Several challenges in monitoring and assessing desertification

Abstract

Desertification is one of the most serious environmental and socioeconomic problems in the world. Desertification has got ever-increasing attention from scientists to policy makers worldwide. Monitoring and assessing desertification (MAD) has been a key and extreme important work, for combating desertification in threatened areas. Tremendous progress has been made in MAD during the last several decades, including multi-level indicator system, various kinds of extracting and assessing method of desertification information, etc. In particularly, Remote Sensing has become an important data source and technology in MAD due to its strength of macroscopic, synthesis, abundant information, quickly updated data, but it focused primarily on biophysical symptoms and involved some uncertainties challenging MAD. In this paper, several key challenges in MAD were reviewed and discussed. Some findings were given, mainly including: (1) the reference frame or baseline of desertification usually lacking of enough scientific support from environmental background reconstruction and ecosystem dynamics, (2) effective and readily accessible monitoring indicators of desertification usually lacking of reliability and scientific basis derived from bio-physics mechanism of desertification process, (3) underemphasized temporal and spatial scales of desertification and the scale effect, as well as (4) those extracting and assessing methods of real desertification information in need of improvement. Finally, some suggestions were put forward for advancing desertification research and providing authentic desertification information, including more distinct desertification connotation, addressing desertification research at multiple temporal and spatial scales, integrated application of multisource remote sensing data, closely combining MAD with field research work about desertification processes, establishing and protecting natural ecosystems' reserves with different climate types and vegetation types for desertification baselines, etc.

Assessing environmentally sensitive land to desertification using MEDALUS method in Mongolia

“…The assessment was conducted using the most detailed data available in macro scale, and we expect future studies using more detailed and updated data to analyze site-specific desertification assessment using the modified MEDALUS methodology suggested in this study. Which means, the spatio-temporal scale and resolution matter should be considered with data availability and proper desertification indicators based on established assessment and policy aims in certain region (Liu et al 2015).…”

Effects of RapidEye imagery’s red-edge band and vegetation indices on land cover classification in an arid region

“…Land desertification in arid regions is one of the most serious environmental and socio-economic problems in the world, and this issue has been receiving continuous attention from governments and scientists (Batterbury and Warren, 2001;Han et al, 2015;Liu et al, 2015). Climate variability and human activities, such as inappropriate and unsustainable land use, are the main driving factors of desertification (Wang et al, 2006;Zhang et al, 2010;Wu et al, 2011;Ge et al, 2013).…”

Spatial-Temporal Pattern of Human-Induced Land Degradation in Northern China in the Past 3 Decades—RESTREND Approach

“…The land degradation of northern China is affected by both natural and human-induced factors, but the dominant factors of different spatial-temporal scales vary [40]. It is believed that different results may be due to multiple scale effects in land degradation and the complexity and uncertainty of human activities in northern China [41]. For example, there are many areas with high land degradation values in the Northwest (Figure 4), where precipitation increases (Table 2) and drought mitigates during 1982–1990.…”