Ecosystem Services of Urban Green Infrastructure and Policy Aspects: Emphasis on Biodiversity Conservation and Climate Change Mitigation and their Economic Value in Hawassa City, Ethiopia

PIs: Yoseph Melka (Ph.D.) et al., 2020

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This thematic research project was focused on ecosystem services of urban green infrastructures (UGIs) and its policy aspects with emphasis on woody plant species conservation,  climate change adaptation and mitigation as well as their economic value in the case of Hawassa City, Ethiopia. The research work was conducted from  January 2009 up to January 2012 E.C. (3 years ). The purpose of  the research project was:  

1. to assess woody plant species diversity and their richness in selected UGI; identify the actual benefits for UGI for the urban dwellers; estimate carbon stock of selected UGI and its role for carbon sequestration and climate change mitigation;
2. to estimate the economic values of marketable products and other ecosystem services part of UGIs of the city.
3. to assess urban UGI related policy, strategies, manuals and standards

 Interdisciplinary approaches were implemented for research design and sample selection. Standard scientific methods were employed for data collection and analysis by considering the protocol of each sub-project linked to the main goal of the project. Accordingly, a total of 173 sample plots from various UGI clusters were sampled for woody plant species inventory, for measuring soil physical properties and carbon.  A total of 260 residential houses were sampled to examine the role of UGIs on house price, on property value and to estimate the maximum willingness to pay (MWTP) of residents of the city to develop and management of recreational services. In addition, a proportional random sample of 300 residential home gardens was surveyed to identify marketed products from residential home gardens and to estimate the net benefit of urban green area management practices. In order to estimate the recreational value of city parks in Hawassa, the survey was conducted on randomly selected 202 individual visitors (142 domestic and 60 foreign).  A total of 200 city residents were randomly selected and interviewed to evaluate the implementation of policy, strategy, standard, and institutional arrangement, as well as for finding the policy and institutional gaps regarding UGIs development.

Regarding the sampling design and data collection techniques, for the urban parks, a line transect having 10m*10m plot and 1m*1m nested sample plots were laid by using systematic random sampling techniques. The smallest quadrant was placed in all corners and the center of the larger quadrant to count seedlings and collect soil samples. The distance between plots within the transect line was 200m and with a 100m distance interval between the transect line to measure biomass and estimate carbon stock. For all open green spaces and festive areas, a 10m x10m and five 1mx1m nested square sample plots were laid by using a systematic random sampling technique. For institutional and religious compound green spaces, a 20m*20m and five 1mx1m nested square sample plots were laid by using a systematic random sampling technique. For the linear green spaces, a 2m x50m and 10m*10m plots for the median and the roadside were laid systematically having 200m distance between consecutive plots because of uniformity of the species. The bigger plots were used for collecting woody plant species while the nested sample plots were used for soil sample collection. In all UGI clusters, trees having a diameter ≥ 5 cm were recorded.  Height and DBH ( at 1.3m from the ground) were measured. Soil samples from all UGIs clusters were taken from two soil depths (0-30cm and 30-60cm). For evaluating land use land cover changes of the Hawassa city field survey (primary data); Secondary data: orthophoto, a satellite image with high resolution; Hawassa city structural plan; DEM and written document were used by using GPS and measuring tape,  ArcGIS and  AutoCAD data collection instruments and software. For the social, economic and policy components of the study, a mixed approach consisting of qualitative and quantitative data collection techniques such as desk review, household and visitor survey, group discussions,  key informant interview and field observations were employed. Depending on the nature of the data, descriptive and inferential statistics, as well as content analysis, were employed.

