Riparian Wetland Mapping and Inundation Monitoring Using Amplitude and Bistatic Coherence Data From the TanDEM-X Mission

Abstract

This paper focuses on bistatic coherence as an additional feature complementing amplitudes in classification space, permitting to monitor temporal changes in water extent on the wetland comprising surface water and inundated vegetation. The research was conducted on a herbaceous wetland. The TanDEM-X (TDX) images were acquired during the science phase: in bistatic mode with long perpendicular baselines. Two different sets of observations were computed: polarimetric amplitudes and interferometric coherences in single-pass mode. Next, the datasets composed of a multitemporal stack of images were classified using objectbased image analysis (OBIA). The main outcome of the experiment is that bistatic coherences increased greatly the overall accuracy of expected thematic classes. The overall accuracy (OA) shows that thematic categories were classified with higher accuracy when the bistatic coherence complemented polarimetric amplitudes. The OA is greater than 85% for all analyzed datatakes. The accuracy achieved using amplitudes only was higher than 70% but varied overtime. The bistatic coherence at X-band turned out to be really helpful in mapping high vegetation, which can be an indicator that this methodology can be directly used in the monitoring of common reed mowing or mapping highly invasive vegetation. Additionally, we could observe that short inundated vegetation was also mapped correctly, allowing flooded areas in this floodplain to be mapped with great precision throughout the growing season.

Assessment of Changes in Key Ecosystem Factors and Water Conservation with Remote Sensing in the Zoige

“…The average water area of Zoige county from 2001 to 2020 was approximately 42.77 km 2 . It exhibited an increasing trend.…”

“…Wetlands represent the transitional zone between terrestrial and aquatic ecosystems, and possess a unique ecosystem and functional characteristics [1,2]. At present, changes in vegetation and water bodies are basic factors that reflect the status of and changes in wetland ecosystems, and are key indicators of wetland shrinkage and restoration monitoring based on satellite remote sensing [3,4].…”

“…It is a key area for biodiversity protection both in China and worldwide [8]; it is also an important habitat for wildlife species, such as the black-necked cranes and white-tailed sea eagles, and is highly sensitive to climate change [9,10]. The Zoige Wetland National Nature Reserve was established in 1998 and covers an area of 1665.70 km 2 . The alpine swamp wetland ecosystems, black-necked cranes, and other rare animals are especially targeted for protective measures.…”

Finding Out Suitable Index for Wetland Mapping in Barind Plain of India and Predicting Dynamics of Its Area and Depth

“…Mapping and monitoring of historical wetlands trends and its dynamics especially in terms of its areal extent and depth of water, play a vital role for implementation of any wetland management plans (Hird et al, 2017;Kaplan and Avdan, 2018;Mleczko et al, 2021).…”