A Comprehensive Review of Remote Sensing in Wetland Classification and Mapping: <i>Current progress and future</i>
Shuai Yuan, Xiangan Liang, Tianwu Lin, Shuang Chen, Rui Liu, Jie Wang, Hongsheng Zhang, Peng Gong
Abstract
Wetlands constitute critical ecosystems that support both biodiversity and human well-being; however, they have experienced a significant decline since the 20th century. Since the 1970s, researchers have employed remote sensing technologies for wetland classification and mapping to elucidate the extent and variation of wetlands. Although several review articles have summarized developments in this field, a comprehensive and in-depth synthesis remains lacking. This review article aims to address the following key questions: 1) What is the scientific importance of wetlands? 2) What are the major data sources and methods used in wetland classification and mapping? 3) What are the driving factors behind wetland changes? 4) What are the prevailing research paradigms and their limitations? 5) What challenges and opportunities lie ahead in the context of technological innovation and global environmental change? To answer these questions, we conducted a meta-analysis of over 1,200 peer-reviewed publications, analyzing trends in wetland types, mapping methods, sensor usage, and geographic focus. We review and synthesize current knowledge of wetland features, data availability, and methodological advances. Furthermore, we examine typical wetland mapping products and explore intrinsic driving factors across various spatial and temporal scales. Finally, we discuss major research limitations and propose future directions to improve wetland classification and monitoring in the era of global change. This review consolidates current understanding in wetland remote sensing and provides actionable recommendations to promote scientific progress in wetland studies.