Comparison of Multi-Year Reanalysis, Models, and Satellite Remote Sensing Products for Agricultural Drought Monitoring over South Asian Countries

Abstract

The substantial reliance of South Asia (SA) to rain-based agriculture makes the region susceptible to food scarcity due to droughts. Previously, most research on SA has emphasized the meteorological aspects with little consideration of agrarian drought impressions. The insufficient amount of in situ precipitation data across SA has also hindered thorough investigation in the agriculture sector. In recent times, models, satellite remote sensing, and reanalysis products have increased the amount of data. Hence, soil moisture, precipitation, terrestrial water storage (TWS), and vegetation condition index (VCI) products have been employed to illustrate SA droughts from 1982 to 2019 using a standardized index/anomaly approach. Besides, the relationships of these products towards crop production are evaluated using the annual national production of barley, maize, rice, and wheat by computing the yield anomaly index (YAI). Our findings indicate that MERRA-2, CPC, FLDAS (soil moisture), GPCC, and CHIRPS (precipitation) are alike and constant over the entire four regions of South Asia (northwest, southwest, northeast, and southeast). On the other hand, GLDAS and ERA5 remain poor when compared to other soil moisture products and identified drought conditions in regions one (northwest) and three (northeast). Likewise, TWS products such as MERRA-2 TWS and GRACE TWS (2002–2014) followed the patterns of ERA5 and GLDAS and presented divergent and inconsistent drought patterns. Furthermore, the vegetation condition index (VCI) remained less responsive in regions three (northeast) and four (southeast) only. Based on annual crop production data, MERRA-2, CPC, FLDAS, GPCC, and CHIRPS performed fairly well and indicated stronger and more significant associations (0.80 to 0.96) when compared to others. Thus, the current outcomes are imperative for gauging the deficient amount of data in the SA region, as they provide substitutes for agricultural drought monitoring.

Observed Changes in Meteorological Drought Events during 1981–2020 over Rwanda, East Africa

“…In some areas, the severity and frequency of droughts can lead to water scarcity conditions, whereas overexploitation of existing water resources can worsen the effects of droughts [85]. Various studies demonstrate that drought is among the most dangerous distractive disaster in the current warming world [86][87][88][89], impacting natural resources such as sustainable water and environment, agriculture, ecology, and biodiversity [79,[90][91][92]. The present study shows that drought occurrences are increasing, which may lead to severe impacts on water resources and agriculture management in a country with a high population density like Rwanda.…”

Projected Changes in Socioeconomic Exposure to Heatwaves in South Asia Under Changing Climate

“…In 1998, 2015, India experienced severe HWs resulting in more than 2,000 deaths, and these HWs events are considered the most deadly events worldwide (Aadhar & Mishra, 2019; Mishra et al., 2017). Similarly, Pakistan has witnessed many severe HWs events that have claimed thousands of lives across the country (Khan et al., 2019; Shahzaman, Zhu, Bilal, et al., 2021; Shahzaman, Zhu, Ullah, et al., 2021). The persistence of extremely hot days and nights is evident mostly over arid to semiarid zones; hence these zones are at a greater risk to HWs (Saleem et al., 2021).…”

Biochar enhances wheat crop productivity by mitigating the effects of drought: Insights into physiological and antioxidant defense mechanisms

“…[ 47 ] in wheat and Brassica napus under water-stress, respectively, which is in consistent with our findings. Plant cell dehydration and reduced turgidity cause altered protoplasmic activities, which reduce cell division and result in lower plant height [ 48 , 49 ]. When compared to the control, the higher application of BC during a drought dramatically boosted plant height of wheat.…”