Research On Monitoring And Early Warning Model Of River Crab Aquaculture Environment

Eriocheir sinensis H. Milne-Eswards belongs to Crustacea, Decapoda, Grapsidae, Eriocheir, known as river carb, is a special product in China. In recent years, river carb is one of aquatic products in rising demand at home and abroad market and river carb has been an important aquaculture object for its rich nutrition and special taste. In summer with high temperature and high density, the river crab’s main rearing model has so many of unconsumed organism and fluid mud in the bottom of the ponds, which will consume dissolved oxygen, so the crabs will face a common threat from hypoxia. In the culture of crabs, water quality is one of the most significant factors that affect the growths of Mitten Crab. With the development of modern crabs breeding technology, the needs of the dissolved oxygen prediction is more and more intense. This paper designs a water quality monitoring system for crabs culture after analyzing a lot of literatures and surveying at the aquaculture farm, and establishes a dissolved oxygen forecasting model based on Hidden Markov Model (HMM) in crabs breeding science and technology demonstration center The real-time prediction system of dissolved oxygen was built in remote server. There are three aspects we have achieved:1. In view of the demand of dissolved oxygen forecast, we designed a water quality monitoring system based on wireless sensor network through literature review, expert interviews and field monitoring. In order to fulfill the requirement of dissolved oxygen forecast, the water quality monitoring platform was designed to achieve automatic monitoring of water quality parameters, including dissolved oxygen, water temperature, humidity, rainfall and atmospheric pressure. It’s realized that water quality management with both on-site and remote monitoring center by using ZigBee and GPRS as close and remote communication protocols, so that the technologists can receive real-time data and tackle the exception.2. Established the dissolved oxygen prediction model based on Hidden Markov Model (HMM), modified and optimized the model by fusing weather forecast data into HMM in allusion to the shortcoming of HMM has error forecast when the weather change rapid. Experiment and results show that optimized model has a good performance on an hour dissolved oxygen prediction and meets the requirements of precision and speed.3. Developed the real-time prediction system of dissolved oxygen in remote server, fulfilled the following functions:The real-time monitoring shows of many kinds of parameters, including dissolved oxygen, water temperature, humidity, rainfall and atmospheric pressure and so on; The real-time monitoring shows of one hour dissolved oxygen prediction; Realized intelligent management of crabs breeding, if the real-time monitoring or forecasting of dissolved oxygen is below 4 mg/L, the aerator automatic is opened automatically and the exception messages are sent to the technologists.The system was tested and the results showed that:water quality monitoring system work stability. The data collected and transformation is effective and reliable. Dissolved oxygen real-time prediction system is effective in the process of crabs culture which can help protect the crabs from short of dissolved oxygen.