Water Count Time Series - Landsat, DETSI Algorithm, Queensland

This dataset indicates the presence and persistence of water across Queensland between 1988 and 2022. Water is one of the world’s most important resources as it’s critical for human consumption, agriculture, the persistence of flora and fauna species and other ecosystem services. Information about the spatial distribution and prevalence of water is necessary for a range of business, modelling, monitoring, risk assessment, and conservation activities. The water count product is based on water index and water masks for Queensland (Danaher & Collett 2006) and represents the proportion of observations with water present across the Landsat time series as a fraction of total number of possible observations for the period 1 Jan 1988 to 31 Dec 2022. The product has two bands where band 1 is the number of times water was present across the time series, and band 2 is the count of unobscured (i.e. non-null) input pixels, or number of total observations for that pixel. Cloud, cloud-shadow, steep slopes and topographic shadow can obscure the ability to count water presence.

本数据集展示了1988年至2022年间昆士兰州（Queensland）境内水体的存在状况与持续特征。水体是全球最为重要的资源之一，对人类用水、农业生产、动植物物种存续及其他生态系统服务均具有关键意义。有关水体空间分布与覆盖情况的信息，可应用于各类商业活动、建模研究、监测工作、风险评估与生态保护实践。本水体计数产品基于昆士兰州的水体指数与水体掩膜（Danaher & Collett 2006）构建，以1988年1月1日至2022年12月31日期间所有有效观测的总数量为基准，表征陆地卫星（Landsat）时间序列中检测到水体的观测占比。该产品包含两个波段：波段1为时间序列内检测到水体的总次数，波段2为无遮挡（即非空值）的输入像素总数，亦即对应像素的有效观测总次数。云、云影、陡坡与地形阴影会干扰水体存在情况的计数过程。