Assessment of Soil Properties and Groundwater Dynamics in Parts of Shiwalik Piedmont and Alluvial Plains of North-Western India: Using Hydrogeological and Geospatial Techniques
摘要
The interface between soil and water is pivotal for groundwater recharge, particularly in our study area comprising recharge and discharge zones within the piedmont Shiwalik region and the alluvial area. With an annual average rainfall of 880 mm, major soil types include sandy soils in recent floodplains, newer alluvial regions, and loamy soils in the Shiwalik Piedmont zone. Infiltration studies at 12 locations revealed varying capacities, with infiltration rates exceeding 50 mm/h in sandy soils of newer alluvial areas, ranging from 10 to 50 mm/h in the Shiwalik piedmont zone, and approximately 10 mm/h in older alluvial areas with loamy soils. Analysis of soil samples collected from 14 locations within 1 m below ground level (m bgl) indicated a dominant presence of sand, accounting for approximately 71% of soil composition, along with clay mixed with silt (28%) and a small fraction of slime (1%). These soil deposits resulted from paleo-tractive currents, displaying graded suspension characteristics in the study area (i.e parts of Yamuna Nagar district, Haryana state, India). The lithological data analysis revealed an unconfined aquifer extending up to 140 m bgl, with isopach (granular zone thickness) ranging widely from less than 40 m to over 100 m. Groundwater utilization through tube wells was extensive, with 95% of 8736 tube wells in operation, predominantly distributed in the southwest or southern parts of the study area. Isopach conditions, variations in hydraulic conductivity, and higher yields influenced this distribution pattern. Tube wells in this area exhibited high discharge rates (> 1000 liters per minute (lpm)) compared to those in the Shiwalik Piedmont zone (< 1000 lpm yields). Annual groundwater recharge was estimated at 274 mm/year in the Shiwalik piedmont zone and 326 mm/year in the alluvial plains. Groundwater levels, both shallow and deep, were influenced by hydrological recharge and discharge conditions, with groundwater flow observed in a northeast-to-southwest direction, driven by variations in hydraulic gradients. Therefore, the interaction between soils and groundwater is intricately linked, with each influencing the other and playing a crucial role in groundwater recharge.