水文气象过程对千岛湖氮磷变化的影响 |
Influence of Hydrometeorological Processes on Nutrient Dynamics in Qiandao Lake |
投稿时间:2018-08-28 修订日期:2019-07-14 |
DOI:10.15928/j.1674-3075.2019.05.002 |
中文关键词:千岛湖 营养盐 水文过程 气象因素 |
英文关键词:QiandaoLake nutrient hydrological processes meteorological factors |
基金项目:中国科学院前沿科学重点研究项目(QYZDJ-SSW-DQC008);国家自然科学基金项目(41830757);中国科学院南京地理与湖泊研究所“一三五”战略规划项目(NIGLAS2017GH04);淳安县环境保护局招标项目(CAZFCGGK2016-111);杭州市社会发展科研专项(20150533B06) |
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中文摘要: |
作为一类人工调节的重要水资源,水库营养盐含量等水质指标受水文气象过程的影响很大。为探索我国东南山区水库营养盐的时空变化规律,以钱塘江流域千岛湖(新安江水库)为例,利用2016年8月至2017年12月的水质调查数据,结合同期气温、降雨量和入库流量等气象水文数据,分析了水文气象过程对千岛湖水体氮、磷等营养盐浓度的影响特征。结果显示:(1)千岛湖营养盐浓度具有较大的时空差异性,TN浓度0.69~2.06 mg/L,平均值为(1.12±0.26)mg/L,高值出现在冬季和春季;TP浓度0.004~0.096 mg/L,平均值为(0.030±0.021) mg/L,高值出现在春季;空间上呈现为河流区到湖泊区浓度逐渐降低的趋势;(2)千岛湖降雨量、入库流量及气温等水文气象条件存在显著季节差异(P<0.01),3~7月的降雨和入库流量超过总量的70%,高温出现在7-8月,月均温度高达30℃;(3)氮磷营养盐浓度与入库流量的相关性强于降雨,且入库流量及降雨对磷的影响更大;不同区域对入库流量的响应时间存在差异,河流区响应最快,其次是过渡区,湖泊区最慢,反映出氮、磷在水库扩散过程中的滞后性;(4)温度通过影响水体浮游植物生长带来的水体颗粒态氮、磷变化影响水体TN、TP浓度,但是不同湖区的响应也不相同;3~7 d的累积温度与过渡区氮、磷的关系好于河流区,可能与过渡区浮游植物生长与营养盐浓度变化更为敏感有关。研究表明,水文气象过程对大型水库水体氮磷的影响作用强烈且复杂,物理扩散与沉降、化学变化及生物生长累积等作用使得水体氮磷浓度对水文气象过程响应具有较大的时空差异性,在水库水质管理和机制分析中应当充分考虑这种非同步性。 |
英文摘要: |
Reservoirs play an important role in regulating water quality in aquatic systems and nutrient loading in reservoirs is influenced by hydrological and meteorological process. Qiandao Lake (Xin'anjiang Reservoir) is the largest artificial fresh water lake and a strategic water resource in the Yangtze River delta area. In this study, we analyzed the effects of hydrological and meteorological process on the spatial-temporal distribution of nutrients in Qiandao Lake. The objectives were to explore the nutrient dynamics and better understand the underlying factors for reservoirs in the southeastern mountainous area of China and to provide a database for preserving the ecology and managing the water resources of Qiandao Lake. From August 2016 to December 2017, physicochemical variables related to water quality were monitored monthly at five sampling sites (three sites in the riverine zone, one site in the transition zone and one in the lacustrine zone) and hydrometeorological conditions were recorded, including air temperature, inflows and rainfall. Results are as follows: (1) The ranges of TN and TP in Qiandao Lake were 0.69-2.06 mg/L and 0.004-0.096 mg/L and averaged (1.12±0.26) mg/L and (0.030±0.021) mg/L. Nutrient concentrations exhibited obvious spatial-temporal variation. The concentrations of TN and TP both decreased from riverine zone to lacustrine zone. The TN concentration in Qiandao Lake peaked during winter and spring, and TP peaked in the spring. (2) Rainfall, inflow and air temperature varied significantly by season (P<0.01). Rainfall and inflow from March to July exceeded 70% of the annual total and the highest temperatures were in July and August, averaging 30 °C. (3) TN and TP concentrations displayed stronger correlation with cumulative inflow than with rainfall and the cumulative inflow and rainfall affected phosphorus more than nitrogen. The response time of nutrient concentrations to inflow varied by zone, with the riverine zone responding the most quickly, followed by the transition zone and then the lake, reflecting the lag time of nutrients being carried downstream and then mixing in the reservoir. (4) Temperature influenced TN and TP levels by affecting phytoplankton growth and therefore the proportions of soluble and particulate nitrogen and phosphorus. TN and TP levels were more closely related with the cumulative temperature (3-7 days) in the transition zone than the riverine zone, due to the larger sensitivity of phytoplankton growth to variation of nutrient concentrations. In summary, hydrometeorological conditions exerts significant, but complex, effects on the nutrient condition in large reservoirs. The effects of physical mixing and sedimentation, chemical alteration and biomass accumulation lead to large spatial and temporal heterogeneity of nutrients. These unsynchronized ecological characteristics should be considered when developing water quality management plans for reservoirs. |
笪文怡,黎云祥,朱广伟,许海,刘明亮,兰佳,王裕成,吴志旭,郑文婷.2019.水文气象过程对千岛湖氮磷变化的影响[J].水生态学杂志,40(5):9-19. |
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