Author(s): Yang Mingzhi; Jing Huan; Xu Jijun

Linked Author(s): Jijun Xu

Keywords: Soil Moisture Condition Index; agricultural drought; relative soil moisture; irrigation; Beijing-Tianjin-Hebei region

Abstract: Irrigation was an important factor affecting the development of agricultural drought, but it had not been taken into account in the Soil Moisture Condition Index (SMCI), which led to a large deviation in drought monitoring. In this work, the water balance equation in the SMCI was revised by an irrigation threshold method. The two SMCI indices were used to describe the dry-wet replacement process in the Beijing-Tianjin-Hebei region during 1993~2012, and the results of simulated soil moisture values and drought judgement right rates were compared by referring to the real drought conditions based on the measured soil moisture data. The results of comparative analyses were as follows: (1) The annual average relative error of the modified soil water balance equation was 5.1%, while that of the original equation was 26.2%, which was significantly higher than that of the modified equation. (2) The drought judgement right rates of the modified SMCI index were higher than those of the original SMCI index. The annual judgement right rate of the original SMCI index was 52.2%, but that of the modified SMCI index was 61.9%, which was 9.7% higher than that of the original SMCI index. Therefore, the modified SMCI index not only effectively improved the accuracy of soil moisture simulation results, but also had higher monitoring accuracy of agricultural drought, which had obvious advantages in drought assessment in the large-scale irrigated farming areas. This work was of great significance to guide drought prevention and risk management in large-scale agricultural areas.

DOI: https://doi.org/10.64697/IAHR-APD2024_P261

Year: 2024