Which of the following is/are the possible consequence/s of heavy sand mining in riverbeds? 1. Decreased salinity in the river 2. Pollution of groundwater 3. Lowering of the water-table Select the correct answer using the code given below:

1. Statement 1 is incorrect. Excessive sand mining can deepen the riverbed and potentially lead to saline water intrusion in coastal areas if the river mouth is lowered, thus increasing, not decreasing, salinity upstream. 2. Statement 2 is correct. Sand acts as a natural filter for groundwater. Removing large quantities of sand can reduce this filtering capacity, making the underlying aquifers more vulnerable to pollution from surface sources. 3. Statement 3 is correct. The riverbed sand holds water and helps recharge groundwater. Excessive sand mining removes this layer, reducing the water retention capacity of the riverbed and potentially leading to the lowering of the water-table in adjacent areas.