HYDERABAD: Indiscriminate expansion of irrigated areas and cultivation of water-intensive crops in the catchment area of Himayatsagar, which lead to excessive use of groundwater, are diminishing precious rainwater harvesting efforts.
Researchers at ICRISAT Development Centre (IDC) came to this conclusion after conducting a study on historical data on climate, land use, watershed structures and groundwater levels in the catchment areas of Himayatsagar.
The study revealed that between 1980 and 2007, there was a significant decline in the streamflow (3.03 mm/year) and groundwater levels (0.22 m/year) in Himayatsagar (HS) catchment area.
Groundwater storage has declined at a rate of 5 mm/y due to the impact of land use changes while hydrological structures resulted in a decline of 2 mm/y, making the impact of human intervention more than that of hydrological structures with about 2.5 times the higher impact on groundwater.
Speaking to TNIE, Dr Rajesh Nune, Hydrologist, IDC said: “We have studied the catchment area of Musi river and Krishna river basin and Himayatsagar. The drainage networks in the catchment area of Himayatsagar have been occupied either as crop farms or for real estate.”
“Due to the availability of water and free electricity provided by the government, the farmers are cultivating water-intensive crops like paddy, sugarcane, maize and vegetables than the annual rainfall they receive,” he said.
“Most of the farmers have dug borewells to supply water to the field at different depths. This is leading to a reduction of groundwater levels. As Telangana has a lot of rock formations, the groundwater rises and also depletes faster.”
“According to future studies based on this model, there might be a need to change the crop calendar as well because the State is expected to witness the highest rainfall in September, instead of August, by the end of this century owing to the rising temperatures and climate change,” he opined.