The main focus has been on watershed management, water budgeting and source water protection for water quantity, quality and non-point source pollution. Processes of soil erosion, infiltration, irrigation and drainage. Modelling and management of non point source pollution. This includes modelling of infiltration, surface and subsurface drainage, overland flow, soil erosion by water, sediment transport, sediment and pollutants (nitrogen, phosphorus and pathogens) transport through vegetated areas along the stream, quality of surface and tile drainable water as affected by manure, nutrients and pesticides. Water harvesting by rainfall runoff inducement, seepage control and evaporation reduction. The present research focus is on water budgeting, variable source area hydrology, change in precipitation and temperature regimes due to climate change and their impact on agricultural water management, the development of tools for source water protection, watershed management and design of vegetative filter strips based on the characteristics of upland watershed or characteristics of runoff water to manage stream water quality, and for estimation of Total Maximum Daily load (Pollutant loads a water body can accept with impairment). I am involved in the development advisory tools such as Phosphorus Index and Nitrogen Index, to identify appropriate practices to manage agricultural water quality.
Watershed System Capacity: Development of tools to assess water quantity and quality and identify opportunities to improve it in watersheds including consideration of the watershed system capacity to absorb contaminants, as well as the quality of water relative to its use by various sectors and techniques to identify sources of contaminants, evaluation of social acceptability (barriers) and economic feasibility. Development of BMPs to reduce the risk of soil degradation, pollution of drainable water and development of improved tools and decision support systems, for source water protection. Development of educational and technological transfer tools to improve watershed management by rural agro-food industries. Most noticeable research includes the development of modelling tools (GAMES/GAMESP, GDVFS, AGNPS-GDVFS tool kit), the procedure for evaluation of hydrology and nonpoint source pollution models, temporal variability in soil erosion and hydraulic characteristics, experimental procedures for variable source area hydrology, targeting and multi-tier approaches for watershed management, use of waste water in agriculture and simple tools for identification of climate change. In addition, he has been providing technical assistance to extension agents, officials in the public and private sectors in planning, design, development, management and evaluation agricultural management systems related to irrigation, drainage (both surface and sub-surface), soil erosion and non-point source pollution control.
Water Quantity: This work focus on the development of water resources in the arid and dry land regions of India by rainfall runoff inducement, seepage control and evaporation reduction in earthen rural reservoirs estimation of rural and agricultural (irrigation and livestock) water demand and design of water distribution systems. Water quality research is also related to water problems in arid areas including the use of domestic waste water rich in surfactants in irrigation and its impact on soil quality. The other work on water quantity focused on the assessment of various components of water budget (surface water and ground water) and their temporal variability.
Water Quality: The focus of my water quality work has been on sediment, phosphorus, Nitrogen, Pesticide and pathogens from rural and agricultural point and nonpoint sources. I have been involved in the development of tools, applicable at the farm, field and agricultural watershed for the identification of sources of runoff, ground water recharge and pollution, their contribution to the flows and water quality at the watershed outlet or to the reservoir, selection of BMP for the improvement of water quality to meet water demand, development of remedial strategies and monitoring programs. At present, my research is focusing on the development of tools for the identification of variable source (runoff generating and ground water recharge areas), design of vegetative filter strips along the stream based on the characteristics of the upland runoff (originating from non-point and distributed rural point sources). The water quality indicators being evaluated are sediment, phosphorus, nitrogen and coliform bacteria. The new directions being includes development of system capacity for a water body for a particular pollutant without impairment of water body. The present focus is on phosphorus, nitrogen, pesticide and pathogens. In the future the focus will be extended to bio-aerosols, hormonally active compounds, antibiotics and heavy metals. I have been involved in the development management models for farm planning and agricultural watershed planning.