亚洲精品久久久久久一区二区_99re热久久这里只有精品34_久久免费高清视频_一区二区三区不卡在线视频

Seventy-one percent of our planet is covered with water. And water, together with air, is the origin of life. But freshwater makes up only 0.2 percent of the total water reserves on Earth, the rest being saltwater. Therefore, freshwater is a precious resource and, in some places, a very rare one.

 

At the 2000 United Nations' Millennium Declaration and the declaration passed by the world summit on sustainable development in 2002, the water crisis was listed as the most severe challenge humanity would face in the next decade.

 

The declarations made it clear that half of the world's rivers were seriously polluted or their water volume had dropped sharply and that 40 percent of the planet's population was threatened by a shortage of water.

 

In China, the total volume of freshwater resources is 2.8 trillion cubic meters, or 2,200 cubic meters per head. The per capita freshwater resources of the country is only 31 percent that of the world's average. In view of this, protection of the precious water resources is all the more important.

 

The negative outcome of the massive construction of reservoirs and hydropower stations over the last decades is beginning to emerge.

 

The rivers in northern China are over-tapped. For example, the utilization ratio of the water resources in the Haihe and Liaohe rivers is 80 percent, while that of the Yellow River is 70 percent. It is, however, internationally accepted that the ratio should stay below 40 percent.

 

Consequently, water supply is very much strained. In a normal year, for example, the country sustains a shortfall of 40 billion cubic meters of water and an average of 20 million hectares of farmland are affected by drought each year. In addition, underground water resources in the north China Plain are over-extracted.

 

After the promulgation of the Water Law in 1988 and the new Water Law in 2002, nationwide water administration systems were established. And the concepts and ideas in this regard have been upgraded. In the wake of the flooding of the Yangtze and Nenjiang rivers in 1998, for example, the country's top authorities decided to convert large areas of reclaimed land to forestry, pasture and lakes.

 

Sustainable development-oriented water conservation policies were also formulated.

 

Water resources are unevenly distributed in China. The north claims 60.5 percent of the country's total cultivated land but has only 16 percent of the total water resources. The south, however, has 39.5 percent of the total arable land but 84 percent of the national water resources. On the North China Plain and in the Liaohe River valley, per head water resources are only 300 cubic meters, much the same as in Israel.

 

The situation is compounded by the increasingly heavier pollution caused by industrial development and urbanization. In 2000, for instance, a total of 74.7 billion cubic meters of wastewater was discharged, of which 53.4 billion cubic meters went into rivers. The extensive use of chemical fertilizers and pesticides and the contamination caused by poultry breeding make the pollution all the worse.

 

In the north, many rivers are polluted or simply dry up. In the south, water quality in rivers and lakes deteriorates sharply. The overriding task in many places is therefore to make sure the masses have clean water to drink.

 

In recent years, some cities in the eastern developed coastal areas have carried out water-system projects that integrate water security, water environment and waterscape. These cities include Shaoxing in Zhejiang Province and Zhangjiagang and Taicang in Jiangsu Province. Big cities such as Beijing, Shanghai, Guangzhou, Shenzhen and Wuhan have also embarked on programs involving water-system management and up-to-date water conservation techniques.

 

In 1998, the State Council delegated responsibility to the Yellow River Water Conservation Committee, which has been operating successfully for nearly five decades, for the central management and control of the water resources of the 5,464-kilometre Yellow River. As a result, no drying-up in any section of the river occurred in five years, despite the drought that affected the river valley for a number of years.

 

At the same time, the management and control of the Tarim River in the Xinjiang Uygur Autonomous Region and the Heihe River in northeast China's Heilongjiang Province have been strengthened. In addition, reforestation has been carried out in many areas. Grazing on the grasslands was banned and replanting programs carried out. All this was done to improve water and soil conservation.

 

In recent years, the reform of water management has been advanced in urban areas. In Shenzhen, Shanghai, Beijing and 1,350 counties across the country, for example, a unified water management mechanism is being experimented with.

 

A short supply of electricity has triggered off the chaotic development of hydropower generation. In view of this, the authorization of the construction of large-scale hydropower stations needs to be put under stricter control and closer scrutiny. The principle should be applied that the stakeholders in these big hydropower projects and the areas that benefit from them should pay for any environmental damage brought by the projects.

 

The State Council proposed last year that a new water system be set up nationwide, the water-use licensing system be improved, the scope of fees levied on water resource use be extended to cover wider areas and reform of the water pricing mechanism be promoted.

 

Protection of water resources should have higher priority over tapping water resources, according to the State Council. Also, a quota of total pollution should be imposed in keeping with the pollution-absorbing capacity of the river. In addition, economic development along the valley of a river should be based on the river's total water volume and its pollution-absorbing capacity. At the same time, development of water-saving forestry and agriculture should be encouraged.

 

It is hoped that, with 20 years of Herculean efforts, the goals of zero growth in water use and wastewater discharge will be achieved in the country.

 

(China Daily December 28, 2006)