Agricultural Drought Risk Assessment in Southwest China

Abstract

Drought disasters jeopardize agricultural production and are expected to become more serious in the context of global climate change. However, in China, little attention has been paid to evaluating agricultural drought risk in humid areas (such as in Southwest China), which have also been affected by severe drought in recent years. In this work, we used the Standardized Precipitation Evapotranspiration Index (SPEI), which was computed from high-quality monthly precipitation and temperature data from 92 rain-gauge stations across Southwest China, to study the drought characteristics (e.g., intensity, duration, and frequency) and their decadal variations from 1960 to 2017. Furthermore, we applied a widely accepted conceptual model that emphasizes the combined role of drought hazard (calculated by the intensity and frequency of drought) and agricultural drought vulnerability (integrated with high-resolution soil properties, climate, topography, irrigation, and gross domestic product) to conduct a spatial assessment of agricultural drought risk at a 1-km grid scale. The results revealed that drought has become more serious and frequent in Southwest China, especially since the 2000s. About 27.4% of the agricultural area has been exposed to an extremely high risk of drought, 33.5% to a high risk, 22.5% to a moderate risk, and 16.6% to a low risk. The extreme agricultural risk areas were located mainly in northeastern and southeastern Chongqing, southwestern Sichuan, northeastern and eastern Guizhou, and central and eastern Yunnan. Our findings highlighted that more attention should be paid to the agricultural drought risk in humid regions of China. Furthermore, this work could set the stage for policy makers and practitioners to take measures to reduce the agricultural drought risk in Southwest China.

Analysis of Agricultural Drought Risk Based on Information Distribution and Diffusion Methods in the Main Grain Production Areas of China

“…As the drought continued to develop, the correlation coefficient became lower. Zeng ZQ et al concluded that the main meteorological reason for the high frequency of extreme drought was the combined effect of abnormal decreases in rainfall and continued increases in temperature [29]. Wang HJ et al indicated that drought in China was mainly concentrated around the changes in light and moderate drought and wind speed, precipitation, temperature were the most sensitive variable in northwest China, while in south China it was precipitation, followed by wind speed, temperature, relative humidity, and sunshine duration [44].…”

“…In recent years, there has been an increasing trend that emphasizes the combined role of drought hazard and drought vulnerability to conduct a risk assessment. For example, Zeng et al assessed agricultural drought risk by combining the role of drought hazard (calculated by the intensity and frequency of drought) and agricultural drought vulnerability in southwest China [29]. David et al presented a method for obtaining indices and maps of vulnerability to drought in Mexico; indices and maps were based on a set of socioeconomic and environmental indicators [46].…”

“…Linlin Fan et al used Copulas to quantify the curve between drought and water scarcity in the Metropolitan Areas [30]. Wang et al established an integrated drought risk model based on the relation curve of drought joint probabilities and drought losses of multi-hazard-affected bodies [31].In summary, most of the previous studies have considered the hazard factor and socio-economic factors when assessing drought vulnerability [23][24][25][26][27][28][29]. Some studies performed on the vulnerability curve, which is more accurate due to qualifying of the relationship between crop yield and drought [30,31].…”

Spatiotemporal Variations of Meteorological Droughts and the Assessments of Agricultural Drought Risk in a Typical Agricultural Province of China

“…The SPEI runs at a monthly time step and requires the monthly P and PET as inputs. Similar to SPI, the SPEI must be associated with a specific timescale to reflect the impact of previous water deficits on current drought status [19,21,23,24]. The term drought timescale refers to the time lag that typically exists between the start of water shortage and the identification of its consequences [32].…”

“…Here, we only focus on the assessment of agricultural drought risk. Some studies have evaluated agricultural drought risk in China [23][24][25]. These studies provide valuable insights into where agricultural production is more likely to be affected.…”