Science and Engineering Connect

Assessment of Climate Change Impact on the Streamflow in Mae Ngat Basin, Chiang Mai

2025-04-25T07:49:20+07:00

Background and Objectives: Climate change has significantly affected water resources worldwide, including Thailand. This is especially true for watershed areas, which are vital for agriculture and local water use. One such area is the Mae Ngat watershed in Chiang Mai Province, a tributary of the upper Ping River, where the Mae Ngat Somboon Chon Dam serves as the primary water reservoir. Studies over the past decade have shown that this region has experienced increasing variability in rainfall, in terms of frequency, intensity and timing. This has led in turn to flash floods during the rainy season and droughts during the dry season. Such climatic uncertainty has impacted streamflow, ecosystems, agriculture and the overall efficiency of water resource management in the basin. To address this uncertainty, the present study aimed to assess the impact of climate change on streamflow and inflow into the Mae Ngat reservoir using the Soil and Water Assessment Tool (SWAT) model. The analysis incorporated climate data from the Coupled Model Intercomparison Project Phase 6 (CMIP6), which were spatially downscaled to a daily scale using the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6). This dataset is highly suitable for watershed-scale hydrological impact assessments and supports long-term water management planning under changing climatic conditions.

Methodology: The SWAT model was developed using input data, including topography, land use, soil characteristics and local meteorological records within the Mae Ngat watershed. The basin was subdivided into multiple sub-basins to enhance the spatial accuracy of hydrological process simulation. Model calibration and validation were performed using observed streamflow data from station P.56a during the period 2003–2014. Model performance was evaluated using statistical indicators, yielding R² of 0.80, NSE of 0.80, and PBIAS of -1.31%, indicating satisfactory agreement between the simulated and observed data and the model suitability for future projections. Future climate projections were obtained from 10 Global Climate Models (GCMs) under CMIP6. Four greenhouse gas emission scenarios were applied: SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5. Daily downscaled data from NEX-GDDP-CMIP6 were used. Simulations covered two future periods: 2031–2050 and 2051–2070, with the historical baseline of 2003–2014. Streamflow outputs were analyzed on annual, monthly and spatial scales to assess changes and trends in water availability under different climate change scenarios.

Main Results: The projection results indicate that annual streamflow in the Mae Ngat watershed is expected to increase under all future climate scenarios. Notably, under SSP1-2.6 and SSP2-4.5, streamflow is projected to rise by approximately 54.07%–88.14% and 53.64%–76.32%, respectively. For SSP3-7.0, the projected increases are 35.79% and 70.91%, while SSP5-8.5 shows increases of 60.30% and 78.34% during the two future periods. Spatial analysis reveals that the central and lower parts of the watershed are mostly affected, with significant increases in streamflow that heighten the risk of flooding during the rainy season. Meanwhile, drought conditions remain a concern during the dry season due to the uneven distribution of rainfall throughout the year. Monthly-scale analysis shows that both SSP1-2.6 and SSP2-4.5 result in more evenly distributed increases in streamflow throughout the year, potentially reducing hydrological extremes. In contrast, SSP3-7.0 maintains dry-season streamflow levels close to the historical baseline, implying continued drought vulnerability. Additionally, SSP5-8.5 exhibits significant increases in streamflow during August and September, raising the likelihood of flash flood events. These contrasting seasonal patterns underscore the necessity of developing flexible and adaptive water resource management strategies to cope with both flood and drought risks under changing climate conditions.

Conclusions: Based on the SWAT model simulation using downscaled CMIP6 climate projections, streamflow in the Mae Ngat watershed is projected to increase during the period 2031–2070 under all greenhouse gas emission scenarios. Notably, SSP1-2.6 and SSP2-4.5 show a more consistent and evenly distributed increase in the streamflow throughout the year, while SSP3-7.0 and SSP5-8.5 exhibit higher variability, with increased flows during the rainy season and decreased flows during the dry season. These findings highlight a dual-risk scenario, i.e., flooding and drought, that may compromise the stability of the watershed's hydrological system. The calibrated SWAT model proves to be a reliable and effective tool for long-term water resource planning and management under future climate change conditions.

Practical Application: The results of the present study can be used as a policy-support tool for integrated and adaptive water resource management in the Mae Ngat watershed. Recommended strategies include enhancing reservoir capacity through structural improvements or supplementary storage facilities to handle peak rainfall; proper designs of effective drainage systems to mitigate flash flood risks in downstream areas are also recommended. Seasonal water allocation planning and promotion of water-efficient agriculture during the dry season are also essential. The integration of weather monitoring systems, predictive models and information technology can support strategic decision-making in such terms as crop scheduling, smart irrigation systems and early warning mechanisms. The presented framework and findings can also be applied to other watersheds in Thailand with similar hydrological and climatic characteristics, contributing to national resilience against future climate variability.

