Arid Zone Research ›› 2021, Vol. 38 ›› Issue (4): 1085-1093.doi: 10.13866/j.azr.2021.04.20

• Plant and Plant Physiology • Previous Articles     Next Articles

Simulation of vegetation change based on BP-SVM mode

JIA Songtao1(),HUANG Shengzhi1(),WANG Hao2,LI Ziyan1,HUANG Qiang1,LIANG Hao1   

  1. 1. State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi’an University of Technology, Xi’an 710048, Shaanxi, China
    2. State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
  • Received:2020-12-15 Revised:2021-02-10 Online:2021-07-15 Published:2021-08-03
  • Contact: Shengzhi HUANG E-mail:jst20156458@163.com;huangshengzhi7788@126.com

Abstract:

Vegetation is an important link that connects the biosphere, atmosphere and hydrosphere, and has an important impact on the watershed in the ecological environment and on the exchange of water and heat. Previous studies focused on correlation analyses between the normalized difference vegetation index (NDVI) and climate factors, but the lag and the increase of forecast factors were rarely used to improve the precision of the NDVI model. Thus, this article compared the prediction performance of the multiple linear regression, artificial neural network and support vector machine, then selected the model with the highest precision. Using conventional factors (rainfall and temperature), the prediction performance was tested when soil moisture and sunshine duration were increased, which affect vegetation growth, and the time lag effect between the different factors and NDVI were considered. (1) SVM had the strongest fitting ability and the highest NDVI prediction accuracy. The root-mean-square error of the Jing River Basin and the Beiluo River Basin were reduced by more than 1.8%. (2) The root-mean-square error (RMSE) of Jing River Basin decreased by up to 8.8% when soil moisture, sunshine and other factors were added. (3) Considering the lag time, the root-mean-square error of the Jing River Basin and the Beiluo River Basin decreased by 15% and 11%, respectively, and the predicting accuracy of NDVI was improved further, thus increasing the reliability of the model. These prediction results have an important reference significance for the formulation of ecological protection strategies and the guidance of ecological restoration in the future.

Key words: support vector machines, prediction accuracy, prediction model, time-lag effect, vegetation coverage