Towards understanding climate change: Impact of land use indices and drainage on land surface temperature for valley drainage and non-drainage areas.

The continuous increase of urbanization and industrialization brought various climatic changes, leading to global warming. The unavailability of meteorological data makes remotely sensed data important for understanding climate change. Therefore, the land surface temperature (LST) is critical in understanding global climate changes and related hydrological processes. The main objective of this work is to explore the dominant drivers of land use and hydrologic indices for LST in drainage and non-drainage areas. Specifically, the relationship between LST changes, land use, and hydrologic indices in Northeast Qena, Egypt, was investigated. The Landsat 5 and 8 imagery, Geographic Information System (GIS), and R-package were applied to identify the change detection during 2000-2021. The normalized difference between vegetation index (NDVI), bare soil index (BSI), normalized difference built-up, built-up index (BUI), modified normalized difference water index (MNDWI), and soil-adjusted vegetation index (SAVI) were employed. The non-drainage or mountain areas were found to be more susceptible to high LST values. The comprehensive analysis and assessment of the spatiotemporal changes of LST indicated that land use and hydrologic indices were driving factors for LST changes. Considerably, LST retrieved from the Landsat imaginary showed significant variation between the maximum LST during 2000 (44.82°C) and 2021 (50.74°C). However, NDBI has got less spread during the past (2000) with 10-13%. A high negative correlation was observed between the LST and NDVI, while the SAVI and LST positively correlated. The results of this study provide relevant information for environmental planning to local management authorities.

Fabrication and characterization of thermally-insulating coconut ash-based geopolymer foam.

This study aims at synthesizing porous coconut ash (CA)-based geopolymer foam with high thermal insulation property. Sodium hydroxide (NaOH), alumina slag (AS) and water contents as the main parameters, which affect the performance hardened CA, have been studied. The porosity was developed by hydrogen gas resulted from the interaction of Al metal, in AS, with NaOH. The compressive strength, bulk density, porosity and thermal conductivity were evaluated. The results proved that the AS has a potential impact on the reduction of thermal conductivity of CA-based geopolymer foam by creation of high porous system. Open celled hardened CA-based geopolymer with high porosity (∼87%), low thermal conductivity (∼0.045 W/m·K), compressive strength (1.3 MPa) and bulk density (∼0.60 g/cm3) was obtained when 7% AS (by weight of CA powder) and water to CA powder ratio of 0.4 were used.