There are many forms of cold water, mainly spring water, mountain streams, groundwater, ground drainage of deep-water reservoirs, rivers and lakes in mountainous areas or plateaus, and meltwater from snow-capped mountains. , mainly distributed in Northeast China, Central China, South China and Southwest China. As a special water resource, the development and utilization of cold water began to rise gradually in 1980s, and cold water fish farming, fishing industry and agricultural irrigation have begun to take shape. Because the most important temperature attribute of cold water resources is greatly influenced by geographical distribution and environment, the current domestic utilization mode is relatively single and the benefit is not high. How to fully tap the potential value of cold water resources and improve its sustainable utilization level is the key to the development of cold water resources.

Chenzhou City, Hunan Province was approved by the State Council in May 2065438+2009 to create a national sustainable development agenda innovation demonstration zone with the theme of "sustainable utilization and sustainable development of water resources". Zixing City is a county-level city in Chenzhou City, which has unique cold water resources and is called "Water City". With a water surface of 240,000 mu and a storage capacity of 810.20 billion cubic meters, Dongjiang Lake is the "second water source" in Chen Heng area of Changsha, Zhuzhou and Xiangtan. The water in Dongjiang Lake passes through the dam to form a height difference, and then flows out from the bottom of the lake with a depth of 1.57 meters, forming a huge "cold water resource pool". The water temperature of the downstream Jiang Xiaodong River is kept below 10℃ all the year round, and the annual runoff reaches10.50 billion cubic meters, which ensures the sustainability of cold water supply. The water quality of lakes keeps the first-class standard of People's Republic of China (PRC) Surface Water Environmental Quality Standard all the year round. The potential value of excellent water quality as a water source is as high as 40 billion yuan, which also provides an important guarantee for the development and utilization of cold water resources.

Over the years, Zixing City has made full use of the special advantages of cold water resources in subtropical areas, actively explored the utilization paths of cold water resources in energy conservation and emission reduction, cold water breeding, tourism upgrading and other aspects, and initially formed a "Zixing model" for the sustainable utilization of cold water resources. Dongjiang Lake Data Center uses natural cold source refrigeration to realize green, energy-saving and safe operation, Zixing Hospital of Traditional Chinese Medicine South Hospital uses water source heat pump air conditioning system to practice energy-saving and environmental protection, and aquaculture relies on cold water to realize scientific and large-scale cold-water fish culture, promote local people's livelihood and well-being, and realize a substantial increase in the total value of ecological assets, reaching more than 200 billion yuan on the premise of ensuring that ecological functions and services are not reduced; In addition, due to the temperature difference between cold water and cold water, the "misty little Dongjiang" landscape is not only famous at home and abroad, but also influential in the field of photography, creating considerable added value for tourism.

& gt& gt？ Utilization of cold water resources in energy saving

The sustainable utilization of cold water resources in Zixing City has achieved initial results in energy saving. Developing high-energy industries in a low-energy way can not only achieve good energy-saving and emission-reduction effects, but also help effectively alleviate climate change and bring remarkable ecological and economic benefits. Dongjiang Lake Data Center uses abundant, cold and stable cold water resources and adopts "multi-mode natural water cooling technology" to cool the data room, reducing energy consumption and operating costs. Under normal operation, the data center can save more than 50 million kWh of electricity and reduce carbon dioxide emissions by 5.54 million tons. It is understood that during the operation of the data center, the lake water cold source refrigeration mode can be used for more than 99% of the time. Since the operation of 20 17, the electric air conditioning refrigeration system mode has not been started; And its application status is stable, and its PUE value is stable between 1.05- 1. 19, which is far lower than the average PUE of the 624 largest IT companies in the world, ranking first in China and second in the world. If the carbon trading quota saved by cold water refrigeration system is sold to enterprises in need, the annual carbon dioxide emission saved can be sold at least 654.38+0.29 billion yuan according to the recent market price.

