Alternative Stabilizer for Mud Concrete

Cement is one of the key stabilizers for earth constructions since Roman civilization. The invention of cement was one step in the human civilization. However, cement has many issues especially when it comes to the environmental conservation. The production of cement creates a lot of carbon dioxide and destroys the natural setting to some extent due to the high consumption of clay and lime. Therefore, this study was conducted to alter the cement in mud concrete block. The study started with an inventory of alternative stabilizers that can be found in nature as well as in the human production. And then, the chemical patterns of those stabilizers were carefully identified to alter the typical Portland cement. Several mix proportions were tested and developed to alter the cement and found that the following materials can be developed to alter cement. A natural stabilizer such as tree resins, latex rubber stabilizer, waste ash, rice husk ash and many other ashes can be developed to chemically stabilize the earth blocks. However, out of the invented stabilizers, fly ash and rice husk ash have the high potential to replace cement

Environmental flow assessment : an Analysis

Natural flow of a river is recognized as vital to sustaining riverine ecosystems. The biotic composition, structure and function of aquatic ecosystems depend largely on the hydrologic regimes; however flows of the world’s rivers are increasingly being modified through impoundments. Therefore calculation of the optimum flows for a healthier river is essential but there is no simple figure that can be given for the environmental flow requirements of rivers. Environmental flows refer to water for ecosystems. Ecosystems, however, provide a wide range of valuable services to people. Concept of the environmental flow was initiated not only to discover the river health and to manipulate river flow regimes, but also to get the maximum harvest from free flowing waters. Hence, providing for environmental flows is not exclusively a matter of sustaining ecosystems but also a matter of supporting human well being. As demand for freshwater continues to rise and ways are sought to improve water productivity, decision-making bodies at local, basin and national levels require accurate information on the role of river flows in sustaining a wide range of environmental benefits. For that reason assessment of environmental flows may contribute to setting management rules and monitoring their impact on river health

Wild Grass Types as Green Roofing Materials for Urban Landscapes in a Tropical Climate

Urban cities, especially in tropical context emphasis on alternative green covers namely green roofs in order to mitigate Urban Heat Island Effect. Grass is a widespread green roofing material, predominantly for extensive green roofs. This study was aimed (a) to explore the growth performance of selected wild grass types under different irrigation conditions and (b) to select the most suitable wild grass type for green roofs under minimum irrigation in tropics. Five wild grass types (belongs to Genus Digitaria, Genus Chrysopogon, Genus Cynodon, Genus Panicum and Genus Isachene) were selected and they were tested with Bouteolea dactyloides (Buffalo grass) as the control on reinforced concrete slab models. Performances of the grasses were evaluated under two irrigation schedules; irrigation once in five days (I1) and irrigation once in 10 days (I2).Tested parameters were vertical growth, horizontal growth, plant survival percentage, Leaf Area Index (LAI), root density, leaf density, grass density and ranking procedure for visual appearance. Results of this study indicated that under both irrigation schedules, Digitaria spp. showed the highest performances (After six weeks of treatments, for I1 and I2; vertical growth: 6.2 cm and 6.0 cm , horizontal growth: 17.6 cm and 16.1 cm , plant survival percentage: 99.1% and 97.8% , LAI: 0.64 and 0.58 , root density: 0.0017 g/cm3 and 0.0014 g/cm3, leaf density: 0.0013 g/cm3 and 0.0012 g/cm3 , grass density: 0.0043 g/cm3 and 0.0042 g/cm3, respectively) and Panicum spp. showed the lowest performances (After six weeks of treatments, for I1 and I2; vertical growth: 15.11 cm and 14.8 cm , horizontal growth: 7.2 cm and 6.5 cm , plant survival percentage: 96% and 92.5% , LAI: 0.47 and 0.43 , root density: 0.0013 g/cm3 and 0.0012 g/cm3, leaf density: 0.0011 g/cm3 and 0.0009 g/cm3 , grass density: 0.003 g/cm3 and 0.0025 g/cm3, respectively) compared to Bouteolea dactyloides while Chrysopogon spp. showed better growth performances next to Digitaria spp. Though Isachene spp. showed better ground coverage compared with Digitaria spp., it showed less plant survival percentage. Therefore, Isachene spp. is not suitable as a green roofing material in tropical context. Digitaria spp. is the best wild grass spp. from the selected wild grasses which gave high tolerance for water scarcity in tropical context under tested irrigation schedules. Further researches should be carried out beyond three months for further evaluation of growth performances of the selected grass spp.Keywords: Green roofing materials, Tropical context, Wild grasse

