Water harvesting technologies are being promoted at the household level in Oromia Region. Among the different types of surface runoff water harvesting structures adopted in the region, earthen pond seems to be the major one practiced by many farmers. Huge numbers of earthen ponds have been implemented to date in different sites. However, the problem of seepage is not adequately addressed; loss of water from the ponds due to seepage and evaporation has been reducing the performance of the ponds. These days, polyethylene membrane has been provided by the government to solve the problem and this membrane has been found to reduce seepage loss by 90%. Unfortunately, the membrane is too costly and not easily available to all farmers.
Therefore, to alleviate the situation, alternative methods of reducing seepage loss were investigated in this experiment. Biological and physical methods for reducing seepage were evaluated in small ponds constructed in permeable silty clay soils of the Region. The biological method involved use of bio-plastic sandwiches made up of successive layers of soil, manure, vegetative material and soil. The physical method involved compacting of existing soil and treating the surface by termite mold mix soil. The biological methods reduced the mean cumulative seepage rate by 47% and the physical treatment reduced by 21% after 90 days of wetting compared to the untreated soil. Therefore, both methods can be cost effectively applied by the farmers.
Table of Contents
1. INTRODUCTION
2. LITERATURE REVIEW
2.1. Water Harvesting
2.1.1. Benefits of water harvesting
2.1.2. Types of water harvesting structures
2.2. Definition and Scope of farm pond
2.2.1. Design of farm pond
2.2.2. Earthen pond Implementation in Oromia Region
2.3. Seepage Loss
2.3. Conceptual approach for analyzing the vertical seepage rate in ponded water bodies
2.3.2. Permeability
2.3.3. Particle size
2.3.4. Other soil physical properties
2.3.5. Seepage Losses Reduction
3. MATERIALS AND METHODS
3.1. Description of the study sites
3.1.1. Location
3.1.2. Climatic condition of the area
3.1.3. The Soil conditions of the experimental site
3.2. Determination of some of the soil physical properties
3.2.1. Particle size analysis
3.2.2. Bulk density determination
3.2.3. Infiltration rate test
3.3. Alternative means for reducing seepage loss from earth ponds
3.3.1. Physical Approach
3.3.2. Biological Approach
3.3.3. Experimental Design
3.3.4. Date Collection
3.3.5. Statistical Analyses
4. RESULTS AND DISCUSSIONS
4.1 Characterization of Seepage Reduction Efforts in the Region
4.1.1 Earthen ponds implementation in the region
4.1.2 Seepage reduction efforts in the region
4.2. Investigation of alternative methods for reducing seepage loss from earthen ponds
4.2.1. Soil Physical Properties
4.2.2. Seepage rate of the treatments
Research Objectives and Core Themes
This thesis aims to investigate effective, affordable, and local alternative methods for reducing water seepage in earthen ponds located in the Oromia region, thereby enhancing water availability for small-scale agriculture. The research focuses on identifying the limitations of currently used pond technologies and evaluating the performance of physical and biological lining and compaction methods.
- Characterization of current seepage reduction efforts for earthen ponds.
- Evaluation of soil physical properties influencing seepage rates.
- Comparative analysis of compaction treatments and bio-plastic sandwich lining.
- Assessment of seepage reduction through experimental field setups.
Excerpt from the Book
3. MATERIALS AND METHODS
For characterization of the existing seepage reduction efforts some sites were visited in Chiro, Doba, Darolebu, Messela, Adami Tullu and Fentale woredas in west Hararghe and Easter Showa zones of the region respectively.
To investigate alternative methods for reducing seepage loss from earthen ponds (i.e. the effects of compaction of existing soil, termite mound mix soil and bio-plastic sandwich material on reducing seepage loss of water in earthen ponds), a field experiment were conducted on a test plot of having a total area of 120 m2. The location of this area is at the close proximity of Chiro Agricultural Technical Vocational Educational Training (ATVET) College in the West Hararghe zone of the Oromia regional sate. The site is part of the Chercher highlands situated between 901'-903' north latitudes and 40051'-410 53' east longitudes.
