YASHIL TOMLARNING SHAHAR ISSIQLIK OROLINI KAMAYTIRISH SAMARADORLIGI VA UNI BELGILOVCHI OMILLAR

Annotatsiya. Maqolada yashil tomlarning shahar issiqlik oroli (UHI) ta’sirini kamaytirish bo‘yicha xorijiy tadqiqotlar tizimli va qiyosiy tahlil qilinib, ularning termik samaradorligini belgilovchi asosiy omillar umumlashtirilgan. Tahlil qilingan manbalarda quruq iqlimlar uchun umumiy sovitishning median qiymati 3 °C ni tashkil etishi, ayrim tadqiqotlarda tom sirt harorati qariyb 20 °C gacha, turli vegetatsiyali eksperimental yashil tomlarda esa eng issiq soatlarda nazorat variantiga nisbatan 3,1–4,4 K gacha pasayishi qayd etilgan. Grafik, foto-eksperimental va qiyosiy ma’lumotlar sintezi suv tanqis sharoitlarda termik samaradorlikni o‘simliklarning qurg‘oqchilikka chidamliligi va suv talabi bilan birgalikda baholash zarurligini ko‘rsatdi. Umumlashtirilgan natijalarga ko‘ra, yashil tomlarning eng kuchli bevosita ta’siri sirt haroratida (Ts) namoyon bo‘ladi, havo harorati (Ta) va shahar miqyosidagi UHI ga ta’siri esa yashil tomlar qamrovi, fazoviy taqsimoti hamda shahar morfologiyasiga bog‘liq. Ushbu natijalar issiq-quruq shaharlarda yashil tomlarni qurg‘oqchilikka chidamli vegetatsiya va suvdan samarali foydalanish yechimlari bilan integratsiyalash zarurligini asoslaydi.

Kalit so‘zlar: yashil tom, shahar issiqlik oroli (UHI), sirt harorati, termik samaradorlik, issiq-quruq iqlim, qurg‘oqchilikka chidamli vegetatsiya, suv samaradorligi, shahar morfologiyasi.

Abstract. This study systematically and comparatively analyzes international research on the mitigation of the urban heat island (UHI) effect by green roofs and synthesizes the key factors determining their thermal performance. The reviewed studies report a median overall cooling effect of 3 °C in arid climates, while some studies indicate reductions in roof surface temperature of up to approximately 20 °C. Experimental green roofs with different vegetation types showed temperature reductions of 3.1–4.4 K relative to the control during the hottest hours of the day. The synthesis of graphical, photographic, experimental, and comparative evidence demonstrates that, under water-scarce conditions, thermal performance should be evaluated together with plant drought tolerance and water requirements. The synthesized findings indicate that the strongest direct cooling effect of green roofs occurs at the surface-temperature (Ts) level, whereas their effects on air temperature (Ta) and city-scale UHI depend on green-roof coverage, spatial distribution, and urban morphology. These findings support the integration of drought-tolerant vegetation and water-efficient strategies into green-roof design for hot-arid cities.

Keywords: green roof, urban heat island (UHI), surface temperature, thermal performance, hot-arid climate, drought-tolerant vegetation, water efficiency, urban morphology.