Grantee Research Project Results
Final Report: Scalable and Sustainable Water Harvesting in Rural Uganda
EPA Grant Number: SU834765Title: Scalable and Sustainable Water Harvesting in Rural Uganda
Investigators: Tollner, E. W. , Ssegane, Herbert , Kasisira, Levi , Mulamba, Peter
Institution: University of Georgia , Makerere University
EPA Project Officer: Page, Angela
Phase: I
Project Period: August 15, 2010 through August 14, 2011
Project Amount: $9,602
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2010) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Sustainable and Healthy Communities , P3 Awards , Sustainable and Healthy Communities
Objective:
Fish farming in Uganda is predominantly practiced by poor people in villages for subsistence with ponds of usually less than 500 m² and production in the range of 5 kg to 10 kg/100 m² per annum. Many of the ponds are just dug in swampy/wetland areas or micro-watershed concentrated storm runoff areas without proper planning or guidelines that take into considerations the ecological and environmental impacts. This has led to drying up of ponds and massive encroachment on wetlands and riparian buffers. Also, on the national coverage, there was no detailed map of Uganda depicting areas that are suitable for inland fish farming while accounting for the need to control encroachment on wetlands and riparian buffers. The project goal was to develop strategies to better employ water capture in Uganda by modeling for surface catchment and site evaluation in the presence of potential surface water runoff. The specific objectives included: (1) use of geographic information systems (GIS) and remote sensing (RS) to develop an aquaculture site suitability map for Uganda; (2) develop guidelines on site selection of ponds to ensure reliable water supply and sustainable ecological existence within the micro-watershed; and (3) construction of pilot pond for demonstration and future instruction purposes. The approach for the physical research began with remote sensing and GIS assessment of site suitability for Uganda with emphasis on soils, topography, climate, access to farm inputs and access to markets. Working with host country personnel, sites were identified for the preliminary screening analysis based on GIS analysis and the spreadsheet tool (developed by the lead investigator). Potential sites were further analyzed using infiltration or seepage pits.
Summary/Accomplishments (Outputs/Outcomes):
The major suitability study findings relate to the crisp and fuzzy suitability maps developed for Uganda. For both the crisp and the fuzzy approaches, over 98 % of the land was classified as moderately suitable or as suitable. Overall, the crisp method classified 16,322 hectares (0.09 %) as very suitable compared to zero hectares (0 %) by the fuzzy method. Simultaneously, the crisp method gave 297,344 hectares (1.96 %) as unsuitable compared to 168,592 hectares (0.96 %) by the fuzzy method. Of the 138 surveyed fish ponds that were operational, the crisp method classified 71 % as suitable while 29 % as moderately suitable while the fuzzy method classified 71.7 % as suitable while 28.3 % as moderately suitable.
There were five major outcomes or outputs from EPA P3 phase I funding in addition to extra funds from AquaFISH-CRSP;
- Two suitability maps of Uganda for pond based fish farming. The first map was based on crisp classification while the second on fuzzy classification. The maps were developed using a multi criteria evaluation of seven variables that included water requirement, water temperature, soil texture, slope gradient, potential for farm gate sales, access to local and regional markets, and availability of farm inputs. The site suitability maps designated major wetlands as protected sites that should not be considered for pond based fish farming.
- A two day workshop was held at the host institution (Makerere University, Uganda) that brought together the major stakeholders (researchers from local institution, fish farmers, and U.S. lead advisors). The first day focused on the state of aquaculture, water availability, pond construction challenges, and use of GIS and RS in site selection. The second day focused on use of an excel spreadsheet tool for proper design and planning for levee and watershed based ponds.
- Pond construction is underway at the selected site for demonstration purposes and for future educational purposes and information dissemination. The site is close to an education facility Makerere University uses to retool national extension workers.
- Visited two farmer groups in Gulu (Uganda) that work with Gulu University to support orphans through fish farming. This region of the country has been devastated with 20 years of war and with the return of peace, fish farming is one of the activities that have been embraced by the local populace. Discussions centered on possible collaborations between Gulu University, Makerere University, and the U.S. institutions.
- A paper has been submitted to Journal of Applied Aquaculture for publication.
Conclusions:
The GIS implementation of crisp and fuzzy methods to model site suitability for Tilapia and Clarias farming generated different maps. For both the crisp and the fuzzy approaches over 98 % of the land (excluding wetlands and gazette areas) was classified as suitable or moderately suitable. However, the spatial distribution of suitable and moderate suitability by the two classifications varied. The difference in suitability values was more dominant in the northeastern part of the country and areas around the shores of Lakes Victoria and Kyoga. Suitability values based on the fuzzy method are recommended because the fuzzy method models the fuzziness of the human cognitive processes such that suitability classes do not have sharp (crisp) boundaries but degrees of membership between classes. Unsuitable areas can still be used for aquaculture but the farmer/investor must be aware that higher costs of production may result from selecting a lesssuitable site. For example, where water is abundant but soil is too sandy, or slopes are too steep, small ponds or tanks can be used with accompanying water exchange.
Key concerns regarding pond construction were side slope stabilization and levee compaction. For the compaction, farmers expressed interest in a simple manually operated tool that can easily be transported to any site. The second challenge was excess water during the wet months and drying up of ponds during the dry months. Recommendations were made for reservoirs that can store water during the wet months to supply ponds during the dry months. The reservoirs can also function as sediment traps to minimize shock sediment and nutrient loadings into nearby wetlands. An undergraduate team of students can be assigned these tasks as part of their senior design project. The AquaFISH-CRSP project does not sponsor reservoir and pond construction, it focuses on market analysis, linking up different stakeholders, technical assistance, and information dissemination. The EPA P3 phase II funding will enable implementation of these recommendations.
Supplemental Keywords:
Site suitability, sustainability, wetlands, riparian buffers, watershed models, sediment, water harvesting, fish farming, pond design, GIS, remote sensing, multi criteria evaluation, crisp sets, and fuzzy setsRelevant Websites:
UGA College of Engineering Exit
AquaFish Innovation Lab (formerly AquaFish CRSP) Exit
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.