Agriculture is the single largest contributor to India’s economy and the most important factor that drives this sector, is the availability of water resources. Prof. D. Nagesh Kumar of Indian Institute of Science is working on finding better ways of managing irrigation sources through Remote Sensing data.
Remote sensing is to collect information aboutan object’s size, shape or character without being in contact with it.Satellite based Remote Sensing methods are used in sectors like agriculture, mapping, disaster management, meteorology, land use planning, water resource management, mineral exploitation etc.
The primary source of water for India, the monsoons, are highly uncertain. This results in droughts in some regions and famines in others. However, there are other sources like reservoirs, ground water, tanks, ponds and other small storage structures. Remote sensing technology can be of great help in managing such unsteady and diverse water resources.
In a recent interview, Prof. Nagesh Kumar talks about his exciting journey in the field of Remote Sensing and his learnings about its various tools that evolved through time.
The most common applications of Remote Sensing in agriculture and irrigation management are crop area estimation, crop condition estimation (to know whether the crops are stressed due to lack of water or suffer from pest infection) and crop discrimination (to know what crops are being grown like paddy, sugarcane etc.). Furthermore, water requirement of specific crops and crop yield can also be estimated.
Dr. Nagesh Kumar has carried out several case studies to assess the above-mentioned applications. One of his achievements is assessing the Bhadra Irrigation System in Karnataka. In another case study on Rajolibanda Diversion Scheme in the drought-prone region Mahaboobnagar in Andhra Pradesh; he analysed the status of Irrigated Cropping and the demand and supply status of water. The team suggested that the farmers use less water intensive and drought resistant crops.
Further applications of Remote Sensing in irrigation management includes Irrigation Advisory Services (IAS) . They provide aid to farmers in improving irrigation efficiency and thus optimizing agricultural productivity. They also schedule the irrigation program through the available information from Remote Sensing data on crop type, agro- meteorology and soil moisture availability, etc. However, the information generated through Remote Sensing and GIS is quite technical. This creates a gap in its efficacious use.“If the people involved in Irrigation Management are properly trained, it is easily possible for them to communicate the information to the local farmers in simpler terms” says Dr. Nagesh.
The recent droughts in Maharashtra have questioned the future of water resources of India. They are a grim portrayal of the dearth of effective irrigation management practices in our country. India is among the least ranked countries in irrigation efficiency, i.e. amount of agricultural productivity per unit amount of water used. But on a positive note, quoting Dr. Nagesh “Through the use of Remote Sensing and GIS, it is possible to estimate the severity of impending drought at each location (at village or finer level). Proper crop management (by using drought resistant crops and less water intensive crops) irrigation management can be improved substantially.”
Remote Sensing holds immense potential for better assessment and management of our natural resources. However, during cloud cover in monsoons, the Optical Satellite Remote Sensing techniques fail to give any effective information. In order to overcome such setbacks, Dr. Nagesh, and his team is planning to use advanced Microwave Remote Sensing technology which can easily penetrate the clouds and make observations. In future, they intend to use techniques like Hyperspectral Remote Sensing to finely discriminate among the crops and help with crop condition assessments.
Dr Nagesh Kumar is the Chairman of the Centre for Earth Sciences, Professor, Department of Civil Engineering, and Associate Faculty, Interdisciplinary Centre for Water Research, Indian Institute of Science. He can be reached at +91 80 2293 2666.