Combat the sea ice Geographic Information System

 

For the vast majority of residents living in coastal areas, in addition to experiencing strong winds and low temperatures in winter, there is also a worry-the sea ice disaster. What is sea ice? In a narrow sense, it refers to the ice formed by sea water. In a broad sense, however, sea ice is a general term for Ice floating on the sea. It includes not only frozen ice in the sea, but also ice from lakes, rivers, and ice falling from glaciers. In China, sea ice disasters occur from time to time, especially in the last two years. Due to the influence of the cold wave, the Bohai Sea has suffered severe freezing, and a large number of fishing vessels cannot go abroad or even be frozen, seriously damaging the aquaculture industry, many ports have experienced severe ice conditions, which has brought great difficulties to maritime shipping.

Stacked sea ice

 

We used to fight against sea ice as early as by experience accumulation. We will speculate on the freezing situation this year based on previous years, such as where ice is easily frozen and where ice is likely to be thick. With the emergence of meteorological forecasts, marine forecasts and other related services, we can use these auxiliary methods to predict the generation of sea ice more scientifically and accurately. Is there a way to show us at a glance the specific impact of sea ice on the production and living of coastal residents? In the "2010 Esri Chinese college student GIS software development competition", several students from the ing School of Shandong University of Science and Technology, under the guidance of a teacher, used a technology called geographic information system, the sea ice generation and disaster assessment in the Bohai Sea were studied in depth.

 

Geographic Information System (GIS) is an important tool, technology, and discipline for obtaining, processing, managing, and analyzing geospatial data. According to relevant statistics, after entering the information society, 80% of the information people access every day is related to geospatial information, and all aspects of our daily life are firmly branded with time and space. Therefore, spatial thinking is a way of thinking that cannot be ignored when we understand, analyze, and solve problems.

 

As for the sea ice issue, we are not only concerned about the regions where sea ice is generated, but also about the distribution of sea ice thickness and density in these frozen areas, as well as the impact on maritime shipping and marine breeding areas, this provides a reference for us to develop response strategies.

 

Related Knowledge shows that the formation of sea ice is related to many factors, including the quality of sea water (salinity of sea water), air weather conditions (wind speed, temperature, solar radiation, precipitation, humidity, etc) the coastline and the degree of sea water pollution. We cannot take all factors into consideration when studying this issue. In this way, the actual operation is relatively difficult; in addition, it is not conducive to us to identify the "main crux" of the problem ". That is to say, we need to find the "Main Aspects" of "main contradictions ". In this case, we need to summarize, refine, and select the relevant factors, and finally find out the main factors that affect the results.

 

The research team of Shandong University of Science and Technology found that salinity and temperature are the decisive factors affecting sea ice generation. After finding these factors, we need to further determine their specific impact on sea ice generation. In this case, the researchers need to combine the relevant knowledge and the information they have mastered to conduct a comprehensive analysis and deduction, and finally find the association between these factors and the final result. This process is called "modeling ". Modeling refers to the process of establishing conceptual relationships, mathematics, and/or computer models. A model is a highly abstract and generalized relationship between things. It is a refined expression that removes irrelevant and secondary impact factors. It is understood that there are a large number of off-the-shelf models in GIS software, such as spatial statistical analysis models and hydrological models, to facilitate users' direct calls. If a proper model is not found in the model library, you can quickly build a model using the modeling tool provided by the model library. After the model is created, the collected monitoring data can be used to calculate the specific distribution of coastal sea ice. Similarly, through some arithmetic operations and operations, we can obtain the level chart of sea ice thickness and sea ice density.

 

 

Sea ice thickness classification chart: Based on the calculation results, the sea ice thickness is divided into five levels. The deeper the color, the thicker the sea ice.

 

Another advantage of geographic information systems is the ability to present the computing results in an intuitive visual form of "map. In this way, the density and thickness of the frozen areas are clearly displayed in the figure. This is not helpful for us to further develop our response strategies. For example, if a fishing boat is trapped, an ice-breaking ship parked on the shore needs to be rescued. Through this system and the model we have already created, we can calculate which ice-breaking ship was parked nearby for rescue and what path the ship should take. We all know that the distance between two points is the shortest. However, in real life, we cannot simply choose a straight line because of obstacles or other reasons. Here, it is possible that on this line, there is a region with extremely thick sea ice and extremely high density. If the ice-breaking ship passes directly, not only cannot it break through this region, it is very likely that they are still frozen and in danger. Therefore, we need to use the system to select an optimal path with short distance and low ice breaking costs.

 

On this basis, the research team made further analysis, such as the impact of sea ice on marine aquaculture areas. As before, they first identified several major influencing factors, such as the thickness of the sea ice (affecting the length of the ice sealing period) and the density of the sea ice (affecting the collection and increase of seafood revenue) the speed of sea ice (the rapid generation of sea ice will pose a great threat to marine vessels), and then conduct modeling analysis to determine the effect of sea ice on marine farming areas. Likewise, we can analyze the impact of sea ice on offshore buildings, especially offshore oil wells and gas fields.

 

Classification of damage disasters in the breeding area: According to the calculation results, the damage degree of the breeding area is divided into six levels. The purple area represents the most affected area.

It can be seen that with the geographic information system tool, we can convert plain text descriptions and data reports and other materials into vivid visual expressions, and also use tools such as models, perform spatial analysis. Currently, GIS has been widely used in all walks of life and has become an important basis for relevant units and departments to make decisions.