importance for improving the performance of newly installed soil and water conservation practices.
Author: Haimanote Kebede Bayabil Publisher: ISBN: Category : Languages : en Pages : 296
Book Description
With the objective to ameliorate the impact of recurrent drought and severe erosion, nonindigenous soil and water conservation structures are ubiquitous in the Ethiopian highlands. Nevertheless, erosion and drought remain critical problems in the sub-humid and humid highlands. The less than optimum performance of the non-indigenous practice is caused in part by not taking the varying landscape and climate conditions into account that determine the spatial pattern of runoff and erosion and thereby the performance of soil and water conservation practices. This dissertation research was conducted with the objectives of understanding runoff generation processes and spatial and temporal runoff and erosion patterns at different (plot and watershed) scales. In addition, we investigated the potential of biochar, charcoal, and deep-rooted crops to improve soil hydraulic properties and greenhouse gas emissions. Field and laboratory experiments were conducted in the 113 ha Anjeni watershed during the 2012 and 2013 rainy monsoon phases. Field infiltration tests were conducted and soil samples were analyzed for selected soil parameters. Soil column experiments were conducted to assess the effects of biochar and charcoal amendments on moisture retention and permeability of soils. Runoff and erosion rates were measured from 24 runoff-erosion plots and at watershed outlet. In addition, gas samples were collected using static chambers and analyzed for nitrous oxide and methane emissions. Results showed that while poor soil conditions (acidic, high clay and low organic matter content) are common, saturation excess runoff was the dominant runoff mechanism. Rainfall intensity would exceed median infiltration rate only 21% of the time. Soil degradation level and tillage significantly affected runoff. Sediment concentration and yield increased with greater plot length from 3 m to 15 m, but decreased at a plot length of 30 m. Sediment rating coefficients were also affected by plot size and with the progression of the rainy monsoon phase. Wood charcoal improved permeability of soils near saturation (10 and 30 kPa). However, effect of charcoal on runoff and erosion at plot level was not significant. Significant differences were observed between seasonal nitrous oxide emissions, with greater fluxes observed during the end of the rainy monsoon phase. Overall findings of this dissertation research imply that hillslope runoff and erosion rates are greatly variable both spatially and temporally. Taking the spatial pattern and mechanisms of runoff generation into account is of paramount importance for improving the performance of newly installed soil and water conservation practices.
Author: Ademola K. Braimoh Publisher: Springer Science & Business Media ISBN: 140206778X Category : Science Languages : en Pages : 269
Book Description
Poor land management has degraded vast amounts of land, reduced our ability to produce enough food, and is a major threat to rural livelihoods in many developing countries. This book provides a thorough analysis of the multifaceted impacts of land use on soils. Abundantly illustrated with full-color images, it brings together renowned academics and policy experts to analyze the patterns, driving factors and proximate causes, and the socioeconomic impacts of soil degradation.
Author: Christian David Guzman Publisher: ISBN: Category : Languages : en Pages : 175
Book Description
Soil erosion and soil conservation are two of the biggest challenges for farmers, economic development plans, and academics in rural agricultural watersheds worldwide. This study compares erosion risk estimates and analyzes the underlying framework of models being used around the world exemplified by the Universal Soil Loss Equation (USLE) and infiltration excess runoff principles. Variations in modelled erosion processes in the Debre Mawi, Ethiopia were compared to field observations, community perceptions, and results from a saturation excess erosion model. In the first analysis, USLE did not capture the spatial representation of erosion due its misrepresentation of the main hydrological processes in humid highland watersheds: saturated pathways, subsurface flow, and gully formation. The investigation also analyzed erosion risk perceptions to better evaluate opportunities for community land management. Interviewed farmers considered themselves heterogeneous actors who have personal reservations to address before being able to work cooperatively. Also, they view government efforts as relevant but advocated more integration of farmers' ideas. Their perception of risk is based on how their lives are changing and what they anticipate will be their best for their families' future. Lastly, these insights were used to model runoff and sediment transport in this watershed with an adjusted Parameter Efficient Distributed Model. The watershed receives unpaved road flow contributions, so an integrated flow contribution needed to be represented. The added Hortonian flow adjustment to the PED model integrated both infiltration- and saturation-excess flow regimes. The discharge (NSE = 0.70) and sediment concentrations (NSE = 0.71) results on a daily scale demonstrated progress from previous work but need to better address high influxes of sediment from gullies. The results show that a more comprehensive approach to spatial distribution of erosion estimates is possible and necessary for more effective soil and water conservation in the sub humid Ethiopian Highlands. Keywords: Sediment transport, USLE, Community knowledge, Hortonian flow, Dunnean flow.
Author: Awulachew, Seleshi Bekele Publisher: IWMI ISBN: Category : Languages : en Pages : 319
Book Description
This proceeding provides the papers and discussion results of a two-day workshop that was organized at International Water Management Institute (IWMI) office in Addis Ababa during the period of February 6-8, 2009 in relation to CPWF Project 19 – Improved water and land management in the Ethiopian Highlands and its impact on downstream stakeholders dependent on the Blue Nile. Short title: Upstream Downstream (USDS) in the Nile. The project is being under implementation during the last one and half years in partnership with various institutions that include International Livestock Research Institute, Cornell University, Omdurman Islamic University-UNESCO Chair in Water Resources, Addis Ababa University, Bahir Dar University, Amhara Regional Agricultural Research Institute and Forum for Social Studies. The main aims of the workshop had been: Bring together key stakeholders relevant to the project; Present, debate and validate the intermediate results of the project; Disseminate key results to wider audiences through workshop participating stakeholders; Follow up on the progress of the project and plan remaining tasks of the project. The workshop focus themes were: General characterization of the Blue Nile Basin; Watershed modeling and analysis; Water demand and allocation modeling and simulation; Policy and institutions of the water management in the Blue Nile basin.
