济南市1970—2016年降雨侵蚀力时空变化

摘要

降雨侵蚀力是反映降雨引起土壤侵蚀能力大小的关键指标,对水土流失的监测、预报及治理具有重要的意义.本研究利用济南市48个雨量站1970—2016年日降雨数据,采用Mann-Kendall非参数趋势检验和突变检验、小波周期分析(Wavelet Analysis)、泰森多边形及ArcGIS逆距离加权插值(IDW,Inverse Distance Weighted)等方法分析了济南市降雨侵蚀力的时空变化特征.结果表明:(1)济南市多年平均降雨侵蚀力是3774. 91 MJ·mm·hm-2· h-1·a-1,年际变化整体呈现不显著的增长趋势,存在着3～6年、7～11年和19～25年3类不同尺度的周期变化规律,在1980年和1990年附近发生突变;(2)降雨侵蚀力年内分布不均,多集中在6—9月,春季和夏季表现为微弱的上升趋势,秋季和冬季表现为下降趋势;(3)降雨侵蚀力与降雨量的空间分布规律相似,中部和南部地区明显高于北部和西南地区,东西部差异不明显,且大部分区域的年降雨侵蚀力表现为不显著增长的趋势;(4)各雨量站的变异系数(Cv)范围是0. 28～0.49,且多数雨量站1990—2016年平均降雨侵蚀力比1970—1989年增加10%以上;(5)不同地形区的降雨侵蚀力与降雨量都存在较好的相关关系,而与海拔的相关关系不显著.%Soil erosion has been recognized as one of the most serious ecological environment issues, catching the growing concerns over years. Rainfall is naturally responsible for soil erosion. The rainfall erosivity is a sensitive reflection of potential soil erosion induced by precipitation. It is of great significance to the monitoring, forecasting and control of soil erosion. In this study it collected rainfall data from 48 rainfall stations in Jinan City from 1970 to 2016, and used the Mann-Kendall non-parametric trend test and mutation test, wavelet analysis, and ArcGIS inverse distance weighted (IDW) interpolation methods to investigate the temporal and spatial characteristics of erosive erosivity in Jinan City. Results showed that:(1) The average annual rainfall erosivity for 1970-2016 in Jinan City was 3774.91 MJ·mm·hm-2·h-1·a-1. The interannual variation as a whole presented non-significant growth trend. In the 3～6 years, 7～11 years and 19～25 years, there were 3 types of periodic variation with different scales, and changes occurred abruptly around 1980 and 1990. (2) Rainfall erosivity was unevenly distributed through a year, mostly concentrated from June to September. The rainfall erosivity showed a slight upward trend in spring and summer, and declined in autumn and winter. (3) The spatial distribution of rainfall erosivity was consistent with the pattern of precipitation. In the central and southern regions they were significantly higher than those in the north and southwest regions, but there was no significant difference between the east and the west, and the annual rainfall erosivity in most regions showed no significant increase. (4) The variation coefficient of rainfall erosivity for all rainfall stations was between 0.28 to 0.49, and as comparing with the average annual rainfall erosivity during 1970 -1989, it increased by more than 10% during 1990 -2016 at most of the rainfall stations. (5) There was a good correlation between rainfall erosivity and precipitation in different terrain areas, but there was no significant correlation with elevation.