Development of integrated wetland change detection approach: In case of Erdos Larus Relictus National Nature Reserve, China

Di Liu; Wei Chen; Gunter Menz; Olena Dubovyk

doi:10.1016/j.scitotenv.2020.139166

Development of integrated wetland change detection approach: In case of Erdos Larus Relictus National Nature Reserve, China

Sci Total Environ. 2020 Aug 20:731:139166. doi: 10.1016/j.scitotenv.2020.139166. Epub 2020 May 4.

Authors

Di Liu¹, Wei Chen², Gunter Menz³, Olena Dubovyk⁴

Affiliations

¹ State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
² Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, PR China. Electronic address: chenwei19@tju.edu.cn.
³ Remote Sensing Research Group (RSRG), Department of Geography, University of Bonn, Meckenheimer Allee 166, 53115 Bonn, Germany.
⁴ Center for Remote Sensing of Land Surfaces (ZFL), University of Bonn, Bonn 53113, Germany.

PMID: 32438090
DOI: 10.1016/j.scitotenv.2020.139166

Abstract

Wetlands are threatened by the global warming and the human exploitation pressure, and have been shrinking quickly in recent years. Timely and accurate wetland area change detection is the primary task for wetland conservation and restoration. The objective of this study is to develop an integrated change detection approach which integrates the advantages of spectral mixture analysis (SMA) and change vector analysis (CVA) for the change identification of wetland dynamics. In the proposed approach, water, vegetation and soil fractions of wetlands were derived by SMA; then, the detailed change information (including change magnitude and 12 change direction categories) were calculated through CVA. The proposed approach was applied for the wetlands change in Erdos Larus Relictus National Nature Reserve (ELRNNR), China, using time-series Landsat images during 1977-2017. We found that the wetland faced serious degradation, with water fraction changed to soil (5.79 km²), to vegetation (1.35 km²) and to both soil and vegetation (3.53 km²). From 1977 to 2000, a slight degradation occurred in the northeast edge of Bojiang Lake and a marginal degradation in Bojiang and Houjia Lakes inside the ELRNNR, with water fraction changed to soil and vegetation. During 2000-2010, severe degradation occurred in ELRNNR, and from 2010 to 2017, the wetland was more susceptible to the precipitation change and human activities. Analysis of the result indicated that the long-term drought and effects of mismanagement as well as misuse by human beings were the driving factors of wetland degradation. The proposed approach in this study achieves a higher accuracy than the classification approach to detect wetland change, with the ability to obtain more detailed change information.

Keywords: Change vector analysis; Erdos Larus Relictus National Nature Reserve; Integrated change detection approach; Spatio-temporal pattern; Spectral mixture analysis; Wetland dynamics.