Application of a Thermosiphon-Tube Drying Chamber with Waste Heat from a Charcoal Kiln

2025-08-25T10:38:21+07:00

Background and Objectives: Energy efficiency and sustainability are key issues in agriculture and industry, particularly in charcoal production processes where a large amount of heat is wasted. Recovering and reusing the heat in such processes as drying, which often face a problem related to energy efficiency, leading to high energy consumption and long drying time, represents an interesting alternative to the problem. The present study focused on the development and application of a thermosyphon drying chamber that utilizes waste heat from a charcoal kiln to improve the drying efficiency. The thermosyphon drying system drew heat directly from the kiln and effectively transferred it to the drying chamber. The objectives of this research were: (1) to design and develop a thermosyphon drying chamber and (2) to evaluate the heat distribution efficiency and its effects on product quality. The study also examined the potential of thermosyphon technology to optimize drying conditions, ensuring better energy conservation while maintaining product integrity.

Methodology: The study involved the design and development of a thermosiphon drying chamber, which consists of a drying compartment and a combustion chamber. The thermosiphon system used 30 stainless steel heat pipes filled with R134a refrigerant as the working fluid to facilitate passive heat transfer. Experiments were conducted using fresh turmeric as the test material; turmeric was made into slices of different thicknesses (2, 4, and 6 mm). The drying efficiency was assessed by measuring moisture loss, water activity (a_w) and color changes at 90, 120 and 150 min. Thermal efficiency measurement was also made to compare the heat retention capacity of the system with that of a conventional drying chamber.

Main Results: Drying turmeric using the thermosyphon (TS) system increased moisture loss from 64.97% (No TS) to 80.43% at 90 min of drying (2 mm thickness) and reduced water activity (a_w) from 0.91 to 0.75 at the same time. Extending the drying time to 150 min further decreased a_w to 0.63 (TS), while in the No TS system it remained higher at 0.87. In a hypothetical feasibility comparison, TS system enabled 2 drying cycles per day, compared to 1 cycle in the case of No TS, thereby increasing the amount of fresh turmeric that can be processed in a day from 10 kg/day to 20 kg/day; these amounts resulted in the increased yield of dried turmeric from 1.8 kg/day to 3.6 kg/day. The total income increased from 270 to 540 baht/day. Although the initial cost of the TS system was higher (9,000 Baht compared to 6,000 Baht), TS system demonstrates strong potential for increasing productivity and income.

Conclusions: Thermosyphon drying chamber utilizing waste heat from a charcoal kiln could enhance the heat transfer efficiency and reduce the drying time of turmeric more effectively than a conventional system. However, a_w values that still exceeded the safety threshold highlight the limitation of the system for turmeric drying. Nevertheless, the technology may be more suitable for other herbs with different structural characteristics. Improvements in temperature and airflow control are recommended. The system shows potential for applications ranging from household to industrial scale and could help reduce the reliance on conventional energy sources in the processing of agricultural products.

Practical Application: Thermosyphon drying system can be integrated into agricultural and industrial drying operations to improve energy efficiency and reduce operating costs. The ability to utilize waste heat from a charcoal kiln makes it a sustainable option for postharvest processing, benefiting farmers and small-scale producers. Furthermore, its low-maintenance design and reduced reliance on electric heating make it an economically viable choice for remote areas with limited resources. Additionally, the low-maintenance design and reduced dependency on electrical heating elements make it an economically viable solution for remote and resource-limited areas.

An Exploratory Factor Analysis of Lean Construction Elements Reflecting Project Management Performance among Local Construction Enterprises

2025-05-14T15:38:55+07:00

Background and Objectives: The construction industry remains a pivotal sector in national development, yet it frequently faces systemic inefficiencies, including project delays, cost overruns, and materials waste. These challenges are especially pronounced among local construction enterprises, which often operate with limited resources, simple organizational structures, and minimal access to modern technologies. The adoption of Lean Construction Concepts (LCC) has gained increasing attention as a viable solution to address the issues. Lean construction emphasizes minimizing waste, while maximizing value creation, aiming to optimize construction processes and improve labor productivity throughout project execution. Despite the growing global adoption of lean methodologies, their implementation in Thailand’s local construction sector remains underexplored, particularly regarding how various lean components influence overall project management performance. The main objective of this study was to identify and classify the structural elements of lean construction that significantly affect project management efficiency within local construction enterprises in Thailand. This research aims to bridge the existing knowledge gap and provide a systematic framework tailored to the unique challenges faced by such enterprises.

