三级aa视频在线观看-三级国产-三级国产精品一区二区-三级国产三级在线-三级国产在线

We have launched E-mail Alert service,subscribers can receive the latest catalogues free of charge

 
 

A Systematic Evaluation of the State of Water Security in China and a List of Problems

( drc ) 2018-04-16

By Gu Shuzhong, Li Weiming & Jia Shaofeng

Research Report Vol.20 No.2, 2018

Water is the source of life, the essential factor of production, the foundation of ecology, and the fountain of human civilization. In history of Chinese civilization, water control and civilization were very closely correlated with one another. So-called security refers to the state that a country or region can, or the ability it has to, acquire, in a timely, sustainable, reliable and economically reasonable manner, water resources and water resource products as needed of acceptable quality and quantity, maintain a good ecological environment, and mitigate floods and droughts. At present, China is confronted with a very complex water security situation, which is exacerbated by a multitude of problems like water resource shortage, water pollution, aquatic damage, drought and flooding. On the other hand, water security in China is facing many new situations, e.g. the new norm of economic development, and the country’s drive to seek new growth energy and new-type urbanization and industrialization, eradicate poverty, comprehensively build a moderately prosperous society, advance ecological and green development, cope with climate change and protect biodiversity, which are not just opportunities but challenges. Given this background, it is necessary to have a systematic evaluation and understanding of water security situations in China and identify main problems in this respect in the hope of providing some insights needed for the country’s decision-making concerning national security, resource security and the improvement of the water control system.

I. Indicators System for Evaluation of Water Security in China

1. Creating an indicators system for evaluation of water security in China

This study adopted the analytic hierarchy process (AHP) to create a system of indicators for the evaluation of water security. In view of the importance and system completeness of water security, indicators at the level of criteria for the evaluation of water security in China were created from the following five aspects: a) Adequacy in quantity, used to measure if the quantity of water resources in a region can satisfy human needs of economic activity (industrial, agricultural, etc.) and everyday life; b) water quality compliance, used to measure if the quality of water complies with water quality requirements for the use of water for living, productive and ecological purposes; c) sustainability, used to measure if water resources can guarantee their own quantity, human needs for development and utilization, and needs of ecological functions; d) cost affordability, used to measure the ability of water users to pay for water they use, and of the society to afford water supply costs; and e) flood protection, used to measure the incidence of floods in a region and its flood control ability and measures. The sub-criteria of each criterion were then determined, and specific indicators of each sub-criterion were hand-picked based on correlations between indicators and on the principle of minimizing their multicollinearity and maximizing data availability. There was finally formed a 20-indicator system for the evaluation of water security in China (see Table 1).

2. Determination of the weights of indicators

This study determined the weights of indicators based on the AHP and the Delphi method. Questionnaires were first answered by water security experts, and then a non-parametric test method involving multiple matched samples - more specifically, Kendall’s W - was employed to test the scores in respect of consistency. The results showed that the value of W which the experts scored was 0.583 and the p-value of the significance level was 0, suggesting good consistency of the results; the results also passed the significance test and could ensure the objectivity and reliability of the weights.

3. Evaluation of water security in China

Based on the indicators system for the evaluation of water security in China, a systematic evaluation of water security situations in China was the conducted in three dimensions, i.e. the country on the whole, provinces, and river basins. Data needed for the evaluation came from available statistics in the latest years, as well as data from water resource surveys and evaluations and some data the study team processed. Standards were defined for the indicators, and on this basis, indicator data were processed and the indicators scored and weighted, finally arriving at scores of the criteria and the sub-criteria and the overall score for water security in China. Each indicator was evaluated on a scale from 1 to 100: a score of 90 or higher signifies “very good”, 80 to 89.9 “good”, 70 to 79.9 “moderate”, 60-69.9 “acceptable”, and a score below 60 denotes “unacceptable”.

