Analysis of Dry Wheat Yield Trend using Drought Identification Indicators in North Khorasan Province

Abstract

Aim: Understanding the impact of drought on agricultural yields is a pivotal concern in food security. Consequently, this study utilized the drought identification index (RDI) and the effective drought identification index (eRDI), which integrates effective precipitation in its computations, to assess the output of dryland wheat in the North Khorasan province. Material & Method: Four distinct methods were applied to incorporate effective precipitation, encompassing the approaches of the FAO and USBR, as well as two techniques adopted from the USDA. These metrics were applied using monthly rainfall and temperature data from meteorological stations within the province. A comparative analysis was conducted to evaluate the wheat production performance across various periods, and the correlation coefficient between these methods and wheat production yield was determined. Additionally, the yield trend of dryland wheat in different cities was studied using the Mann-Kendall test and Sen's estimator. Finding: Minimal disparity is among the diverse methods for determining effective precipitation. Although the eRDI method displayed superior outcomes, the correlation coefficient analysis indicated that the production performance of each city is more sensitively affected by the precipitation values within specific time scales. Conclusion: Similar outcomes to those of the investigated trends indicated a notable adverse trend in dryland wheat production at the Bojnord and Esfarayen stations, alongside an insignificant positive trend in other cities. Innovation: This study's innovation lies in applying effective precipitation within the eRDI index and comparing various experimental methods to ascertain it for integration into the equations of the said index. Given its unique climatic conditions and critical role in the nation's wheat production, this province assumes significant importance. However, limited research has been conducted on agricultural drought in this region thus far, underscoring the need for further studies to bolster regional food security.

Keywords

• time scale
• wheat production
• jump
• trend
• food security