Dynamic Estimation of Forest Volume Based on Multi-Source Data and Neural Network Model

Dasheng Wu, Yongquan Ji


It is quite necessary to explore some more efficient and reliable estimation models which could integrate or, in some cases, substitute the traditional and expensive measuring techniques in forest resources management owing to the rising investigation costs. Thanks to their flexibility and adaptability, artificial neural networks (ANN) constitute a valid approach for modelling complex long-lived dynamic forest ecosystems.

The evaluation indexes set was established, including 17 factors: elevation, slope, aspect, surface curvature, solar radiation index, topographic humidity index, tree ages, the soil depth, the A-layer depth of soil, canopy density, Normalized Difference Vegetation Index (NDVI), and the spectral characteristics of the bands from Enhaced Thematic Mapper (ETM+) or Thematic Mapper (TM), Band 1 to Band 5, and Band 7 from Landsat. Then, integrating the remote sensing images of ETM+ or TM, Digital Elevation Model (DEM), and forest resource planning investigation data of fir of the key forestry city of Longquan, Zhejiang Province, China, the membership of each factor was empirically fitted by polynomials, and the forest volumes were estimated via an improved back propagation (BP) neural network (NN) model with Levenberg-Marquardt (LM) optimization algorithm (LM-BP). The results showed that the average individual relative errors (IARE) were from 26.38% to 34.41%; the group relative errors (GRE) were from 2.04% to 6.69%, and all of the group estimation precisions were more than 90% which is the highest standard of overall sampling accuracy about volume of forest resource inventory in China.

Full Text:


DOI: https://doi.org/10.5539/jas.v7n3p18

Copyright (c)

Journal of Agricultural Science   ISSN 1916-9752 (Print)   ISSN 1916-9760 (Online)  E-mail: jas@ccsenet.org

Copyright © Canadian Center of Science and Education

To make sure that you can receive messages from us, please add the 'ccsenet.org' domain to your e-mail 'safe list'. If you do not receive e-mail in your 'inbox', check your 'bulk mail' or 'junk mail' folders.