From April to October 2023, most of the hydrothermal conditions in the northern desertification area were conducive to vegetation growth, but the vegetation growth in Gansu, Inner Mongolia and other sand source areas was poor due to drought and the number of windy days increased, resulting in an increase in sand and dust weather in the central and eastern parts of northern China compared with the same period last year.
Abstract:In the main growing season of 2023 (April to October), most of the precipitation in the northern desertification area was less than normal and more than in 2022, and the hydrothermal conditions were conducive to vegetation growth, and the vegetation coverage was more preferred than that in the same period in 2022, but the vegetation growth deviation in most parts of Gansu and the central and western parts of Inner Mongolia was not conducive to inhibiting surface sand and dust. The comprehensive monitoring results of the ecometeorological model show that the area of height and extreme sand and dust in northern China in 2023 will decrease by 06 percentage points, but the area prone to moderate sand and dust increased by 20 percentage points, the area of mild and non-susceptible sand and dust decreased by 14 percentage points. Ground sand and dust observation statistics show that the sand and dust weather in most parts of Xinjiang from April to October 2023 is significantly less than that in the same period in 2022However, due to the poor vegetation growth and the high number of windy days in Gansu, Inner Mongolia and other sand source areas, the number of sand and dust weather days in most of the central and eastern parts of Northeast China, North China and Northwest China was 1 6 days more than that of the same period last year.
It is expected that this winter (December 2023 to February 2024), * the precipitation in the central and eastern regions, southeastern Inner Mongolia, most of North China, and the southern part of Northeast China will be more than 1 5 percent, which is conducive to suppressing the occurrence of sand and dust weather;However, the surface vegetation in the northern desertification area is in the overwintering period in winter, and the ability to inhibit sand and dust is weak. Suggestion: All localities should pay close attention to weather changes, and appropriately take measures such as crop stubble and withered grass cover to reduce surface soil exposureAt the same time, attention should be paid to artificial snow enhancement, water storage and moisture conservation, and improvement of the surface ecological environment.
1. In the main growing season in 2023, most of the northern desertification areas have more precipitation than in 2022, which is conducive to vegetation growthDrought in central and western Gansu and western Inner Mongolia is not conducive to vegetation growth
In the main growing season (April to October) in 2023, the precipitation in most of the desertification areas in the north was less than that in the same period of the normal year (Fig. 1), and the precipitation in the southwestern and eastern parts of Xinjiang, the central and western parts of Gansu, and the central, western and southeastern parts of Inner Mongolia was 3 8 percent lessThe water conditions in the northeast of Inner Mongolia, most of Northeast China, the central and southern parts of North China, the southeastern part of Northwest China, and the central and northeastern parts of the Qinghai-Tibet Plateau were better than normal. Compared with the same period in 2022, from April to October 2023, the precipitation in most parts of the north is more, of which the precipitation in most parts of central and eastern Xinjiang, the central part of Xinjiang, and the northern part of Qinghai is 3 to 2 times more, but the precipitation in the central and western parts of Gansu, the west and southeast of Inner Mongolia, and the central and southern parts of the Northeast region is less than 3 5 percent, and drought conditions occur in some areas, and vegetation growth is greatly affected.
Fig. 1 Precipitation from April to October 2023 compared with the average (left) and 2022 (right) periods.
From April to October 2023, the temperature in most of the desertification areas in northern China was slightly higher than normal, and the temperature in most parts of Xinjiang, Gansu, Inner Mongolia, most of Ningxia, the central and southern parts of Northeast China, and the eastern part of North China were 1 2 (Fig. 2), and the thermal conditions were better than normal. Compared with the same period in 2022, the temperature in most parts of the north is basically flat.
Fig. 2 Comparison of the temperature from April to October 2023 with the same period in 2022 (left) and 2022 (right).
