Water Modelling-Modelled Data-Annual Permitted Take (APT)

Annual permitted take (APT) is a critical component of sustainable resource management, balancing the need for water resource utilisation with the preservation of ecosystems. It is a crucial mechanism for ensuring the long-term annual sustainable diversion limits (SDLs) set under the Murray-Darling Basin Plan are not exceeded, and that enough water is available for the environment. APT is the maximum amount of water permitted to be taken for consumptive purposes each year, and has been enforced since July 2019\r\n\r\nA method for determining APT is part of each water resource plans (WRPs) developed by the Basin states under the Commonwealth Water Act 2007. When the method is applied over the Basin Plan reference period (1895–2009), the annual APT must be equal to or less than SDL.\r\n\r\nAn APT model is a major component of the APT calculation method. It is used to calculate the APT that would be expected in a year, given that year’s water availability and climatic conditions. APT is calculated at the end of each year and compared to actual take in that year, with the difference added to a public register of take. SDL compliance is tracked using the cumulative difference (from water year 2019–20).\r\n\r\nAPT models are configured using estimates of the river management and development (public and private infrastructure) conditions in a river system across the water resource plan period. These estimates include:\r\n\r\n• irrigated crop area and planting decisions\r\n\r\n• water entitlement holders’ distribution and use patterns\r\n\r\n• how storages are operated to supply water for consumption and the environment.\r\n\r\nThe data set provided contains flows at several gauges in each river system, as simulated by the annually extended APT model. Notwithstanding the model’s inherent limitations, these are a fair representation of those we would expect under current conditions development and operation rules. They can be compared with flows simulated by other key scenario models, such as long-term average annual extraction limit (LTAAEL) model or without development (WOD) model.

年度许可取水量（Annual Permitted Take, APT）是可持续水资源管理的核心组成部分，旨在平衡水资源利用需求与生态系统保护目标。该机制是确保墨累-达令流域计划（Murray-Darling Basin Plan）设定的长期年度可持续分流限额（Sustainable Diversion Limits, SDLs）不被突破，并为生态环境预留充足水量的关键手段。APT指每年可用于消耗性用途的最大许可取水量，该制度自2019年7月起正式实施。

确定APT的方法是流域各州依据《2007年联邦水法》（Commonwealth Water Act 2007）制定的各水资源规划（Water Resource Plans, WRPs）的核心内容之一。当该方法应用于流域计划基准期（1895–2009年）时，年度APT不得超过SDLs。

APT模型是APT计算方法的核心组成部分，用于基于当年的水资源可利用量与气候条件，估算当年的预期APT。APT于每年年末完成核算，并与当年实际取水量进行比对，二者差值将被记入取水量公开登记册。自2019-2020水文年起，通过累计差值追踪SDL合规情况。

APT模型依据水资源规划周期内河流系统的河流管理与开发（含公共与私营基础设施）条件的估算值进行配置，此类估算值包括：

• 灌溉作物面积与种植决策

• 水权持有者的水量分配与使用模式

• 蓄水设施为满足用水需求与生态供水的运行方式。

本数据集包含各河流系统内多个水文测站的径流数据，由年度更新的APT模型模拟生成。尽管该模型存在固有局限性，但这些数据能够合理反映当前开发与运行规则下的预期径流情况，可与其他关键情景模型（如长期年均取水限额（Long-Term Average Annual Extraction Limit, LTAAEL）模型或无开发（Without Development, WOD）模型）的模拟径流进行对比。