Research on the Influence of Small-Scale Terrain on Precipitation

Abstract

Terrain plays an important role in the formation, development and distribution of local precipitation and is a major factor leading to locally abnormal weather in weather systems. Although small-scale topography has little influence on the spatial distribution of precipitation, it interferes with precipitation fitting. Due to the arbitrary combination of small, medium and large-scale terrain, complex terrain distribution is formed, and small-scale terrain cannot be clearly defined and removed. Based on the idea of bidimensional empirical mode decomposition (BEMD), this paper extracts small-scale terrain data layer by layer to smooth the terrain and constructs a macroterrain model for different scales in Central China. Based on the precipitation distribution model using multiple regression, precipitation models (B0, B1, B2 and B3) of different scales are constructed. The 18-year monthly average precipitation data of each station are compared with the precipitation simulation results under different scales of terrain and TRMM precipitation data, and the influence of different levels of small-scale terrain on the precipitation distribution is analysed. The results show that (1) in Central China, the accuracy of model B2 is much higher than that of TRMM model A and monthly precipitation model B0. The comprehensive evaluation indexes are increased by 3.31% and 1.92%, respectively. (2) The influence of different levels of small-scale terrain on the precipitation distribution is different. The first- and second-order small-scale terrain has interference effects on precipitation fitting, and the third-order small-scale terrain has an enhancement effect on precipitation. However, the effect of small-scale topography on the precipitation distribution is generally reflected as interference.

Contribution of Climatic Factors and Human Activities to Vegetation Changes in Arid Grassland

“…The possible reason is limited precipitation in arid and semi-arid regions, which may be the main factor limiting vegetation growth [63]. It is also possible that the southwestern region is connected to the Loess Plateau region, and some studies have shown that topography significantly influences the spatial distribution of precipitation [64].…”

Severe Precipitation Phenomena in Crimea in Relation to Atmospheric Circulation

“…Significantly more frequently, SWPp are observed in mountainous region of Crimea (224 cases in Aj-Petri) and SCC (106 cases in Yalta); however, precipitation is observed in the steppe region of the peninsula extremely rarely (only seven cases in Razdolnoe). One can put such a contrast in the number of cases of SWPs down to an influence of terrain relief on precipitation formation [25,26]. In particular, the precipitation depends on the height of the slopes, the horizontal dimensions of the uplands, the orientation, and the openness in relation to the moisture-carrying flow and general conditions of weathering.…”

Factors Affecting the Spatiotemporal Variation of Precipitation in the Songhua River Basin of China

“…They also observed that heavy rainfall days exhibited a decrease before 2013, and the decreasing trend was alleviated after 2013. Given the spatiotemporal variability of mean and extreme precipitation climatology, several studies have analyzed the reasons for the observed differences [21][22][23][24][25], including geographical factors [26][27][28][29], global warming [30][31][32], circulation factors [11,[33][34][35][36], and urbanization [37,38].…”