A novel method is proposed for the development of ecosystem specific water quality indices in accordance with specific guidelines for the protection of aquatic life and with the capacity to demonstrate annual cycles, spatial and temporal variations, and trends in water quality. An ecosystem-specific water quality index for the Santiago-Guadalajara River (SGR-WQI) was developed using a method based entirely on multivariate statistical methods and historical data distributions. The SGR-WQI was developed using data from 13 water quality monitoring stations in the Santiago-Guadalajara River basin, collected monthly from 2009 to 2019 by the State Water Commission of Jalisco, México. The behaviour of 44 water quality parameters was statistically analyzed. It was found that 17 of the parameters best represented the water quality of the River. Parameter selection also considered the legal limits, established by the Government of Mexico, for the protection of aquatic life. To consider the protection of aquatic biota in the assessment of the index, a method was proposed to incorporate these limits in the development of rating curves providing the WQI with high sensitivity to parameter values that are outside the legal limits. Furthermore, a well-structured method based on multivariate statistical techniques was used to determine the parameter weights that best distinguish between sampling points and seasons, clearly reflecting temporal and spatial variability, as well as to demonstrate the annual cycle and trends in water quality. Colour maps were generated from the calculated SGR-WQI values, showing those sections of the river with lower water quality, and thus providing a simple visual to assist in management of the River system. The methodology proposed can be used elsewhere to develop ecosystem specific water quality indices that evaluate surface water for protection of aquatic life in accordance with local limits/standards/guidelines and that adequately reflect spatial and temporal variability in agreement with the specific context.

根据保护水生生物的具体指导方针，提出了一种开发生态系统特定水质指数的新方法，该方法能够展示年度周期、空间和时间变化以及水质趋势。圣地亚哥-瓜达拉哈拉河 (SGR-WQI) 的生态系统特定水质指数是使用完全基于多元统计方法和历史数据分布的方法开发的。SGR-WQI 是使用圣地亚哥-瓜达拉哈拉河流域 13 个水质监测站的数据开发的，这些数据由墨西哥哈利斯科州水务委员会从 2009 年到 2019 年每月收集。对44个水质参数的行为进行了统计分析。结果表明，其中 17 个参数最能代表河流的水质。参数选择还考虑了墨西哥政府为保护水生生物而制定的法律限制。为了在指数评估中考虑对水生生物群的保护，提出了一种方法，将这些限制纳入评级曲线的开发，使 WQI 对超出法定限制的参数值具有高度敏感性。此外，采用基于多元统计技术的结构良好的方法来确定最能区分采样点和季节的参数权重，清楚地反映时空变异性，并展示水质的年度周期和趋势。根据计算的 SGR-WQI 值生成彩色图，显示水质较低的河流部分，从而提供一个简单的视觉效果来帮助管理河流系统。建议的方法可用于其他地方开发生态系统特定水质指数，根据当地限制/标准/准则评估地表水以保护水生生物，并根据具体情况充分反映时空变异性。