Stream metabolism data for core sites in Gwynns Falls: high temporal frequency (5-10min resolution) measurements of dissolved oxygen, photosynthetically active radiation, temperature, discharge and depth.

An ongoing component of the Baltimore urban long-term ecological research (LTER) project (Baltimore Ecosystem Study, BES) is the use of the watershed approach and monitoring of stream water quality to evaluate the integrated ecosystem functioning of Baltimore. The LTER research has focused on the Gwynns Falls watershed, which spans a gradient from highly urban, urban-residential, and suburban zones. In addition, a forested watershed serves as a reference. The long-term sampling network includes four longitudinal sampling sites along the Gwynns Falls mainstem, as well as several small (40-100 ha) watershed within or near the Gwynns Falls, providing data on water quality in different land use zones of the watersheds. Each study site is continuously monitored for discharge and is sampled weekly for water chemistry. Those data are available elsewhere on the BES website. We are interested in studying the bioreactivity of streams in our watersheds in an attempt to quantify how streams themselves may affect or be affected by water quality. To assess the bioreactivity of streams, we measure whole stream metabolism, which is an integrative metric which quantifies the production and consumption of energy by a stream ecosystem. Stream metabolism represents how energy is created (primary production) and used (respiration) within a stream; it can be thought of as a stream breathing, with primary production being similar to an inhale, and respiration as an exhale. We are monitoring stream metabolism in each of our long-term water quality monitoring stations by deploying sensors that record dissolve oxygen and temperature of the stream every five minutes, and we also have deployed light sensors to record irradiance every five minutes at long-term BES water chemistry streams, which is needed for metabolism modeling. In addition, each dissolved oxygen sensor is located near a USGS gage which estimates discharge every 15 minutes. We used USGS manual discharge estimations linked with channel geometry measurements to develop a unique discharge-stream depth relationship (contact AJ Reisinger for details). The combination of the USGS discharge data and our discharge-depth relationship allows us to estimate average daily discharge and depth. We have included these data as well as dissolved oxygen, temperature, and PAR, allowing metabolism to be scaled on an areal basis. Primary production and respiration of streams integrate all biological activity in a stream, and therefore are good metrics to assess the state of an ecosystem. These metrics can also be used to predict other ecosystem functions. This dataset includes all information needed for whole-stream metabolism modeling using the streammetabolizer R package. Data will updated as it becomes available from the core stream study sites (see http://md.water.usgs.gov/BES for a detailed description of these sites). Codes and abbreviations 1 - pobr - Pond Branch forested reference site - Forested reference. Preliminary monitoring from 10/24/2012 - 11/12/2012. Monitored continuously for metabolism beginning February 2016. 2 - barn - Baisman Run at Ivy Hill Road - Suburban unsewered. Preliminary monitoring from 10/24/2012 - 11/13/2012. Monitored continuously for metabolism beginning February 2016. 3 - drkr - Dead Run at Kernan Drive - Urban. Preliminary monitoring 10/24/2012 - 11/29/2012. Monitored continuously for metabolism beginning February 2016. 4 - gfgb - Gwynns Falls at Gwynnbrook Avenue (Delight) - Suburban. Preliminary monitoring 10/24/2012 - 11/11/2012. Monitored continuously for metabolism beginning February 2016. 5 - gfcp - Gwynns Falls at Caroll Park - Urban. Preliminary monitoring 10/24/2014 - 11/29/2012. Monitored for metabolism continuously beginning February 2016. 6 - gfgl - Gwynns Falls at Glyndon - Suburban. Monitored continuously for metabolism beginning February 2016. 7 - gfvn - Gwynns Falls at Villanova - Urban. Monitored continuously for metabolism beginning February 2016. 8 - mcdn - Gwynns Falls Tributary at McDonogh - Agricultural. Monitored for metabolism continuously beginning February 2016. Note: Data collected prior to 2016 are formatted to be used in the BASE metabolism package in R (see Grace et al. 2015 in Limnology and Oceanography). Data collected beginning in February 2016 are formatted to be used in the streammetabolizer metabolism package in R (see Appling et al. 2018 in Journal of Geophysical Research: Biogeosciences) Column,Column Name,Variable-if different than Column Name (units) A,Site, Site Name B,Date, Date (mm/dd/yyyy) C,Time, Localt time (hh:mm) D,I, PAR (umol/m2/s) E,tempC, Temperature (deg C) F,DO.meas, measured dissolved oxygen concentration (mg/L) G,DO.sat, concentration of dissolved oxygen at 100% saturation with the atmosphere (mg/L) H. atmo.pressure, atmospheric pressure (atm) - if this isn�t known it can be estimated based upon elevation H,salinity, salinity - this should be zero for freshwater I,Q, discharge (L/s) J,D, depth (m) Methods: Dissolved oxygen and temperature are logged every five minutes on a miniDOT (PME, Inc.) deployed at a representative location in the stream. Irradiance (I) is recorded as photosynthetically active radiation (PAR) using either Odyssey loggers (Dataflow Systems Limited, Christchurch, NZ) or HOBO Pendant Temperature/Light loggers (Onset Computer Corporation, Bourne, MA, USA) deployed at a representative location near the stream. Elevation is estimated using Google Earth. Average daily discharge is downloaded from USGS gauging stations located at each individual study site. We developed site-specific depth-discharge relationships using USGS manual discharge measurements with channel geometry. These specific relationships are then used to back-calculate average stream depth from daily average Q downloaded from USGS. Beginning in 2016, miniDOTs were deployed continuously at each long-term BES water chemistry site. During continuous deployment, miniDOTs are cleaned weekly, and downloaded quarterly. miniDOTs are calibrated annually per manufacturer recommendation. miniDOTs are logged together in supersaturated water for one hour prior to and after deployment. This equilibration period allows for any drift correction over the course of the deployment.

