Krishna River Basin

Humans derive a variety of benefits from rivers, and the interconnection between river systems and human civilizations is known since ages. Large-scale anthropogenic and natural perturbations affect river (basins), which in turn, often have negative impacts on humans. Indian Peninsular rivers (e.g. the Krishna, Kaveri and the Godavari) bear significance across regional and global domains. Concern on closing of the Krishna river basin has brought forward the issue of water allocation amongst the user states. Hence, it is imperative to have crucial understanding of the geology, climate, rainfall, water resources, geomorphology, soil types and structure of the Krishna river basin. Krishna ranks as fifth largest river basin in India with a catchment area of ~2.6 × 10⁵ km². The river traverses a length of ~1400 km across the states of Maharashtra, Karnataka and Andhra Pradesh, before draining into the Bay of Bengal. The geology of the basin is dominated by basalts and crystalline rocks with alluvium, lateritic soils as minor components. It has about thirteen major tributaries (the Bhima and the Tungabhadra are the two largest) and several small-to-large-scale reservoirs for irrigation and/or hydropower generation schemes (e.g. Nagarjuna Sagar and Srisailam). The climate of the region is mostly semi-arid and dry except for humid regions along the Western Ghats. Soils in the basin are generally shallow in depth, and they belong to the type Entisols, Alfisols and Vertisols (black soils for cotton and sugarcane). The major cultivations of the basin are rice, sugarcane and oil seeds. Concerns are raised about shrinkage of the basin, frequent emergence of extreme events such as floods and degradation of water quality of the Krishna and its tributaries. Despite no major annual rainfall variation, observation of large-scale decrease in water discharges in both upper and lower reaches of the basin has stressed the need of management and allocation of water resources in the basin. Flooding in the recent years, in 2006 and in 2009, highlights the role of various human activities that might have contributed to the causes of flooding. Significant actions need to be taken to reduce the socio-economic losses such extreme events bring into the KRB. Water quality issues have also been reported by several workers, resulting mostly from discharges from the industrial towns such as Pune, Satara, Kurnool and Vijayawada. In order to minimize the effect caused by anthropogenic perturbations, the need is to pursue the recommendation proposed by experts (engineers, management specialists, geologists, economists, agricultural scientists, water quality chemists, government experts, etc.). Humans need to extract the socio-economic benefit from a river (basin); however, it should come with greater accountability to preserve the basin.