Water is the source of life, however, shortage of water resource has become the worlds major challenge. To ease worldwide contradiction of water supply and demand, the United Nations (UN) passed a resolution in 1993 to announce March 22 the World Water Day. The World Water Day 2015 is themed as" Water and Sustainable Development ". In China, from March 22 through 28 we celebrate the Water Week. Theme of World Water Day 2015 and China Water Week this year is " conserve water resource to secure water security."
In terms of natural resource, Chinas total water resource ranks sixth globally, but due to a large population base, our per capital water resource is very slim. Among the 192 countries with water statistics record, Chinas per capital water resource ranks 127th, identified by UN as one of the 13 countries with most prominent water issues.
Second, water resource are not evenly distributed. Half of the countrys population reside in the four river basins, including Yangtze River and Pearl River basin, and contribute to half of the GDP and enjoy 81% of the countrys water resource. However, in the 6 largest river basins of the north, half of the countrys population contribute to half of its GDP and farm on 65% of arable land, although they have only 19% of the overall water resource. Third, water resource are not evenly distributed throughout the year. China has continental monsoon climate, with obvious rainy season. Although annual rainfalls of London and Paris are similar to that of Beijing and Harbin, monthly rainfalls of London and Paris are evenly distributed, while in Beijing, half of the annual rainfall concentrate in 20 days. Therefore, we have to build reservoirs to save water in flood seasons to be used in dry seasons. Severe shortage of water resource in China is primarily caused by the above three factors. Development and utilization of water resource is very difficult, thus requiring great attention of the country.
China faces four major water resource-related problems: obvious contradiction between supply and demand of water resource, severe water pollution, aquatic ecosystem degradation as well as the frequent outbreak of extreme and emergencies. A unified objective basis of scientific background of China's water issue is that the basin water cycle has evolved. Basin water cycle consists of natural water cycle and social water cycle. They are interdependent, restrict and influence each other, thus accelerating the evolution of basin water cycle, and leading to a series of resource effects, ecological effects and environmental effects. To cope with those problems, we need a unified scientific basis, that is to reveal the mechanism of, recognition of the laws of and process simulation of the “nature-society” bilateral water cycle and the accompanying process evolution, and to coordinate and balance from multi-dimensions.
Water crisis is a common problem faced by the world, becoming another serious social crisis ranking after the oil crisis. In such a situation, we should keep studying from five aspects and take measures to actively cope with water resource crisis: first, research and establish water crisis early warning system to monitor real-time the situation of water resource, evaluate future developments and effectively reduce the impact of emergent water crisis on society and economy. Second, the governments at all levels and the relevant functional departments work together to accelerate the establishment of emergency response system of water resource crisis. Third, strengthen water resource argumentation, strictly control the total quantity of water extracted, make science-based allocation plan of basin water and prevent excessive exploitation of water resource in the region. Fourth, widely popularize knowledge about environmental protection, enhance the public's awareness of water resource protection and strengthen the various water saving measures so as to construct a water-saving society. Fifth, make efforts to protect water environment, strictly control the total pollutants into the river and improve the ecological environment. At present, our country has implemented a scientific strategy to secure water security, identified specifically 172 major water security project. State and governments at all levels are increasing investment and proactively implementing practicable measures so as to ensure water resource security in the environment of economic and social development.endprint