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Water security crucial for a beautiful and green China |
Author: isi网站管理员-刘成 Source: Updated: 2024-01-23 |
Water has had the greatest of impacts on China's rulers and policymakers throughout history. Nearly half of the disasters in ancient China were related to water, and the rise and fall of dynasties were often linked to water availability and protection from floods. Extensive droughts have toppled at least six of the principal dynasties that ruled China. And the country's capital was shifted twice in ancient China due to serious water scarcity. In modern times, the catastrophic consequences of mega-droughts have been greatly reinforced by high levels of environmental pollution, shrinking water sources, and the need to supply potable water to huge pockets of populations.
LI MIN/CHINA DAILY
Sound management vital to water-scarce country China accounts for nearly 21 percent of the global population but has only 6 percent of the world's freshwater, and per capita water availability in China is about 25 percent of the global average. Hence, to ensure long-term water security, China's water management practices and processes have to be one of the best in the world. China has a rich history of water development. For example, three of the prominent irrigation projects completed before the Common Era are still in operation. The Zhengguo Canal in Shaanxi province, built more than 2,500 years ago, turned the 40,000 hectares of the originally barren Guanzhong farmland fertile. The Dujiangyan Irrigation System was built around 256 BC, and still irrigates more than 750,000 hectares of farmland. And the Lingqu Canal in Guilin, Guangxi Zhuang autonomous region, built around 214 BC, is today an integral part of the picturesque city's socioeconomic life. Poor water management could be an existential threat to any country, because a country's socioeconomic development depends on the availability of water and safeguards against floods. In fact, China's top leadership has spoken about water and water-related issues more than all other presidents or prime ministers of OECD countries put together. Unlike coal, oil and natural gas, which break down after use, water is a renewable resource. This means used water can be collected and properly treated, and then reused. With good policies, this virtuous circle can continue indefinitely. Water management techniques and cost-effective technologies have been available for decades to make the circular use of water possible. For example, Windhoek, capital of Namibia, has been collecting, treating and purifying all its wastewater and then supplying it as potable water for more than 50 years now, without any adverse impacts on human health. As a water-scarce country, but being much richer and technologically more advanced than Namibia, China can adopt similar types of circular economy practices, at least for the industrial use of water. China, like most other countries, has primarily used supply-side solutions to make water available whenever a city or town has required additional volumes of water. In recent decades, as the country's water requirement has increased, it has fulfilled it through the extensive use of large-scale inter-basin transfers, including through the mammoth South-North Water Transfer Project. In the near future, however, China may need to use demand management practices to reduce the relatively high use of water by households, and the industrial and agricultural sectors. And although it has been reducing per hectare use of water in agriculture since 2005, similar breakthroughs have been slow in coming in the industrial and household sectors. China's per capita household water consumption is high. Even though water tariffs have been gradually increased since the early 1990s, they are still below the cost recovery level and lower than those in many developing countries. Unless water prices are gradually increased to the scarcity value level, per capita water use will continue to be high, and the Chinese people will fail to embrace the water conservation ethos. Higher prices will reduce per capita use of water by half without preventing any person from leading a healthy and productive life. Of course, the increased tariff should come with targeted subsidies for the poor.
Overall quality of water deteriorates China's per capita GDP has grown phenomenally, from $318 in 1990 to more than $12,700 in 2022. This continually increasing standard of living means Chinese people's diets have changed radically from being primarily cereal-based in 1990 to one that is high on animal protein today. This change in diet has greatly increased the use of water to produce protein-based diet and has a big impact on the quality of water. In fact, the overall quality of water in China has deteriorated due, among other things, to a massive increase in animal waste, especially because it is difficult to dispose animal waste in an environmentally friendly way even in highly developed countries. China's economic and industrial development during the past four decades is unparalleled in history. But till the recent past the country could not properly manage its industrial wastewater, both in terms of quantity and quality. And yet in most countries, including China, industrial water use, as a percentage of total water used, has been steadily increasing. In contrast, the use of water in agriculture has been declining. This means the volume of industrial wastewater has progressively increased, so has water pollution. To address the issue, the authorities have to better manage industrial wastewater. In this regard, the Water Pollution Prevention and Control Action Plan that the Chinese government issued in 2015 signaled the beginning of a new era of proper management of industrial wastewater, because the plan, under the supervision of the Ministry of Ecology and Environment, requires all industrial wastewater to be treated and tested to ensure it meets the safety standards before releasing it into rivers and canals.
Major challenges in water security China faces three major challenges in ensuring long-term water security. How to reduce the growing demand of households, and the industrial and agricultural sectors? How to meet the challenges created by extreme hydro-meteorological events such as heavy floods, prolonged droughts and very high and very low temperatures in the coming decades? How to respond to "black swan" events such as the COVID-19 pandemic, and the Russia-Ukraine and Israel-Palestine conflicts that can have a huge impact on its water, food and energy supply? Globally, climate change has created one of the biggest uncertainties for water management. Even up to three-four years ago, climatologists and water management experts grossly underestimated the magnitude, frequency, durations and timing of extreme hydro-meteorological events. Extreme weather events are becoming more common these days. Major droughts and floods and record-high temperatures, which hit different parts of China during the past three years, are being experienced much earlier than expected. Extremely high and low temperatures can reduce or disrupt agricultural production, and raise electricity consumption. Such events will also have major implications for water management, and the scale and extent of climate change in the future are mostly unknown and unpredictable at present. On the positive side, it is now possible to reliably forecast rainfall seven days in advance. With China's excellent water infrastructure and good hydro-meteorological observation, it is now possible to forecast heavy rainfall six to seven days in advance. Thus, reservoirs can be emptied before such heavy downpours to prevent heavy floods. With good planning and management, the impacts of one-in-100-year flood can now be drastically reduced, although it will require extensive use of sensors, robotics, artificial intelligence, machine learning and big data analysis, as well as satellites for images from inaccessible terrains to do so. In the future, China has to upgrade the skills of experts and officials in all major river basins to better manage millions of data points, which have to be immediately analyzed and acted upon. Prolonged droughts, however, are altogether a different issue. Regrettably, given our present state of knowledge, it is not possible to forecast a drought with any degree of certainty. And there will unlikely be major breakthroughs in drought forecast before 2035 at the earliest. Ensuring water security in the future will be a challenging task for all countries, including China. But China has made remarkable progress in improving water management since 2005. And evidence suggests that it will continue to make advances in this field. Accordingly, there are good reasons to be cautiously optimistic of China's water future. Asit K. Biswas is the editor-in-chief of River, a distinguished visiting professor at the University of Glasgow, the United Kingdom, director of Water Management International, Singapore, and chief executive of the Third World Centre for Water Management, Mexico; Cecilia Tortajada is the associate editor-in-chief of River, a professor at the School of Social and Environmental Sustainability, the University of Glasgow, UK; and Zhao Changsen is a professor at the Beijing Normal University. The views don't necessarily reflect those of China Daily.
(Source: China Daily) |
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