New study sustains snowmelt flood risk assessments in NW China

LANZHOU -- Chinese researchers have conducted a new study on the spatio-temporal distribution of snowmelt floods and disaster risk assessments in China's northwestern region, holding promise for disaster prevention and control of this region.

The study constructed a comprehensive risk assessment framework for snowmelt floods in northwestern China. It proposed strategies to tackle the challenges of snowmelt floods in the region, according to the Northwest Institute of Eco-Environment and Resources (NIEER) under the Chinese Academy of Sciences.

Snowmelt floods are one of the cryospheric disasters. With global climate warming and the increasing frequency of extreme events, snowmelt floods have led to significant damage. It is urgent to strengthen the disaster risk assessment, said Xu Min, NIEER researcher and leader of the study.

Based on the snowmelt runoff simulated by a model with related data over the 1948-2022 period, the study constructed a snowmelt flood identification threshold model and a disaster risk assessment framework. It systematically analyzed the evolution characteristics and disaster risk distribution of snowmelt floods in Northwest China.

The results indicated that the snowmelt runoff in northwest China showed a significant increasing trend and exhibited a spatial pattern of being more abundant in the northwest and southwest edges while less in the country's central and eastern regions.

In northern Xinjiang, snowmelt floods occurred relatively infrequently, but with large magnitudes, while around the Qilian Mountains, snowmelt floods were more frequent but of smaller magnitudes. The longest duration of snowmelt floods was observed in the Kashgar and Yarkant rivers, according to the study.

Based on a comprehensive assessment of hazard, exposure, vulnerability and adaptability, high and very high-risk areas account for 15.5 percent of the region.

Therefore, it is urgent to enhance monitoring and early warning systems, and implement corresponding disaster prevention and mitigation measures in large mountainous basins in the region, said Xu.

The study results have been published in the journal Geography and Sustainability.