What are the disadvantages of traditional hydrological monitoring of environmental water quality?

The traditional hydrological monitoring of environmental water quality is based on hand carrying portable instruments to the site or continuous monitoring at fixed stations, which is time-consuming and laborious, and the analysis results lag far behind the actual water quality changes, and the degree of automation is low, so it is difficult to make a comprehensive and effective evaluation and analysis of the water environment, which greatly improves the decision-making difficulty of water environment management.