三江源地区生长季降水特征对土壤水分的影响  

Effect of precipitation in growing season on soil moisture in the Sanjiangyuan region

作　　者：李璠[1,2] 颜亮东 赵梦凡[1,2] 张娟 LI Fan;YAN Liangdong;ZHAO Mengfan;ZHANG Juan(Institute of Qinghai Meteorological Science Research,Xining 810001,China;Qinghai Key Laboratory of Disaster Prevention)

机构地区：[1]青海省气象科学研究所,西宁810001 [2]青海省防灾减灾重点实验室,西宁810001

出　　处：《干旱区资源与环境》2022年第6期121-128,共8页Journal of Arid Land Resources and Environment

基　　金：中央级公益性科研院所基本科研业务费专项(IDM2018011);国家自然科学基金(41861049)资助。

摘　　要：降水是影响土壤水分的直接因素,对三江源地区生态保护工程具有重要意义。文中采用烘干法测定2003-2018年4-10月每隔10天土壤重量含水量,并结合逐日降水资料,统计分析了三江源地区降水量级和降水频次对土壤水分的影响。结果表明:土壤水分与降水的季节变化均表现为三段式,4月上旬至7月上旬,降水量级增加,无降水日数减少,土壤水分增加,7月中旬至8月中旬,降水平稳变化,土壤水分减少,8月下旬至10月下旬,降水量级减少,无降水日数增加,土壤水分增加。对不同深度土壤水分而言,降水量每增加1mm, 10cm土壤重量含水率增加0.47%,随着土层加深,增速逐渐变大,20cm和30cm的增加速率分别为0.46%/mm、0.41%/mm,无降水日数每增加1d, 10cm土壤重量含水率减小3.8%,随着土层加深,减速逐渐变小,20cm和30cm的减小速率分别3.3%/d、2.3%/d,对不同时段而言,降水在5月下旬至8月下旬对土壤水分的影响表现为显著相关性(P<0.01),对不同地区而言,降水对高寒草原栗钙土土壤水分的影响大于高寒草甸的其他类型土壤,且对低海拔地区土壤水分的影响大于高海拔地区。摸清降水对土壤水分的影响,科学指导三江源地区生态工程工作意义重大。Precipitation is a direct factor affecting soil moisture, so it is important for ecological engineering in the Sanjiangyuan region.In this paper, soil weight moisture capacity was measured every 10 days from April to October during 2003-2018. Combined with daily precipitation data, the effects of precipitation grade and frequency on soil moisture in the Sanjiangyuan region were statistically analyzed. The results showed that the seasonal variation of soil moisture and precipitation showed a three-stage pattern.From early April to early July, the precipitation grade increased, the non-precipitation day decreased and the soil moisture increased. From mid-July to mid-August, the precipitation changed smoothly and the soil moisture decreased. From late August to late October, the precipitation grade decreased, the non-precipitation day increased and the soil moisture increased. For the soil moisture at different depths, the soil moisture content at 10 cm increased by 0.47% when the precipitation increased by 1 mm. With the deepening of soil layer, the growth rate gradually increased. The increase rates of 20 cm and 30 cm were 0.46%/mm and 0.41%/mm. The soil moisture content at 10 cm decreased by 3.8% when the number of days without precipitation increased by 1 d. With the deepening of soil layer, the deceleration gradually decreased. The decrease rates of soil moisture at 20 cm and 30 cm layers were 3.3%/d and 2.3%/d, respectively. For different periods, soil moisture change was significantly correlated to precipitation change from late May to late August(P<0.01). For different regions, the influence of precipitation on moisture of chestnut soil in alpine steppe was greater than that of other types of soil in alpine meadow, and the influence in lower altitude areas was greater than that in higher altitude areas. Finding out the influence of precipitation on soil moisture has great significance to guide scientifically the ecological engineering work in Sanjiangyuan area.

关 键 词：三江源地区 降水格局 土壤水分 

分 类 号：S152.7[农业科学—土壤学]