| 摘要: |
| 为探究农业种养模式变化对平原水网区河湖水量水质的影响，以江汉平原四湖总干渠为研究对象，基于2010-2023年观测数据分析了年际年内水量水质变化特征，利用遥感影像、统计年鉴等数据识别了不同土地利用类型的年际变化，并查明了近10a不同类型氮磷污染负荷的变化趋势，运用冗余分析（RDA）和相关性热图（correlation）重点探讨了农业种养模式变化下总干渠水量水质的响应规律。研究结果表明：①2010-2023年，四湖总干渠水体总氮总磷浓度在年际上呈现出“先增加再减小后趋于稳定”，年内表现为“冬春季低、夏秋季高”，而在空间上则表现为“出入渠口低、中间高”；总干渠年内排水量主要集中在4月~9月，约占全年的65.7%。②近10a，四湖流域农业种养模式变化显著，主要表现为旱地耕作面积缩减约15%，稻田种养面积增加约19%，淡水养殖面积在2010-2016年增加了约2%，而在2016-2022年缩减了4%以上。③四湖总干渠水量变化特征除受降雨量影响外，还与流域内不同土地利用类型的降雨径流量变化相关，其中水田和旱地是主要影响因素，其贡献分别占总水量变化的366%和-236%。④近10a，四湖总干渠氮磷浓度变化特征与流域内氮磷污染负荷变化极显著正相关（解释度为79.7%，*p＜0.01），而引起流域内氮磷污染负荷变化的主要影响因素是淡水养殖和畜禽养殖；此外，稻田种养对氮磷负荷的贡献近10a从6%增至26%，氮磷污染负荷占比逐渐凸显，未来水环境污染风险不容忽视。 |
| 关键词: 农业种养模式 平原水网区 四湖总干渠 水量水质 氮磷浓度 |
| DOI： |
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| 基金项目:国家自然科学基金区域创新发展联合基金(U21A20156)；国家自然科学基金长江水科学研究联合基金(U2340219) |
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| The water quantity and quality characteristics of Four Lakes Main Channel and its response to the changes in agricultural cropping-breeding mode |
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Hu Yan-Ping,Wang Zhen-hua,Shao Dong-guo,Long Meng,Song Ke-zheng,Zhai Wen-liang
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Changjiang River Scientific Research Institute
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| Abstract: |
| To explore the impact of the changes of agricultural cropping-breeding mode(ACBM) on the water quantity and quality of rivers, Four Lakes Main Channel(FLMC) in the Jianghan Plain was taken as the research object. Based on observation data from 2010 to 2023, the trend of annual water quantity and quality changes was analyzed. Remote sensing images and statistical yearbook data were used to identify the interannual area change characteristics of different land utilization types, and the trends of nitrogen and phosphorus point source load were ascertained nearly 10 years, and redundancy analysis (RDA) and Correlation heat map were applied to explore the response of the main channel’s nitrogen and phosphorus concentration to the changes.The results indicate that: ①From 2010 to 2023, the concentration of total nitrogen and total phosphorus in FLMC , which the inter-annual was "increase and then decrease and then tend to be stable", the annual performance was "low in winter and spring, high in summer and autumn", and the spatial performance was "low and high in the middle of the inlet and outlet". The annual displacement of the total trunk canal is mainly concentrated in April to September, accounting for 65.7% of the whole year. ②In recent 10 years, the ACBM in the Sihu Basin has changed significantly, mainly showing that the dry land cultivation area has decreased by about 15%, the paddy field cultivation area has increased by about 19%, and the freshwater aquaculture area has increased by about 2% from 2010 to 2016, and decreased by more than 4% from 2016 to 2022. ③The variation characteristics of the total water quantity in the FLMC are not only affected by rainfall, but also related to the variation of rainfall runoff of different land use types in the basin, among which paddy field and dry land are the main influencing factors, and their contributions account for 366% and -236% of the total water quantity change, respectively.
④In recent 10 years, the changes of N and P concentration in the FLMC were positively correlated with the changes of N and P pollution load in the basin (79.7% interpretation, *p < 0.01), and the main factors that caused the changes of N and P pollution load in the basin were freshwater breeding and livestock breeding. In addition, the contribution of rice field cultivation to N and P loads increased from 6% to 26% in nearly 10 years, and the proportion of N and P loads gradually became prominent, and the risk of water environment pollution in the future cannot be ignored. |
| Key words: agricultural cropping-breeding mode plain water network plain water network area Four Lakes Main Channel(FLMC) the water quantity and quality characteristics nitrogen and phosphorus concentration nitrogen and phosphorus flux |
