湖北省侵蚀性降雨时空分布特征

Temporal and Spatial Distribution Characteristics of Erosive Rainfall in Hubei Province

侵蚀性降雨是南方红壤区剧烈水蚀的原动力,因此分析其时空分布特征对于区域内水土保持相关研究有十分重要的意义。选取国家气象数据网站数据(2014—2020年)、结合水土保持监测站点人工观测数据(2016—2019年),对湖北省4个水土保持分区24个监测站点的侵蚀性降雨标准及降雨侵蚀力进行了分析、计算,并用克里格模型进行插值。结果表明:湖北省整体的降雨侵蚀力从西北到东南逐渐增加,与降雨量的空间分布表现出相同特征,同时降雨量与侵蚀性降雨量表现出高度协同性。全省年平均降雨量813.88~1 590.15 mm(2014—2020年),多年平均年降雨量为1 201.98 mm,多年平均侵蚀性年降雨量为603.53 mm。多年平均侵蚀性年降雨量占多年平均年降雨量的50.21%,多年平均侵蚀性降雨频次(天数)为14次,平均次侵蚀性降雨量为46.88 mm。根据多年平均半月侵蚀力计算结果分析可知,湖北省全省多年平均年降雨侵蚀力值为6 650.10 MJ·mm/(hm^(2)·h·a)。省内年内降雨侵蚀力时间分布基本符合正态分布。4—10月总降雨侵蚀力值为6 202.10 MJ·mm/(hm^(2)·h·a),占全年降雨侵蚀力值的93.26%。研究结果有助于指导省内水土保持规划,并对不同时段针对性防治水土流失具有一定的参考意义。

Erosive rainfall is the driving force of severe water erosion in the red soil region of south China. Therefore, it is of great significance to analyze its spatial and temporal distribution characteristics for the study of regional soil and water conservation. In this paper, the erosive rainfall standard and rainfall erosivity of 24 monitoring stations in four soil and water conservation regions of Hubei Province were analyzed and calculated based on the national meteorological data website data and the artificial observation data of soil and water conservation monitoring stations, and the Kriging model was used for spatiotemporal interpolation. The results show that the rainfall erosivity of Hubei Province increased gradually from northwest to southeast, which showed the same characteristics as the spatial distribution of rainfall;annual average rainfall of the whole province ranged from 813.88 mm to 1 590.15 mm, the average annual rainfall was 1 201.98 mm, the annual average erosive rainfall was 603.53 mm;The annual average erosive rainfall accounted for 50.21% of the annual average rainfall, the annual average frequency of erosive rainfall was 14;the average single erosive rainfall was 46.88 mm;according to the calculation results of annual average half month erosivity, the average annual rainfall erosivity of Hubei Province was 6 650.10 MJ·mm/(hm^(2)·h·a);The temporal distribution of annual rainfall erosivity in Hubei Province basically conformed to normal distribution;the total rainfall erosivity from April to October was 6 202.10 MJ·mm/(hm^(2)·h·a), accounting for 93.26% of the annual rainfall erosivity. These results are helpful to the planning of soil and water conservation in the province, and it has a certain guiding significance for the prevention and control of soil erosion in different periods.