Lo studio rileva che l'estrazione della sabbia fluviale sta superando la riserva naturale

A study published in the Reviews of Geophysics journal reveals that river sand mining is occurring at rates far exceeding the ability of natural processes to replenish the resource, posing a significant threat to ecosystems and human settlements worldwide. Researchers from Nanyang Technological University, Singapore (NTU Singapore), conducted a comprehensive analysis drawing on 411 peer-reviewed studies spanning nearly five decades, highlighting the urgent need for improved management practices. On December 5, 2025, scientists aboard a survey boat on the Tien River near Long Khanh Island, Vietnam, employed advanced acoustic and bathymetric tools to map the riverbed and evaluate the effects of sand extraction. Their findings underscored the alarming pace at which sand is being removed from rivers, often surpassing natural sedimentation rates by multiple times. This imbalance leads to deepened riverbeds, weakened banks, reduced groundwater levels, and deteriorated water quality, effects that ripple through both environmental systems and human communities. The research team, comprising 26 international experts in fields such as river sand mining, sediment transport, deltas, ecology, and sustainability, examined case studies from diverse regions including Southeast Asia, South Asia, China, Africa, Europe, and South America. Their work revealed that the consequences of unregulated sand mining extend beyond physical alterations to river landscapes. It threatens critical infrastructure, disrupts aquatic habitats, and jeopardizes agricultural lands, fisheries, and the livelihoods of millions of people living in riverine and deltaic zones. Associate Professor Edward Park, leading the NTU team, emphasized that while sand is vital for urban expansion and infrastructure development, especially in rapidly growing economies like Singapore and Southeast Asia, its over-extraction poses severe risks. He called for a shift in governance approaches, advocating for the integration of satellite monitoring, field surveys, and sediment-budget analyses to guide sustainable extraction practices. Such methods could enable authorities to identify suitable locations for mining, determine allowable quantities, and safeguard ecologically sensitive areas. Despite the clear implications of their findings, the study noted a persistent data gap in many countries. Only 27% of the reviewed studies provided quantitative assessments of sand extraction volumes, while 24% explored the drivers behind demand. A majority—69%, focused instead on the ecological and socio-economic impacts of sand mining. This disparity highlights the challenges faced by policymakers in addressing the issue effectively. Without accurate data, governments struggle to implement targeted interventions or enforce regulations. In an effort to bridge this knowledge gap, Park’s team developed a satellite-based method to monitor sand mining activities in the Mekong River region. Applying this technique, they estimated that over 50 million metric tonnes of sand were extracted annually, significantly exceeding the legally allowed limit of approximately 20 million metric tonnes. More than 60% of this volume was reportedly mined illicitly, indicating widespread non-compliance with existing regulations. The study underscores the complexity of managing river sand resources, particularly in regions experiencing rapid urbanization and infrastructure development. As global demand continues to rise due to expanding populations and increasing construction projects, the pressure on river systems intensifies. Addressing these challenges requires coordinated efforts among governments, scientific institutions, and local communities to ensure that sand extraction aligns with ecological resilience and long-term sustainability.