Tehseen Javed

Department of Environmental Sciences, Kohat University of Science & Technology, Kohat, 26000 KPK, Pakistan

Monitoring agricultural drought in arid regions like Pakistan's Peshawar Valley is challenging due to limited data availability. Remote sensing provides valuable data, such as precipitation, land surface temperature, normalized difference vegetation index, and relative soil moisture, for assessing drought conditions across different spatial and temporal scales. However, these parameters often fail to capture the complexity of agricultural drought and its impact on crops. Introduced a new composite drought index called the "Temperature Vegetation ET Dryness Index" (TVEDI) to address this challenge. This index builds upon the Temperature Vegetation Precipitation Dryness Index (TVPDI) by incorporating key factors like NDVI, LST, and remotely sensed evapotranspiration (ET) through advanced techniques involving 3D space and Euclidean distance calculations.

This study conducted a comprehensive analysis comparing TVPDI and TVEDI with commonly used drought indices like the standardized precipitation index (SPI) and standardized soil moisture index (SSI). Additionally, we explored their relationships with crop yield to understand how these indices represent the spatial and temporal distribution of agricultural drought in the Peshawar Valley from 1986 to 2018.

Our findings demonstrate that TVEDI surpasses TVPDI in several aspects. While both indices exhibit similar temporal patterns to the 3-month SPI and SSI, TVEDI displays a more robust correlation (correlation coefficient, r = 0.78-0.82) with these indices compared to TVPDI (r = 0.73-0.76). Moreover, when considering crop yield as a measure of crop response to agricultural drought, TVEDI shows a significant positive correlation (r = 0.60-0.80), slightly outperforming TVPDI (r = 0.30-0.48). These results underscore the effectiveness of incorporating ET into TVEDI, enabling it to capture changes in soil moisture, crop water status, and their subsequent impact on crop yield more effectively.

In conclusion, our study highlights TVEDI as a promising tool for assessing agricultural drought in data-scarce regions like the Peshawar Valley. This development is crucial for addressing climate change and promoting water-saving agriculture in arid areas, ensuring food security and sustainable farming practices.