Abstract

In this study, discharge at the outlet of Xijiang River, the biggest sub-basin of the Zhujiang River, was simulated and projected from 1961 to 2099 using the hydrological model HBV-D. The model uses precipitation and temperature data from CISRO/MK3–5, MPI/ECHAM5, and NCAR/CCSM3 under three greenhouse gas emission scenarios (SRES A2, A1B, B1). The results in water resources and flood frequency suggest that annual precipitation and annual runoff would increase after 2050 relative to the reference period of 1961–1990. In addition, increasing trends have been projected in area averaged monthly precipitation and runoff from May to October, while decreasing trends in those from December to February. More often and larger floods would occur in future. Potential increase in runoff during the low-flow season could ease the pressure of water demand until 2030, but the increase in runoff in the high-flow season, with more often and larger floods, more pressure on flood control after 2050 is expected. LIU, L.-L., T. JIANG, J.-G. XU, et al., 2012: Responses of hydrological processes to climate change in the Zhujiang River Basin in the 21st century. Adv. Clim. Change Res., 3 (2), doi: 10.3724/SP.J.1248.2012.00084.

Abstract

Following disastrous flooding in several river valleys over eastern China in 1755, serious flooding occurred in the middle and lower reaches of the Yellow River in 1756 and 1757, a rarely seen precipitation pattern of north-flood and south-drought in China for two successive years. This is a serious meteorological disaster and extreme climatic event taking place under the climatic background of a warm phase of the Little Ice Age. In this paper, by means of historical literature records, the rainy and flooding situation and the weather characteristics of these years are reconstructed and the maps depicting areas of prolonged rain, flood and concomitant famine, insect pest, and pestilence are made. The results show that, in 1755, the middle and lower reaches of the Yellow River and the Yangtze River, and the Huaihe River Basin experienced a prolonged rainy season with multiple torrential rain events. The continuous rainy period exceeded 40 days in the Huang-Huai Region. An early Meiyu occurred, and the duration of the Meiyu period in the lower Yangtze River Basin was 43 days, the longest in the 18th century. Particularly in Nanjing the annual rainfall of 1755 was 1, 378 mm, the highest record of the 18th century. The year of 1755 is characterized by lower temperature in summer, early frost in autumn, and heavy snowfall and freezing rain in winter. These characteristics are extremely similar to those of 1823 and 1954, two typical years of extreme rainfall. And all these three years with extreme precipitation are corresponding to the minimum phase of the solar activity cycle. Zhang, D.-E., 2012: A study of the large scale flooding over eastern China in 1755. Adv . Clim . Change Res ., 3 (3), doi: 10.3724/SP.J.1248.2012.00128.

Abstract

The study investigated the trend of extreme flood events in the Pearl River basin during 1951–2010. Stream flow data at 23 gauging stations were used for the study. The Pearson type III distribution was selected for the flood frequency analysis. Results indicate that extreme flood events increase significantly in the Pearl River Basin since 1980. At the 23 gauging stations, there are 16 (70%) stations show positive (increasing) trends in 1981–2010. Most of the 16 stations are located along the West River and North River. While 7 (30%) stations show negative (decreasing) trends, and are found in the East River and the southeast region of the West River Basin. Wu, Z.-Y., G.-H. Lu, Z.-Y. Liu, et al., 2013: Trends of extreme flood events in the Pearl River Basin during 1951–2010. Adv. Clim. Change Res., 4 (2), doi: 10.3724/SP.J.1248.2013.110.

Abstract

In 2011, we observed how “graceful failure” through planned destruction of portions of the Birds Point Levee by the US Army Corps of Engineers (USACE) was enacted to alleviate extreme flooding on the Mississippi River. This action, while flooding thousands of acres of croplands as intended, reduced flooding and potential damage to waterway infrastructure and populated communities downstream. Recent trends and future climatic projections indicate that we will have more of these “extreme” flooding situations in our future. Therefore, this project focused on exploring the potential feasibility to utilize other locations along the inland waterway system where “graceful failure” or planned breach of levees may be used as a means of flood protection for downstream communities and infrastructure. Spatial analysis techniques were used with development of specific criteria to screen national-level data sets to identify probable locations for such mitigative approaches. The criteria were primarily focused on identifying non-urbanized, non-developed land where intentional flooding for storage of flood waters would minimize impacts. Each location that was identified as a potential candidate was further evaluated for capacity for flood water detention. A consolidated set of areas were identified that could provide some storage capacity for flood mitigation. Additional engineering and localized analysis would be necessary to vet the areas for actual storage implementation. However, this study provides an example of an unconventional approach to flood mitigation on inland waterways which could reduce the need for disaster response and assist in transportation planning during extreme flood conditions.