| 高原湖泊周边浅层地下水:磷素时空分布及驱动因素 |
| 摘要点击 3016 全文点击 1071 投稿时间：2021-09-23 修订日期：2021-11-04 |
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| 中文关键词 浅层地下水 磷(P) 时空分布 高原湖泊 驱动因素 |
| 英文关键词 shallow groundwater phosphorus (P) spatiotemporal distribution plateau lakes driving factor |
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| 中文摘要 |
| 高原湖泊周边农田磷肥的大量施用和城镇村落的聚集造成了土壤剖面磷素不断累积和含磷污染物的大量排放，加剧了湖泊周边浅层地下水的磷污染，磷随湖泊周边区域浅层地下径流入湖也影响着高原湖泊的水质安全.2019~2021年雨季和旱季，通过对云南8个湖泊周边农田和居民区水井进行监测，分析了452个浅层地下水样中磷浓度的时空差异及驱动因素.结果表明，季节变化和土地利用影响了浅层地下水中磷浓度及其组成，表现为雨季浅层地下水中磷浓度大于旱季，农田大于居民区；溶解性总磷（DTP）是总磷（TP）的主要形态，占75%~81%，溶解性无机磷（DIP）是DTP的主要形态，占74%~80%.8个湖泊周边近30%的样本TP浓度已超过地表水Ⅲ水标准（GB 3838），其中，洱海（52%）、杞麓湖（45%）、星云湖（42%）和滇池（29%）湖泊周边地下水磷的超标率远高于阳宗海（16%）、抚仙湖（13%）、程海（6%）和异龙湖（5%）.影响浅层地下水磷浓度的关键因子是土壤剖面中水溶性磷（WEP）、含水率（MWC）、土壤有机质（SOM）、总氮（TN）、pH和浅层地下水中pH、水位（P<0.05）.土壤WEP、SOM、TN、MWC和地下水中pH的增加显著增加了浅层地下水中DIP和DTP浓度，而地下水位的降低显著减少了地下水中DTP和DIP的浓度. |
| 英文摘要 |
| The extensive application of phosphorus fertilizers to croplands and the aggregation of towns and villages around plateau lakes has resulted in the continuous accumulation of phosphorus in the soil profile and the discharge of phosphorus pollutants, which causes phosphorus pollution in shallow groundwater around the lakes. The phosphorus entering the lake with shallow underground runoff in the region around the lake also affects the water quality safety of plateau lakes. The spatiotemporal differences in phosphorus concentrations in 452 shallow groundwater samples and the driving factors were analyzed by monitoring wells in croplands and residential areas around the eight lakes in Yunnan province during the rainy and dry seasons from 2019 to 2021. The results showed that seasonal changes and land use influenced phosphorus concentrations and their composition in shallow groundwater. The concentration of phosphorus in shallow groundwater in the rainy season was higher than that in the dry season, and it was also greater in cropland than that in residential areas. DTP was the dominant form of TP, accounting for 75%-81%, and DIP was the dominant form of DTP, accounting for 74%-80%. Nearly 30% of the samples around the eight lakes had TP concentrations exceeding the surface water Class Ⅲ standard (GB 3838); the exceeded rates of phosphorus in groundwater around the Erhai Lake (52%), Qiluhu Lake (45%), Xingyun Lake (42%), and Dianchi Lake (29%) were far higher than those of Yangzonghai Lake (16%), Fuxianhu Lake (13%), Chenghai Lake (6%), and Yilonghu Lake (5%). The key driving factors of phosphorus concentrations in shallow groundwater were water-soluble phosphorus (WEP), water content (MWC), soil organic matter (SOM), total nitrogen (TN), pH in the soil profile, and pH and groundwater level in the shallow groundwater (P<0.05). The increases in WEP, SOM, TN, and MWC in the soil and pH in groundwater significantly increased the concentrations of DIP and DTP in shallow groundwater, whereas the decrease in groundwater level significantly reduced the concentrations of DTP and DIP in the groundwater. |
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