松花坝水源区水窖对坡耕地地表径流及N、P输出的控制效果

通过3年的野外定点监测,研究昆明松花坝水源区微区域集水系统对坡耕地地表径流集蓄及径流面源污染物输出的控制效果,结果表明:一座容量为20 m3的水窖可集蓄坡度5°～25°、水平面积128～556 m2的产流量,集水区面积随坡度增大或作物覆盖度减小而相应减小;雨季,水窖每蓄水1 m3可同时蓄积总氮、硝态氮、铵态氮、总磷、磷酸盐分别达到0.38～1.60、0.26～0.92、0.03～0.31、0.04～0.13、0.02～0.06 g,有效减少了N、P随径流的输出量;旱季,随着水窖蓄水量减少,总氮、硝态氮、铵态氮浓度增大,而到次年雨季,其浓度值又会急剧降低。

Control Effect of Rainfall Collecting Cellar in Songhuaba Water Source Area to Surface Runoff and Nitrogen and Phosphorus Output of Slop Farmland

Through three-year field point monitoring,the paper study the control effect of micro area water collecting system of Songhuaba water supply region in Kunming to surface runoff accumulation and non-point source pollutant output of slop farmland.The outcomes show that a capacity for 20 m 3 rainfall collecting cellar can store slope as 5 ° ～ 25 °,projection area of 128 ～ 556 m 2 runoff yield and water catchment area decreases with slope increase or crop coverage decrease.During the rainy season,every 1 m 3 storage of cellar cistern can also accumulate total nitrogen,nitrate nitrogen,ammonia nitrogen,total phosphorus and phosphate reach to 0.38 ～ 1.6 g,0.26 ～ 0.92 g,0.03 ～ 0.31 g,0.04 ～ 0.13 g and 0.02 ～ 0.06 g respectively,effectively reducing the output of N and P with runoff.During the dry season,the concentration of total nitrogen,nitrate nitrogen,ammonia nitrogen of runoff in cellar cistern increases.And when the next rainy season comes,the concentration of the three nitrogen will be sharply reduced.