Journal of Geo-information Science >
An Analysis on the Spatio-temporal Variability of Precipitation in Dianchi Basin
Received date: 2014-09-26
Request revised date: 2014-11-14
Online published: 2015-04-10
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Precipitation is one of the most important factors of climate, and the analysis of spatio-temporal variability of precipitation is a primary way to understand the formation and development of regional water resources. Furthermore, the trend of the spatio-temporal variability of precipitation directly affects the structure, service function and spatial distribution of various ecosystems. Based on the monthly precipitation data from 1953 to 1987 and from 2007 to 2012, using regression analysis, anomaly, spatial autocorrelation, Mann-Kendall test, Co-kriging interpolation considering the influence of elevation (DEM), and cross-validation, we conducted an analysis on the spatial and temporal variability of precipitation in Dianchi basin. The results are stated in the following sections: (1) from 1953 to 1987, the precipitation tends to increase in spring, autumn and winter, but decrease in summer; from 2007 to 2012, however, the precipitation tends to decrease in all seasons except in autumn. (2) An increasing trend was discovered in the annual precipitation (11.12mm/10a) during the 35 years, and it generally revealed a fluctuation pattern of “down-up-down”; however, a downward trend of precipitation is significant from 2007 to 2012. (3) The indices of Moran’s I are negative during the 35 years, which reveals a main negative correlation that is different from the period of 2007 to 2012. The analysis of LISA shows that the spatial heterogeneity tends to change with respect to the geographical location and time. (4) The spatial distribution of annual rainfall is similar to the rainfall during the rainy season, which is a cross-distribution indicated by two high-value and two low-value areas. In addition, the spatial extent of heavy rain events is decreasing, and the spatial extent of light rain events is increasing.
LIU Jiaxu , LI Lijuan , LI Jiuyi , WANG Zhiyong . An Analysis on the Spatio-temporal Variability of Precipitation in Dianchi Basin[J]. Journal of Geo-information Science, 2015 , 17(4) : 451 -461 . DOI: 10.3724/SP.J.1047.2015.00451
Fig. 1 Terrain map of Dianchi basin图1 滇池流域地形图 |
Fig. 2 Time series of precipitation and climate tendency rate in each season图2 不同季节降水量与气候倾向率 |
Fig. 3 The M-K test figures from 1953 to 1987图3 1953-1987年间M-K检验 |
Fig. 4 Accumulative anomaly curves of precipitation in each season图4 各季节降水量累计距平曲线 |
Fig. 5 Characteristic curves of precipitation for annual and rainy season图5 年和雨季降水特征曲线 |
Tab. 1 Statistics of universal Moran's I表1 全局Moran's I统计表 |
时段 | 指标 | 春季 | 夏季 | 秋季 | 冬季 | 雨季 | 年均值 |
---|---|---|---|---|---|---|---|
1953-1987 | Moran's I | -0.232 | -0.191 | -0.167 | -0.187 | -0.212 | -0.223 |
Z值 | -0.580 | -0.267 | 0.009 | -0.329 | -0.734 | -0.741 | |
2007-2012 | Moran's I | 0.023 | 0.536 | 0.287 | 0.120 | 0.552 | 0.438 |
Z值 | 0.605 | 5.801 | 3.266 | 1.099 | 4.979 | 5.592 |
Fig. 6 The LISA analysis schematic of annual and rainy season precipitations图6 雨季和年均值的LISA值分析 |
Fig. 7 Rainfall map in Dianchi basin obtained by interpolation of Co-kriging图7 滇池流域Co-kriging雨量插值图 |
Tab. 2 Characteristic value of Co-kriging model表2 Co-kriging模型特征值 |
时段 | 指标 | 平均值 | 均方根 | 标准平均值 | 标准均方根 | 平均标准误差 |
---|---|---|---|---|---|---|
1981-1987 | 年平均值 | 1.20 | 134.1 | -0.01563 | 1.1416 | 129.2 |
1981-1987 | 雨季均值 | -0.83 | 117.3 | -0.05498 | 1.2274 | 110.7 |
2007-2012 | 年平均值 | -0.34 | 108.3 | -0.03382 | 1.2911 | 87.8 |
2007-2012 | 雨季均值 | -0.57 | 82.6 | -0.03380 | 1.2485 | 71.0 |
The authors have declared that no competing interests exist.
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