Drought severity–duration–frequency curves: a foundation for risk assessment and planning tool for ecosystem establishment in post-mining landscapes

Eastern Australia has considerable mineral and energy resources, with areas of high biodiversity value co-occurring over a broad range of agro-climatic environments. Lack of water is the primary abiotic stressor for (agro)ecosystems in many parts of eastern Australia. In the context of mined land rehabilitation quantifying the severity–duration–frequency (SDF) of droughts is crucial for successful ecosystem rehabilitation to overcome challenges of early vegetation establishment and long-term ecosystem resilience. The objective of this study was to quantify the SDF of short-term and long-term drought events of 11 selected locations across a broad range of agro-climatic environments in eastern Australia by using three drought indices at different timescales: the Standardized Precipitation Index (SPI), the Reconnaissance Drought Index (RDI), and the Standardized Precipitation-Evapotranspiration Index (SPEI). Based on the indices we derived bivariate distribution functions of drought severity and duration, and estimated the recurrence intervals of drought events at different timescales. The correlation between the simple SPI and the more complex SPEI or RDI was stronger for the tropical and temperate locations than for the arid locations, indicating that SPEI or RDI can be replaced by SPI if evaporation plays a minor role for plant available water (tropics). Both short-term and long-term droughts were most severe and prolonged, and recurred most frequently in arid regions, but were relatively rare in tropical and temperate regions. Our approach is similar to intensity–duration–frequency (IDF) analyses of rainfall, which are crucial for the design of hydraulic infrastructure. In this regard, we propose to apply SDF analyses of droughts to design ecosystem components in post-mining landscapes. Together with design rainfalls, design droughts should be used to assess rehabilitation strategies and ecological management using drought recurrence intervals, thereby minimising the risk of failure of initial ecosystem establishment due to ignorance of fundamental abiotic and site-specific environmental barriers, such as flood and drought events

Policy coherence for resilience in Sri Lanka coherence of climate change adaptation (CCA) disaster risk reduction (DRR) and sustainable development goals (SDGs)

