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We developed a robust InSAR processing strategy that can effectively mitigate severe decorrelation noise in a large volume of InSAR data. We mapped the average land subsidence rate (2017–2020) over the 131,572 km2 Upper Texas and Louisiana coasts from Sentinel‐1 data, with ∼2 mm/yr accuracy based on independent GPS and tide gauge validation at 189 locations. The improved InSAR observations reveal widespread subsidence that was previously undetected in coastal wetlands and rural areas with small communities. Our InSAR surface deformation map is at the spatial scale that overlaps with the scale of hydrodynamic model grids. This allows us to integrate InSAR observations into operational storm surge models to analyze future flooding risks due to relative sea level change. We found that these subtle millimeter‐to‐centimeter subsidence features can substantially increase hurricane‐induced inundation, and passive flood mapping (known as the "bathtub" approach) can lead to inaccurate flood risk predictions. Plain Language Summary: The analysis of future storm surge risks along the Gulf Coast often focuses only on projected sea level rise estimates due to the lack of spatially dense land subsidence data. Here we show advances in spaceborne Interferometric Synthetic Aperture Radar (InSAR) techniques can enable the retrieval of coastal subsidence patterns over a 131,572 km2 region along the Gulf Coast of the United States, a challenging terrain for InSAR analysis due to the presence of dense vegetation coverage. Our results reveal widespread subsidence features due to oil and gas production, groundwater pumping, and wetland degradation that were previously undetected. Physics‐based storm surge modeling shows that the detected subtle millimeter‐to‐centimeter land subsidence can substantially elevate flood water depth and flood extent. We demonstrate that the relationship between coastal subsidence and flood depth increase is complex, and communities vulnerable to future flood risk are highly variable along the Gulf Coast of the United States. Key Points: A robust InSAR processing algorithm enables accurate retrieval of subtle surface deformation signals over densely vegetated Gulf CoastInSAR reveals many coastal subsidence features that were previously undetected by existing GPS and tide gauge stationsStorm surge modeling suggests that passive flood mapping based on topography can lead to inaccurate flood risk predictions [ABSTRACT FROM AUTHOR]

Global warming induces temperature variations and sea level changes for a long period of time. Many coastal cities around the world have experienced the harmful consequences of sea level changes and temperature variations. The city of Shanghai in China also suffers from the serious consequences of these two climatic factors. The geological and climatic conditions of Shanghai make it sensitive to flooding risks during heavy rainfall events. This paper analyses the conditions of sea level changes, temperature variations, and heavy rainfall events in Shanghai. Correspondingly, eustatic sea level change, tectonic movement of the continent, and land subsidence in Shanghai have effects on sea level changes. Correlation analysis indicates extraordinary short duration rainfall events have a relationship with temperature variations due to global warming. Moreover, the number of extraordinary torrential rainfall events also has a correlation with sea level changes. Pluvial flooding and potential damage to coastal structures are more likely to have serious effects as the number of flooding hazard events due to global warming and sea level changes increases. This study also established that to efficiently protect the environment, control economic losses, and prevent potential hazards, extra countermeasures including monitoring, forecasting, and engineering technology treatment should be adopted. Monitoring measurements combined with a database system on a website was found to be useful for forecasting and simulating flooding hazards. For systematic sustainable urban water system management, appropriate treatment technologies, such as sustainable urban water system, which can control and manage water quantity and quality, namely "the Sponge City", should also be considered. [ABSTRACT FROM AUTHOR]

The Egyptian government is showing a great interest on the lateral population extension in the deserts. Accordingly, a number of roads were constructed. Sohag – Safaga new highway in the Eastern Desert that connects the Nile Valley with the Red Sea is an example of such roads. A number of developmental extensions have been proposed aligning roads including agricultural, urban, industrial, touristic, and commercial projects. These extensions need different studies concerning their sustainability to protect them from any hazard that may act on them and to make use of the available natural resources that are required for development. These natural resources include engineering construction materials, soil for agriculture, surface and subsurface water resources, and mineral wealth. The study area is characterized by different geomorphological units: mountains belts, sandstone and limestone plateaux, wadi terraces, wadi bottoms, alluvial fans, out wash plains, sand sheets, sand dunes, and hilly areas. The water resources in the study area include groundwater obtained from a number of existing water wells and surface water that can be utilized by retaining water from flashflooding. This research mainly depends on using recent satellite images of Misrsat-1, Landsat TM5, and ASTER with the aid of Geographic Information Systems (GIS). Different soil types that were delineated are mostly suitable for agricultural landuse. The suitability of this agriculture depends on the availability and quality of the irrigation water.

