1.1. Background and Significance of the Study
As we all know, people's food, clothing, housing and transportation cannot be separated from environmental factors, common factors such as atmosphere, water or geology, all affect our quality of life and even survival. Both the general monitoring of water quality and the monitoring of other parameters of environmental increased in the application field are of great significance to human health and the hygiene of water environment. Hui, H. (2020) elaborates on the important role of water. As far as the actual situation is concerned, the proportion of potable water to all water resources is very small, it is about 0.2% of the total water volume. Not only that, water resources are also facing increasing pollution and the status quo is deteriorating. The resources for production and survival are suffering an unprecedented impact. Ziran, L. (2019) describes the current situation of water environment in China. Effective monitoring and evaluation of water resources is a key measure to achieve water resources management and protection. Recently, the Ministry of Ecology and Environment has issued the Emergency Monitoring Program to deal with the New Coronary virus infection pneumonia, which clarifies the necessity of water quality monitoring. Therefore, the research and design of the water quality monitoring system has very important display significance.
The key of water quality monitoring is to measure the parameters of water body effectively to judge the quality of water, to get whether it meets the standard of use, and to take effective measures. Generally speaking, water quality monitoring has the characteristics of complex composition, mutation and wide distribution. Sandeep, B., & Geetha G. (2020) point out the characteristics of water quality monitoring. The traditional water quality monitoring requires the monitoring personnel to adopt the method of manual spot check. The monitoring takes a long time, consumes human and financial resources seriously, and cannot respond to the current water quality situation in real time and accurately. Some are even difficult to monitor where environmental conditions are poor. This series of problems has led to the traditional manual monitoring far from meeting the needs of modern monitoring. Jianjun, Z., Yifu, S., & Weida, C. (2021) analyze the shortcomings of traditional water quality monitoring methods. With the development of sensor technology and wireless sensor network technology, the application of sensors and the wireless sensor network to water quality monitoring has changed the situation of traditional manual collection, but with the increasing nodes of sensors arranged in monitoring sites, the capacity of data has become larger, which makes the limited bandwidth of wireless sensor network blocked, even paralyzed, affected by the environment, and the data between nodes are redundant and contradictory. In addition, there are many shortcomings in the evaluation method of water quality. For improving the performance of the water quality monitoring system, this paper applies multi-sensor data fusion technology and wireless sensor network technology to monitor water quality. Wireless sensor network technology can accomplish tasks independently according to different environment. Jingxiang, L., & Wenlang, L. (2020) introduce the wireless sensor network. The introduction of multi-sensor data fusion technology can effectively fuse information, reduce the capacity of transmitting data, enhance the precision of monitoring, it makes real-time monitoring and evaluation of water quality faster and more accurate. So it can protect and manage water resources timely and effectively.
In order to overcome defects of the traditional monitoring methods for water quality, improve the intelligent and scientific level of water quality monitoring and management, ensure human health, completely eliminate water pollution and better protect the environment, we have carried out the research and design of intelligent water quality detection system based on multi-sensor data fusion technology.
Intelligent monitoring of water quality began to rise abroad later. Since 1959, the Ohio River water quality has been monitored in the United States. Since then, the New York State Environmental Protection Agency has also begun to establish its own automatic water quality monitoring system. The continuous multi-parameter water quality meter was only used in the 1980s. At present, the automatic on-line system and the semi-automatic off-line system have been built in the world. Most of these systems have comprehensive indexes to monitor water pollution, including water temperature, turbidity, PH, conductivity, dissolved oxygen and so on. Zhonghua, H. (2017) summarizes the current situation of water quality monitoring abroad. Water quality monitoring in China has gone through three stages. It started in the late 1950s and early 1970s, its main work was to collect the data of natural water quality and tested its composition. The second stage was from the early 1970s to the mid-1980s, which was the period when China's water quality monitoring was on the right track. During this period, not only functional departments, testing and research centers of water conservancy monitoring were established, but also a series of normative documents were issued, which laid a solid foundation for the standardization work in this field. The last stage is from the mid-1980s to the present, which is a period of fast growth of water conservancy. Many experts have done numerous studies in this field, and realized the effective monitoring of water quality, but failed to realize the real-time, reliable and accurate monitoring of water quality. Ping, Z. (2020) summarizes the current situation of water quality monitoring in China.