Purpose:Policy coherence is a complex and tough task for many developing nations because their capacity to examine and deliver evidence-based inputs to policymaking is limited, and policy dialogue platforms need to be effectively used. Resolving these difficulties is a critical requirement for policy consistency. As a result, the study focuses on the level of policy coherence for climate change adaptation (CCA), disaster risk reduction (DRR) and sustainable development goals (SDG) in Sri Lanka and suggests routes for policy coherence for Resilience. This study aims to investigate the coherent approach of CCA, DRR and SDG; to identify concerns in policy documents addressing the coherence of CCA, DRR and SDG in local context; and to propose policy coherence suggestions for resilience in Sri Lanka.Design/methodology/approach:Methodology comprises a review and content analysis of 17 policy and legal documents in Sri Lanka and a qualitative study. The qualitative approach consists of semistructured interviews that obtained deep and broad expertise knowledge with ten government representatives and stakeholders. Both content analysis and interview data were analyzed by using NVivo.Findings:It was discovered that there are several issues with the coherence of policies in Sri Lanka, including the fragmented approach, lack of integration, inadequate coordination, limited resources and lack of monitoring and evaluation. The policies are inspired by international frameworks, and local implementations are not focused, leading to inadequate implementation of policies. The lack of development cooperation for the use of innovative approaches, such as climate-resilient infrastructure and environmentally friendly solutions for CCA and DRR, further aggravates the situation. Another concern is the lack of land use management and responsibility for the development of physical infrastructure for DRR integration with CCA. It is found that there is a limited community involvement which is vital for the implementation of policies. Local implementations are encouraged to fill the gaps in existing policies/acts. The analytical framework of the study is based on a preliminary examination of policy documents, a review of the literature and discussions with practitioners. The framework reflects the current situation of policy integration which addresses strategic, conceptual, institutional, operational and financial coherence. The research suggests pathways for achieving policy coherence in CCA, DRR and SDG in Sri Lanka, such as enhancing the strategic coherence by improving goals to increase the coherence within CCA, DRR and SDG; improving the credibility of the unified approach for developing DRR and CCA risk assessments; intensifying institutional cooperation and stakeholder management; improving the common monitoring and evaluation; establishing implementation strategies; and increasing the community involvement.Research limitations/implications:The study on policy coherence in Sri Lanka recommends increasing community and professional involvement, conducting more research, developing a national strategy, increasing capacity building, strengthening international collaboration and fostering multisectoral collaboration. These recommendations can help improve policy coherence between CCA, DRR and SDGs, align policies with national goals and priorities and improve implementation effectiveness. By implementing these recommendations, Sri Lanka can address the challenges of climate change and natural disasters and achieve SDGs.Practical implications:The study on policy coherence for resilience in Sri Lanka has practical implications, including improved coordination and resource allocation, increased capacity building, improved reputation and sustainability. By integrating CCA, DRR and SDGs, this study can help Sri Lanka become more resilient to climate change and natural disasters, achieve SDGs and become a responsible actor in the international community. These implications can contribute to a more sustainable future and ensure that development goals are achieved in a way that is resilient to climate change and natural disasters.Social implications: Increased community participation: the study emphasizes the importance of community involvement in the policy development process. This can help build trust between communities and government agencies, improve transparency and ensure that policies are developed in a way that is responsive to local needs and priorities.Originality/value:Based on the identified existing loopholes in the policies and pathways to policy coherence, the issues in policymaking could be overcome. It could be used to establish strong linkages between policies based on CCA, DRR and SDGs to achieve long-term resilience

Comparative Study of Embodied Energy in Different Walling Materials

Calculating embodied energy of a construction material is a wholistic method of measuring the environmental sustainability factor because by reducing embodied energy can mitigate the environmental pollution. Along resolution, the embodied energy is the amount of all the energy devoured while manufacturing transporting constructing and maintaining specific product. Sri Lanka is using brick and cement block as main walling material. Brick walling materials use 1,5541 MJ of energy per 100 ft2 and cement block using 1,1542.9 MJ per 100 ft2. In this study, the embedded energy of brick and other mostly available walling materials such as cement blocks, wattle and daub, mud concrete block, rammed earth wooden planks and steel sheets were accounted and compared according to the origin of energy consumption. The processes of walling material were carefully studied and analyze to calculate embodied energy. One 100 ft2 square (10x10 ft) was used to measure and compare the embodied energy content. Then overall rank was given considering the embedded energy cost and usability factor.According to the collected data, the most industrious walling materials such as brick and cement blocks consuming large amount of energy in the manufacturing process. Wattle and daub is the obvious eco-friendly walling material. Since the study compare walling material, overall soil blocks made of cement and soil (altering wattle and daub) shows best results with minimum embedded energy and yet provide essential strength to support the structure. Notwithstanding, replacing brick and cement block with alter walling material would save millions of trees.Keywords: Embodied Energy, Energy content, Process analysis, Walling material