The South Hospital of Zixing City Hospital of Traditional Chinese Medicine, through the construction of water source heat pump air conditioning circulation system utilization project, uses the low temperature advantage of cold water resources at 8- 15℃ to supply refrigeration, heating and domestic hot water, which can fully meet the needs of hospital air conditioning and hot water supply. Under normal operation, it can save about 2 1.3kWH of electricity every year, which is equivalent to 78.65,438+0 tons of standard coal, and reduce the emissions of carbon dioxide, sulfur dioxide, nitrogen oxides and soot by 204.6 tons, and the energy-saving benefit can reach 58%. Compared with traditional air conditioners, using cold water and using water source heat pump air conditioning circulation system can save more than 200,000 yuan of electricity every year.

Utilization of Cold Water Resources in Characteristic Aquaculture

Zixing City has developed characteristic aquaculture such as rainbow trout (salmon), sturgeon, fragrant fish and alpine flower fish. Relying on the unique advantages of cold water resources. In 2020, the aquaculture area of cold-water fish in the city will exceed 50,000 mu, and the output is conservatively estimated to reach 6.5438+0.2 million tons per year, and the income will reach at least 900 million yuan. In addition, scientific cultivation of cold water can also play a positive role in purifying water bodies. Taking fish with an annual output of/kloc-0.2 million tons as an example, simple calculation can reduce the nitrogen content of water body by 300,000-420,000 tons and the phosphorus content by 3.6-/kloc-0.8 million tons respectively for Zixing. Nowadays, rainbow trout (salmon) breeding has become a business card of Zixing characteristic fishery, which has promoted the development of a series of related industries such as feed, transportation and catering. Zixing City will also establish 100 "salmon" food chain stores, expand the scale of "salmon" catering, enhance the "salmon" catering culture, further promote the development of tourism, and extend, open up and form an industrial chain; Sturgeon and its derivatives have been exported to Southeast Asia and the European Union. Alpine flower fish has also developed into a national geographical indication certification and protection product. Cold water resources in characteristic aquaculture have the characteristics of high efficiency, sustainability, replicability and easy popularization.

& gt& gt？ Utilization of cold water resources in tourism upgrading

The Dongjiang Lake in Zixing City has now become a well-known tourist attraction in China, and the most famous one is the "misty Little Dongjiang River", which is caused by the temperature difference effect of cold water. From April to June every year 10, in the downstream of Dongjiang Lake Scenic Area, the total length from Dongjiang Lake Tourist Center to Dongjiang Dam is about 12 km, and the water vapor atomization forms a unique natural landscape of "misty little Dongjiang", which not only drives and enhances the influence of local photography culture, but also helps to enhance the additional benefits of local tourism. According to the statistics of relevant departments, in 20 19 years, Zixing * * received tourists17,800,900 person-times, realizing the total tourism revenue108.34 million yuan; In 2020, the per capita disposable income of rural residents in Zixing City was 23 164 yuan, which was 46.28% higher than that of 20 15/5834 yuan. The Dongjiang Lake Photography Art Museum has also been built in the local area, which provides a platform for photographers and tourists to exchange photography culture and collect, display and record the scenery of Dongjiang Lake. Hunan Tourism Photography Exhibition, Chenzhou Tourism Photography Exhibition and Zixing Tourism Photography Exhibition have been established for many years. If the "Wudu Xiaodongjiang" scenic spot is used as the radiation source in the future, and the whole Dongjiang Lake scenic spot is driven to become a first-class photography creation base, its added value will bring tens of billions of economic benefits.

Nowadays, Zixing City has gradually formed an operable, reproducible and popularized Zixing model of sustainable utilization of cold water resources through the exploration and scientific utilization of cold water resources, which has a demonstration role in promoting the green development of Chenzhou City and provides practical experience for implementing the 2030 sustainable development agenda. First of all, this is because local residents, governments and other stakeholders have a strong awareness of ecological environmental protection since the 1990s. Secondly, the water quality and potential value of cold water resources can be maintained by taking water-based measures, actively striving for legislative protection, improving supporting plans and systems, paying close attention to ecological construction, and strengthening environmental improvement and monitoring. Third, through the application of scientific and technological means and methods, to ensure the sustainable utilization of water resources. In the future, we should rationally consider whether there are potential risks of water pollution and ecological environment destruction during the utilization of cold water resources.