The experimental site is situated in relatively semi-arid climatic areas. The other sites selected for characterization of seepage reduction efforts also typically represent arid to semi- arid climatic areas of the region. As far as the experimental site is concerned the seasonal rainfall record in the area characterized by bimodal rainfall pattern (distribution) with a peak in April and August. The main rainy season referred as (“Meher”) occurs in summer months of July to September and the minor rainy season (“Belg”) occurs in the month of March to May that supplies 38% (312.5mm) of average annual rainfall (Mohamed, 2003). The metrological data recorded at Mi’esso indicated that the mean annual rainfall for Assebe Teferi for eleven Years (1991-2001) was found to be 734.6 mm. The mean and maximum air temperature recorded during June and December for Assebe Teferi was found to be 20 and 29.10c respectively. The potential evapotranspiration for the area was also found to be 1554 mm per year.
Summary of Chapters
1. INTRODUCTION: This chapter contextualizes the role of agriculture in the economy of Ethiopia/SSA countries and addresses the critical issue of water scarcity, focusing on the potential and challenges of water harvesting via earthen ponds.
2. LITERATURE REVIEW: This chapter examines existing knowledge on water harvesting technologies, design principles for farm ponds, and the various physical and technical factors contributing to seepage losses.
3. MATERIALS AND METHODS: This chapter details the field site descriptions, experimental design for testing alternative seepage reduction treatments, and the specific soil physical analysis procedures employed.
4. RESULTS AND DISCUSSIONS: This chapter presents the data obtained from the field experiments, analyzing the effectiveness of different compaction-based and material-based treatments on reducing seepage rates in earthen ponds.
Keywords
Earthen ponds, Water harvesting, Seepage loss, Compaction, Bio-plastic sandwich, Termite mound soil, Oromia region, Soil physical properties, Irrigation, Infiltration, Permeability, Water conservation, Agricultural engineering.
Frequently Asked Questions
What is the primary focus of this research?
This research focuses on investigating and validating alternative, cost-effective methods to reduce significant water seepage losses in earthen ponds, which are crucial water storage structures for rural communities in the Oromia region.
What are the central themes of the work?
The core themes include analyzing current water harvesting infrastructure, understanding soil physical characteristics that affect permeability, and testing biological and physical methods to improve the structural integrity of earthen ponds.
What is the primary research goal?
The primary goal is to provide farmers with practical and locally available solutions to minimize pond seepage, thereby securing irrigation water during dry spells and improving agricultural productivity.
Which scientific methods are utilized?
The research utilizes experimental field trials based on a randomized complete block design, alongside laboratory analysis of soil physical properties such as bulk density, particle size distribution, and infiltration rates.
What topics are covered in the main body?
The main body covers the theoretical background of pond seepage, site-specific climatic and soil analysis, detailed descriptions of treatment applications (compaction of existing soil vs. termite mound soil vs. bio-plastic sandwich), and the statistical evaluation of seepage data.
How is this work characterized?
This work is characterized by its applied focus on regional agricultural engineering, emphasizing Sustainable development through locally adapted materials and methods tailored to resource-poor settings.
Why are polyethylene membranes not considered the final solution by the author?
While effective at reducing seepage, polyethylene membranes are identified as being too costly and often unavailable to the average small-holder farmer, prompting the need for the cheaper alternatives tested in this study.
How does the "bio-plastic sandwich" method function?
The bio-plastic sandwich treatment involves layering organic materials such as cow dung, straw, and "cathadolis" leaves, which, when compacted with soil, create a barrier that significantly reduces seepage compared to untreated clay soil.
- Arbeit zitieren
- Dr. Adeye Dereje Mamo (Autor:in), 2005, Investigating Alternative Methods for Reducing Seepage Loss from Earthen Ponds, München, GRIN Verlag, https://www.grin.com/document/1306339