On 10 May 2016, Guangdong Province, China, suffered a heavy rainstorm. This rainstorm flooded the whole city of Guangzhou. More than 100,000 people were affected by the flooding, in which eight people lost their lives. Subway stations, cars, and buses were submerged. In order to analyse the influential factors of this flooding, topographical characteristics were mapped using Digital Elevation Model (DEM) by the Geographical Information System (GIS) and meteorological conditions were statistically summarised at both the whole city level and the district level. To analyse the relationship between flood risk and urbanization, GIS was also adopted to map the effect of the subway system using the Multiple Buffer operator over the flooding distribution area. Based on the analyses, one of the significant influential factors of flooding was identified as the urbanization degree, e.g., construction of a subway system, which forms along flood-prone areas. The total economic loss due to flooding in city centers with high urbanization has become very serious. Based on the analyses, the traditional standard of severity of flooding hazards (rainfall intensity grade) was modified. Rainfall intensity for severity flooding was decreased from 50 mm to 30 mm in urbanized city centers. In order to protect cities from flooding, a "Sponge City" planning approach is recommended to increase the temporary water storage capacity during heavy rainstorms. In addition, for future city management, the combined use of GIS and Building Information Modelling (BIM) is recommended to evaluate flooding hazards. [ABSTRACT FROM AUTHOR]

Flooding hazards caused by heavy rainfall in Shanghai have been reported extensively in the last 15 years. Geologically, Shanghai is sensitive to flooding hazards due to low-lying ground caused by land subsidence. Climatically, Shanghai is in the East Asia monsoon area and frequently experiences torrential rains. In this study, data from fifty-four pluvial flooding events between 2001 and 2015 were collected and analysed. The influence factors contributing to pluvial flooding are evaluated, and recommendations for protective measures are presented. The pluvial flooding prevention capacity in Shanghai is controlled by rain water storage and discharge capacity, which is associated with the sewer network, pumping stations and its sluice and pumping gates. Within the last three decades, the number of local torrential rainfall events and short-duration torrential rains has increased annually. However, the rain water storage capacity has decreased dramatically and the rain water discharge capacity has become limited during this period. In an extreme case, the discharge function of the sewer network was even temporarily lost because of flooding of the distributaries of the Huangpu River. Thus, in order to prevent flooding hazards caused by heavy rain, it is suggested that a large sluice and pumping station between the Huangpu River and the Yangtze River estuary is constructed in the near future, considering the continuous subsidence of the city and the ongoing rising sea levels. [ABSTRACT FROM AUTHOR]

Abstract: The Egyptian government is showing a great interest on the lateral population extension in the deserts. Accordingly, a number of roads were constructed. Sohag – Safaga new highway in the Eastern Desert that connects the Nile Valley with the Red Sea is an example of such roads. A number of developmental extensions have been proposed aligning roads including agricultural, urban, industrial, touristic, and commercial projects. These extensions need different studies concerning their sustainability to protect them from any hazard that may act on them and to make use of the available natural resources that are required for development. These natural resources include engineering construction materials, soil for agriculture, surface and subsurface water resources, and mineral wealth. The study area is characterized by different geomorphological units: mountains belts, sandstone and limestone plateaux, wadi terraces, wadi bottoms, alluvial fans, out wash plains, sand sheets, sand dunes, and hilly areas. The water resources in the study area include groundwater obtained from a number of existing water wells and surface water that can be utilized by retaining water from flashflooding. This research mainly depends on using recent satellite images of Misrsat-1, Landsat TM5, and ASTER with the aid of Geographic Information Systems (GIS). Different soil types that were delineated are mostly suitable for agricultural landuse. The suitability of this agriculture depends on the availability and quality of the irrigation water. [Copyright &y& Elsevier]

The Yangtze River Basin and Huaihe River Basin in Southern China experienced severe floods 1998 and 2016. The reasons for the flooding hazards include the following two factors: hazardous weather conditions and degradation of the hydrological environment due to anthropogenic activities. This review work investigated the weather conditions based on recorded data, which showed that both 1998 and 2016 were in El Nino periods. Human activities include the degradations of rivers and lakes and the effects caused by the building of the Three Gorges Dam. In addition, the flooding in 2016 had a lower hazard scale than that in 1998 but resulted in larger economic losses than that of 1998. To mitigate urban waterlogging caused by flooding hazards, China proposed a new strategy named Spongy City (SPC) in 2014. SPC promotes sustainable city development so that a city has the resilience to adapt to climate change, to mitigate the impacts of waterlogging caused by extreme rainfall events. The countermeasures used to tackle the SPC construction-related problems, such as local inundation, water resource shortage, storm water usage, and water pollution control, are proposed for city management to improve the environment. [ABSTRACT FROM AUTHOR]

Current sea level change is mainly induced by global warming which is believed to increase the sea level if sustained for a sufficiently long period of time. Many coastal cities around the world have suffered adverse effects as a consequence of sea level change. Shanghai is a coastal city which is located on the estuary of the Yangtze River with an elevation ranging from 3 to 4 m. Its geological and climatic conditions make the city sensitive to flooding risk caused by heavy rain and sea level change. This paper analyses the recent sea level change and heavy rainfall in Shanghai. Regional rates of sea level change can be divided into i) the rate of eustatic sea level change; ii) tectonic movement of the continent; and iii) land subsidence in Shanghai. A correlation analysis shows that the number of local torrential rains and short duration torrential rains correlates with sea level change. Incidents including pluvial flooding, sea water intrusion and potential damage to coastal structures will be more serious if the rate of sea level change continues to rise. To protect the environment and to control economic losses, more countermeasures should be established to prevent the potential hazards. [ABSTRACT FROM AUTHOR]