北東アジアにおけるダスト輸送について : ゴビ砂漠地域におけるダストの発生、分布とその輸送の事例研究

酪農学園大

Spatial and Temporal Patterns of NDVI Response to Precipitation and Temperature in Mongolian Steppe

Abstract: Understanding of recent trends of the vegetation cover changes, and its relationship with the climate change will be helpful in more accurate prediction of the vegetation cover changes. The accurate prediction of vegetation cover is helpful in reduction of loss and damages to the economy of the country. Rainfall is one of the limiting factors of animal productivity and socio-economic development of Mongolia. In this study we analyzed temporal patterns of NDVI in relation to precipitation and/or air temperature in steppe zone of Mongolia. NDVI from the SPOT VEGETATION data, at a spatial resolution of 1 km and 10 day intervals, were used to investigate the vegetation variations in Mongolia during the period from 2003 to 2009. Then, GIS and remote sensing techniques were used to examine the relationship between precipitation/temperature and the NDVI in Mongolia, and the seasonal change of NDVI is taken as a tool for drought monitoring. The results indicated that the NDVI values changed in relation to different amount of precipitation and maximally responds to the variation of precipitation with a lag of about 10 days and 20 days during vegetation period

Spatial and Temporal Patterns of NDVI Response to Precipitation and Temperature in Mongolian Steppe

Understanding of recent trends of the vegetation cover changes, and its relationship with the climate change will be helpful in more accurate prediction of the vegetation cover changes. The accurate prediction of vegetation cover is helpful in reduction of loss and damages to the economy of the country. Rainfall is one of the limiting factors of animal productivity and socio-economic development of Mongolia. In this study we analyzed temporal patterns of NDVI in relation to precipitation and/or air temperature in steppe zone of Mongolia. NDVI from the SPOT VEGETATION data, at a spatial resolution of 1 km and 10 day intervals, were used to investigate the vegetation variations in Mongolia during the period from 2003 to 2009. Then, GIS and remote sensing techniques were used to examine the relationship between precipitation/temperature and the NDVI in Mongolia, and the seasonal change of NDVI is taken as a tool for drought monitoring. The results indicated that the NDVI values changed in relation to different amount of precipitation and maximally responds to the variation of precipitation with a lag of about 10 days and 20 days during vegetation period

Bacterial Characteristics of Dust Particle Saltation in Gobi Dust Sites, Mongolia

The Gobi Desert is a major source of Asian dust events, and the resulting health hazards have increased significantly in recent years. We reported that a variety of live bacteria were distributed in the Gobi Desert in relation to land use. Bacterial distribution was confirmed in the environment and on the land used by animals; however, bacterial saltation due to dust events has not been investigated in detail. In this study, to understand the distribution of surface bacteria in the atmosphere by dust saltation, live bacteria in four dust-generating areas in the Gobi area were monitored using an artificial dust generating device. The live bacteria were detected by experimental saltation at a wind speed of 6.5–8 m/s in all areas. A certain number of live bacteria are constantly saltated by dust events, and these bacteria depend on land use. Moreover, the bacterial saltation strain depended on land use and diversity, indicating that live bacteria are lifted into the environment by dust events. These findings indicate that dust events saltate environmental bacteria on the ground, suggest the risk of animal-derived bacterial saltation affected by land use, and present cross-border public health challenges to be considered in the future

Distribution of Viable Bacteria in the Dust-Generating Natural Source Area of the Gobi Region, Mongolia

The Gobi Desert is a major source of dust events, whose frequency of occurrence and damage caused have recently significantly increased. In the present study, we investigated the types of live bacteria present in the surface soil of the Gobi Desert in Mongolia, and determined their genetic identification as well as their geographical distribution. During the survey, four different topographies (dry lake bed, wadi, well, and desert steppe) were selected, and land characteristics were monitored for moisture and temperature. The surface soil was aerobically cultured to isolate bacterial colonies, and their 16s rDNA regions were sequenced. The sequence data were identified through NCBI-BLAST analysis and generated phylogenetic trees. The results revealed two phyla and seven families of isolates from the sample points. Each isolate was characterized by their corresponding sample site. The characteristics of land use and soil surface bacteria were compared. Most of the bacteria originated from the soil, however, animal-derived bacteria were also confirmed in areas used by animals. Our findings confirmed the existence of live bacteria in the dust-generating area, suggesting that their presence could affect animal and human health. Therefore, it is necessary to further investigate dust microbes based on the One Health concept