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

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

Analysis of Climate Variable and Fisherman Perception on Climate Change Divers in Negombo Lagoon Area

Climate change has undoubtedly become one of the most contentious issues in the international environmental debates and has escalated the impacts on fishery industries and fishing communities globally. This study was conducted to quantify the variations in climate variables, and coastal vegetation that may affect the fisheries industry due to climate change over past three decades in the Negombo lagoon area. Further, the knowledge and awareness of fisheries and associated communities on climate change was investigate. To understand the dynamics of the precipitation and temperature, monthly data for 30 years (1989-2022) were collected from the Department of Meteorology and 19 Module Bio-climatic Variables (MBV) were calculated to determine the climatologycal variation. The change in the coastal vegetation was analyzed using the Landsat 8 satellite using ArcGIS 10.8. A questionnaire survey and a focus group discussion were carried out as assess the knowledge, awareness and impact of climate change in the fisheries community (n=80). The mean annual and minimum and maximum precipitation ranged from 118.6 mm-268.6 and 0.6 mm - 826.6 mm. The mean, maximum, and minimum temperatures varied from 28.8o C- 32.3o C, 33o C-34o C and 29o C-30o C. Out of 19 MBV variables, 9 variables had increasing trends while 3 variables had decreasing trend. The change percentage of coastal vegetation cover from 1992-2002, 2002-2012, 2012-2022 was observed as 35.71%, 4.99% and 6.13%. As per the peoples‘ knowledge of climate change, it was highlighted that around 50% of respondents does not have a proper idea on what is climate change (40% of respondents stated that the variation of precipitation and wind is the climate change drivers; Further, 40% of respondents attested that land use change with time has accelerated climate change while 30% of respondents mentioned that lack of coastal awareness and restoration programs is the second main reason for accelerated climate change that affect the fishery industry). The outcomes of the focus group discussion revealed that fishing activities are heavily affected by climate change drivers, and some engage in alternative jobs in extreme climatic conditions to feed their families. Finally, fishery communities highlighted the need for the government and other responsible authorities to take necessary actions to adapt and strengthen the resilience to climate change. This study corroborates the timely and topical obligation for sustainable fisheries management action planning for the Negombo area. Keywords: Climate change, Coastal mangrove vegetation-precipitation-temperature change, Fisheries communities, Knowledge, Awareness, Negomb

A New Three-Pillar Score System to Reduce the Sustainable Subset Heterogeneity within the GREENSL Rating System in Sri Lanka

Sustainable development is achievable only by integrating and acknowledging three main sustainability pillars (Environment, Social, and Economic) during the decision-making process. Sustainable/Green construction has become a major part of the sustainable development process in Sri Lanka today. Sustainable/Green buildings are evaluated using both international (LEED, BREEAM, CASBEE, Green globes, etc.) and local (GREENSL, Blue-Green Sri Lanka) green building rating systems. Most of these international green building rating systems have unequal credit point distribution among three sustainability subsets which causes heterogeneity among subsets. Thus, this research was designed to evaluate two local green building rating systems (GREENSL Version 2.0, and Blue-Green Sri Lanka for government constructions Version 1.0) to identify this heterogeneity in the local context. The credit point distribution among three sustainability subsets within the two selected rating systems was evaluated by analyzing the categories and criteria of these two rating systems. Here, when criteria represented one or more pillars of sustainability, the credit points belonging to such criteria were equally divided into those two subsets. The results revealed that three subsets were not equally considered in the GREENSL (Environment (52.1%), Social (21.6%), Economic (26.3%)) and Blue-green Sri Lanka for government constructions (Environment (48.4%), Social (17.2%), Economic (34.4%)) rating systems. Thus, there is a sustainable subset heterogeneity that is dominated by environmental sustainability. As achieving the exact 33.3% point distribution among three sustainability pillars is difficult, new point distribution percentages were proposed as 40% for the environment and 30% each for both social and economic sustainability pillars. Finally, a new three-pillar score system was proposed that can be used together with the GREENSL overall score for the buildings to reduce this subset heterogeneity by adopting the proposed point distribution percentages above. This study suggested that the building needs to fulfill both the total category score and the proposed three- pillar score to qualify for the respective GREENSL award (Platinum, Gold, Silver, and Green certified) to reduce the sustainable subset heterogeneity within this rating system. Keywords: GREENSL for the built environment, Sustainability subsets, Sustainable subset heterogeneity, Three-pillar score syste

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

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

Thermal Evaluation of Vertical Greeneries for Building Façade with Different Orientations and Shading Percentages by Design-builder Simulation

