Pang Yan, Xiang Song, Chu Zhao-sheng, Xue Li-qiang, Ye Bi-bi
Huan Jing Ke Xue. 2015 Nov;36(11):4005-12.
We studied the relationship between agricultural land and water quality of inflow river in Erhai Lake Basin, by means of spatial and statistical analysis, from the perspective of comprehensive agricultural land and the area percentage of different types of agricultural land. The obtained results indicated that inflow water quality showed a significant spatial difference, the inflow TP pollution in the western inflow rivers of Erhai Basin was serious. The major pollution indicators in the northern and southern inflow rivers (except for D3) were organic matter and nitrogen. The area percentage of agricultural land had a significantly indicative effect on the water quality of inflow river. The area percentage of comprehensive agricultural land negatively correlated with permanganate index, NH4(+) -N, TN and TP contents in wet season, the correlation coefficients were - 0.859, - 0.565, - 0.693, - 0.181. It negatively correlated with permanganate index and NH4(+) -N content in dry season, the correlation coefficients were - 0.384, - 0.328. It had positive relationships with and TN, TP content in dry season, the correlation coefficients were 0.221 and 0.146. The area percentage of different types of agricultural land had an obviously indicative effect on the inflow water quality. Farmland positively correlated with TN and TP contents both in wet and dry seasons. The correlation coefficients between farmland and TN, TP were 0.252, 0.581 in rainy season and were 0.149, 0.511 in dry season. It had positive and negative relationships with permanganate index, NH4(+) -N content in wet season and dry season, respectively. The correlation coefficients between farmland and permanganate index, NH4(+) -N were 0.388, 0.053 in rainy season and were -0.137, -0.147 in dry season. Forest land exhibited an opposite performance to that of farmland. The correlation coefficients between forest land and TN, TP, permanganate index, NH4(+) -N were - 0.526, - 0.275, - 0.469, -0.155 in rainy season and were -0.012, -0.100, 0.282, 0.151 in dry season. Fishpond had a weakly indicative effect on TN and TP contents. Meadowland and orchard had a similar performance with that of farmland in wet season, but were opposite to that of farmland in dry season. Therefore, management for farmland, meadowland and orchard in the north and south during wet season should be emphasized during the agricultural nonpoint source control in Erhai Lake Basin.
我们从综合农用地及不同类型农用地面积占比的角度，运用空间分析和统计分析方法，研究了洱海流域农用地与入湖河流水质的关系。研究结果表明，入湖水质存在显著的空间差异，洱海流域西部入湖河流的入湖总磷污染严重。北部和南部入湖河流（D3除外）的主要污染指标为有机物和氮。农用地面积占比对入湖河流水质具有显著的指示作用。综合农用地面积占比在湿季与高锰酸盐指数、NH₄⁺-N、总氮和总磷含量呈负相关，相关系数分别为-0.859、-0.565、-0.693、-0.181。在干季，它与高锰酸盐指数和NH₄⁺-N含量呈负相关，相关系数分别为-0.384、-0.328。它与干季总氮、总磷含量呈正相关，相关系数分别为0.221和0.146。不同类型农用地面积占比对入湖水质具有明显的指示作用。农田在湿季和干季与总氮、总磷含量均呈正相关。农田与总氮、总磷在雨季的相关系数分别为0.252、0.581，在干季分别为0.149、0.511。它在湿季和干季与高锰酸盐指数、NH₄⁺-N含量分别呈正、负相关。农田与高锰酸盐指数、NH₄⁺-N在雨季的相关系数分别为0.388、0.053，在干季分别为-0.137、-0.147。林地表现出与农田相反的情况。林地与总氮、总磷、高锰酸盐指数、NH₄⁺-N在雨季的相关系数分别为-0.526、-0.275、-0.469、-0.155，在干季分别为-0.012、-0.100、0.282、0.151。鱼塘对总氮、总磷含量的指示作用较弱。草地和果园在湿季表现与农田相似，但在干季与农田相反。因此，在洱海流域农业面源污染控制中，应重点加强湿季南北部农田、草地和果园的管理。