Methodology: The study adopted a quantitative research methodology, using Exploratory Factor Analysis (EFA) to uncover the underlying structure of lean construction elements that influence project management performance. Data were collected through a structured questionnaire survey distributed to local construction professionals across Thailand. A total of 115 valid responses were obtained, satisfying statistical adequacy tests. The Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy was found to be 0.845, while Bartlett’s test of sphericity yielded a p-value < 0.001, indicating that the dataset was suitable for factor analysis. Items with a Measure of Sampling Adequacy (MSA) below 0.50 were excluded to enhance model accuracy. Reliability was confirmed through Cronbach’s alpha values of 0.927 and 0.938 for the factor groups and the overall instrument, respectively, indicating high internal consistency.

Main Results: The EFA results reveal six key components comprising 31 variables that collectively explained 59.70% of the total variance. The identified factors are: (1) cost and quality, emphasizing process improvement, elimination of redundancy, and resource optimization; (2) strategy and planning, underscoring the importance of effective project scheduling, budget adherence, and personnel management; (3) safety, highlighting the implementation of safety measures and proper use of personal protective equipment to prevent accidents and health risks; (4) people and processing, which focus on reducing task duration, enhancing labor efficiency, and streamlining procurement and logistics; (5) waste, emphasizing reduction of materials waste and promotion of 5S principles for environmental and operational efficiency; and (6) health and accident, which relate to monitoring accident rates, ensuring health standards, and minimizing disruptions caused by workplace incidents. The variable with the highest factor loading (0.818) pertains to materials waste reduction, reflecting its critical importance in resource-constrained local enterprises.

Conclusions: The study successfully establishes a comprehensive framework for understanding how lean construction elements impact project management performance among local construction enterprises in Thailand. The six-factor model provides empirical support for the strategic implementation of lean principles, illustrating their effectiveness in enhancing cost efficiency, process reliability, safety performance, and environmental sustainability. These findings emphasize the importance of tailored lean applications that consider the unique operational characteristics of local firms, such as capital constraints and labor management challenges. The research contributes to the broader field of lean construction by extending its practical relevance to developing economies, where localized adaptation is crucial for successful implementation.

Practical Application: The study offers practical insights to local construction practitioners, project managers, and policymakers seeking to improve project outcomes through lean methodologies. By categorizing the essential elements of lean construction into six actionable components, the findings provide a structured implementation roadmap for local enterprises. Project managers can use these insights to prioritize lean strategies that directly enhance productivity and efficiency, including waste reduction, strategic planning, and safety compliance. Moreover, the research lays the groundwork for developing training programs, organizational policies, and performance monitoring tools aligned with lean construction principles. Future research should expand this model to examine its applicability in large-scale infrastructure projects and conduct comparative analyses with international case studies. Such extensions will foster the creation of globally informed best practices and reinforce the long-term sustainability and competitiveness of Thailand’s construction sector.

Extraction of Natural Dyes from Mangrove Forests to Increase Values of Creative Economy

2025-05-22T17:32:51+07:00

Background and Objectives: The integration of knowledge, culture, technology, and creativity under the concept of creative economy plays a vital role in enhancing the economic value of local resources. Mangrove forests are among the high-potential natural resources, with ecological, economic, and social significance. However, conventional uses of mangrove resources often generate a large amount of waste, e.g., fallen leaves and bark, that is typically discarded as valueless. If such materials can be developed into innovative natural textile dyes, their value can be sustainably enhanced; adverse environmental impacts would also be alleviated. This research therefore aimed to explore the dyeing properties of waste materials from mangrove ecosystems and to develop a high-quality natural dye extraction process suitable for creative design in line with sustainable development principles.

Methodology: The present study employed experimental research in combination with qualitative analysis. Five types of waste materials from the mangrove ecosystem in Yisan Subdistrict, Amphawa District, Samut Songkhram Province, were selected: mangrove leaves, mangrove bark, nipa palm husks, seablite, and sea purslane. These materials, collected from community activities, were tested for dye extraction via boiling in seawater. Three types of mordants derived from local context viz. wood vinegar, alkaline ash from mangrove charcoal, and mangrove mud were applied. The extracted dyes were tested on three types of fabric: silk, cotton, and linen. Additionally, the dye liquids were transformed into a powdery form by adding sodium carbonate to induce crystallization, making the dye ready-to-use in a powdered format. The results were then analyzed to propose a strategy that can add value to local resources through sustainable creative economy approaches.

Main Results: Dye extraction from the five types of mangrove ecosystem waste materials via boiling in seawater (at a ratio of 2 kg raw material to 20 liters seawater, boiled at 100°C for 1 hour) yielded earth-tone color shades. Mangrove leaves, bark, nipa husks, and sea purslane produced various shades of brown, while seablite produced a green tone. Color tones could be modified using natural mordants: wood vinegar enhanced brightness; mangrove mud deepened the tone to grey; and alkaline ash from mangrove charcoal intensified the color. The alkaline ash reacted with plant materials in the following ways: dye from mangrove leaves and bark shifted to reddish-brown, seablite turned olive green, and sea purslane shifted to yellow. The extracted dyes showed strong adherence to silk fabric. Furthermore, transforming the dye liquid into a powdery form was successful by adding 5% sodium carbonate and stirring at 60°C for 30–60 minutes until crystallization occurred, enabling grinding into a ready-to-use powdered dye.