Green facades are the innovative forms of vertical greenery systems which are good strategies for urban greenery to improve the micro-climatic conditions of the area. This research study examines the benefits of cooling load by the simulation of the typical building. Design-builder energy plus simulation tool is used to estimate the annual cooling energy of the typical building which consists of three stories with four façade orientations with varying shading percentages to determine the optimum vertical greenery solution while taking shading percentage and façade direction into account. Design-builder software was validated by measuring the 24-hour temperature of the existing indirect vertical garden. The validation study was carried by using a basic linear regression model analysis using Mini tab software. Under five shading percentages (0%, 25%, 50%, 75%, and 100%), the building was designed with four orientations (North, East, South and West). As a consequence, there were twenty possible situations, each with four regions and four orientations. Each scenario's yearly annual cooling load was estimated and compared to a reference condition for a building without plants using the software. For four major orientations with varying different shade percentages, an indirect green façade with Thunbergia laurifolia was integrated. Validation results exhibit R2 value was 0.976, indicating that the model can express 97.6% of the actual data changes. In terms of economics, the building façade with 25% and 50% greenery coverage with a south orientation and 75% greenery coverage with east orientation are the best vertical greenery solutions. The ideal façade is the one that is completely covered in greenery (100%) and faces east. Keywords: Design-builder, Indirect green facade, Orientation, Simulatio

The Perceived Palatability of Forage Plants of Wild Asian Elephants in Sri Lanka

The dilemmatic human-elephant conflict and the loss of forage lands due to the ever-increasing population density of Sri Lanka indicate the need to increase sustainable forage availability. Asian elephants feed on different plant species depends on the plant palatability. The feeding behavior of wild elephants provide the basis for enhancement of forage availability through elephant-specific conceptual conservation strategies in habitat enrichment to keep elephants inside the fragmented landscapes. The literature on the elephant forage plants in Sri Lankan forests and lands is limited and there are gaps in the knowledge on the plant palatably in relation to the elephant forage preferences. Thus, the present study explores the perceived palatability of elephants‘ forage in different provinces in the country. A list of palatable plant species was compiled based on the literature, field surveys, and the results of interviews conducted with wildlife experts. A questionnaire was developed from the list of palatable plant species and validated through wildlife experts and a pilot sample. The survey method of the research was used to collect information from a sample of respondents with field experience and expertise in the subject. The responders were chosen at random, and a piloted and validated questionnaire was administered through the Google form. Perceived palatability score was calculated from the responses considering their human perception towards forage plants. The data were analyzed for frequency distribution and mean comparison was performed using one-way analysis of variance procedures. Twenty-two common elephant forage plants were recognized from eight provinces on the island, included 03 herbaceous, 14 grasses, and 05 sedges. These plants speculatively thrive well in most of the elephant ranging areas. As far as provinces in the dry zones are concerned, it can be assumed that the probability occurrence of the selected plants is similar. The perceived palatability scores vary across the provinces, and plant types. The distribution of elephant forage plants in the island indicates an ecological provenance, inferring the influence of the general climatic conditions of the island. Of the listed 22 forage plants, Pennisetum purpureum, Sacciopelsis interrupta, Panicum maximum, and Echinochloa glabrescens were dominant over the rest, having relatively higher perceived palatability scores. Further, studies are required to have a complete image of the spatiotemporal variation of the four forage plants identified. The study showed the significance of the availability of forage plants and their palatability levels to secure and sustain the grazing forages for wild elephants in Sri Lanka.  Keywords: Perceived forage palatability, Human-elephant Conflict (HEC), Asian elephants (Elephas maximus), Grazing forages, Wildlife conservation, Sri Lanka&nbsp

Effect of Turf Roof Slabs on Indoor Thermal Performance in Tropical Climates: A Life Cycle Cost Approach

Urbanization related to population growth is one of the burning issues that the world is facing today. Parallel to this, there is visible evidence of a possible energy crisis in the near future. Thus, scientists have paid attention to sustainable development methods, and in the field of building construction also, several innovations have been proposed. For example, green roof concept is one of such which is considered a viable method mainly to reduce urban heat island effect, to regain lost land spaces in cities, and to increase aesthetics in cities. The present study was aimed at investigating the impact of green roofs on indoor temperature of buildings, the effect of different types of roofs on the air conditioning loads, and the life cycle cost of buildings with different types of roofing. The study was conducted in several phases: initial small-scale models to determine the heat flow characteristics of roof top soil layers with different thicknesses, a large-scale model applying the findings of the small-scale models to determine temperature fluctuations within a building with other common roofing systems, a computer simulation to investigate air conditioning loads in a typical building with cement fiber sheets and green roof slabs, a comparative analysis of the effect of traditional type roofs and green roofs on the air conditioning loads, and finally an analysis to predict the influence of traditional type roofs and green roofs on life cycle cost of the buildings. The main findings of the study were that green roofs are able to reduce the indoor temperature of buildings and are able to achieve better heat transfer through the roof, and, thus a lower cooling load is necessary for air conditioning and has the possibility of reducing life cycle cost of a building.</jats:p