Geophysical prospecting for potential Groundwater resources to access yield for industrial use, Betamcherela, Andhra Pradesh, India
Country:India Region: Kurnool, Andhra Pradesh Period: 2016 Commodity: Groundwater
The investigation was aimed at finding pockets with potential ground water resources in a hard rock terrain in Vempalle formation under Cuddapah supergroup wherein in rock units mainly comprised of quartzite, chert, basic intrusive & banded iron formation. In such kind of terrain ground water is expected only in restricted zones running through fractures in the rock. Marking zones with presence of clay is also an important cue for conditions holding the groundwater. Hence, the project entailed the following,
- Electrical Imaging to generate 2D Resistivity & IP Imaging in order to map the sub-surface up to 130 m below ground level in a resolution of 05 m.
- Process & interpret 2D resistivity sections to mark zones of possible moisture content; correlate these sections with one derived from IP results & identify the possible clay zones.
- Generate a comprehensive plan of the ground water regime prevalent in the area & recommend location for drilling of bore-well for testing & extraction.
2D IP survey was conducted using ARES -II equipment manufactured by GF Instruments, Czechoslovakia with transmitter power of 850 Watt. 04 Lines of 300 m length (each) were planned & data acquired up to a depth of 130 m from surface level.
The results were interpreted from presence of fracture zone & potential ground water regime along with possible clay zones at depth ranging between 80 m to 130 m. The interpretation prompted to recommend water holes at 02 locations. Post drilling one of the holes yielded xxx of water thus proving efficiency of the investigation conducted.
Conceptual Storm Water Management for installation of Solar Park near Nambula Pulakunta, Andhra Pradesh
Country: Anantapur, Andhra Pradesh Region: Kurnool, Andhra Pradesh Period: 2018 Commodity: Hydrological Studies
The storm water management report for NP Kunta Mega Solar Power Project was prepared with the aim at assessing parameters influencing the local environment which may have a consequence as an outcome of the developmental project and plausible ways to mitigate the same.
Important environmental factor such as rainfall pattern & its intensity, drainage runoff, & critical conditions of runoff evaluated based on past events and rainfall pattern, erosional factors attributed by land cover and terrain conditions, geology were incorporated in the studies.
Monthly rainfall data recorded by Indian Meteorological Department (IMD) for a span of 37 years, short term rainfall events, diurnal data from Global Weather station etc were evaluated. CARTOSAT – 1 based DEM Elevation data from National Remote Sensing Agency (NRSC) was used for drainage & catchment studies. The study also included Land cover (LANDSAT-8 satellite data) topographic data, soil data and geological information.
Analysis was done in GIS platform. Basin & sub-watershed delineation were done using Soil & Water Assessment Tool (SWAT). Runoff estimation, flow velocity, peak discharge, time of concentration are generated in GIS for the watershed. Statistical analysis is used to derive intensity of rainfall for the period 1979-2014 (global weather data) and intensities for return periods for 02, 05, 10, 25, 50, 100 and 150 years were derived to generate Design storm spanning between 15 minutes to 600 minutes.
Taking cognizance of all the stated parameters & numerous derivate, a regulated area has been earmarked as area which shall not be available for development. Rest of the area is expected not to adversely impact in the post development scenario inside the project site.
Hydrological analysis for surface runoff and identification of accumulation zones, IIT Palakkad Campus, Kerala, India
Country: India Region: Palakkad, Kerela State Period: 2018 Commodity: Hydrological Studies
Hydrological studies encompassing under-construction IIT Palakkad campus was undertaken with the objective to assess conditions in the watershed influencing the campus area for an efficient management of the hydrological regime in terms of potential flooding and inundation.
Watershed analysis included delineation of catchment limits, simulation of drainage conditions, assessment of runoff & other related parameters and ultimately, estimation of the peak volume & discharge expected in the watershed based on IMD data well as CWC published report. The approach involved Geographic Information System (GIS) based analysis and hydrological assessment for volume & discharge using HEC-HMS. Terrain parameters such as elevation, slope & land use, and hydrological parameters such as soil erosivity, flow accumulation, runoff, peak discharge, time of concentration, velocity of overland flow was also analysed in spatial domain.
Critical volume of runoff at the campus outlet is estimated at 15,28,000 m3 at a peak discharge of 10.3 m3/sec in HEC-HMS software. The values are estimated based on peak rainfall event of 170 mm in July 1992, which is also the value of 25 years return period. Estimating the downstream drainage capacity at 15 m3/sec, evacuation time of the discharge is estimated at 28 hours. During peak discharge, a volume of about 240,000 m3 of access water will be retained within the campus in a 24-hour period. This volume is likely to inundate about 12-hectare area up to contour level between 105 & 104 m, which may affect a part of the academic building area as well. Since, management of hydrological regime is necessary to avoid undue circumstances of flooding & inundation, appropriate measures in maintaining natural flow, retaining buffer of drainage, diversion of drainage, erection of retention structures to accommodate access volume and velocity breaks, appropriate sluice designs for efficient evacuation of water etc have been recommended. In order to accommodate the estimated excess volume, water accumulation ponds in 02 positions have been erected in the entry & exit of the main drainage alignment while designed drainage pathways have been reinforced to withstand in peak discharge event.