巴尔的摩城市长期生态研究（Long-Term Ecological Research, LTER）项目（又称巴尔的摩生态研究，Baltimore Ecosystem Study, BES）的持续组成部分，采用流域方法与河流水质监测手段，评估巴尔的摩的综合生态系统功能。该LTER研究聚焦于Gwynns Falls流域，该流域涵盖高度城市化、城市住宅与郊区的土地利用梯度。此外，项目设置了森林流域作为对照参考系统。长期采样网络包含沿Gwynns Falls干流的4个纵向采样点位，以及Gwynns Falls流域内或邻近的数个小型（40-100公顷）流域，以获取不同土地利用类型流域的河流水质数据。每个研究点位持续监测径流量，并每周采样分析水化学组分。相关数据可通过BES官网的其他板块获取。

本研究旨在探究流域内溪流的生物反应性，以量化溪流本身如何影响水质或受水质影响。为评估溪流生物反应性，我们测量了全溪流代谢速率——这是一项整合性指标，用于量化溪流生态系统的能量生产与消耗过程。溪流代谢速率表征了溪流内部的能量产生（初级生产）与消耗（呼吸作用）过程，可以类比为溪流的“呼吸”：初级生产类似“吸气”，呼吸作用则类似“呼气”。

我们通过部署传感器在各长期水质监测点位监测溪流代谢速率：传感器每5分钟记录一次溪流的溶解氧与水温；同时在长期BES水化学监测溪流点位部署光照传感器，每5分钟记录一次辐照度，该数据为代谢模型建模所必需。此外，每个溶解氧传感器均部署在美国地质调查局（United States Geological Survey, USGS）的水文测站附近，该测站每15分钟估算一次径流量。我们结合USGS手动径流量估算值与河道地形测量数据，建立了专属的径流量-水深关系（详情可联系AJ Reisinger）。结合USGS径流量数据与我们建立的径流量-水深关系，我们可以估算日均径流量与水深。本数据集包含上述数据，以及溶解氧、水温与光合有效辐射（Photosynthetically Active Radiation, PAR）数据，支持按面积尺度计算代谢速率。溪流的初级生产与呼吸作用整合了溪流内的所有生物活动，因此是评估生态系统状态的优良指标，也可用于预测其他生态系统功能。

