Climate change and water resources： Case study of Eastern Monsoon Region of China

This paper addresses the impact of climate change on the water cycle and resource changes in the Eastern Monsoon Region of China （EMRC）. It also represents a summary of the achievements made by the National Key Basic Research and Development Program （2010CB428400）, where the major research focuses are detection and attribution, extreme floods and droughts, and adaptation of water resources management. Preliminary conclusions can be summarized into four points： 1） Water cycling and water resource changes in the EMRC are rather complicated as the region is impacted by natural changes relating to the strong monsoon influence and also by climate change impacts caused by CO2 emissions due to anthropogenic forcing; 2） the rate of natural variability contributing to the influence on precipitation accounts for about 70%, and the rate from anthropogenic forcing accounts for 30% on average in the EMRC. However, with future scenarios of increasing CO2 emissions, the contribution rate from anthropogenic forcing will increase and water resources management will experience greater issues related to the climate change impact; 3） Extreme floods and droughts in the EMRC will be an increasing trend, based on IPCC-AR5 scenarios; 4） Along with rising temperatures of 1 ~C in North China, the agricultural water consumption will increase to about 4% of total water consumption. Therefore, climate change is making a significant impact and will be a risk to the EMRC, which covers almost all of the eight major river basins, such as the Yangtze River, Yellow River, Huaihe River, Haihe River, and Pearl River, and to the South-to-North Water Diversion Project （middle line）. To ensure water security, it is urgently necessary to take adaptive countermeasures and reduce the vulnerability of water resources and associated risks.

Trends of Extreme Flood Events in the Pearl River Basin during 1951-2010

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.

Detection and Attribution of Observed Changes in the Hydrological Cycle under Global Warming

The progress and advances of the detection and attribution of changes in the hydrological cycle in the IPCC Assessment Reports of WGI and WGII from 1990 to 2007 are reviewed. Accomplishment and endorsed by the joint Expert Meeting on Detection and Attribution in 2009, the Good Practice Guidance Paper （GPGP） for IPCC Lead Authors with its main content and characteristics are briefly introduced. Based on the review and the purpose of the GPGP, some characteristics on the detection and attribution of global warming and of changes in the hydrological cycle are presented.

REVIEW AND PROSPECTS OF HYDROLOGICAL COMPONENT DEVELOPMENT OF ESCAP/WMO TYPHOON COMMITTEE

Hydrological Component has been one of three essential parts of ESCAP/WMO Typhoon Committee.The Working Group on Hydrology(WGH)established at TC 33rd Session in 2000 is the first working group among three basic components of the Committee,which has been repeatedly recognized as the most active component in the Committee who has integrated conducted successfully a number of cooperation projects and integrated actions among Members.In the past decade,WGH has implemented wide range activities under the framework of Strategic Plan of the Committee.The achievement of those cooperation projects played very important roles in promoting the capacity building on hydrological monitoring,forecasting and early warning among Members.This paper introduced the Term of Reference for WGH and its high priorities,and summarized the activities conducted in recent decade.The paper also reviewed the progresses in TC Members on hydrological observation and monitoring network,hydrological data collection and transmission,hydrological information and forecasting,and establishment of flood forecasting system.The paper also pointed out the development direction and the area to be enhanced for hydrological component in future,including:(1)application of QPE/QPF in flood forecasting and establishment of the coupled hydro-meteorological modeling;(2)development of impact-based,risk-based and community-based flood forecasting and warning system,including storm surge,urban flood,sediment disaster(flash flood,landslide and mudflow);and(3)application of internet of things(IOT),big data,cloud computing,and mobile internet in flood monitoring,forecasting and early warning,and better response,particularly in flood inundation mapping and QPE/QPF products application.