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Floods are among the world's most devastating natural disasters, causing immense damage and accounting for a large number of deaths world-wide
. Good flood management policies play an extremely important role in preventing floods. It is well known that China has more than 5000 years of experience in flood management policy beginning with the reign of DaYu and Gun. Although culturally related, Japanese flood management developed differently from that of China. Under rapid development of civil engineering technology, flood management was achieved primarily through the construction of dams, levees and other structures. These structures were never adequate to stop all floods, and recent climate change driven extreme events are ever more frequently overwhelming such infrastructure. It is important to take a historical perspective of Japanese and Chinese flood management in order to better manage increasingly frequent extreme events and climate change. We present insights taken from an historical overview of Japanese and Chinese flood management policies in order to guide future flood risk management policy
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Yang, H.; Luo, P.; Wang, J.; Mou, C.; Mo, L.; Wang, Z.; Fu, Y.; Lin, H.; Yang, Y.; Bhatta, L. D.
Climate and human-driven changes play an important role in regional droughts
. Northwest Yunnan Province is a key region for biodiversity conservation in China, and it has experienced severe droughts since the beginning of this century; however, the extent of the contributions from climate and human-driven changes remains unclear. We calculated the ecosystem evapotranspiration (ET) and water yield (WY) of northwest Yunnan Province, China from 2001 to 2013 using meteorological and remote sensing observation data and a Surface Energy Balance System (SEBS) model. Multivariate regression analyses were used to differentiate the contribution of climate and vegetation coverage to ET. The results showed that the annual average vegetation coverage significantly increased over time with a mean of 0.69 in spite of the precipitation fluctuation. Afforestation/reforestation and other management efforts attributed to vegetation coverage increase in NW Yunnan. Both ET and WY considerably fluctuated with the climate factors, which ranged from 623.29 mm to 893.8 mm and –51.88 mm to 384.40 mm over the time period. Spatially, ET in the southeast of NW Yunnan (mainly in Lijiang) increased significantly, which was in line with the spatial trend of vegetation coverage. Multivariate linear regression analysis indicated that climatic factors accounted for 85.18% of the ET variation, while vegetation coverage explained 14.82%. On the other hand, precipitation accounted for 67.5% of the WY. We conclude that the continuous droughts in northwest Yunnan were primarily climatically driven; however, man-made land cover and vegetation changes also increased the vulnerability of local populations to drought. Because of the high proportion of the water yield consumed for subsistence and poor infrastructure for water management, local populations have been highly vulnerable to climate drought conditions. We suggest that conservation of native vegetation and development of water-conserving agricultural practices should be implemented as adaptive strategies to mitigate climate change
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The deterministic or stochastic nature of vegetation succession has been a bone of contention in plant ecology, and at the same time a key to vegetation restoration
. On the slopes of the Minshan Mountain in Western China, frequent and intense geological tectonic activities cause plant communities with various succession ages array closely together, providing an ideal platform to test vegetation succession models. The plant communities of 17 nearby slope sites with similar elevation, gradient, aspect and parent soil material were selected for plant community investigation. The communities were categorized into three succession age groups: early stage (4 years), 30-60 years, and over 60 years. Researchers found that (1) the species richness, species evenness, Shannon-Wiener index and species dominant index all increased with the succession, indicating an obvious species adding process in the community development; (2) the species substitutions were significant in early succession (early stage to 30 years), but the importance values of major functional groups (nitrogen fixing species, dry-tolerant species and leanness-resistant species) showed no evidence of decrease from year 4 to year 60 and over, suggesting that physical conditions (water, nutrition) have strongly controlled the species assemblage through the functional group compositions on the sites; (3) the within-group community similarities decreased from over 0.515 in year 4 to 0.251 in year 60 and over, illustrating a tendency of stochastic direction of vegetation succession in the later stage. We concluded that the organismic model does not satisfactorily explain the succession process
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