Study On Locust Plagues Monitoring Based On Locust Habitat Factors

Inner Mongolia grassland is the largest grassland and natural pasture in China,and also is the main base of animal husbandry production in China.It covers an area of about 27% of the total area of grassland in China.It is not only an important protective barrier in the north of China,but also a natural defense line to prevent the surface wind and sand from blowing.It plays an indispensable role in conserving water resources and preventing windstorms and fixing sand in the land.In recent years,due to climate change,ecological environment deterioration and other reasons,locust plagues have occurred from time to time.When locust plagues occur,huge swarms of locusts will eat grass,destroy surface vegetation,change soil structure,cause grassland desertification,and seriously affect the production and living safety of people.The application of remote sensing technology in the study of locust habitat monitoring has a great advantage for monitoring locust plagues in Inner Mongolia Grassland in an all-round and large-scale way.In this paper,taking Ar Horqin Banner as the research area,the habitat factors of locusts were extracted from topography,meteorology,soil and vegetation.The suitable thresholds of each habitat factor were determined and the evaluation model of locust habitat suitability was built to evaluate locust habitat,so as to provide a scientific basis for the prevention and control of locust plagues.(1)The effects of habitat factors on the occurrence of locusts were studied by using synthetic method and correlation analysis method,and the suitable thresholds of each habitat factor were determined by using the method of partition statistics and combining with the ecological characteristics of locust.The results shows that: locusts are mainly affected by temperature,TVDI,NDVI and sunlight hours during spawning stage,and the suitable thresholds of each habitat factor were 16-38?,0.75-0.95,0.1-0.75 and ? 270 h.Locust eggs are mainly affected by accumulated precipitation in freezing,winter,excavation and ground temperature during overwintering stage,and the suitable thresholds of each habitat factor are ?10mm,1-10 mm and 5-20 mm,?-30?.Locust eggs are mainly affected by ground temperature and TVDI during incubation stage,and the suitable thresholds of each habitat factor are 16-35?,0.7-0.9.Locusts growth stage is mainly affected by TVDI,NDVI and temperature,and the suitable thresholds of each habitat factor are 0.75-0.95,0.25-0.75,25-40?.(2)Based on the suitable threshold of locust habitat factors,the suitability evaluation model of locusts was constructed in four physiological stages,namely,spawning stage,overwintering stage,incubation stage and growth stage.Based on the law of locusts development and evolution,the habitat suitability of the whole life cycle was evaluated.Based on the locust habitat factors from August 2016 to July 2017,the spatial distribution of locust habitat suitability in 2017 was retrieved.The results showed that the most suitable habitat distribution area was consistent with the locust plague area surveyed by the agriculture and Animal Husbandry Bureau of Ar Horqin Banner,and the more suitable habitat distribution area was basically consistent with the locust plague area in recent years.(3)According to the study of locust habitat suitability,it is found that the distribution pattern of habitat suitability index is low in the West and North,high in the East and South Central.The eastern part and the central and southern part of Ar Horqin Banner are the potential occurrence areas of locust plague.We should strengthen the work of disaster prevention and mitigation from the aspects of monitoring mechanism,policy funds,scientific prevention and control.In this study,remote sensing technology is used to extract the locust habitat and combine with the relevant ecological characteristics of locusts to study the locust suitable habitat in Ar Horqin Banner.Through the establishment of locust habitat suitability evaluation model to predict the occurrence area of locust plague in a large scale,which will provide ascientific basis for the government and relevant departments to do a good job of disaster prevention and mitigation deployment in advance,so as to improve the efficiency of locust plague prevention and control.