The design and performance evaluation of drip irrigation systems are essential for achieving optimal efficiency and uniformity. This study emphasizes the importance of assessing existing designs and the various factors influencing their performance. With the advancement of computer technology, numerical models have become invaluable in the hydraulic design of irrigation systems. This research employs IRRICAD software to simulate flow and pressure characteristics and compares these simulations with experimental data to validate accuracy. Key findings include the validation of IRRICAD for its accuracy, features, and accessibility; the critical role of selecting correct parameters for simulation models; and a comprehensive understanding of irrigation performance measures crucial for evaluating overall system efficiency. The study introduces a novel methodology for evaluating drip irrigation systems by collecting pressure and dripper flow data and inputting them into the IRRICAD program to diagnose and identify issues related to zone performance and system flows. These issues are typically manifested through variations in pressure and dripper flow rates. The study also involves determining the dripper exponent of flow, which is then reentered into the program for thorough system evaluation. This study evaluates the hydraulic performance of a drip irrigation system designed for the University of Sulaimani using IRRICAD software, laboratory testing of drippers, and field measurements. The model's outputs were compared with actual measurements to validate its accuracy. Laboratory tests indicated a mean flow variation of 0.028, which is favorable, and a mean coefficient of variation (CV) of 0.013, which is considered excellent. Field measurements for hydraulic performance were conducted at a constant operating pressure, assessing parameters such as the Emitter Discharge Coefficient of Variation (Vqs), Hydraulic Design Coefficient of Variation (Vhs), Emitter Performance Coefficient of Variation (Vpf), Emission Uniformity (EU), Christiansen Uniformity Coefficient (CU), and Statistical Uniformity of Emitter Discharge (Us).The results revealed that CU, EU, and Us fall within the excellent classification, with CU and EU exceeding 90% efficiency. The Vqs value is below 0.1, indicating excellent performance, while Vhs falls within the 10-20% range and Vpf within the 5-10% range, both indicating very good performance. Additionally, a comparison of pressure values between field measurements and two data sources from the IRRICAD software showed minimal differences: 0.313 for Field Observations (OPF), 0.315 for IRRICAD Observed Points (OPI), and 0.324 for the IRRICAD Summary Report (SRI). These minimal differences suggest that IRRICAD's estimates closely align with field observations. To validate the IRRICAD model, the mean squared error (MSE), mean absolute error (MAE), and root mean squared error (RMSE) were calculated. For discharge values, the errors were 2.29, 1.09, and 1.48, respectively, while for pressure values, the errors were 0.08, 0.26, and 0.28, respectively. This comparison demonstrates that using pressure values for evaluating and improving irrigation system performance with IRRICAD software yields better accuracy and less deviation from modeled values, particularly when pressure-compensating drippers are employed. The study's insights into the design and performance evaluation of drip irrigation systems underscore the importance of accurate simulation models and comprehensive performance assessments in achieving optimal irrigation system performance. The experimental results show that the IRRICAD software closely aligns with field data, demonstrating minimal discrepancies and confirming its utility for accurate performance evaluation. Furthermore, the research explores different scenarios to understand the impact of varying parameters on system performance. The findings highlight the importance of accurate pressure and flow measurements, as discrepancies in these can significantly affect the system's efficiency. The study also identifies common issues such as excessive pipe velocity and nozzle pressures outside the specified operational range, suggesting areas for system optimization. This study's insights into the design and performance evaluation of drip irrigation systems emphasize the critical role of accurate simulation models and comprehensive performance assessments. The novel method proposed for assessing irrigation systems, validated through rigorous experimental comparison, provides a robust framework for future research and practical applications aimed at enhancing irrigation efficiency and sustainability.