Results show that in the UGIs of Hawassa, a total of 81 different species of woody plants belonging to 37 families were identified.  The highest species richness was recorded in green spaces of institutional compound (ICGS) (61 species), followed by amenity green spaces (AGS) (53 species), religious compound green spaces (RCGS) (37 species) and linear green spaces (LGS) (11 species).  The lowest diversity was recorded in LGS. Fabaceae is found to be the dominant family across the whole studied clusters which could be attributed to the existence of urban exploiter/opportunistic species in this family. Exotic species dominate the three UGI clusters that are AGI, ICGS and LGS while RCGS are dominated by indigenous species. The highest similarity (64%) was recorded between AGS and RCGS. The expansion of such exotic species in UGIs of Hawassa is one of the key reasons for the loss of indigenous species and thereby to the significant reduction in the vital role to be played by the urban ecosystem services.  The present study further showed the UGIs clusters of Hawassa city were holding a remarkable carbon stock both in their above and below-ground biomass with a mean above-ground biomass carbon of 70.23 t C ha-1. Moreover, non-accessibility to litter and dead wood due to continuous sweeping in most of the UGI clusters included in the study. Thus, the significance of the litter in carbon accumulation in UGI clusters is not investigated in the current study. . Besides, the soil organic carbon (SOC) stock in UGI of Hawassa City ranged from 34.47 t C ha-1 to 96.63 t C ha-1. The total ecosystem carbon stocks (living woody biomass plus soil) in UGI of Hawassa city ranges from 120.61 to 165.5 t C ha_-1 with a mean of 148.55 t C ha-1. The highest and lowest carbon stock was recorded in RCGS and LGS, respectively.

This result indicates that if a significant effort has been made to develop and manage recreational sites in the city, the number of visitors and stay time will increase, which thereby indicates enhancement of the economic contribution of recreational sites to the city in general in many ways including employment generation. Likewise, the result pointed out that the domestic and non-domestic attribute's value of Gudumale and Tabor mountain recreational sites has a good possibility to be better than the current ones in many dimensions, which include enriching wildlife and plant biodiversity, improved infrastructure for access, and stay on site. In this study employing the hedonic pricing, technique, evidence has been found that proximity to Lake Hawassa, state of residential home garden, and local area green space management were significant positive factors that influence house price. However, proximity to main GIs, Millenium Park, and Tabor Mountain have been found impacting house prices negatively, which might be associated with incidence violence and insecurity incidences in the specified sites. The positive contribution of urban green infrastructures was also found recognized by city residents. Furthermore, the study revealed that different strategies and standards had been developed by the federal government in the past two decades, but those documents are not properly cascaded into the regional and local levels and not directly to the development and management of UGI in the country. Likewise, the documents are not well understood by experts, government officials, and the public as a whole. Overall, there are no clear urban green infrastructure policies at the national and regional level, but the issues of UGI are often incorporated in other policies such as GTP, Environment policy, urban development policies, etc.; this indicates that UGI issues are not taken seriously to deserve a policy framework to promote it. In addition, the study finds weak institutional arrangement, low level of public participation, low level of community awareness, weak implementations of existing manuals, lack of budget, lack of skilled manpower, low and less legally bounded coordination among stakeholders. The study recommends the need to formulate urban green infrastructure policy, awareness creation, assigning qualified professionals on each position, allocate sufficient budget, formulate and enforce rules and regulations, enhance integration among different stakeholders and improve the institutional capacities of local agencies.  Finally, simplifying the complexity of the current institutional arrangement of Hawassa city and localizing a clear structure at the sub-city level by minimizing ambiguity.

Based on the findings, good practices, and lessons learned from the current study, the followings are recommended as further intervention areas for better management of UGIs in Hawassa city.

In-depth investigation and evaluation of the current management activities and plant species site preference in the UGI clusters, which will inform appropriate biomass estimation model in the urban setting.