本数据集包含使用streammetabolizer R包进行全溪流代谢建模所需的全部信息。核心溪流研究点位的详细描述可访问http://md.water.usgs.gov/BES获取，数据将随核心点位的新观测结果持续更新。

### 代码与缩写
1. pobr：Pond Branch森林对照点位——森林参考系统。2012年10月24日至11月12日开展初步监测，自2016年2月起持续监测溪流代谢速率。
2. barn：Ivy Hill Road处的Baisman Run溪流——郊区无污水处理系统区域。2012年10月24日至11月13日开展初步监测，自2016年2月起持续监测溪流代谢速率。
3. drkr：Kernan Drive处的Dead Run溪流——城市区域。2012年10月24日至11月29日开展初步监测，自2016年2月起持续监测溪流代谢速率。
4. gfgb：Gwynnbrook Avenue（Delight）处的Gwynns Falls溪流——郊区区域。2012年10月24日至11月11日开展初步监测，自2016年2月起持续监测溪流代谢速率。
5. gfcp：Caroll Park处的Gwynns Falls溪流——城市区域。初步监测时段为2014年10月24日至2012年11月29日，自2016年2月起持续监测溪流代谢速率。
6. gfgl：Glyndon处的Gwynns Falls溪流——郊区区域。自2016年2月起持续监测溪流代谢速率。
7. gfvn：Villanova处的Gwynns Falls溪流——城市区域。自2016年2月起持续监测溪流代谢速率。
8. mcdn：McDonogh处的Gwynns Falls支流——农业区域。自2016年2月起持续监测溪流代谢速率。

> 注：2016年之前采集的数据适配R语言BASE代谢包（详见Grace等人2015年发表于《Limnology and Oceanography》的研究）；2016年2月起采集的数据适配R语言streammetabolizer代谢包（详见Appling等人2018年发表于《Journal of Geophysical Research: Biogeosciences》的研究）。

### 数据列说明
| 列序号 | 列名 | 变量说明（若与列名不同）及单位 |
|--------|------|--------------------------------|
| A | Site | 点位名称 |
| B | Date | 日期（mm/dd/yyyy） |
| C | Time | 当地时间（hh:mm） |
| D | I | 光合有效辐射（PAR，单位：μmol/m²/s） |
| E | tempC | 水温（单位：℃） |
| F | DO.meas | 实测溶解氧浓度（单位：mg/L） |
| G | DO.sat | 大气饱和状态下的溶解氧浓度（单位：mg/L） |
| H | atmo.pressure | 大气压强（单位：atm）；若参数未知可基于海拔估算 |
| H | salinity | 盐度；淡水系统盐度应为0 |
| I | Q | 径流量（单位：L/s） |
| J | D | 水深（单位：m） |

### 监测方法
溶解氧与水温每5分钟记录一次，数据由部署在溪流典型位置的miniDOT传感器（美国PME公司）采集。辐照度（I）以光合有效辐射（PAR）形式记录，使用的设备包括Odyssey数据记录仪（新西兰克赖斯特彻奇Dataflow Systems Limited公司）或HOBO Pendant温度/光照记录仪（美国马萨诸塞州伯恩Onset Computer Corporation公司），部署在溪流附近的典型位置。海拔高度通过Google Earth估算。

日均径流量数据从各研究点位对应的USGS水文测站下载获取。我们结合USGS手动径流量测量数据与河道地形测量数据，建立了点位专属的径流量-水深关系。随后利用该专属关系，基于从USGS下载的日均径流量数据反推得到平均溪流水深。

自2016年起，我们在每个长期BES水化学监测点位持续部署miniDOT设备。持续部署期间，每周对miniDOT进行清洁，每季度下载一次数据；每年按照制造商建议对miniDOT进行校准。部署前后，将miniDOT置于过饱和水中1小时进行平衡校准，该平衡时段可用于校正部署期间的传感器漂移。