Blowout Morphometrics and Mass Balances

The Gonghe Basin on the Qinghai-Tibet Plateau has a cold, arid climate and suffered severe land degradation. Climate change as well anthropogenic activities including overgrazing have resulted in widespread blowout development formation of some Earth’s largest blowouts. blowouts are part an aeolian dominated landscape that passes from deflation zone to grass covered plain, then through increasing size complexity transverse barchanoid dunes migrating into valley Yellow River. A combination structure-from-motion (SfM) optical drone mapping, ground-penetrating radar (GPR) soil pits used investigate scour hollows depositional lobes. Comparisons volumes sediment removed with deposited within adjacent lobes varies between sites. lobe volume is invariably less than hollow. This can, part, be attributed reworking lobe, distributing sand further downwind uplifting dust. However, much difference can measurement technique, particularly where GPR was employed calculate volumes. wavelength limits its ability resolve thin layers resulting underestimate at margins thickness equal to, or than, GPR. For layers, beneath resolution GPR, suggest closer match eroded albeit large uncertainty. We put forth two hypotheses explain spatio-temporal evolution dune field. increase could either reflect propagation instability; it result upwind instability, which started highest points subsequently migrated northwesterly direction, towards lower elevations. Recent optically stimulated luminescence dating appear support latter hypothesis.