Spatio-Temporal Analysis and Uncertainty of Fractional Vegetation Cover Change over Northern China during 2001–2012 Based on Multiple Vegetation Data Sets

Linqing Yang,Shunlin Liang,Kun Jia,Duanyang Liu,Meng Liu,Yunjun Yao,Xiangqin Wei,Xiaotong Zhang

doi:10.3390/rs10040549

Abstract

Northern China is one of the most sensitive and vulnerable regions in the country. To combat environmental degradation in northern China, a series of vegetation protection programs, such as the Three-North Shelter Forest Program (TNFSP), have been implemented. Whether the implementation of these programs in northern China has improved the vegetation conditions has merited global attention. Therefore, quantifying vegetation changes in northern China is essential for meteorological, hydrological, ecological, and societal implications. Fractional vegetation cover (FVC) is a crucial biophysical parameter which describes land surface vegetation conditions. In this study, four FVC data sets derived from remote sensing data over northern China are employed for a spatio-temporal analysis to determine the uncertainty of fractional vegetation cover change from 2001 to 2012. Trend analysis of these data sets (including an annually varying estimate of error) reveals that FVC has increased at the rate of 0.26 ± 0.13%, 0.30 ± 0.25%, 0.12 ± 0.03%, 0.49 ± 0.21% per year in northern China, Northeast China, Northwest China, and North China during the period 2001–2012, respectively. In all of northern China, only 33.03% of pixels showed a significant increase in vegetation cover whereas approximately 16.81% of pixels showed a significant decrease and 50.16% remained relatively stable.

Highlights

Northern China has typical characteristics of fragile ecological situations and is one of the most sensitive and vulnerable regions in China
The GEOV1 Fractional vegetation cover (FVC) product demonstrated that the FVC values were higher than those from SEVIRI in the Validation Report of Land Surface Analysis Vegetation Products (2008)
Mu et al noted that GEOV1 FVC product was generally overestimated for crops by up to 0.20 in the Heihe Basin

Summary

Introduction

Northern China is a key area deserving of scholarly attention. Faced with these problems, the Chinese government has realized the seriousness of the situations and has implemented a series of policy measures to ease the environmental crisis. Vegetation, which is bonded soil, climatic, hydrologic, and other elements in the whole ecosystem, is a sensitive indicator of climate change and human activities and influences climate by affecting the energy, water, and carbon cycle [5,6,7]. Vegetation can increase precipitation, runoff regulation, reduce flood and drought, reduce pollution, and improve the ecological environment. Vegetation change can affect the energy balance as well as biochemical and biophysical processes [8]

Methods

Results

Conclusion