The state of water security in the dimension of the country on the whole was first evaluated. The overall score of water security in China is 84.17 (Table 2), signifying a “good” ranking. Of the 5 criteria of water security, cost affordability scored the highest, at 98.18, signifying a “very good” ranking; adequacy in quantity and sustainability scored 88.12 and 86.13 respectively, signifying a “good” ranking; water quality compliance and flood protection scored lower, at 76.33 (lowest) and 76.43 respectively. So far as the country on the whole is concerned, therefore, the most prominent water security problems at present are about water quality and flooding. As is shown in Table 3, lower scores occurred mainly to the following indicators: Length in percentage terms of rivers with Class I to III water quality, number in percentage terms of lakes with Class I to III water quality, rate of water flow into the sea (or abroad), average ratio of losses from flooding to GDP in 3 years, average percentage of flooded cities in 3 years (0.1458) Flood control ability, and rate of embankments up to flood control standards.

The country’s provinces and river basins were also evaluated in terms of water security. And results showed that the southern parts of the country on the whole scored higher than the northern parts, with the lowest scores occurring to such areas in the Hai and Yellow River basins as Hebei, Beijing and Tianjin (see the section below for details).

II. List of Problems with Water Security in China

The study proposed a list of problems with water security in China based on the forgoing evaluation results as well as on actual situations facing the country and its regions.

1. Relatively low degrees of satisfaction in terms of regional demand for water, and the problem of excessive water resource development is prominent

The adequacy in quantity and the sustainability of water resources in China scored relatively high: so far as water supply and demand is concerned, the available quantity at present of water resources in China is greater than that of demand for water and can in the general sense satisfy water demand for living and productive purposes; the degree of development and utilization of surface and underground water resources is less than 20%, falling within the moderate to low pressure range of water resources. But some areas still face the problem of serious water supply and demand pressure and of excessive water resource development.

There is the most apparent contradiction between supply and demand of water resources in the northern Chinese basins of the Yellow, Huai and Hai Rivers; particularly in Beijing, Tianjin, Hebei and other places on the North China Plain as well as in Henan and Shandong in the Huai River basin, where, due to dense populations and developed industrial and agricultural economies there, water resources can hardly satisfy water use demand. Though living, industrial and agricultural water demand has been satisfied with cross-regional water transfer projects being gradually completed and urban and rural water supply infrastructure improved, the pressure from the contradiction between supply and demand of water resources, against a backdrop of rapid industrialization and urbanization, can still hardly be eased in quite a long time to come. On the other hand, the north and northwest parts of the country face considerable water resource pressure for higher degrees of water resource development and utilization in support of local water demand. Phenomena exist of severe over-extraction of underground water in the region of Beijing, Tianjin and Hebei, at a rate near or above 100%, which is the country’s only region that scored below the unacceptable level. And by comparison with historical data, this region has a remarkable decline in the aggregate quantity of water resources and foreign water resources, suggesting a risk that water resources are in themselves unsustainable.

...

If you need the full text, please leave a message on the website.

 
主站蜘蛛池模板: 免费观看性欧美特黄 | 狠狠久久亚洲欧美专区 | 国产河南妇女毛片精品久久 | 欧美激情一区二区三区蜜桃视频 | 精品一本久久中文字幕 | 男女啪啪免费观看网站 | 青青热久免费精品视频精品 | 国产成人一区二区三区影院免费 | 亚洲午夜精品久久久久久成年 | 日韩精品中文字幕视频一区 | 综合久久久久久久综合网 | 国产精品夜色视频一区二区 | 亚洲人精品 | 黄网站色年片在线观看 | 欧美三极 | 成人国产三级在线播放 | 亚洲精品一区二区三区国产 | 国产精品久久久久久免费 | 国产一区二区在线视频 | 亚洲免费毛片 | 国产 在线 | 日韩 | 91精品国产美女福到在线不卡 | 亚洲欧美成人在线 | 99re8免费视频精品全部 | 久久精品国产69国产精品亚洲 | 国产成人精品999在线 | 欧美草比| 九九精品在线播放 | 在线亚洲精品防屏蔽 | 农村寡妇一级毛片免费看视频 | 亚洲精品456人成在线 | 亚洲尹人香蕉网在线视颅 | 国产精品美女自在线观看免费 | 亚洲美女在线观看播放 | 美国一级毛片oo | 欧美成人观看视频在线 | 久久久日韩精品国产成人 | 91在线精品免费观看 | 清纯唯美亚洲综合日韩第 | 国产精品国产三级国产在线观看 | 分享一个无毒不卡免费国产 |