Centroid sampling: A variant of importance sampling for estimating the volume of sample trees of radiata pine

Wood, G. B.; Wiant, Harry V.; Loy, Richard J.; Miles, Joe A.

doi:10.1016/0378-1127(90)90027-9

Cited by 38 publications

(12 citation statements)

References 3 publications

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“…These results support the empirical evidence of Forslund (1982), whereby the average center of gravity of aspen boles without branches is located at 3/10 of the bole height from its base. Wood et al (1990) also showed the importance of the point on the stem at a relative height of approximately 0.3. They obtained a minimum bias in the estimation of tree volume, using centroid sampling for 114 trees of radiata pine, where the point of sampling was fixed at the height of the centroid.…”

Section: Model Selection For Practicementioning

confidence: 92%

A rapid method for estimating the median diameter of the stem profile of Norway spruce (Picea abies Karst) trees

Vasilescu¹,

Tereşneu²,

Dinulică³

2017

iForest

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The median diameter of a longitudinal section of the stem may be used to determine the stem volume. However, to calculate stem volume, many measurements of diameter at different heights along the stem are required. Therefore, this approach is not generally applied because time-consuming and expensive. Here, we propose a novel, more rapid method to obtain median diameter using the area of the stem profile. A total of 218 height/diameter classes from more than 5000 spruce trees (Picea abies Karst.) were used to compute the median diameter using the classical method. In parallel, a regression model to assess the median diameter was developed. The strongest predictor of the median diameter for the stem profile was the diameter at breast height (R 2 = 0.9985). Statistical analysis revealed that the height of the median diameter on the stem profile was 0.3 × H (tree height). The model was verified on standing and felled trees, revealing that differences between classical computations and the proposed model were less than 2% in most cases (86.24% of trees). The median diameter of the stem profile provides valuable information on stand architecture that could help in advancing our understanding on the mechanical stability of Norway spruce trees (i.e., delineating breakage point), growth model predictions, and competition among trees.

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Section: Model Selection For Practicementioning

confidence: 92%

A rapid method for estimating the median diameter of the stem profile of Norway spruce (Picea abies Karst) trees

Vasilescu¹,

Tereşneu²,

Dinulică³

2017

iForest

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“…Wood volume was estimated for individual trees by approximating the centroid method (Wood et al 1990, Yavuz 1999) using tree height and two stem diameter measurements. These measurements are expanded to tree-level volume estimates by using equations for sections of a cone.…”

Section: Analysis Methodsmentioning

confidence: 99%

Federated States of Micronesia's forest resources, 2006

Donnegan¹,

Butler²,

Kuegler³

et al. 2011

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“…As a semi-distributed model, the SWAT model automatically assigns precipitation data from the rain gauge nearest to the center of a sub-watershed as the areal rainfall input, which is called the centroid method (Wood et al 1990). This traditional method may cause inherent uncertainties because of the following reasons: Rain gauges far from the centroid of a sub-watershed may be abandoned despite their potential value; the effects of climate variation and elevation change are theoretically important, but are not considered in the current version of SWAT model.…”

Section: Model Inputsmentioning

confidence: 99%

Uncertainty analysis for nonpoint source pollution modeling: implications for watershed models

Shen

Xie

Chen

et al. 2014

Int. J. Environ. Sci. Technol.

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Uncertainty is inherent in watershed modeling but it is not fully acknowledged in model applications. This review focuses on uncertainty issues related to the Soil and Water Assessment Tool (SWAT) model, which is one of the most useful tools for simulating nonpoint source (NPS) pollution processes. We considered numerous studies that addressed three types of uncertainty in detail, i.e., the model inputs, parameters, and model structure. It has been shown that rainfall data, in terms of the spatial rainfall variability and the accuracy of the measured data, play a key role in the accuracy of the SWAT model. Geographic information system inputs, including the digital elevation model, land use map, and soil type map, have also been identified as key sources of input errors. With respect to the parameter uncertainty and model structural uncertainty, it is anticipated that the complex, nonlinear structure, and numerous parameters included in the SWAT model may lead to a failure to identify parameters, as well as equifinality phenomenon. We also compared some widely used uncertainty analysis methods, such as the generalized likelihood uncertainty estimation and first-order error analysis, to provide reliable guidance for the application of the SWAT model. This study benefits a wide range of researchers, who are concerned with uncertainty issues in NPS pollution modeling, and it provides insights into the application of watershed models in the development of watershed programs.

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Centroid sampling: A variant of importance sampling for estimating the volume of sample trees of radiata pine

Cited by 38 publications

References 3 publications

A rapid method for estimating the median diameter of the stem profile of Norway spruce (Picea abies Karst) trees

A rapid method for estimating the median diameter of the stem profile of Norway spruce (Picea abies Karst) trees

Federated States of Micronesia's forest resources, 2006

Uncertainty analysis for nonpoint source pollution modeling: implications for watershed models

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Centroid sampling: A variant of importance sampling for estimating the volume of sample trees of radiata pine

Cited by 38 publications

References 3 publications

A rapid method for estimating the median diameter of the stem profile of Norway spruce (Picea abies Karst) trees

A rapid method for estimating the median diameter of the stem profile of Norway spruce (Picea abies Karst) trees

Federated States of Micronesia&#39;s forest resources, 2006

Uncertainty analysis for nonpoint source pollution modeling: implications for watershed models

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Federated States of Micronesia's forest resources, 2006