Wessex Water Night Flow Monitoring

Overview Reporting of leakage from water networks is based on the concept of monitoring flows at a time when demand is at a minimum which is normally during the night. This dataset includes net night flow measurements for 10% of the publisher’s total district metered areas. This 10% has been chosen on the basis that the telemetry on site is reliable, that it is not revealing of sensitive usage patterns and that the night flow there is typical of low demand. Key Definitions District Metered Area (DMA) The role of a district metered area (DMA) is to divide the water distribution network into manageable areas or sectors into which the flow can be measured. These areas provide the water providers with guidance as to which DMAs (District Metered Areas) require leak detection work. Leakage The accidental admission or escape of a fluid or gas through a hole or crack Night Flow This technique considers that in a DMA, leakages can be estimated when the flow into the DMA is at its minimum. Typically, this is measured at night between 2am and 4am when customer demand is low so that network leakage can be detected. Data History Data Origin Companies have configured their networks to be able to continuously monitor night flows using district meters. Flow data is recorded on meters and normally transmitted daily to a data centre. Data is analysed to confirm its validity and used to derive continuous night flow in each monitored area. Data Quality Not all DMAs provide quality data for the purposes of trend analysis. It was decided that water companies should choose 10% of their DMAs to be represented in this data set to begin with. The advice to publishers is to choose those with reliable and consistent telemetry, indicative of genuine low demand during measurement times and not revealing of sensitive night usage patterns. This may mean the DMAs from which data are published are not consistent between data releases. Data Consistency There is a concern that companies measure flow allowance for legitimate night use and/or potential night use differently. To avoid any inconsistency, it was decided that we would share the net flow. Critical National Infrastructure The release of boundary data for district metered areas has been deemed to be revealing of critical national infrastructure. Because of this, it has been decided that the data set shall only contain point data from a centroid within the DMA. Data Triage Review Frequency Every 12 months, unless otherwise requested. Publish Frequency Annually Data Limitations Some of the flow recorded may be legitimate nighttime usage of the network. Some measuring systems automatically infill estimated measurements where none have been received via telemetry. These estimates are based on past flow. The reason for a fluctuation in night flow may not be determined by this dataset but potential causes can include seasonal variation in nighttime water usage and mains bursts. Supplementary Information Below is a curated selection of links for additional reading, which provide a deeper understanding of this dataset: 1. Ofwat – Reporting Guidance https://www.ofwat.gov.uk/wp-content/uploads/2018/03/Reporting-guidance-leakage.pdf 2. Water UK – UK Leakage https://www.water.org.uk/wp-content/uploads/2022/03/Water-UK-A-leakage-Routemap-to-2050.pdf概述 供水管网漏损报告的编制基于在需求最低时段（通常为夜间）监测流量的核心理念。本数据集涵盖了发布方所有计量分区（District Metered Area，DMA）中10%区域的夜间净流量实测数据。选取该10%区域的依据为：现场遥测数据可靠、不会泄露敏感用水模式，且该区域的夜间流量符合低需求时段的典型特征。 关键定义 计量分区（District Metered Area，DMA）：计量分区的作用是将供水配水管网划分为可管理的区域或分段，以便精准测量流量。此类区域可为供水运营商提供决策指引，帮助其确定哪些计量分区需要开展漏损检测工作。 漏损：流体或气体通过孔洞或裂隙意外进入或逸出的现象。 夜间流量：该方法的核心逻辑为，在计量分区内，当流入该分区的流量处于最低水平时，可估算管网漏损量。通常选取凌晨2时至4时的时段进行测量，此时用户用水需求较低，便于精准检测管网漏损。 数据历史 数据起源：供水企业已完成管网配置，可通过分区流量计持续监测夜间流量。流量数据由流量计记录，通常每日传输至数据中心。工作人员会对数据进行有效性校验分析，并用于推导各监测区域的连续夜间流量。 数据质量：并非所有计量分区都能提供适用于趋势分析的高质量数据。最初决定由供水企业选取其10%的计量分区纳入本数据集。相关指导建议发布方选取遥测数据可靠且稳定、测量时段内的流量能体现真实低需求特征、且不会泄露敏感夜间用水模式的区域。这意味着不同数据发布批次中纳入的计量分区可能存在不一致。 数据一致性：存在各企业对合法夜间用水及/或潜在夜间用水的流量核算标准存在差异的顾虑。为避免数据不一致问题，本数据集采用净流量数据进行共享。 关键国家基础设施：计量分区的边界数据被认定可能泄露关键国家基础设施信息。因此，本数据集仅包含计量分区内质心点的点位数据。 数据筛选复核频率：每12个月进行一次数据筛选复核，另有明确要求的情况除外。 发布频率：每年发布一次。 数据局限性：部分记录的流量可能属于管网合法夜间用水。部分测量系统会自动补填通过遥测未获取到的估算数据，此类估算基于历史流量数据。本数据集无法确定夜间流量波动的具体原因，潜在诱因可能包括夜间用水的季节性变化及管道爆裂。 补充信息 以下为精选的补充阅读链接，可帮助您更深入地理解本数据集： 1. 英国水务监管办公室（Ofwat）——漏损报告指南 https://www.ofwat.gov.uk/wp-content/uploads/2018/03/Reporting-guidance-leakage.pdf 2. 英国水务协会（Water UK）——英国漏损管控路线图至2050年 https://www.water.org.uk/wp-content/uploads/2022/03/Water-UK-A-leakage-Routemap-to-2050.pdf