Dynamic and dry/wet variation of climate in the potential extent of desertification in China during 1981–2010

Abstract

The potential extent of desertification in China (PEDC), composed by arid, semi-arid and dry sub-humid regions, was re-determined using a high spatial resolution meteorological dataset and by applying the Thornthwaite method, which was recommended by the UNCCD for division of dryland zones (extremely arid, arid, semi-arid, dry sub-humid zones). The dynamic and the dry/wet trends in climatic variation in the general PEDC during 1981-2010 were statistically analyzed using several different methods. The newly calculated area of the general PEDC is approximately 3.222 9 10 6 km 2 , accounting for 33.6 % of China's terrestrial. However, the results of a decadal spatial analysis indicated that the actual reduction appeared in the western region, where the general PEDC shrank to lower altitude areas. Meanwhile, the eastern border of the general PEDC was expanded to the east and southeast. Over three decades, the lower mountainous areas in northwestern Qinghai-Tibetan Plateau have experienced an obviously alternating process of drought-wetness-drought, the semi-arid and dry subhumid regions in the east of the Helan Mountains as well as the Junggar Basin have experienced an alternating process of wetness-drought-wetness, and the vast arid region in the west of the Helan Mountains has experienced a process of drought-drought-wetness. In the most recent decade, most areas, except for the major western mountainous regions, have been experiencing a wet trend, which is favorable for combating desertification.

On the long‐term changes of drought over China (1948–2012) from different methods of potential evapotranspiration estimations

“…It is a combination of the energy balance and the mass transfer methods, taking into account the effects of sunlight, air temperature, humidity and wind speed on PET (Yin et al, ; Tegos et al, ; Li et al, ). The Thornthwaite method is also widely used for PET estimation, but considers only the effect of temperature (Sun et al, ). It is suspected that using different methods to estimate PET may finally affect the derived drought severity and thus lead to biased assessment (Sun et al, ; ).…”

A 1973–2008 Archive of Climate Surfaces for NW Maghreb

“…In contrast with climate atlases, where period summaries are made before interpolation to yield a single layer of the corresponding variable (e.g., WorldClim [2]), climate archives consist of sequences of layers throughout the period at the working temporal resolution. Climate archives are used directly for topics that include, for example, observed climate change, shifting desert boundaries [3], impact dynamics of drought events [4], or relationships between climate and vegetation productivity [5]. Indirect uses involve post-processing the monthly sequences to produce a climate atlas.…”

Arid–humid variations in the summer climate and their influence mechanism in Asian monsoon margin of Northwest China during 1960–2010: A case study in the Alashan Plateau

“…Furthermore, the selected spatial scale significantly differed from most extant studies. Some studies selected entire China as the study region (Chen and Sun, 2015;Sun et al, 2015;Yuan et al, 2017), Ma and Fu (2006) focused on entire Northern China, and Hu et al (2019) focused on the arid regions of Central Asia including the five states of Central Asia and northwestern China wherein all provided important evidence for arid-humid variations in climate and its possible influence mechanism at large spatial scales. However, arid-humid variations in climate and its possible influence mechanism still necessitate a more detailed discussion at a secondary spatial scale (Huang et al, 2019) and especially in the areas of the climate transition zone such as the transition zone between Asian monsoon and westerly winds.…”