[1] A few studies suggest that infiltration rates within streambeds increase during the flood season due to an increase in the stream stage and the remove of the clogged streambed. However, some studies suggest that a new clogging layer will quickly form after an older one has been eroded, and that an increase in water depth will compress the clogging layer, making it less permeable during a flood event. The purpose of this work was to understand the impact of floods on infiltration rates within a disconnected stream. We utilized pressure data and daily streambed infiltration rates determined from diurnal temperature time series within a streambed over a period of 167 days for five flood events. Our data did not support the theory that floods linearly increase the infiltration rate. Since the streambed was clogged very quickly with a large load of suspended particles and compaction of the clogged layer, infiltration rates were also low during the flooding season. However, due to an increase in the wet perimeter within the stream during flooding periods, the total recharge amount to the aquifer was increased.

This paper takes Xi'an, which is a western city in China, experiencing the rapid urbanization, as the research object. It uses 2000 Landsat7 ETM+, 2010 Landsat5 TM and 2016 Landsat8 OLI images as data sources to inverse and normalize surface temperature. Thermal field intensity index (HFI) and urban heat island proportion index (UHPI) were introduced to quantitatively assess the temporal and spatial variation of heat island in Xi'an.