From degradation to restoration: Remote sensing tracks Asia’s struggle for sustainable drylands

Across Asia's vast drylands, a new study reveals a critical imbalance between degradation and recovery. Researchers analyzed two decades of satellite data and developed an integrated ecohealth-neutrality framework to track how land ecosystems have changed from 2000 to 2020. The findings show that while ecohealth began improving after 2012, degradation still dominates, with about 22% of the region's land (196 million hectares) remains degraded, compared to only 13% (119 million hectares) showing recovery. This 8% “land debt” indicates the fragile balance between human activity and ecosystem resilience. The study calls for tailored restoration strategies to close this gap and achieve land degradation neutrality (LDN) across Asia by 2030.

Drylands, covering over 40% of Earth's surface, sustain billions of people who depend on them for food, water, and livelihoods. Yet these ecosystems, especially in Asia, are rapidly losing their vitality due to overgrazing, deforestation, and climate stress. One in three hectares of Asian dryland is now degraded, with crop yields projected to drop by half by mid-century. Despite major restoration programs like the Great Green Wall and Landscape Partnership Asia, progress has remained fragmented. Facing these persistent challenges, scientists recognized the urgent need for a continent-wide monitoring approach to quantify ecohealth changes, understand their drivers, and determine whether restoration efforts are keeping pace with degradation.

A team from the Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, together with partners from Rwanda, Belgium, and New Caledonia, has mapped the ecological health of Asia's drylands. Their research, published (DOI: 10.34133/remotesensing.0897) on October 10, 2025, in Journal of Remote Sensing, integrates the Land Degradation Neutrality (LDN) framework with a regional ecohealth assessment model to track ecosystem vitality, soil moisture, and land use dynamics over 20 years. The results reveal a compelling story of recovery and degradation, showing that Asia's drylands remain in fragile equilibrium between continued decline and measurable improvement.

The study examined dryland regions stretching from Central Asia, Kazakhstan, Uzbekistan, Turkmenistan, Tajikistan, and Kyrgyzstan, to East Asia, encompassing Mongolia and China’s arid provinces of Xinjiang, Gansu, Ningxia, and Nei Mongol. Using high-resolution satellite data, researchers quantified ecosystem vitality and land provisioning capacity by combining indicators such as vegetation indices (NDVI), soil moisture, topography, and land cover. They found that ecohealth declined steadily until 2012 but began improving thereafter, especially in East Asia, where large-scale afforestation and conservation programs took effect. Gansu, Ningxia, and Nei Mongol emerged as “bright spots” of recovery, while Central Asia, particularly Kazakhstan, remains the most degraded. Within the LDN framework, about 22% of land showed signs of degradation and 13% improvement, leaving a “land debt” of 76.9 million hectares that must be restored to achieve balance. The research identifies land use change, urbanization, and mismanaged water systems as major drivers of degradation, while reforestation and sustainable rangeland management offer promising paths toward recovery.

“LDN is more than a target; it's a test of our ability to coexist with the land,” said Dr Yaning Chen, corresponding author of the study. “Our satellite-based framework reveals that while East Asia’s drylands are bouncing back through science-driven restoration, Central Asia's ecosystems remain vulnerable to unsustainable irrigation and land use. Achieving neutrality means more than offsetting losses, it requires understanding local realities and strengthening cooperation across borders. Only by aligning human activity with ecological resilience can we restore the health of Asia's drylands.”

The findings provide a practical blueprint for achieving the UN's Sustainable Development Goal 15.3 on LDN. By identifying where and why ecohealth declines, the framework helps policymakers target interventions such as drought-tolerant afforestation, efficient water management, and climate-smart agriculture. The study's “avoid-reduce-reverse” pyramid offers a stepwise strategy: prevent new degradation, rehabilitate affected areas, and enhance ecosystem resilience. This approach can be applied to other arid regions worldwide, linking scientific monitoring with community action. Ultimately, restoring Asia's drylands is not only about reclaiming lost land; it's about securing the ecological foundation for sustainable development and human well-being.

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References

DOI

10.34133/remotesensing.0897

Original Source URL

https://doi.org/10.34133/remotesensing.0897

Funding information

Study area overview of Asian drylands showing (A) national and provincial boundaries, (B) elevation in meters, and (C) current land cover classification (2020).

About Journal of Remote Sensing

The Journal of Remote Sensing, an online-only Open Access journal published in association with AIR-CAS, promotes the theory, science, and technology of remote sensing, as well as interdisciplinary research within earth and information science.

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