Spatial and Temporal Variations of Drought in Inner Mongolia, China

Abstract

Drought has become an important natural disaster, affecting the development of Inner Mongolia, as an important animal husbandry region in China. In this study, the characteristics and trends of the Inner Mongolia drought are thoroughly analysed by calculating the standardised precipitation evapotranspiration index (SPEI) at different time scales, based on monthly precipitation and temperature data from 40 national meteorological stations in Inner Mongolia from 1958 to 2019. Subsequently, the area drought intensity (ADI), which is a comprehensive evaluation indicator for evaluating drought intensity within the region, is proposed, taking into account the effects of the persistent drought on drought intensity. The results show that drought has increased during this period, with a remarkable increase in the frequency and the area of drought. The areas with stronger drought intensity are mainly located in the west, north central, and the western area of the east. Since 2000, March to October are identified as drought-prone months and April is characterised as the month with the highest frequency of drought. The inflection points of SPEI and climate conditions both appeared in 1990s and it is speculated that the increase in drought may have been caused by excessive temperature rise. The frequency, coverage area, and continuous duration of drought have increased greatly after climate mutation in this region. According to the changes in the spatial distribution of the ADI and frequency of drought occurrence, the drought-stricken areas shifted from the southeast to the northwest after climate mutations. The findings from this study provide a theoretical basis for the drought management of Inner Mongolia.

The Study of Drought in Future Climate Scenarios in the Huang-Huai-Hai Region

“…When the standard statistical variable is Z c > 0, this indicates that the time series has a rising trend. When it is Z c < 0, this indicates that the time series has a decreasing trend [21].…”

“…The Mann-Kendall (MK) trend test is a non-parametric method [21], which has a wider test range, and the required data does not need to follow a specific distribution. It is commonly used to examine the variation trend of a data series with time [39].…”

“…However, SPI calculation only considers the precipitation impact on drought, disregarding changes caused by the temperature rise. Due to different calculation focuses of various drought indexes, there will be deviations in evaluation results [21]. Yao et al [22] found that drought severity was mainly affected by evapotranspiration in regions with substantial evapotranspiration changes in Xinjiang, China.…”

Characteristics of Agricultural Droughts and Spatial Stratified Heterogeneity and Dependence of Dominant Factors in Inner Mongolia Autonomous Region, China

“…Figure 3 demonstrates the ranges of mild and more serious droughts in different seasons in the Inner Mongolia Autonomous Region from 2000 to 2019 [23]. In the last 20 years, the average annual range of droughts in Subregion I fluctuated in the range of 3.33%~95.00% [24]; the range of agricultural droughts is ≥50%.…”

Assessment of Drought Indexes on Different Time Scales: A Case in Semiarid Mediterranean Grasslands

“…Generally, the SPI and SPEI time frame can be defined from 1 up to 24 months. Depending on the drought monitoring time frame, the most used time scales are the monthly, the quarterly (3-months) and the annual [20,21]. Multiple challenges have been examined through the literature regarding the multi-time-scale approach.…”