Comparing greenhouse gas emissions of precast in-situ and conventional construction methods

2018 ◽  
Vol 173 ◽  
pp. 124-134 ◽  
Author(s):  
Yingbo Ji ◽  
Kaijian Li ◽  
Guiwen Liu ◽  
Asheem Shrestha ◽  
Jinxi Jing
2021 ◽  
Author(s):  
Ain Kull ◽  
Iuliia Burdun ◽  
Gert Veber ◽  
Oleksandr Karasov ◽  
Martin Maddison ◽  
...  

<p>Besides water table depth, soil temperature is one of the main drivers of greenhouse gas (GHG) emissions in intact and managed peatlands. In this work, we evaluate the performance of remotely sensed land surface temperature (LST) as a proxy of greenhouse gas emissions in intact, drained and extracted peatlands. For this, we used chamber-measured carbon dioxide (CO<sub>2</sub>) and methane (CH<sub>4</sub>) data from seven peatlands in Estonia collected during vegetation season in 2017–2020. Additionally, we used temperature and water table depth data measured in situ. We studied relationships between CO<sub>2</sub>, CH<sub>4</sub>, in-situ parameters and remotely sensed LST from Landsat 7 and 8, and MODIS Terra. Results of our study suggest that LST has stronger relationships with surface and soil temperature as well as with ecosystem respiration (R<sub>eco</sub>) over drained and extracted sites than over intact ones. Over the extracted cites the correlation between R<sub>eco</sub> CO<sub>2</sub> and LST is 0.7, and over the drained sites correlation is 0.5. In natural sites, we revealed a moderate positive relationship between LST and CO<sub>2</sub> emitted in hollows (correlation is 0.6) while it is weak in hummocks (correlation is 0.3). Our study contributes to the better understanding of relationships between greenhouse gas emissions and their remotely sensed proxies over peatlands with different management status and enables better spatial assessment of GHG emissions in drainage affected northern temperate peatlands.</p>


2020 ◽  
Author(s):  
Theresa Klausner ◽  
Mariano Mertens ◽  
Heidi Huntrieser ◽  
Michal Galkowski ◽  
Gerrit Kuhlmann ◽  
...  

<p>Urban areas are recognised as a significant source of greenhouse gas emissions (GHG), such as carbon dioxide (CO<sub>2</sub>) and methane (CH<sub>4</sub>). The total amount of urban GHG emissions, especially for CH<sub>4</sub>, however, is not well quantified. Here we report on airborne in situ measurements using a Picarro G1301-m analyser aboard the DLR Cessna Grand Caravan to study GHG emissions downwind of the German capital city Berlin. In total, five aircraft-based mass balance experiments were conducted in July 2018 within the Urban Climate Under Change [UC]<sup>2</sup> project. The detection and isolation of the Berlin plume was often challenging because of comparatively small GHG signals above variable atmospheric background concentrations. However, on July 20<sup>th</sup> enhancements of up to 4 ppm CO<sub>2</sub> and 21 ppb CH<sub>4</sub> were observed over a horizontal extent of roughly 45 to 65 km downwind of Berlin. These enhanced mixing ratios are clearly distinguishable from the background and can partly be assigned to city emissions. The estimated CO<sub>2</sub> emission flux of 1.39 ± 0.75 t s<sup>-1 </sup>is in agreement with current inventories, while the CH<sub>4</sub> emission flux of 5.20 ± 1.61 kg s<sup>-1</sup> is almost two times larger than the highest reported value in the inventories. We localized the source area with HYSPLIT trajectory calculations and the high resolution numerical model MECO(n) (down to ~1 km), and investigated the contribution from sewage-treatment plants and waste deposition to CH<sub>4</sub>, which are treated differently by the emission inventories. Our work highlights the importance of a) strong CH<sub>4</sub> sources in the surroundings of Berlin and b) a detailed knowledge of GHG inflow mixing ratios to suitably estimate emission rates.</p>


2018 ◽  
Vol 52 (3) ◽  
pp. 947-954 ◽  
Author(s):  
Andrea Orellana ◽  
Ian J. Laurenzi ◽  
Heather L. MacLean ◽  
Joule A. Bergerson

2021 ◽  
Vol 13 (8) ◽  
pp. 4445
Author(s):  
Pietro Rimoldi ◽  
Jonathan Shamrock ◽  
Jacek Kawalec ◽  
Nathalie Touze

Dykes, or levees, are structures designed and constructed to keep the water in a river within certain bounds in the event of a flood. In relation with climate change, more frequent floods, of higher intensity, can be expected due to anthropogenic emissions of greenhouse gases into the atmosphere. The objective of this review paper is to address the many ways in which geosynthetics contribute to sustainable construction of dykes and thus to water systems management. This review paper, prepared by the four Technical Committees and the Sustainability Committee of the International Geosynthetics Society, briefly describes geosynthetics and their function, dykes and dyke failure modes, before presenting the main focus of the use of geosynthetics for the design and construction of durable dykes to ensure the protection of life and infrastructure. The optimization of dyke construction with geosynthetics to increase their resilience not only results in performance advantages, but also in economic advantages. The way geosynthetics can contribute to mitigating greenhouse gas emissions for a sustainable river management is discussed. This is done not only by allowing more economic construction methods to be implemented, but also solutions with increased resilience to face the extreme stresses related to climate change, while at the same time bringing about a positive contribution to the reduction of greenhouse gas emissions during the construction process itself. Finally, it is shown that by following state of the art standards and design practice any possible risk associated with the use of geosynthetics in dykes can be mitigated.


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