加藤 顕

<title>Abstract</title> Methods to accurately estimate spatially explicit fuel consumption are needed because consumption relates directly to fire behavior, effects, and smoke emissions. Our objective was to quantify sparkleberry (Vaccinium arboretum Marshall) shrub fuels before and after six experimental prescribed fires at Fort Jackson in South Carolina. We used a novel approach to characterize shrubs non-destructively from three-dimensional (3D) point cloud data collected with a terrestrial laser scanner. The point cloud data were reduced to 0.001 m–3 voxels that were either occupied to indicate fuel presence or empty to indicate fuel absence. The density of occupied voxels was related significantly by a logarithmic function to 3D fuel bulk density samples that were destructively harvested (adjusted R2 = .32, P &amp;lt; .0001). Based on our findings, a survey-grade Global Navigation Satellite System may be necessary to accurately associate 3D point cloud data to 3D fuel bulk density measurements destructively collected in small (submeter) shrub plots. A recommendation for future research is to accurately geolocate and quantify the occupied volume of entire shrubs as 3D objects that can be used to train models to map shrub fuel bulk density from point cloud data binned to occupied 3D voxels.

&lt;p&gt;森林のバイオマス量調査は，森林の現存価値の把握および将来的な収量予測のために重要である。ただし，広大な森林を対象とした場合，全個体を測定することは現実的ではないため，対象林地の中にいくつかの標本地を設定し，その中に生育する個体のみ測定を行い，その結果から対象林地全体のバイオマス量推定を行う方法が採られる。ただし，この方法では標本地が対象林地の平均から外れると誤差が大きくなるという課題もある。&lt;/p&gt;&lt;p&gt;一方，人工衛星や航空機から対象の森林全域を調査する，いわゆるリモートセンシングという技術が研究されている。近年では，航空機にレーザーを搭載し，上空より照射したレーザーの反射から広域の3次元データを得る手法が多く用いられている。この手法は高密度，高解像度な測量が可能である一方で，コストが高額かつ結果が得られるまで数ヶ月程度かかる点が課題である。&lt;/p&gt;&lt;p&gt;そこで，より安価で即時性の高い全域測定手法として，無人航空機（Unmanned Aerial Vehicle：UAV，俗称ドローン）に注目した。本報では，無人航空機を用いた効率的な森林のバイオマス量推定手法を考案し，実際にブラジル北部の植林地にて試験した結果について述べる。&lt;/p&gt;

Center for Environmental Remote Sensing, Chiba University develops L Band circularly polarized synthetic aperture radar (SAR) sensor for microsatellite (150 kg class). This paper explains the project, specification, antenna deployment, RF system, and experiment of circularly polarized SAR in anechoic chamber. In the future, this sensor will be employed to monitor global land deformation.

森林の管理には簡易なモニタリング技術が必要である。これまでの3次元データの取得は，レーザーによるデータの取得が行われてきたが，近年Structure from Motion（以下SfM)という技術が利用可能となった。SfMは写真測量の技術であり，小型UAVを用いることで3次元データを簡易的に取得できる。本研究では，北海道大学雨龍研究林において，小型UAVによる空撮画像とSfMを適用することで森林の3次元データを取得し，樹種の違い，季節変化，地形が樹高計測に与える影響について検討した。その結果，季節変化が樹高計測に影響を与えること，展葉時期において高い精度で樹高を計測できることがわかった。

ヒートアイランド現象の緩和対策として，都市緑地による熱環境緩和効果が期待されている。これまでの緑化対策では樹高しか着目されておらず，樹冠構造については考慮されなかった。樹冠構造の異なる緑地を対象に，樹冠構造の発達が地表面温度に影響するか検討した。その結果，樹冠の厚みが増すと日中の表面温度を下げ，夜間の表面温度を下げないことがわかり，昼夜間の温度変化を緩和する効果があった。そのため，樹冠構造を発達することが，都市林におけるヒートアイランド現象緩和機能を強化することがわかった。

In this paper, we estimate and identify, for Entebbe and Kampala areas on the northern shore of Lake Victoria as study areas, the present extent of Cyperus papyrus (papyrus) wetland and its change over time, using RapidEye (5 m resolution) and Landsat (30 m resolution) satellite images. We first estimated land cover for Entebbe area in 2010/2011 by using both RapidEye and Landsat images, second, the performance of Landsat in land cover classification was compared with that of RapidEye, and third, we identified changes in land cover in the last 15 years for the study areas by using Landsat images. The results of GIS analysis of RapidEye revealed that in 2011, 30% of Entebbe area was occupied by wetland, of which 70% was papyrus-covered. Between 1995 and 2010, the share of wetland decreased from 38% to 32% for Entebbe and from 15% to 11% for Kampala, but for both areas, the most decreases occurred in the last 5 years. Urban land use increased in Kampala from 17% to 64%, and from 9% to 23% for Entebbe, but for both areas, the type of land encroached first by the expanding urban land use was non-wetland vegetation, such as crop land, forest and green space, with relatively low encroachment on wetlands until the mid-2000s. However, urban expansion in recent years has reached a stage to encroach wetlands.

