Estimation of potential recharge through direct seeded and transplanted rice fields in semi-arid regions of Punjab using HYDRUS-1D

Abstract

The present study utilizes soil water balance and HYDRUS-1D for estimating and predicting potential recharge in groundwater declining region of central Punjab, respectively. A field experiment was conducted at Punjab Agricultural University, Ludhiana. Two treatments viz direct-seeded (DSR) and transplanted rice (TPR) with three replications, were sown/transplanted during kharif season of 2019. The amount of water applied through rainfall/irrigation was recorded and bottom flux was measured using frequency domain reflectometry (FDR) and then predicted using HYDRUS-1D in order to assess potential groundwater recharge which was further compared with deep percolation determined using soil water balance. The performance of the HYDRUS-1D was evaluated using RMSE, NSE, and R 2 and found to be performing well. The paired t-test (t = 1.28 and t = 1.30 for TPR and DSR, respectively) was found to be non-significant at P = 0.05 which showed the correspondence between predicted and estimated parameters. The percentage change between estimated and predicted potential groundwater recharge was found to be 0.7% and 2.32% in TPR and DSR, respectively. The study revealed that there was 9% water saving and 14.6% more deep percolation (cumulative bottom flux) in DSR as compared to TPR that may potentially contribute to groundwater recharge.

Influencing Factors and Evaluation of Groundwater Ecological Function in Arid/Semiarid Regions of China: A Review

“…For example, the preferential flow theory has solved the heterogeneity of water transport in vadose zones, while the lysimeter experiment method is well-suited for field-scale application [79]. The combination of various methods [80], such as in-situ monitoring using the zero flux surface method and the numerical simulation techniques, can better describe the water transport process in the vadose zone. Nevertheless, the research on the transformation mechanism of water flux between vegetation-vadose zone-groundwater remains limited.…”

Effect of Alternate Wetting and Drying (AWD) and Other Irrigation Management Strategies on Water Resources in Rice-Producing Areas of Northern Italy

“…The coupling of hydrological, crop and water management models is becoming crucial in addressing the effects of new irrigation practices in agricultural areas, as it allows the study of the different phenomena involved in such complex systems [14,15]. 'Physically-based' models (e.g., HYDRUS-1D and 2D/3D, SWAP) [16][17][18][19], developed to simulate water movements in the unsaturated soil on the basis of the Richards equation [20] are generally applied at the field level, while more 'conceptual' models (e.g., APEX, SWAT/SWAT+) [4,[21][22][23], usually based on a bucket approach, are implemented to simulate irrigation planning and management over large areas in a distributed or semi-distributed mode, as they require less data and computational effort. In traditional rice-growing areas, where there is a strong interconnection between irrigation and groundwater dynamics, deep percolation from paddy fields and canal networks recharges the water table, which in turn contributes to water discharges in rivers, irrigation networks and natural springs, thus increasing water availability for agricultural areas further downstream and at the same time reducing irrigation water requirements in fields with shallow groundwater conditions.…”