Irrigation and Thermal Buffering Using Mathematical Modeling


  • Yara Yasser Elborolosy

    The Albert Nerken School of Engineering at the Cooper Union, New York, NY 10003, US

  • Harsho Sanyal

    The Albert Nerken School of Engineering at the Cooper Union, New York, NY 10003, US

  • Joseph Cataldo

    The Albert Nerken School of Engineering at the Cooper Union, New York, NY 10003, US

Received: 13 September 2023 | Revised: 22 December 2023 | Accepted: 25 December 2023 | Published Online: 27 January 2024


Two methods of irrigation, drip, and sprinkler were studied to determine the response of the Javits green roof to irrigation. The control study was dry unirrigated plots. Drip irrigation consisted of irrigation tubes running through the green roof that would water the soil throughout and sprinkler irrigation used a sprinkler system to irrigate the green roof from above. In all cases, the irrigated roofs had increased the soil moisture, reduced temperatures of both the upper and lower surfaces, reduced growing medium temperatures and reduced air temperatures above the green roof relative to the unirrigated roof. The buffered temperature fluctuations were also studied via air conditioner energy consumption. There was a 28% reduction in air conditioner energy consumption and a 33% reduction in overall energy consumption between dry and irrigated plots. Values of thermal resistance or S were determined for accuracy and for this study, there was little change which is ideal. A series of infra-red and thermal probe measurements were used to determine temperatures in the air and sedum. It was determined that the sprinkler irrigation did a better job than the drip irrigation in keeping cooler temperatures within the green roof. A Mann-Whitney U test was performed to verify the variation in moisture temperatures buffering energy consumption. By getting a p-value < 0.05, it indicates that the model is accurate for prediction and medium temperatures were statistically different.


Green roofs, Irrigation, Drip, Sprinkler, Thermal buffering


[1] Jamei, E., Chau, H.W., Seyedmahmoudian, M., et al., 2023. Green roof and energy—role of climate and design elements in hot and temperate climates. Heliyon. 9, e15917. DOI:

[2] Wani, S., Selvaraj, T., Faria, P., et al., 2023. Study on ancient green materials and technology used in Udaipur palace, India: An input to abate climate changes in modern construction. Environmental Science and Pollution Research. 30, 93952–93969. DOI:

[3] Wang, J., Garg, A., Huang, S., et al., 2022. An experimental and numerical investigation of the mechanism of improving the rainwater retention of green roofs with layered soil. Environmental Science and Pollution Research. 29, 10482–10494. DOI:

[4] Richter, M., Dickhaut, W., 2023. Long-term performance of blue-green roof systems—Results of a building-scale monitoring study in Hamburg, Germany. Water. 15(15), 2806. DOI:

[5] Bollman, M.A., DeSantis, G.E., Waschmann, R.S., et al., 2021. Effects of shading and composition on green roof media temperature and moisture. Journal of Environmental Management. 281, 111882. DOI:

[6] Mihalakakou, G., Souliotis, M., Papadaki, M., et al., 2023. Green roofs as a nature-based solution for improving urban sustainability: Progress and perspectives. Renewable and Sustainable Energy Reviews. 180, 113306. DOI:

[7] Raimondi, A., Becciu, G., 2021. Performance of green roofs for rainwater control. Water Resources Management. 35, 99–111. DOI:

[8] Lokesh, S., Kadiwal, N., Chandrashekar, R., et al., 2023. Heat transfer study of green roof in warm and humid climatic conditions. Materials Today: Proceedings. 92, 327–337. DOI:

[9] Wei, T., Jim, C.Y., Chen, Y., et al., 2022. Complementary influence of green-roof and roof-slab thermal conductivity on winter indoor warming assessed by finite element analysis. Energy Reports. 8, 14852–14864. DOI:

[10] Kaiser, D., Köhler, M., Schmidt, M., et al., 2019. Increasing evapotranspiration on extensive green roofs by changing substrate depths, construction, and additional irrigation. Buildings. 9(7), 173. DOI:

[11] Azeñas, V., Cuxart, J., Picos, R., et al., 2018. Thermal regulation capacity of a green roof system in the mediterranean region: The effects of vegetation and irrigation level. Energy and Buildings. 164, 226–238. DOI:

[12] Shahmohammad, M., Hosseinzadeh, M., Dvorak, B., et al., 2022. Sustainable green roofs: A comprehensive review of influential factors. Environmental Science and Pollution Research. 29, 78228–78254. DOI:

[13] Heusinger, J., Sailor, D.J., Weber, S., 2018. Modeling the reduction of urban excess heat by green roofs with respect to different irrigation scenarios. Building and Environment. 131, 174–183. DOI:

[14] Sun, T., Bou-Zeid, E., Ni, G.H., 2014. To irrigate or not to irrigate: Analysis of green roof performance via a vertically-resolved hygrothermal model. Building and Environment. 73, 127–137. DOI:

[15] Xiong, S., 2020. Study on the reverse heat conduction behavior of steel. Open Journal of Safety Science and Technology. 10(1), 24–31. DOI:

[16] Jaffal, I., Ouldboukhitine, S.E., Belarbi, R., 2012. A comprehensive study of the impact of green roofs on building energy performance. Renewable Energy. 43, 157–164. DOI:

[17] Rowe, D.B., Kolp, M.R., Greer, S.E., et al., 2014. Comparison of irrigation efficiency and plant health of overhead, drip, and sub-irrigation for extensive green roofs. Ecological Engineering. 64, 306–313. DOI:

[18] Vandegrift, D.A., Rowe, D.B., Cregg, B.M., et al., 2019. Effect of substrate depth on plant community development on a Michigan green roof. Ecological Engineering. 138, 264–273. DOI:

[19] VanWoert, N.D., Rowe, D.B., Andresen, J.A., et al., 2005. Green roof stormwater retention: Effects of roof surface, slope, and media depth. Journal of Environmental Quality. 34(3), 1036–1044. DOI:

[20] Vanuytrecht, E., Van Mechelen, C., Van Meerbeek, K., et al., 2014. Runoff and vegetation stress of green roofs under different climate change scenarios. Landscape and Urban Planning. 122, 68–77. DOI:

[21] Shetty, N.H., Elliott, R.M., Wang, M., et al., 2022. Comparing the hydrological performance of an irrigated native vegetation green roof with a conventional Sedum spp. green roof in New York City. PLoS One. 17(4), e0266593. DOI:

[22] Zheng, X., Sarwar, A., Islam, F., et al., 2023. Rainwater harvesting for agriculture development using multi-influence factor and fuzzy overlay techniques. Environmental Research. 238, 117189. DOI:

[23] Jain, R.K., 2023. Experimental performance of smart IoT-enabled drip irrigation system using and controlled through web-based applications. Smart Agricultural Technology. 4, 100215. DOI:

[24] Zhang, H., Lu, S., Fan, X., et al., 2021. Is sustainable extensive green roof realizable without irrigation in a temperate monsoonal climate? A case study in Beijing. Science of the Total Environment. 753, 142067. DOI:

[25] Xie, P., Barbarossa, V., Erisman, J.W., et al., 2024. A modeling framework to assess the crop production potential of green roofs. Science of the Total Environment. 907, 168051. DOI:

[26] Eumorfopoulou, E., Aravantinos, D., 1998. The contribution of a planted roof to the thermal protection of buildings in Greece. Energy and Buildings. 27(1), 29–36. DOI:

[27] Alvizuri, J., Cataldo, J., Smalls-Mantey, L.A., et al., 2017. Green roof thermal buffering: Insights derived from fixed and portable monitoring equipment. Energy and Buildings. 151, 455–468. DOI:

[28] Sailor, D.J., Hagos, M., 2011. An updated and expanded set of thermal property data for green roof growing media. Energy and Buildings. 43(9), 2298–2303. DOI:

[29] Abualfaraj, N., Cataldo, J., Elborolosy, Y., et al., 2018. Monitoring and modeling the long-term rainfall-runoff response of the Jacob K. Javits center green roof. Water. 10(11), 1494. DOI:

[30] Dehaene, H., De Neve, J., Rosseel, Y., 2021. A Wilcoxon-Mann-Whitney test for latent variables. Frontiers in Psychology. 12, 754898. DOI:

[31] Hart, A., 2001. Mann-Whitney test is not just a test of medians: Differences in spread can be important. BMJ. 323(7309), 391–393. DOI:

[32] Inyang, U.E., Uwa, I.J., 2022. Heat transfer in helical coil heat exchanger. Advances in Chemical Engineering and Science. 12, 26–39. DOI:


How to Cite

Yasser Elborolosy, Y., Sanyal, H., & Cataldo, J. (2024). Irrigation and Thermal Buffering Using Mathematical Modeling. Journal of Environmental & Earth Sciences, 6(1), 19–32.