基于精细模拟的河流型饮用水水源保护区划分研究

合理划定保护区范围是确保集中式饮用水水源地水质安全的重要保障,同时也应与地方的经济发展相适应。为此,以四川省宜宾市中心城区集中式饮用水水源保护区为例,构建了宜宾市岷江一维水动力与水质模型和水源保护区河段精细的二维水动力与水质模型,依据水源保护区划分相关技术规范,综合MIKE11模型与经验类比法划定饮用水水源保护区长度范围,同时利用MIKE 21FM模型对拟划定河段的敏感指标在最不利情形下的浓度分布进行精密模拟。结果表明,一级保护区长度以取水口为基点上溯1 000 m和下溯100m,二级保护区长度从一级水域保护区上游边界上溯2 000m,下游边界下溯200m;官桥溪处箱涵的建设是菜坝镇取水口成立的前提条件;取水口所在的饮用水水源地一级保护区具备单侧划分水源地保护区的条件。

Study on Division of River Drinking Water Source Protection Area Based on Fine Simulation

Reasonably demarcating the scope of protected areas is an important guarantee for ensuring the water quality safety of centralized drinking water sources. It should also be compatible with the local economic development. For this purpose, both a one-dimensional hydrodynamic and water quality model and a detailed two-dimensional hydrodynamic and water quality model of Minjiang River for the reach of the water source protection area were constructed based on the Yibin City Center in Sichuan Province. The relevant technical specifications were divided according to the water source protection area. The MIKE11 model and empirical analogy method were used to delineate the length of drinking water source protection. At the same time, the MIKE 21 FM model was used to precisely simulate the concentration distribution of the sensitive index of the proposed river section under the most unfavorable conditions. The results show that the length of the first-grade protection zone can be traced back to 1 000 m from the base of the intake, and 100 m down. The length of the second-level protection zone is 2 000 m from the upstream boundary of the first-grade protection zone, and 200 m from the downstream boundary. The construction of the box culvert at Guanqiao Creek is a prerequisite for the establishment of Caiba Town intake. The first grade protection zone for the drinking water source where the water intake is located has the conditions for unilaterally dividing the water source protection zone.