Climate Change and Water Resources Editorial

The special column includes with four papers that will focus on the issue of climate change and water resources security in the Eastern Monsoon Region of China (EMRC), which has the highest population density and the fastest economic development speed, water shortage, drought and flooding and eco-environmental problems in this area are very prominent. All of these four papers will try to answer four questions, i.e., How does the climate and water cycle change in the past? How it will be changing in the future? What is the changing mechanism? How should we adapt these changes? These questions have been studied and become the focus of the National Key Basic Research and Development Program (973 Program) (2010CB428400), as well as the forefront issue of water science in earth system. Major conclusions have several points as follows::

(1) Water cycling and water resources change in CEMR is rather complicated, in which having both strong monsoon influence of natural changes and also from climate change impact caused by carbon dioxide emissions due to anthropogenic forcing. The rate of natural variability contribution to the influence of precipitation accounted for about 70% and the rate of from the anthropogenic forcing accounted for 30% in average of EMRC. However, with the future scenarios of increasing CO₂ emissions, the contribution rate from anthropogenic forcing will be increasing. Thus, water resources management will face to more risk from climate change impact;

(2) For the precipitation indices, northern river basins would become wetter because the increases in wet days and heavy days. Extreme wet events are projected to be more probable in all river basins with the increase in the heavy precipitation days in almost scenarios, which will possibly result in more frequent flooding with greater destructive power, increasing stress on agriculture. Also, extremely floods & droughts in CEMR will be an increasing trend based on IPCC-AR5 scenarios. These researches were applied to assess the climate change projections contained in IPCC-AR5 in four typical large basins in China, including the Liaohe River Basin, Yellow River Basin, Yangtze River Basin, and Pearl River Basin etc;

(3) Along with rising temperatures 1 °C in North China, the agricultural water consumption will increases about 4% total water consumption. Thus, there is significant impact of climate change and its risk on China's eastern monsoon region, which cover almost of eight major river basins, such as Yangtze river, Yellow River, Huai River, Hai River and Pearl River and so on, also to the major water transfer (middle line) project. For the water security issue, it is necessary to taking adaptive countermeasures and measures to reduce vulnerability of water resources and its risk.

(4) With the increasing contribution of CO₂ emissions in the future, climate change is becoming an important driving factor of water cycle change. Therefore, the existing water resources planning, design flood method and the management of water division project will have high risk because of the limiting consideration of the impact of climate change. Even under the worst condition of climate change, the water resource vulnerability in the east monsoon region can reduce by 21.3% and the sustainable development degree can increase by 18.4% if we take the adjustment and countermeasure of the adaptive water resources. It is very important and necessary to implement the adaptive management and countermeasures for dealing with climate change to ensure the water security in China. Under the changing environment, it is urgent to modify the existing standards of water resources planning and the management of major water conservancy projects.

Climate change and water resources: Case study of Eastern Monsoon Region of China
http://www.sciencedirect.com/science/article/pii/S167492781630096X

Coupled modeling of land hydrology–regional climate including human carbon emission and water exploitation
http://www.sciencedirect.com/science/article/pii/S1674927816300892

Bayesian multi-model projections of extreme hydroclimatic events under RCPs scenarios
http://www.sciencedirect.com/science/article/pii/S1674927816300934

Impacts of climate change on agricultural water resources and adaptation on the North China Plain
http://www.sciencedirect.com/science/article/pii/S1674927816300958

Xia Jun, the guest editor of the special issue on climate change and water resources launched in Advances in Climate Change Research, has been engaging in water resources research in Wuhan University and Chinese Academy of Sciences for nearly forty years.

Professor Xia Jun from School of Water Resources and Hydropower Engineering, WHU was elected as a fellow of Chinese Academy of Sciences (CAS in 2015.. Born in September, 1954, he is an expert in hydrology and water resourceand came to teach at Wuhan University in 1991.