What are the causes of the water crisis?

For the sake of research convenience, the water crisis is divided into direct water crisis and indirect water crisis.

Interpretation. A direct water crisis is a direct threat or hazard to water security caused by an emergency, including natural and man-made disasters. Natural disasters are also known as natural crises, such as heavy rains, flash floods, droughts, typhoons, mudslides, and other natural forces that directly destroy the stability of water supply and defense, such as floods and droughts, so that life and property are threatened or endangered.

Although this kind of natural crisis is irresistible, it is generally predictable because there are natural laws to follow. Man-made disasters, also known as man-made crises, refer to the threats or hazards directly caused by people's subjective behaviors to water security, such as man-made water pollution, man-made water project damage, etc. The reason why this kind of man-made crisis is regarded as a direct water crisis is that these man-made emergencies are directly related to water and have relatively fixed actors, such as factories discharging sewage into rivers and reservoirs, and fish bombing incidents around reservoirs.

Indirect water crises refer to those emergencies that seem to have nothing to do with water on the surface, and mainly refer to the threats or hazards to water security caused by man-made disasters, such as war, disease, terrorist activities, strikes, demonstrations and other political or economic emergencies. This year's SARS epidemic has brought about water quality problems in epidemic areas, especially the sewage discharge and treatment problems of hospitals designated for the treatment of SARS patients. This kind of emergency that is ostensibly unrelated to water is generally unforeseeable, very random, and has no regularity to follow, and the water management department cannot judge the regularity of its occurrence based on previous management experience.

Distinguish. It can be seen that there are the following main differences between direct and indirect water crises:

1. From the perspective of causes, the direct water crisis is induced by events directly related to water, and the indirect water crisis is induced by events indirectly related to water;

2. From the perspective of the law of occurrence, direct water crises generally have laws to follow, which can be predicted according to frequency analysis or accumulated management experience, while indirect water crises have no rules to follow, and the accidents are extremely large, and they cannot be predicted;

3. In terms of the frequency and number of occurrences, direct water crises are frequent and large-scale, while indirect water crises are occasional and small.

The quantity of water resources is limited, local environmental changes, the uneven distribution of water resources in time and space, the rapid growth of population, the rapid growth of water consumption in production and living, and the phenomenon of artificial waste of water resources and pollution of water resources.

The current status and problems of water resources are:

The current state of water resources is:Water scarcity is deteriorating, posing a serious threat to ecosystems, food safety and human health. According to statistics, about 100 million people in rural areas do not have access to drinking water that meets the standards every year, and water resources are becoming a valuable strategic resource and a major strategic issue related to the sustainable development and long-term peace and stability of the country's economy and society.

The problem of water is:

1. Serious shortage of water resources:The basic situation of China's water resources is that there are more people and less water, and the spatial and temporal distribution of water resources is uneven, with more in the south and less in the north, more in the coastal areas and less in the interior, more mountains and fewer plains, and only 20% of the cultivated land in the north of the Yangtze River, and nearly 31% of the country's land is arid (with annual rainfall below 250mm), the distribution of productive forces and water and land resources do not match, the contradiction between supply and demand is sharp, and the gap is very large.

2. Serious pollution of water resourcesIn the early days of reform and opening up, the extensive development model that only focused on the speed of development and ignored the environmental impact caused serious pollution of water resources: the sections of rivers flowing through cities were generally polluted.

3. The recycle rate of water resources is lowThe low efficiency of water use in industrial production leads to high costs and poor output value benefits, and the GDP output of unilateral water is 1 3 of the world average. Most cities in the country have serious waste of industrial water, the average reuse rate is only 30-40%, and the average centralized treatment rate of urban domestic sewage in 2009 is not comparable with advanced countries.

The current situation of water resources and the solutions to the problems are:

1. Comprehensive protection and prudent exploitation of groundwaterIn the 70s and 80s of the 20th century, the amount of groundwater extracted was 572 and 74.8 billion tons per year, respectively, reaching 105.8 billion tons at the end of the 20th century, and then remaining above 100 billion tons.

It is increasing at a rate of 2.5 billion tons per year. More than 400 of the country's 657 cities rely on groundwater as a source of drinking water, and 65% of domestic water, 50% of industrial water and 33% of agricultural irrigation water in the northern region come from groundwater.

2. Intensify the direct utilization of seawaterBritain, France, the Netherlands, Italy and other countries directly use seawater instead of fresh water in desulfurization, reinjection oil recovery, ice making, printing and dyeing in thermal power generation, nuclear power, metallurgy, petrochemical and other industries, as well as toilet flushing, ash flushing, washing, and fire protection in daily life. In 2010, the world's seawater direct utilization was nearly 600 billion tons, and the effect of freshwater resource conservation was remarkable.

Current state of water resources: Water scarcity is acute.

Problem: With the development of the world economy, the population is growing, the number of cities is increasing and expanding, and the water consumption is increasing everywhere. According to United Nations estimates, global water consumption was only 400 billion cubic meters in 1900, 3,000 billion cubic meters in 1980 and 3,900 billion cubic meters in 1985.

By 2000, the amount of water needed to increase to 6,000 billion cubic meters per year.

Among them, Asia has the largest water consumption, reaching 3.2 trillion cubic meters per year, followed by North America, Europe, South America, etc. About 1.5 billion people in 80 countries and regions, which account for about 40% of the world's population, lack fresh water, and about 300 million people in 26 countries are severely short of water. What is even more frightening is that by 2025, 3 billion people in the world are expected to face water scarcity, and 40 countries and regions are seriously short of fresh water.

NEED NOTICE:

China's total water resources are less than those of Brazil, Russia, Canada, the United States and Indonesia. Measured by the per capita water resource availability indicator, it is only 1 4 percent of the world average, ranking 110th after it.

Water scarcity is widespread in China and is on the rise. More than half of the country's 670 cities have varying degrees of water shortage. Among them, there are more than 110 serious water shortages.

Dear to your question, this is the case, the current situation of water resources and water pollution is still severe. The main manifestations are: the discharge of industrial wastewater and domestic sewage is large, and the water treatment level and water treatment compliance rate are not high; The water body itself is seriously polluted, and the water quality compliance rate of the water extraction area needs to be improved. The water quality of lakes is worse than that of rivers, the water quality of rivers is worse than that of reservoirs, and the water quality of river sections in densely populated areas in the middle and lower reaches of the same water area is worse than that of upstream areas. The survey data showed that the water quality of about 1 4 water quality monitoring stations showed a deteriorating trend and the water quality was becoming more and more hardening.