Author: Jesús Rodrigo-Comino Publisher: MDPI ISBN: 3039366440 Category : Science Languages : en Pages : 244
Book Description
This Special Issue includes manuscripts about soil erosion and degradation processes and the accelerated rates due to hydrological processes and climate change. The new research included in this issue focuses on measurements, modeling, and experiments in field or laboratory conditions developed at different scales (pedon, hillslope, and catchment). This Special Issue received investigations from different parts of the world such as Ethiopia, Morocco, China, Iran, Italy, Portugal, Greece, and Spain, among others. We are happy to see that all papers presented findings characterized as unconventional, provocative, innovative, and methodologically new. We hope that the readers of the journal Water can enjoy and learn about hydrology and soil erosion using the published material, and share the results with the scientific community, policymakers, and stakeholders to continue this amazing adventure, facing plenty of issues and challenges.
Author: Seifu Admassu Tilahun Publisher: ISBN: Category : Languages : en Pages : 206
Book Description
Despite long term efforts to reduce erosion in the Blue Nile Basin, river sediment concentrations have not declined. Lack of progress on sediment reduction indicates that runoff and erosion processes are not fully understood. The objective of this dissertation was, therefore, to understand runoff and erosion processes by investigating where runoff and erosion takes place in the landscape and to use this information to model erosion. Runoff processes were investigated in Debre Mawi, a 95-ha watershed south of Lake Tana. During the rainy period of the 2010 and 2011 monsoons, storm runoff and sediment concentrations were measured from four subwatersheds and at the main watershed outlet. In addition, perched groundwater tables, infiltration rates, rill erosion from agricultural fields and gully expansion were measured. The results show that saturation excess runoff was the main runoff mechanism because median infiltration rate was only exceeded 3% of the time. Early during rainy period, runoff produced from shallow soils upslope infiltrated before it reached the outlet, and sediment concentrations were very high as rill networks developed on the ploughed land. At the end of July, the bottom lands became saturated, the runoff coefficient at the outlet became greater than upslope areas and rill networks were fully developed reducing the velocities and thereby the sediment concentrations. A semi-distributed hillslope erosion model relating sediment concentration with overland flow using only four calibrated sediment parameters was developed based on input data from various watersheds in Blue Nile Basin. The erosion model assumed that sediment concentration is transport limiting at the beginning of the rainy phase when lands are plowed and source limited at the end. Overland flow was simulated with the semi-distributed water balance hydrology model. The model predicted daily sediment concentrations well in three small watersheds including the Debre Mawi as well as in the Blue Nile Basin at the Sudanese border. The implication of this research is that shallow degraded soils and bottom lands with gullies are the greatest sediment sources and should be targeted for erosion control.
Author: Assefa M. Melesse Publisher: Springer ISBN: 3319187872 Category : Nature Languages : en Pages : 822
Book Description
The book presents the processes governing the dynamics of landscapes, soils and sediments, water and energy under different climatic regions using studies conducted in varied climatic zones including arid, semi-arid, humid and wet regions. The spatiotemporal availability of the processes and fluxes and their linkage to the environment, land, soil and water management are presented at various scales. Spatial scales including laboratory, field, watershed, river basin and regions are represented. The effect of tillage operations and land management on soil physical characteristics and soil moisture is discussed. The book has 35 chapters in seven sections: 1) Landscape and Land Cover Dynamics, 2) Rainfall-Runoff Processes, 3) Floods and Hydrological Processes 4) Groundwater Flow and Aquifer Management, 5) Sediment Dynamics and Soil Management, 6) Climate change impact on vegetation, sediment and water dynamics, and 7) Water and Watershed Management.
Author: Paolo Billi Publisher: Springer ISBN: 9401780269 Category : Science Languages : en Pages : 384
Book Description
This book provides a succinct but comprehensive presentation of key geomorphological locations and topics including information about geomorphological heritage and maps to visit the most important sites. Apart from often being remarkably scenic, landscapes reveal stories that often can be traced back in time tens of million years and include unique events. This is particularly true for Ethiopia where spectacular examples of different landforms are present. Its geomorphology varies from highlands, marked by high volcanoes and incised by deep river gorges, to the rift valley lakes endorheic systems and the below sea level lowlands with characteristic landscapes which are unique in the world. Landscapes and Landforms of Ethiopia highlights all these topics including essential information about geology and tectonic framework, past and present climate, hydrology, geographical regions and long-term geomorphological history. It is a highly informative book, providing insight for readers with an interest in geography and geomorphology.
Author: Haimanote Kebede Bayabil
Author: Haimanote Kebede Bayabil
Author: Ademola K. Braimoh
Author: Lulseged Tamene Desta
Author: Christian David Guzman
Author: Awulachew, Seleshi Bekele
Author: Jesús Rodrigo-Comino
Author: Seifu Admassu Tilahun
Author: Awulachew, Seleshi Bekele
Author: Assefa M. Melesse
Author: Paolo Billi