Amplification of comfort and the air quality with green roof in cities

Since the last few decades the world population has been increasing in a faster rate. With the increasing population, the needs of the people have also increased. Because of that more people have lean towards to move to the cities in search of facilities. The demand for dwellings in the cities has increased. To accommodate this demand, more buildings have been constructed, changing the previous arrangement of the cities. The cities have turned into a compacted space with less vegetation and greenery. Yet again the pervious lands in the urban space have changed to impervious surfaces making the urban climate to be changed peculiarly in terms of temperature and air quality. The more the urban space has become industrialized, the more the air has been contaminated. There are other environmental issues together with the changes for the cities. Due to the increment of artificial surfaces the temperatures of the cities have been increased than the country side allowing the heat island effect to take place making the energy demands of the cities to be high. For these climatic problems the researchers have identified green roofs as a sustainable solution. This research mainly focuses on augmentation of air quality and on reduction of heat island effect, with the replacement of existing flat slabs in the Colombo city in Sri Lanka, with green roofs. A well compacted city area was chosen in the Colombo district. The measurements were taken in terms of temperature, humidity and CO2 in the chosen city. Different special places were chosen for the measurements. The obtained measurements are observed for the identification of the best remedy. With that the expected increment of air quality and expected reduction of the temperatures are modeled with the replacement of existing flat slabs in the area with green roofs. From the results it’s evident that the green roofs can play a major role in enhancing air quality and reducing heat island effect making people to live in cities comfortably and healthily

Success factors in donor funded projects: case study on internal estate roads

Beneficiary participation is an important factor for donor funded projects. Since it gives many benefits and final product to the community, donors are always insisting the projects with beneficiary participation. However, for smooth execution of beneficiary participatory projects has to cross many hurdles for its successful completion. Identify those drawbacks and addressing them is necessary. The Raw data are collected through a questionnaire and analyse those according to the existing data from the donor funded executed project. The results show that there are many factors that affect the successful completion of beneficiary participatory projects. The findings have emphasis on more site visits by the management staff, budget to be suit to the site location and the conditions. Findings has extended to management staff travelling distances, vehicle allocations to staffs, payment procedure, meeting minutes to be distribute on time to site and also recommending to some team building and coordination programmes with management and beneficiary parties

Performance of straw bale houses in tropical climatic condition

Past few decades’ construction industry has become the major contributor to the depletion of natural resources and destruction of nature through Global Warming. On top of all the energy crisis and high energy cost forcing on innovations, which can leads low running cost. Due to all, presently there is a high trend to do research on sustainable construction methods. These techniques are varying country to country, since the climatic conditions are changing with their locality. Even though the roof is the main heat gaining element in a building, walls also add considerable amount of heat to the indoor volumes. Straw bale was considered as a low cost sustainable walling material for many decades due to so many inbuilt qualities, such as low cost, durability and low conductivity. The objective of this project was to identify the effectiveness of Straw Bale as a passive element in Tropical Conditions. Straw walls were compared with other common walling materials using computer simulations together with taking actual measurement in real scale buildings, which are located in the same vicinity. The observations clearly show that the thermal performances of straw bales are much better than other common walling materials used in Sri Lanka

Effect of greenery on co2 concentration inside dwellings

With the urbanization and the rapid development more people have been moving towards cities in search of facilities. With this, demands for dwellings in the cities have increased and more buildings have been constructed, changing the previous arrangement of the cities. The cities have turned into congested areas with less vegetation and greenery. The more the urban spaces have become industrialized, the more the air has been contaminated. This research discusses the effect of surrounding vegetation on indoor air quality of dwellings by checking the difference of CO2 concentration based on actual measurement in Colombo, Kandy and Nuwara Eliya which are situated in three different altitudes, varying amount of vegetation and with largely varying traffic congestion. The results obtained reveal that the effect of vegetation is very high in Colombo when compared to other two cities as the traffic congestion is very high there. In low greenery areas of Colombo, indoor CO2 concentration increases very rapidly in the evening when there isn’t much difference in other two cities. But the difference between mean indoor CO2 levels in greenery and low greenery area is decreasing significantly amongst Colombo, Kandy and Nuwara Eliya. This research indicates that the surrounding vegetation has more impact on indoor air quality in cities with high traffic congestion and low altitudes