Risk Investigation And Assessment Of Water Pollution In The Upper Reaches Of The Yellow River In Lanzhou

With the modernization and informatization rapid development in our country, the acceleration of urbanization process and the water pollution problem are increasingly serious. Water environmental safety has become a major problem today, To solve the water pollution is just around the corner. In recent years, the major water pollution incidents always happened in basin in our country, not only bring the enormous losses to agricultural production, but also seriously effect the safety of people's life and property. So The water security problem was focused, the water quality evaluation is the most important task to guarantee the water security. The risk investigation and assessment of water pollution in the main water source area were of great significance to deal with the sudden major water pollution incidents.As the second largest river in China, the Yellow River is the only drinking water for millions of people in Lanzhou. In the water upstream, with a large number of industrial enterprises and the city, there are numerous sources of pollution, which can cause major water pollution event risk source. It is very important and practically significant to investigate and assess these risk sources for the safe operation of water in the Yellow River, Lanzhou.This paper aimed at the upstream section of the Yellow River in Lanzhou City water. The water quality identification index method, principal component analysis method, grey clustering method and comprehensive pollution index method in the basin in the main stream and its tributaries were respectively choosed to assess the risk of water pollution. the within the basin water quality deterioration trend was analyzed, and the prevention and control countermeasures of the Lanzhou Yellow River upstream water pollution were discussed It provides scientific support for the safety of drinking water in Lanzhou city. The main results are as follows:(1) The single factor evaluation results showed the main pollution factors of the main stream of the Yellow River are total nitrogen, volatile phenol, mercury; The main pollution factors of level 1 tributary of the Yellow River are total nitrogen, ammonia nitrogen, chemical oxygen demand(COD) and mercury; The main pollution factor of secondary tributary of the Yellow River are ammonia nitrogen, total nitrogen, volatile phenol, COD and mercury. It can improve the water quality to take effective measures to reduce the ammonia nitrogen, total nitrogen and COD in quantity.(2) The principal component analysis results showed that the influence of the Yellow River in lanzhou section of the upstream water quality are mainly organic matter, water eutrophication and heavy metal pollution, and secondly controlled by the heavy metal iron, aluminum, arsenic and hexavalent chromium, at the same time influenced by water self-purification ability. The pollution of Level 1 tributary of the Yellow River Huang was serious, and China's river water quality was better.(3) The gray clustering evaluation results showed that the overall water quality is better in lanzhou section of the Yellow River upstream, belong to class I and II water quality, The Huangshui River was heavily polluted.(4) The comprehensive pollution index results showed that weight and weighted superposition comprehensive index evaluation method is more suitable for the water quality assessment of river in the Yellow River than in the upper reaches of the upper reaches of the Lanzhou river. After assessment of the weight and weighted superposition comprehensive pollution index obtained that the serious pollution in the upper reaches of the Yellow River in Lanzhou section are the Huangshui River and Zhuanglang river.(5) Through the upstream of the Yellow River in lanzhou section of water deterioration risk analysis showed that the main stream of the Yellow River main pollutant concentrations was in a declining trend, water quality has improved. However, tributary of the Yellow River water quality pollution condition should cause the attention of relevant departments, especially primary tributaries HuangShuiHe pollution is serious, urgent treatment.(6) In order to solve the problem of water pollution in lanzhou upstream section of the Yellow River, the water pollution prevention and control countermeasures were discussed. The results showed that the formulation and execution of water pollution protection and control regulations, mobilize the people around to protect water sources, strictly implement the principle of "who pollution, who governance". Strengthen the sewage treatment, the new sewage treatment plant, strengthen water quality monitoring and focusing on pollution sources to improve their monitoring ability, increase the number of monitoring.