Why poisonous dust is being formed in Salton Sea
California, US: In the past 25 years, the Salton Sea, the state's most polluted inland lake, has lost a third of its water. According to recent studies, the Colorado River's flow is declining, which is the cause of that decrease.
The quantity of salt and chemicals in the remaining water has rapidly grown as the lake dries up, which has led to a mass extinction of fish and birds, including endangered species. The salty, toxic water that covers the dry lakebed turns it into dust, which causes breathing issues for the locals.
"It is an environmental catastrophe," said Juan S. Acero Triana, UCR hydrologist and lead author of a new study focused on understanding water movement on and below Earth's surface near the Salton Sea, a research field called hydrology. The National Science Foundation's Innovation funded the study at the Nexus of Food, Energy and Water Systems, or INFEWS, program.
There are several theories as to why the water levels are steadily dropping. Some attribute the lake's drying up to climate change and heat. Some people think that agriculture might be to blame. Less water enters the Salton Sea as irrigation systems become more effective and crops are designed to require less water. These, according to the researchers, are not the principal factors contributing to the sea's decline.
According to UCR hydrologist and study co-author Hoori Ajami, "Less water is flowing from the Colorado River into the Sea, and that is driving the problem." The methodologies employed to arrive at this conclusion and its publication in the journal Water Resources Research.
The Salton Sea is an example of an endorheic lake where water enters the lake but does not flow out to any tributaries. The researchers took into account all significant mechanisms affecting this water balance. Due to the combined effects of global warming and water diversion for agricultural and industrial purposes, endorheic lakes all over the world have been diminishing in recent decades at what the researchers call an "alarming" rate.
The researchers developed a hydrologic model to analyse the Salton Sea's decline, taking into account all local factors that affect the lake's water balance, such as climate, soil types, land slope, and plant growth.
The model's geographic information contained information about the Sea itself, as well as the watershed around it, the streams that flow into the lake, and the land area that drains into those streams.
The transboundary basin between California and Baja California Norte on the US-Mexico border made it challenging to collect data for the model, and parties may have been unwilling to contribute information that could affect previously acquired water rights. However, UCR researchers were able to recreate long-term water balance dynamics and pinpoint decreased Colorado River flows as the primary reason for the Salton Sea's decreasing by using publicly accessible data and data mining tools.
However, Acero Triana noted that it is not totally obvious which factor--reductions in California's water allocation levels or the drying up of the Colorado River--is to blame for the fall in Colorado River water levels.
Despite this unresolved uncertainty, the researchers contend that the study should convey to water management organisations and policymakers that the Salton Sea watershed belongs to the Colorado River basin.
A watershed-centric strategy taking into account surface and groundwater resources is required to discover a solution because the sea is typically seen as a separate system, according to Ajami. "As the environmental concerns associated with a diminishing Sea increase, all stakeholders must cooperate to reduce the risk."