Advances in research on wetlands of the Tibetan Plateau

Abstract

About 80% of the global wetlands are being degraded or lost, and wetland ecosystem has become one of the most endangered ecosystems in the world. As a sensitive area to global change and protective barrier for the security of ecosystems in Asia, the Tibetan Plateau has a wetland area of about 13.19×104km2, which is an important part of the wetland ecosystem in China. With increasingly more remote sensing technology applied, Tibetan Plateau wetland research entered a new period of rapid development. This article summarizes remote sensing research literature of the Tibetan Plateau from 1992 to 2013, aiming to provide a reference for Tibetan Plateau wetland research in the future. The following aspects of research are reviewed: monitoring methods, research topics, and existing problems. The analysis shows that:(1) In the past 30 years, the research on Tibetan Plateau wetlands was focused on dynamic change monitoring of wetland area, landscape patterns, and ecological environment based on remote sensing technology. Attention was paid to building models to analyze the trend of change of the wetlands in three dimensions, taking an ecological system perspective.(2) Such research concludes that: 1) From 1990 to 2006, the wetland area generally decrease at an annual rate of 0.13%, and the landscape diversity decline at an annual rate of 0.17%. 2) In contrast, from 2003 to 2009, the depth of the lakes on the Tibetan Plateau had increased at an annual rate of 0.20 m; from 1970 to 2011, water storage of the lakes increased at an annual rate of 2.2 km3; from 1976 to 2009, lake area of the interior drainage area of the plateau increased at an annual rate of 0.83%. 3) From 1965 to 2002, change of the Tibetan Plateau wetlands was controlled by the climate. Wetland degradation and change around areas of human activity are a result of increased human activities. The existing problems of remote sensing research of the Tibetan Plateau wetlands are that: accuracy of digital analysis of remote sensing images and cloud removal need to be improved; a comprehensive perspective is needed for the research of the Tibetan Plateau wetland system. Based on the review, this article identifies the following key areas of future research:(1) Taking full advantage of remote sensing monitoring of wetlands characterized by multidate, multispectral, real- time, dynamic, and repeated coverage. Strengthening comprehensive research and remote sensing research of areas lacking conventional data;(2) Establishing a regional specific wetland remote sensing classification system that is technically operable, and conducting basic research on improving the Tibetan Plateau wetland remote sensing classification system and applications;(3) Focusing more on quantitative study on ecosystem functions of wetlands and decision support system for wetland ecosystem management;(4) Discussing responses and adaptation mechanisms of the Tibetan Plateau wetland ecosystem under the background of global change, especially the differences in responses and adaptation mechanisms under the impacts of different temporal and spatial scales. Coupling the models of hydrology, ecology, meteorology, soil, and environment to predict the trend of wetland degradation and revealing regional differences of response between different areas of the plateau in the face of global change;(5) Advancing remote sensing methods for Tibetan Plateau wetland research, strengthening the integration of RS, GIS, and GPS methods, and promoting the construction of a Tibetan Plateau wetland information platform.