Conclusions: The study of natural dye extraction from mangrove ecosystem materials in Yisan Subdistrict, Amphawa District, Samut Songkhram Province, demonstrates that local waste materials such as mangrove leaves and bark (by-products from charcoal production), nipa husks (leftover from food preparation), and naturally occurring seablite and sea purslane (considered weeds) can be effectively utilized to produce uniquely characteristic textile dyes. The optimal extraction process involves boiling the materials in seawater at 100°C for 1 hour, followed by filtration and dyeing at 60°C. Seawater was found to facilitate better dye adherence to fabrics. The resulting colors belong to the earth-tone family, with vivid and long-lasting shades, especially effective on silk. In addition, wood vinegar, alkaline ash from mangrove charcoal, and mangrove mud serve as natural mordants that enhance colorfastness and allow for shade variation. These findings reflect the potential of local knowledge that can be further developed into creative innovations. The resulting color extraction process uses 100 percent natural resources without chemicals. Green extract from seablite is also noted to be capable of dyeing fabrics, hence exhibiting potential and unique issue that can be used for future commercial development.

Practical Application: The present research highlights the potential of mangrove ecosystem resources as high-quality natural dyes, which can be applied to the development of lifestyle products with strong local identity. These products align with the demands of contemporary consumers who prioritize environmental sustainability, corresponding to the Sustainable Development Goals (SDGs). The ability to generate powdered dye products not only facilitates ease of storage and transportation, but also opens opportunities for commercial-scale production and integration into contemporary product design—ranging from textiles and handicrafts to other creative items. This approach provides a viable pathway for adding economic value to local resources and elevating them to regional and international markets, thereby supporting sustainable community development and grassroots economic empowerment.

Optimal Conditions for Ethanol Production by Simultaneous saccharification and fermentation Using Schizosaccharomyces pombe and Fungal Consortium with Selected Napier Grass Substrate

2025-05-18T01:32:01+07:00

Background and Objectives: Ethanol production from lignocellulosic biomass has attracted considerable interest due to the use of renewable resources, reduction of dependence on fossil fuels, and mitigation of environmental impacts. Napier grass (Pennisetum purpureum) is well-suited for ethanol production because of its high cellulose and hemicellulose contents, rapid growth rate, and ease of cultivation. The conversion of lignocellulose into fermentable sugars involving hydrolysis, when combined with fermentation in a single step, can reduce enzyme inhibition caused by sugar accumulation, leading then to enhanced production efficiency. The objective of the present research was therefore to investigate optimal conditions for ethanol production via the Simultaneous saccharification and fermentation (SSF) method using Schizosaccharomyces pombe and fungal consortia, with selected Napier grass as the substrate.

Methodology: Completely Randomized Design (CRD) was used to schedule the experiments. Substrate was pretreated with 0.5% sulfuric acid at 140 °C for 60 minutes, followed by microwave treatment at 700 W for 15 minutes. Cellulase enzyme was then added at a concentration of 20 U; incubation was then conducted for 48 hours. Subsequently, the mixture was subject to Simultaneous saccharification and fermentation (SSF) using Schizosaccharomyces pombe in combination with fungal strains from the genera Trichoderma, Aspergillus, Rhizopus, and Penicillium. Eight different fermentation formulations were tested.

Main Results: Fermentation of Napier grass via the Simultaneous saccharification and fermentation (SSF) process using S. pombe at a concentration of 10% in combination with Trichoderma sp. at a concentration of 5% for 102 hours yielded a maximum ethanol production of 69.91 g/L. The total soluble solids content remained at 5.10 °Brix, while the residual reducing sugar content was 45.23 mg/g dry weight. After the fourth distillation, the ethanol concentration reached 88.29% v/v.

Conclusions: Co-cultivation of the yeast Schizosaccharomyces pombe and the fungus Trichoderma sp. under optimized fermentation conditions significantly enhanced the efficiency of ethanol production from Napier grass. A continuous decrease in reducing sugars and total soluble solids was observed during fermentation, corresponding to the increase in ethanol concentration.

Practical Application: The findings of the present study can be applied to the development of ethanol production technologies from biomass materials at scales ranging from small to large industrial operations. In regions where Napier grass is locally cultivated as an energy crop, the approach offers a potential to produce renewable energy, reduce dependence on fossil fuels, and add value to community bioresources. Furthermore, it provides a strategic framework for the sustainable management of biomass resources.