表层岩溶带土岩结构对降雨-径流响应特征的影响  

Effect of soil-rock structures on the characteristics of rainfall-runoff responses in epikarst zones

作　　者：徐子凡 陈喜 刘维翰[1] 刘皓 张志才[2] XU Zifan;CHEN Xi;LIU Weihan;LIU Hao;ZHANG Zhicai(Institute of Surface-Earth System Science,School of Earth System Science,Tianjin University,Tianjin 300072,China;College of Hydrology and Water Resources,Hohai University,Nanjing,Jiangsu 210098,China)

机构地区：[1]天津大学地球系统科学学院表层地球系统科学研究院,天津300072 [2]河海大学水文水资源学院,江苏南京210098

出　　处：《中国岩溶》2024年第4期863-875,共13页Carsologica Sinica

基　　金：国家自然科学基金项目(42030506)。

摘　　要：碳酸盐岩在溶蚀作用下形成的表层岩溶带,其上层土壤特性和厚度以及下覆裂隙大小和分布控制降雨入渗、蒸散发和地下径流过程。而不同土岩结构对水文过程的影响尚不明晰。文章构建3种典型土岩结构(薄层石灰土-石灰岩块型、薄层石灰土-白云岩碎石型、厚层土壤-石灰岩碎石型)土柱试验装置并进行观测,通过对比分析,揭示不同土岩结构的产流能力和径流响应特征的差异。结果表明:土岩结构对水平衡有显著影响。厚层土壤(85 cm)极大增加了蒸发量,其产流能力较小,表现为形成地下径流所需的降雨阈值大和形成的径流总量小。相比之下,薄层土壤(20 cm)具有较大的产流能力。当薄层土壤下覆为白云岩碎石时,相比于下覆为石灰岩岩块,碎石表面滞留水分能力较强,导致蒸发损失增加和径流量减少。此外,土岩结构还显著影响降雨-径流响应特征:对于厚层土壤,其对径流的调蓄能力强,洪峰流量显著减小,初始径流和洪峰流量的响应时间延长,但这种延长的幅度随着降雨事件的雨量和强度的增加而减小;对于薄层土壤,其对径流的调蓄能力较弱,其中对于下覆石灰岩岩块结构,裂隙率低、导水性强,在小降雨下容易入渗并形成较大的洪峰;而下覆白云岩碎石结构储水能力较大,在大降雨下,有利于入渗水积蓄,从而形成较大的洪峰。This study was conducted at the Puding Karst Ecosystem Research Station,Chinese Academy of Sciences.Three square columns were set up in the experiment to simulate different soil-rock structures.Each column has a crosssectional area of 1 square meter and a height of 2 meters.The station is located in a warm,humid mid-subtropical monsoon climate zone,with an average annual rainfall of 1,315 mm and an average annual temperature of 15.1℃.The soil-rock structures in this area are diverse,mainly comprising limestone,dolomite,and associated soils.This study aims to reveal the impact of complex soil-rock structures on hydrological processes in the karst areas of Southwest China.In this study,physical models of three typical soil-rock structures(Column a:thin limestone soil over limestone blocks;Column b:thin limestone soil over dolomite gravel;Column c:thick soil over limestone gravel)were constructed,the underground runoff processes formed by natural rainfall were observed,and the water balance and runoff response characteristics under different soil-rock structures were compared.The research findings provide scientific insights into better understanding of the transformation and effective utilization of water resources in karst areas.Three square columns were used as experimental devices in this study to simulate different types of soil-rock structures(combinations of limestone,dolomite,overlying lime soil,and yellow soil).During natural rainfall events,evaporation and runoff of the soil columns with different soil-rock structures were compared and analyzed.Various methods of statistical analysis were employed to quantitatively assess the impact of these structures,revealing the hydrological processes of the complex soil-rock structures in epikarst zones.The main results are as follows.(1)Water Balance:As soil thickness increased(20 cm,23 cm,85 cm),evaporation increased and runoff decreased.Dolomite gravel(Column b)retained more water than limestone blocks(Column a),leading to higher evaporation and lower runoff.Seas

关 键 词：岩溶 土岩结构 地下径流 水量平衡 径流响应特征 

分 类 号：P333[天文地球—水文科学]