• Since the UGI is found to support biodiversity and serve as the carbon sink in the city, studies in mainstreaming it as an integral part of the national and regional biodiversity and carbon stock assessments in the country, along with natural forest assessment, is vital.
• Likewise, promoting further introduction and expansion of multipurpose woody species on green spaces, which help to improve the economic and ecological value of the green areas, need to be studied.
• Economic estimates from Gudumale and Tabor showcases that recreational sites in Hawassa city, including the sites considered in the study, can be potential employment generation sites and sustained revenue generation opportunities for the municipality in particular and those engaged in tourism and hotels related business if developed and managed in similar fashion as in the proposed development and management scenarios/proposals in the CVM and CM. Using economic value estimates as inputs to make a cost-benefit analysis of the development and management of recreational sites, the study strongly evidences that development and management and management of recreational sites should be a priority to municipalities involving stakeholders.
• Proper planning, development, and management standards of UGIs should be produced and enforced involving stakeholders including the local community.
• Arranging training programs to enhance the capacity of decision-makers and employees who are engaged in urban green area management.
• Comprehensive awareness creation program for the society through various media, like, community radio, brochures, newspapers, magazines and conferences.
• Proper implementation of rules and regulations through ordinal scrutiny of the concerned officials and workers in fulfilling their responsibility.
• Demarcating clear boundary for responsibility to manage urban green areas for Sanitation, Beautification, and Parks Development Agency and Environmental Protection Authority of Hawassa city.
• Creating integration among different actors of those who are engaged in urban green areas development and management; including, Sanitation, Beautification, and Parks Development Agency and Environmental Protection Authority, private sectors, Land Development and Management Bureau and the community at large through establishment of development committee which involves delegates from each party.
• Arranging incentives; for instance, tax-free and/or reduction for private sectors that are involved in managing urban green areas and motivating staff members of Sanitation, Beautification, and Park Development Agency financially to alleviate turnover of skilled manpower.
• The study recommends the need to formulate urban green infrastructure policy, awareness creation, assigning qualified professionals to each position, allocate sufficient budget, formulate and enforce rules and regulations, enhance integration among different stakeholders and improve institutional capacities of local agencies. Finally simplifying the complexity of the current institutional arrangement of Hawassa city and localizing a clear structure at the sub-city level by minimizing ambiguity.

Household Energy Sources, Environmental Impacts and Alternative Options:  A Case of Hawassa City

PIs: Zerihun Demrew (PhD) and et al., 2020

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In recent years, renewable energy and improved energy technologies have been attracting the attention of the public and policymakers, particularly for their potential to reduce natural degradation and its environmental consequences. Among renewable energy resources, fuelwood remains a key source of energy for households in developing countries, particularly in the Sub-Saharan region. The household sector is the major consumer of firewood in Ethiopia that contributing to forest degradation and greenhouse gas emissions. The reported study is therefore conducted to assess the household energy sources and consumption pattern, evaluate its contribution to climate change, the performance of the improved stove, and forward a way out. The study was conducted in Hawassa city, the capital city of the Southern Nations Nationalities and People (SNNP) Regional State.

Multi-stage sampling procedure was employed to select sample households. Households with different wealth statuses were involved in the present investigation. Sample households were taken to measure daily firewood consumption. Stove performance test was done to compare firewood consumption of improved and traditional stoves. The result revealed that most households use biomasses as a major household energy source. The average daily firewood consumption of households in Hawella Tulla sub-city, for all wealthy categories, was 7.62 kg/household/day equivalent for the average family size of 6.37. The overall average of annual firewood consumption per household was 2781.3 kg (2.78 tons) and about 1115.04 ha of forest land will be cleared by the households in the sub-city. Burning of this amount of firewood could emit on average 0.93 kg CO₂e day^-1 HH^-1. The average wood consumption of traditional and improved (Yekum mirt) cooking stoves was 2.15 and 1.24 kg/kg dough per stove, respectively. Use of Yekum mirt stove would save 0.91 kg firewood /kg of dough. It is predicted that individual households can save 425.9 (0.43 t) firewood per year from baking Injera. The findings identified affordable, innovative technology that reduces the impact of traditional energy usage; however, the value chain of alternative energy sources in the case of Hawassa city is not strongly institutionalized. All stakeholders need to work on the provision of alternative energy sources and improved energy-saving technologies.