近年のレーザーリモートセンシング技術（LiDAR）の発展により，近距離レーザーを用いた森林構造の詳細なデータを迅速かつ正確に取得できるようになった。これまでは航空機レーザーによる研究が圧倒的に多かったが，地上・車載型の近距離レーザーセンサーが身近に利用可能となり，森林構造計測に利用され始めている。航空機レーザーデータから林分レベルでの平均樹高，単木の梢端，樹冠範囲，樹冠単位での単木判別，成層構造，経年的樹高成長を把握できる。一方，地上レーザーを用いることで，幹を主体とした現存量や正確な立木密度が把握できるようになった。これまで手が届かなく測定不可能であった樹冠を森林の内部から測定でき，人的測定誤差の少ない客観的なデータを取得できる。レーザーデータは森林の光・水環境の推定，森林動態の予測，森林保全などといった生態学的研究に応用されてきた。今後は，生理機能の定量化，森林動態の広域・長期モニタリング，森林保全における環境評価手法など，様々な分野での利用拡大が期待される。樹木の形状や林分の現存量を正確に計測できるだけでなく，様々な生態現象を数値的に把握できるようになることを大いに期待したい。

Point-clouds acquired using remote sensing, such as lasers or photogrammetric techniques, have grown exponentially in the last decade, providing data containing hundreds of millions of points with a density reaching hundreds of thousand points per square centimetre - when working on relatively small areas. This progress has been developed concomitantly with an increasing democratization of UAVs, in such a way that even in hardly accessible areas UAV-based photogrammetric techniques have provided researchers with detailed point-clouds. Provided those dataset, the paradigms have therefore shifted from data collection difficulties, to data processing limitations and usage. The present contribution therefore aims to provide an example of data processing using a voxel-based approach of gravel surfaces in order to derive more than the traditional surface roughness. The algorithm decomposes the surface into voxels and sub-voxels in order to determine if there are surfaces overlapping each other, showing the presence of cavities. Such dataset will then provide the necessary dataset to create metrics to improve the modelling of boundary layers dynamics in computational fluid dynamics for instance.

Forest monitoring for environmental policy requires accurate and efficient ground-truthing techniques in the field. In this paper, a portable terrestrial laser scanner (TLS) is utilized to estimate leaf area index (LAI) of mixed forest stands in Christchurch, New Zealand. Our method converted laser XYZ coordinates to orthographic coordinates to create fish-eye images, from which LAI was estimated. The results were highly correlated with LAI estimates from three traditional techniques: radiation obtained by AccuPAR (R-2 = 0.81), Landsat TM (R-2 = 0.79), and fish-eye lens photography (R-2 = 0.91). This novel technique is a simple and efficient way to collect and analyze LAI and provides good ground truth data for satellite remote sensing.

It is valuable for the control of water quality in lakes to grasp the global functional relationship between phytoplankton biomass (Chlorophyll-a Chl-a), total phosphorous (TP) and total nitrogen (TN) in lake ecosystems. This paper aims at developing a comprehensive model that explains the relationship between Chl-a, TP and TN in lakes under a wide range of environments. Three regression models, the conventional Ordinary Least Squares (OLS) model, random effect panel model and dynamic panel model are compared. Estimation based on water quality data from 396 lakes in 18 European countries reveals that OLS estimation gives comparable parameters to those of many earlier studies, in which both TP and TN are significant determinants of Chl-a. Application of the non-conventional estimation methods alters this parameter structure radically. Station-specific effects being controlled, TN/TP is not a significant factor. The inclusion of auto-regressive effects makes TN insignificant. These results suggest that the concentration of Chl-a could be controlled by reducing the concentration of TP, rather than TN, the effect of which might however be offset by the past concentration of Chl-a. These models were tested by applying them to simulate the relationship for 9 Japanese lakes to show the superior performance of the nonconventional dynamic model.