宁夏黄土丘陵沟壑区降雨侵蚀力特征分析  

Characteristics analysis of rainfall erosivity in the loess hilly and gully region of Ningxia

作　　者：王友胜[1] 杨志 刘冰[1] 马文涛 任正龑 辛艳 赵阳[1] 解刚[1] WANG Yousheng;YANG Zhi;LIU Bing;MA Wentao;REN Zhengyan;XIN Yan;ZHAO Yang;XIE Gang(China Institute of Water Resources and Hydropower Research,State Key Laboratory of Watershed Water Cycle Simulation and Regulation,100048,Beijing,China;Soil and Water Conservation Monitoring Station,Ningxia Hui Autonomous Region,750000,Yinchuan,China)

机构地区：[1]中国水利水电科学研究院,流域水循环模拟与调控国家重点实验室,北京100048 [2]宁夏回族自治区水土保持监测总站,银川750000

出　　处：《中国水土保持科学》2022年第4期34-41,共8页Science of Soil and Water Conservation

基　　金：国家重点研发计划项目“山洪水沙耦合致灾机制研究”(2019YFC1510701);国家自然科学基金“西北黄土区半月尺度降雨侵蚀力模型研究”(42107375),“极端降雨下的黄河典型流域水沙关系演变及其影响因素研究”(51979290);宁夏回族自治区水利科技项目“宁夏水土保持监管关键技术与多维度平台建设研究”(SBZZ-J-2020-13),“黄河宁夏段水土保持适宜治理度与措施格局优化对策研究”(SBZZ-J-2021-12),“宁夏回族自治区水土保持监管机制研究”(SBZZ-J-2021-13)。

摘　　要：为深入了解宁夏黄土丘陵沟壑区降雨和降雨侵蚀力的特点和规律,基于宁夏黄土丘陵沟壑区第二副区王洼小流域35 a间1207次降雨的过程观测资料,采用统计学方法研究次降雨侵蚀力、24个半月降雨侵蚀力年内分布特征及3种日侵蚀力模型在该区域的适用性。结果表明:1)王洼小流域降雨整体以小雨强降雨事件为主,<10 mm的次降雨事件占70.51%,≥50 mm的次降雨事件仅占1.49%;2)年侵蚀力主要是由大降雨事件贡献,次降雨量≥25 mm的侵蚀力占总侵蚀力值的67.00%;3)侵蚀力具有明显的年内集中分配特征,第12~16个半月侵蚀力占年侵蚀力值的83.51%,第15个半月侵蚀力年内最高,占年侵蚀力的31.68%,是潜在水土流失较大的时段。该阶段的地表扰动活动宜进一步加强水土保持措施的落实,减少水土流失的发生;4)在开展侵蚀力计算时,优先推荐在降雨过程资料基础上的EI_(30)计算;在缺少降雨过程资料时,冷暖季模型在年侵蚀力和半月侵蚀力预测的效果更佳。研究结果可为区域水土流失防治提供科学参考。[Background]Rainfall erosivity reflects the impact of rainfall on soil erosion,which is an important factor in USLE(Universal Soil Loss Equation),RUSLE(Revised Universal Soil Loss Equation)and CSLE(Chinese Soil Loss Equation).In-depth study of the characteristics of intra-annual distribution and inter-annual variation of rainfall erosivity is of great significance to improve the accuracy of matching between vegetation cover factor and rainfall erosivity in the corresponding time period,especially for the loess hilly and gully region of Ningxia,where the ecological environment is inherently sensitive and fragile.The few detailed rainfall data of long time series in the loess hilly and gully region of Ningxia,restricted revelation of the characteristics of rainfall erosivity in 24 half-months,and the soil and water control in the loess hilly and gully region of Ningxia demands applicability of models based on daily rainfall data.[Methods]Based on the detailed rainfall data of 1207 rainfall events in Wangwa small watershed in the second subarea of the loess hilly and gully region of Ningxia,the EI_(30) of each rainfall event and the 24 half-month rainfall erosivities were calculated using the method of EI_(30) accumulation,and the characteristics of 24 half-months rainfall erosivities were clarified.Furthermore,three models of YIN Shuiqing cold and warm season model,ZHANG Wenbo model and CREAMS model,were used to validate the performance of three models on predicting rainfall erosivity at semi-month and annual scale,respectively.[Results]1)The overall rainfall in Wangwa small watershed was dominated by light rainfall events,with<10 mm individual rainfall events accounting for 70.51%,and≥50 mm individual rainfall events accounting for only 1.49%.2)The annual erosivity was mainly contributed by heavy rainfall events.The erosivity with a secondary rainfall of≥25 mm accounted for 67.00%of the total erosivity.3)The erosivity had obvious characteristics of centralized distribution within the year.The erosivity in the

关 键 词：降雨 侵蚀力 黄土丘陵沟壑区 宁夏 

分 类 号：S157.1[农业科学—土壤学] P426.6[农业科学—农业基础科学]