نوع مقاله : مقاله پژوهشی

نویسندگان

• مهرداد کریمی مشاور ¹
• مهسا صمدپور شهرک ²

¹ دانشگاه بوعلی

² گروه معماری، دانشگاه بوعلی سینا همدان

چکیده

فضای باز دربرگیرندۀ بخشی از فعالیتهای روزمره می‌باشد که یکی از اصول طراحی در آن توجه به آسایش حرارتی و در نتیجه افزایش حضور افراد است که می تواند منجر به سرزندگی بیشتر فضاهای شهری گردد. در این محیط پوشش گیاهی و درختان نقش عمده‌ای در بهبود شرایط محیطی دارند. به نظر می رسد که افزایش یا تغییر الگوی میزان پوشش گیاهی در شهرها امری ضروری به نظر میرسد. حال در اینجا این سوال مطرح می‌شود الگوی متفاوت کاشت درخت تا چه میزان میتواند بر آسایش حرارتی افراد در فضای باز، تاثیرگذار باشد. تحقیق حاضر با هدف یافتن الگوی مناسب چیدمان درختان در جهت بهبود شرایط آسایش افراد در فضای باز با فرض اینکه تغییر الگوی چیدمان درختی، در شرایط آسایش حرارتی تاثیرگذار می‌باشد، انجام گرفته است. به این منظور چهار نوع الگوی کاشت متفاوت، چهارتایی، شش‌تایی، ردیفی و پراکنده و شرایط بدون درخت با یکدیگر مورد بررسی قرار گرفته است. جهت دستیابی به این منظور از نرم‌افزار انویمت مدل 4.4.5 استفاده شده است. برای اعتبار‌سنجی داده‌های نرم‌افزار انویمت از مقایسه آن با داده‌های محلی بهره گرفته شد. جهت سنجش آسایش حرارتی الگوی متوسط نظرسنجی پیش‌بینی شده (PMV )، به عنوان یکی از مهم‌ترین فاکتورهای تاثیر‌گذار بر آسایش حرارتی، مورد بررسی قرار گرفت. این تحقیق در فضای باز اطراف یکی از مجتمع‌های مسکونی در شهر تبریز در یکی از گرمترین روزهای سال، صورت گرفته است. نتایج تحقیق حاکی از آن است تغییر الگوی کاشت در بهبود شرایط منطقه تاثیرگذار است و الگوی کاشت ردیفی و پراکنده، مناسبترین الگو در جهت بهبود شرایط محیطی می‌باشند.

کلیدواژه‌ها

• آسایش حرارتی
• الگوی کاشت
• فضای باز
• انویمت
• شاخص نظرسنجی پیشبینی شده

موضوعات

• محیط زیست شهری

عنوان مقاله [English]

Evaluation of the effect of tree planting pattern on thermal comfort around residential blocks

نویسندگان [English]

• Mehrdad Karimimoshaver ¹
• mahsa samadpour shahrak ²

¹ Department of Architecture, Faculty of Art and Architecture, Bu-Ali Sina University

² Department of Architecture, Bu-Ali Sina University

چکیده [English]

1. Introduction

The increasing population has changed the morphology of the cities and caused a change in the surrounding environmental conditions. Green space per capita in Iran is about 4.5 square meters per person, which is very different from the global one, which is about 20 to 25 square meters per person (Haashemi et al., 2016). As a result, increasing the amount of greenery in cities seems necessary. Lee et al. (2016) introduce the two factors of shading and ventilation as the main factors in improving the thermal comfort conditions in the environment by trees. Vegetation reduces the mean radiant temperature and improves environmental conditions by evaporating and controlling and reflecting daylight (Salata et al., 2017). Vegetation plays a major role in regulating weather conditions by controlling wind flow and conducting it and reducing its speed and pressure (Perini et al., 2018).

Previous research has mentioned the importance of planting pattern, trees, and vegetation and their impact on the environmental and microclimatic conditions of the region. Now the question arises, what kind of tree planting pattern, among the common planting pattern, can have a better impact on the environment? Therefore, in this study, four common planting patterns of sextuple, quadruple, row, and scattered in the same conditions and with an equal number of trees were selected.

2. Materials and methods

In this research the software of ENVI-met was used because the output of this software provides most of the parameters required for thermal comforts, such as Ta, Tmrt, wind speed, etc (Taleghani et al., 2015), and results have been validated and used by researchers (Taleghani et al., 2018).



3. Results and Discussion:

To measure the data, 5 receptors in the central points of the site were selected. Data and environmental information of the receptors were extracted during the studied hours (10 am to 9 pm) and their mean was calculated for PMV index.

Analysis of the data and figures extracted from the software shows that in the scattered pattern, a more uniform shadow is created in the environment than in other patterns, and also because the trees are scattered in most parts of the site, the solar access is less and more limited than other scenarios. Also, in the row pattern, ventilation conditions are easier than in the scattered pattern, and the warm wind passes through the trees more easily due to the regular arrangement. Therefore, the best planting pattern is one that creates more uniform shade and better ventilation conditions. However, the results of the scattered pattern are the same in most parts of the site, and in some cases, there is little difference between them. As a result, the pattern of tree planting in a scattered and row is better than mass planting and concentrated in certain parts of the site.

4. Conclusion:

The results show that in comparing the treeless scenario with other scenarios, the thermal comfort conditions change to a large extent and all scenarios create better environmental conditions than the treeless state. Also, because the row pattern in most receptors and most hours of the day has a lower average of PMV, it is the best pattern compared to others. Also, the sextuple pattern has a high index in most cases, and the quadruple pattern has a similar function to the sextuple one. Therefore, it can be concluded that the row and scattered pattern create better comfort conditions than other patterns. The results of this research can be used by architects, landscape designers, and urban designers. In this research, different patterns of trees have been compared with each other, so in future research, other plantings such as grass, shrubs, and shrubs and the effect of different planting patterns can be compared with each other.

کلیدواژه‌ها [English]

• Thermal comfort
• Planting Pattern
• Open Space
• Envi-met
• PMV index