No abstract

No abstract

ABSTRACT:Coastal erosion is an issue of widespread concern. As one of the most important economic regions in China, the coast of the Yangtze Delta has been showing a trend towards erosion with global warming and the increasing human activities in the catchment and its estuary. Currently, most published studies about coastal erosion in the area focused on the causes and types of erosion. This paper presents a Decision Support Framework (DSF) for the risk assessment of coastal erosion in consideration of the potential management problems and challenges for economic development in the coastal zone of the Yangtze Delta. The framework consists of four major components: integrated database, GIS-based risk assessment models, scenarios generator and visualization toolkit. Especially, we developed a GIS-based risk assessment model for the muddy coasts of Yangtze Delta. An Analytic Hierarchy Process (AHP) method, which is instrumental in combining computer intelligence and experts' knowledge, was used to weight the variables of the model. The assessment results show the validity of the approach. Accordingly, the DSF will make the specialized data and information more accessible to managers, and has an extensive capability to facilitate communication and synergetic work between humans and computers. In this way, it is expected to make manager make more scientific decision.

No abstract

By analyzing U and Th isotopic compositions of 41 samples in two stalagmites from Hulu Cave, Nanjing, we first discovered that variations of 23SV and a 23 'U o along the stalagmite growth-sequence (covering a period from 75 to 18 kaBP) are in high similarity to summer insolation curve at 33°N and a 18 0-based climate record of the studied stalagmites. The concentration of 238U is mainly controlled by content of organic matter in the soil above the cave. This mechanism can be used to explain our result that 238U curve of stalagmites is in phase with fluctuation of the a 18 0 record of the same stalagmites and summer insolation at cave locality. However, 238U concentration curve v.5. age is, in amplitude, inconsistent with the climatic curves, possibly due to complex processes of soil-water-rock interaction. a 234 u o indicates pedogenic intensity of soil profile above the cave and sensitively reflects alternations of pedogenesis and aeolian accumulation processes of Xiashu loess in Nanjing. Consequently, uranium concentration and its isotope ratio in stalagmites may provide a new proxy for climate change.