@article{oai:nodai.repo.nii.ac.jp:00000572,
 author = {関山, 絢子 and 島田 沢彦 and 横濱 道成 and 豊田 裕道 and Ayako, Sekiyama and Sawahiko Shimada and Michinari Yokohama and Hiromichi Toyoda},
 issue = {1},
 month = {2016-04-20},
 note = {モンゴルで頻発しているゾド(冬季の異常寒波)は,先行して起きる夏季の草地劣化が助長要因の一つである.計画的な放牧のために,夏季の草地状況を広域的かつ連続的に把握することが必要である.また,モンゴルの植生は降雨量の多寡に影響されることが知られており,降雨量によりバイオマスの分布をある程度予測できる.しかし,近年都市周辺の過放牧が深刻化しているため,降雨量とバイオマスの関係が変化していると考えられる.本研究では,MODISデータを用いたバイオマス推定手法を考案した.次に,降雨量に対するバイオマスの応答性を評価し,現地測定したバイオマスとMODIS-LAI(葉面積指数)データの関係からバイオマス推定式を考案した.これまで広く利用されてきたMODIS-NDVI(正規化植生指数)データよりもMODIS-LAIデータを用いた方が,良好な精度で推定できることを示した.次に,降雨量とバイオマスの関係を解析した結果,森林域が近い北部のモンゴル草地と半沙漠域に位置する南部の草地において相関が認められた.したがって北部および南部は,降雨量の多寡にバイオマスが応答していることが示唆された.しかし,首都ウランバートルが位置する中部の草地では,降雨量とバイオマスとの間に相関が認められず,バイオマスは降雨量以外の要因に影響されていることを示した., In recent decades, global climate change and overgrazing has caused grassland degradation in Mongolia. Key industry is livestock husbandry by nomads in this country. However, the damage called dzud which death of livestock by pasture shortage due to grassland degradation has occurred. Thus, development of biomass estimation method and understanding of biomass response to precipitation and the characteristics for planned grazing are needed. Firstly, in order to calculate the biomass estimating equation from MODIS imagery, a regression analysis was performed using the amount of biomass from field survey and vegetation index from MODIS-NDVI and MODIS-LAI in 2003 to 2012. Secondly the relationship and response to estimated biomass from MODIS imagery and precipitation was investigated. Then analysis was conducted in three areas: north area near forest region, central area including Ulan Bator and south area near Gobi desert. As a result, it was found that the accuracy of biomass estimating equation using MODIS-LAI was higher than that using MODIS-NDVI. It was found that biomass reached a peak in the summer season (July or Aug.), and after that, rapidly decreased in each area every year. Precipitation had slightly increased for 10 years in north and central areas, however biomass was remained static. Moreover a significant correlation was found between biomass and precipitation in the north and south area but not the central area. Thus the biomass response to precipitation is shown in north and south areas. It is suggested that condition of grassland degradation by overgrazing exist in the central area, since no relationship exists between precipitation and biomass., E, 4, KJ00009843679, 論文, Article},
 pages = {28--33},
 title = {モンゴル草地におけるMODISデータを用いたバイオマス推定および降雨応答性},
 volume = {60},
 year = {},
 yomi = {セキヤマ, アヤコ and シマダ, サワヒコ and ヨコハマ, ミチナリ and トヨダ, ヒロミチ}
}