 |
| Titel |
Drought evolution characteristics and precipitation intensity changes during alternating dry–wet changes in the Huang–Huai–Hai River basin |
| VerfasserIn |
D. H. Yan, D. Wu, R. Huang, L. N. Wang, G. Y. Yang |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 7 ; Nr. 17, no. 7 (2013-07-23), S.2859-2871 |
| Datensatznummer |
250018941
|
| Publikation (Nr.) |
 copernicus.org/hess-17-2859-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| Abrupt drought–flood change events caused by atmospheric circulation
anomalies have occurred frequently and widely in recent years, which has
caused great losses and casualties in China. In this paper, we focus on
investigating whether there will be a rainfall occurrence with higher
intensity after a drought period in the Huang–Huai–Hai River basin.
Combined with the Chinese climate divisions and the basin's DEM (digital
elevation model), the basin is divided into seven sub-regions by means of
cluster analysis of the basin meteorological stations using the
self-organizing map (SOM) neural network method. Based on the daily
precipitation data of 171 stations for the years 1961–2011, the changes of
drought times with different magnitudes are analyzed, and the number of
consecutive days without precipitation is used to identify the drought
magnitudes. The first precipitation intensity after a drought period is
analyzed with the Pearson-III frequency curve, then the relationship between
rainfall intensity and different drought magnitudes is observed, as are the
changes of drought times for different years. The results of the study
indicated that the occurrence times of different drought levels show an
overall increasing trend; there is no clear interdecadal change shown, but
the spatial difference is significant. (2) As the drought level increases,
the probability of extraordinary rainstorm becomes lower, and the frequency
of occurrence of spatial changes in different precipitation intensities vary.
In the areas I and II, as the drought level increases, the occurrence
frequency of different precipitation intensities first shows a decreasing
trend, which becomes an increasing trend when extraordinary drought occurs.
In the area III, IV and V, the probability of the different precipitation
intensities shows an overall decreasing trend. The areas VI and VII are
located at the mountains with high altitudes where the variation of different
precipitation intensities with the increase in drought level is relatively
complex. (3) As the drought times increase, areas I, II and V, which are
located on the coastal and in the valley or basin, are vulnerable to extreme
precipitation processes; areas III, IV, VI and VII are located in the inland
area, where heavier precipitation is not likely to occur. (4) The local
rainfall affected by multiple factors is closely related with drought
occurrence. The characteristics between the first rainfall intensity after a
drought period and different drought magnitudes (or drought occurrence times)
are preliminarily examined in this paper, but its formation mechanism still
requires further research. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|