@article{oai:nodai.repo.nii.ac.jp:00000406,
 author = {関山, 絢子 and 島田 沢彦 and 豊田 裕道 and 横濱 道成 and Sekiyama, Ayako and Shimada Sawahiko and Toyoda Hiromichi and Yokohama Michinari},
 issue = {1},
 month = {2016-04-20},
 note = {本研究では,モンゴル草地における植生調査とパターン展開法を応用した土壌水分推定手法について,現地調査データへの適用を試みた。調査はモンゴルのトブ県,ドンドゴビ県とヘンティ県における牧草地や耕作放棄地など多様な土地利用状況における全10箇所を対象地とした。植生調査は,植被率の算出と坪刈りによる植物種の同定を行った。次に,可視・近赤外波長域(350-1050nm)が観測可能なセンサを持つ分光放射計を用いて,土壌分光反射率を測定した。分光反射率は,衛星画像への適用を考慮に入れ測定波長域を4バンドに分類し,解析では各バンドの平均値を利用した。植生調査の結果,いずれの調査地においてもイネ科植物が生息していた。また,植被率が同程度の地域でも,土壌水分量に差異が認められた。著者らは,既にパターン展開法を応用した土壌水分推定手法を報告している。屋外実験により測定した土壌分光反射曲線(反射パターン)が,土壌含水比の低下に伴い直線形状に近づいたことから,パターン展開法を応用し,土壌含水比が低い場合の特性を示す直線モデルパターンを考案したものである。現地調査で測定した土壌分光反射率データを用いて土壌水分推定を行った結果,パターン展開により算出した直線モデルパターン展開係数と土壌含水比の間に有意な関係が示された(r^2=0.72)。この際,土壌タイプの考慮は行わなかったことから異なるタイプの土壌を対象にした場合でも良好な精度の土壌水分推定値が得られることが示された。, In this study, we conducted the measurements of soil spectral reflectance and soil moisture content, and vegetation surveys over ten plots within the prefectures of Tov, Dundgovi and Henti of Mongolian grasslands. We attempted to apply a method for estimating soil moisture content to the field measured data. We also collected the data of vegetation species by the quadrate method, and calculated the vegetation cover ratio. The soil spectral reflectance of land surface was measured using a spectroradiometer which had a sensor in visible and near infrared wavelength (Wavelength range : 350-1050nm). For an application to satellite imagery of optical sensors, four spectral bands were selected to be analyzed. The estimation method of soil moisture content by applying pattern decomposition has already been reported. In this investigation, we found that the soil spectral reflectance curve was steep when the soil moisture content is high, and becomes flat when the soil moisture content is low. Thus, in the pattern decomposition method, the flat model pattern is defined as the spectral reflectance pattern that corresponds to completely dried soil. The pattern decomposition coefficient for the flat model pattern was calculated from the pattern decomposition method using flat model pattern. The result of application of the suggested method to soil reflectance pattern from field survey showed a negative correlation (r^2=0.72) between soil water content and the pattern decomposition coefficient for the flat model pattern. This high correlation was shown throughout all the soil types in this study. The result of vegetation survey showed that there was a difference of soil water content between the two survey plots where low vegetation cover ratios were recorded. The reason for this result was assumed to be the effect of soil moisture deficiency or overgrazing., E, 8, KJ00006290839, 論文, Article},
 pages = {63--72},
 title = {モンゴル草地における植生調査とパターン展開法を用いた土壌水分推定},
 volume = {55},
 year = {},
 yomi = {セキヤ, マアヤコ and シマダ, サワヒコ and トヨダ, ヒロミチ and ヨコハマ, ミチナリ}
}