Derived annual statistics of rainfall, streamflow and acidity for the Nant Esgair Garn catchment, Llyn Brianne, Mid Wales, UK. (1982 to 2012)

This dataset comprises of derived annual statistics for measures of rainfall, streamflow, temperature and stream acidity (pH) for a stream, draining a small, approximately 0.6 square kilometres, upland grassland catchment. The stream, Nant Esgair Garn, drains into the Llyn Brianne reservoir, Powys, United Kingdom. The data are for a 31 year period covering 1st April 1982 to 1st April 2012. The streamflow and acidity data are derived from 15 minute resolution observations throughout the calendar year 2013 from associated stream gauging and water quality stations on the Nant Esgair Garn. The monthly rainfall measures presented, were derived from local rain gauges. The monthly temperature measures presented were derived from observations at a weather station near Talgarth, Powys. Routines within the Lancaster University Computer-Aided Program for Time-series Analysis and Identification of Noisy Systems (CAPTAIN) Toolbox for Matlab were used to develop a dynamic model of these data. These models were then used to simulate the 31-year record for which monthly statistics were derived. The statistics were derived to develop greater understanding of the controls on the long-term dynamics of aquatic biodiversity observed by other researchers in this stream. The work was part of the Diversity in Upland River Ecosystem Service Sustainability (DURESS) project, NERC grant NE/J014826/1. Members of staff from the Lancaster Environment Centre, Lancaster University installed, maintained and downloaded the stream gauging and water quality stations and also carried out statistical analysis of the data.

本数据集包含某溪流的降雨、径流、水温以及溪流酸度（pH）指标的衍生年度统计数据，该溪流的汇水区域为面积约0.6平方千米的高地草原流域。该溪流名为Nant Esgair Garn，最终汇入英国鲍伊斯（Powys）地区的林恩布莱恩水库（Llyn Brianne Reservoir）。
本数据集覆盖1982年4月1日至2012年4月1日的31年时长。其中，本次数据集展示的径流与酸度月度指标，其高频原始数据源自2013年全年的15分钟分辨率监测结果，采集自Nant Esgair Garn溪流上配套的径流监测站与水质监测站；月度降雨量指标源自当地雨量站的观测数据；月度气温指标则源自英国鲍伊斯地区塔尔加思（Talgarth）附近气象站的观测数据。
研究采用兰卡斯特大学面向Matlab开发的时序分析与噪声系统辨识计算机辅助程序（Computer-Aided Program for Time-series Analysis and Identification of Noisy Systems，简称CAPTAIN）工具箱中的相关程序，基于上述观测数据构建了该流域的动态模型。随后利用所构建的模型对1982至2012年的31年序列进行模拟，进而得到本数据集所需的月度统计指标。
本次衍生统计数据的构建目的，是为了加深对该溪流中水生生物多样性长期动态调控机制的理解，相关野外生物多样性观测由其他研究人员完成。本研究隶属于高地河流生态系统服务可持续性多样性（Diversity in Upland River Ecosystem Service Sustainability，简称DURESS）项目，受英国自然环境研究委员会（Natural Environment Research Council，简称NERC）资助，项目编号为NE/J014826/1。兰卡斯特大学兰卡斯特环境中心的工作人员负责了径流与水质监测站的安装、维护与数据下载工作，并完成了本数据集的统计分析。