Review on agricultural non-point source pollution monitoring sections layout and pollutant loading estimation in small watershed

流域尺度面源污染的监测是系统认识农业面源污染的发生、迁移及转化过程, 并对其进行有效控制的重要基础. 当前, 田块尺度的面源污染监测方法比较成熟, 而流域尺度的监测, 尤其是监测断面的布设及采样频率设置等方面的研究较少. 本文详细梳理了小流域采样断面布设、采样频率优化和河流断面通量估算3方面的主要进展. 1)从小流域样点布设来看, 包括常规监测采样设计、针对性监测采样设计和融合前两种类型的监测采样设计3种类型, 点位布设方法上有遗传算法、模糊逻辑法、熵值法和模型法等, 样品采集方式包括随机采样、复合采样、综合采样以及连续采样4种类型, 其中复合采样应用广泛；2)从采样频率来看, 1~2周一次的采样频率即可精准获取污染负荷通量, 若需要进一步提高精度, 可在水文/水质变异大的时期提高监测频率及在特殊断面加密布点；3)在通量估算上, 当前主要的计算方法有平均法、插值法和回归/曲线法3类方法, 其中流量加权的浓度估计法、插值算法和LOADEST法是简便且精确的方法, 方法的选择上也可根据不同时期流域污染源特征进一步优化.;Watershed-scale non-point source pollution monitoring is an important basis for systematically understanding the occurrence, transportation and transformation processes of agricultural its effective control. Presently methods at field scale are relatively mature, while applied watershed scale, particularly layout section sampling frequency setting, rarely studied. This paper reviewed main progress layout, optimization loading estimation river sections. From perspective in small watershed, there three types design including probabilistic design, targeted both. Sampling points were located with genetic algorithm, fuzzy logic method, entropy modelling etc. Sample collection include random sampling, compound comprehensive continuous sampling. Compound widely used. Concerning frequency, once every 1-2 weeks sufficient to obtain accurate loading. If higher accuracy necessary, special sections can be increased when hydrology/water quality variation large. For estimation, average interpolation method regression or curve Concentration algorithm by flow-weighted, LOADEST simple exact. Selection could further optimized based on characteristics sources different periods basin.