基于M-K检验和地统计分析的沂蒙山区降雨侵蚀力时空变化趋势研究

Spatiotemporal Variation Trend Analysis of Rainfall Erosivity in Yimeng Mountain Region Based on M-K Test and Geostatistical Analysis

[目的]分析降雨侵蚀力的时空变化特征,为区域土壤流失监测和水土保持工作提供数据支撑。[方法]利用沂蒙山国家级水土流失重点治理区及其周边71个雨量站1980—2018年逐日雨量资料,综合运用冷暖季日雨量公式、M-K检验、地统计插值等方法,对降雨侵蚀力的时空变化趋势进行分析。[结果](1)降雨量和侵蚀性降雨量成中度月集中性(FI>53,CI>0.17),降雨侵蚀力具有高度月度集中性(FI=399.88,CI=0.24),年内变化曲线呈单峰形,峰顶位于7—8月;(2)研究区多年平均降雨量743.52 mm,多年平均降雨侵蚀力3 656.87 MJ·mm/(hm^(2)·h·a),空间上呈现北低南高,西低东高的分布趋势;(3)降雨侵蚀力年际波动属中等变异,总体呈不显著增长趋势。空间上在西北部上升趋势显著(z>1.96),在南部少量区域呈不显著的下降趋势(z<0)。[结论]降雨侵蚀力增加会导致区域水土流失风险提升,因此,应针对区域降雨侵蚀力增加区域,加强水土流失综合防治工作,实现生态环境与经济社会的可持续发展。

[Objective]The spatial and temporal variation characteristics of rainfall erosivity were analyzed in order to provide data support for regional soil loss monitoring and soil and water conservation.[Methods]Based on daily rainfall data from 71 rainfall stations in Yimeng Mountain region and its surrounding areas from 1980 to 2018,the temporal and spatial variation trend of rainfall erosivity was analyzed using the daily rainfall formula,M-K test,geostatistical analysis,and so on.[Results]①Rainfall and erosive rainfall had a moderate monthly concentration(FI>53,CI>0.17),rainfall erosivity had a high monthly concentration(FI=399.88,CI=0.24),and the annual variation curve was unimodal,with the peak occurring from July to August.②The annual average rainfall in the study area was 744 mm,and the annual average rainfall erosivity was 3657 MJ·mm/(hm^(2)·h·a),showing a spatial distribution trend of low in the north and high in the south,low in the west and high in the east.③The interannual variation of rainfall erosivity was moderate,and the overall trend was not significant.Spatially,there was a significant upward trend in the northwest(z>1.96)and an insignificant downward trend in the south(z<0.05).[Conclusion]The increase in rainfall erosivity will increase the risk of regional soil and water loss.Therefore,comprehensive prevention and control of soil and water loss should be strengthened so as to realize the sustainable development of the ecological environment and economic society.