Narkhed-Pandurna Critical Zone Observatory (NP CZO) is set up by National Environmental Engineering Research Institute (CSIR-NEERI), Nagpur, at Madar river watershed (137 sq. km). The NP CZO is bounded between Latitude 21˚25' 30" to 21˚33' 30" and Longitude 78˚ 28' 30" to 78˚ 38' 30" and located at the administrative border of Nagpur (Maharashtra) and Chindwara (Madhya Pradesh) districts in central India.
The watershed has Semi-arid climatic conditions and has seven flows of Basalts overlying the Gondwana. The drainage network in the watershed is dendritic, and it has ephemeral natural streams up to sixth order. The elevation in the watershed ranges from 380m amsl to 620m amsl with an average annual rainfall of 837mm, and the temperature ranges from 12.2 °C to 41.4°C. More than 80% of the watershed is intensively managed with agri-horticultural activities, and groundwater is the primary source of irrigation. Due to excessive groundwater withdrawal in the last few decades to meet the irrigation demand (groundwater Stage development >100.2% in 2020), the watershed faces frequent crop failure and water scarcity.
The baseline data collection is being carried out since March 2018 to understand the structure and dynamics of the critical zone. The study area's hydro-geochemical characterization, water budgeting, and classification and quantification of vegetation patterns are continuously monitored. Remotely sensed data, geophysical tools, onsite monitoring and field observations are conducted for the physical characterization of the critical zone. It includes the mapping and assessing mean regolith thickness, geological features, landuse/landcover pattern, mapping of soil type. The hydro-geochemical characterization includes qualitative and quantitative assessment of water, soil, and rocks.
At present, the N-P CZO is instrumented with: Sap flow system, Automatic Weather Station, soil moisture sensors, and continuous data is recording at every 15-minute interval. The temporal changes in the water table and groundwater quality are measured by a network of observation wells (46 nos). The carbon sequestration potential of forest species and their biodiversity is calculated. The classification and quantification of vegetation along with detailed mapping and aerial extent of various vegetation patterns and agricultural practices in the study area is being carried out regularly. Root water uptake modelling and sensitivity analysis of soil hydraulic parameters were conducted to understand the complete water balance for irrigation of orange orchards and the most influencing soil hydraulic parameter.
The project is presently focusing on the following research questions:
How is groundwater-dependent vegetation (GDVs) affecting Groundwater and Vegetation Dynamics? And how is the presence of GDVs affecting groundwater availability in the earth's critical zone?
What are the ecosystem services of GDVs?
Use of Geophysical tools in deciphering root depths and movement of sap flow in trees