Risk Assessment System Of Alien Species Based On GIS Platform

Risk analysis and early warning system are critical issues and the most effective and economic measures to prevent invasive alien species and becoming an indispensable part of bio-invasion control. Risk assessment, which supplies information for risk management, is an important part of risk analysis. To facilitate the data management of risk assessment and avoid the complex assessment modules and much data processing, Risk Assessment System of Alien Species were developed in this study using Visual Basic computer language and GIS' secondary developing module—MapObjects.Climatic analogy analysis, bio-climatic analogy analysis and multi-factors integrated analysis were used in our Risk Assessment System of Alien Species to predict suitable distribution areas of alien species and their invasion probability around the world. Climatic analogy analysis follows the climatic analogy principles and applies analogy deviation to seek sites whose climate matches the alien species current distribution; bio-climatic analogy analysis ascertains the most suitable sites of alien species by comparing their biological characteristics with the climatic data. Regarding the multi-factors integrated analysis, risk assessment index system of alien species was set up firstly, then 34 parameters related to entry risk, establishment risk, spread risk and hazard risk were chosen and additional parameters were allowed as users need, in the end, the risk values were quantified as assessment of entry, establishment, spread and hazard risk through risk assessment index system. Different approaches were used in this study to predict the potential distribution sites, to have invasion probability more precise, to make the predictive results more readable, different symbols reflect risks referring to geographical distribution.Solenopsis invicta Buren is one of the 100 worst invasive alien species in the world and chosen as a case study of our Risk Assessment System of Alien Species to test its application capability, because there are plenty of research document and references about it and also S. invicta is in early invasion period in China. It tested the application capability of our system and also provided scientific foundation to control S. invicta. The predicted results of climatic analogy analysis, bio-climatic analogy analysis and multi-factors integrated analysis confirmed that East China and South China had high invasion probability, which matches the current real distribution of S. invicta in China. Four classes were made according to the invasion probability with red, orange, yellow and green reflecting high invasion probability to low. The results indicate that Guangdong and Guangxi belong to red level alarm ranges, most areas in East China and Middle China belong to orange where need precaution measures to avoid S. invicta invasion, most parts of Southwest China and North China are in yellow, Northeast and Northwest China are almost in green where common quarantine is enough.