The results of remote sensing monitoring of Fengyun meteorological satellite showed that the average vegetation coverage in northern China from April to October 2023 was generally better than that of the same period in 2022, among which, the vegetation coverage in northern and southern Xinjiang, most of **, southern and eastern Qinghai, central Shaanxi and central and northern Northeast China was 1 10 percentage points higher than that in the same period in 2022, but the vegetation growth deviation in western Xinjiang, most of Gansu, central, western and southeastern Inner Mongolia, and northern North China decreased to varying degrees (Fig. 3).
Fig. 3 Comparison of vegetation coverage in northern China from April to October 2023 compared with the same period in 2022.
2. In 2023, the height and area prone to sand and dust in the northern region will decrease slightly compared with the same period in 2022, and the sand and dust weather in most parts of Xinjiang will be significantly lessHowever, due to the poor vegetation growth and the large number of windy days in Gansu, Inner Mongolia and other sand source areas, the number of sand and dust weather increased in the central and eastern parts of northern China
The results of comprehensive monitoring of ecometeorological models show that the proportion of areas with high altitude and extremely susceptible sand and dust levels in northern China in 2023 will decrease by 06 percentage points, the proportion of areas with medium sand and dust levels increased by 20 percentage points, the proportion of areas with mild and non-susceptible sand and dust grades decreased by 14 percentage points (Figure 4). Among them, the proportion of land area in Xinjiang and Qinghai provinces (regions) with high altitude and extremely susceptible to sand and dust has decreased respectively compared with the same period in 2022. 4 and 45 percentage points, while Gansu, Ningxia and Inner Mongolia increased the proportion of the area with height and extremely sand and dust level, respectively. 8 percentage points.
Fig. 4 Proportion of land area prone to sand and dust of different grades in northern China from 2018 to 2023.
According to the statistics of ground sand and dust observations, the number of days of sand and dust weather in most parts of Xinjiang from April to October 2023 was 1 6 days less than that of the same period in 2022, and 7 10 days less in some areas, and only the southeastern and central parts of Xinjiang had more sand and dust days (Figure 5). Due to the deviation of vegetation growth from April to October 2023 in sand source areas such as central and western Gansu, western Inner Mongolia, south-central Ningxia, and northern Shaanxi compared with the same period in 2022, and the number of days of strong winds (maximum wind speed of 17m s) in most of the above areas was 1 6 days more than that in the same period in 2022. In western Inner Mongolia and other places, the number of days of sand and dust weather in most parts of northern China from April to October 2023 was 1 3 days more than that in the same period in 2022, and the number of days of sand and dust weather in central and western Inner Mongolia, western Jilin, and northern China was 4 6 days longer.
Fig. 5 The number of days of sand and dust weather in northern China from April to October 2023 compared with the same period in 2022.
Fig. 6 The number of days with maximum wind speed of 17 m s from April to October 2023 compared with the same period in 2022.
It is expected that this winter (December 2023 to February 2024), the temperature in most parts of the country will be close to the same period of the year or higher, and the phased characteristics of temperature changes will be obvious, the first winter (December 2023) will be warmer, and the cold air activity will tend to be active in the latter winter (January to February 2024), and the temperature in the northern part of Northeast China, eastern Inner Mongolia, ** and other places will be lower than that of the same period in the normal year. It is expected that the precipitation in most parts of the north this winter will be close to the normal year, and the precipitation in western Xinjiang, northeast Inner Mongolia, northern Heilongjiang, southern Shaanxi and other places will be 1 2 percent less than the same period in normal years, and the precipitation in the central and eastern regions, southeast Inner Mongolia, most of North China, and the southern part of Northeast China will be 1 5 percent more than the same period in normal years, which is conducive to inhibiting the occurrence of sand and dust weather. However, the surface vegetation in the northern desertification area is in the overwintering period in winter, and the ability to suppress sand and dust is weak, and sand and dust weather is prone to occur under the action of strong winds. Recommendations:
1. Pay close attention to weather changes, and appropriately take measures such as crop stubble and withered grass mulching to reduce surface soil exposure to reduce sand and dust on the ground.
2. Actively develop aerial cloud water resources, implement artificial rain and snow enhancement operations, increase soil moisture, reduce soil desertification, and further do a good job in ecological protection and sand and dust defense.