Estimated Sediment Loads and Gully Runnoff for Restoration Effectiveness (NESP TWQ 2.1.4, CSIRO)

This dataset contains preliminary estimates of discharge and loads (Total suspended sediment and total nitrogen) based on monitoring data collected for the NESP Project 2.1.4 Demonstration and evaluation of gully remediation on downstream water quality and agricultural production in GBR rangelands.

The data in presented in this metadata are part of a larger collection and are intended to be viewed in the context of the project. For further information on the project, view the parent metadata record: Demonstration and evaluation of gully remediation on downstream water quality and agricultural production in GBR rangelands (NESP TWQ 2.1.4, CSIRO).

Monitoring of these sites is continuing as part of NESP TWQ Project 5.9. Any temporal extensions to this dataset will be linked to from this record.

Methods:
To estimate loads of suspended sediment (TSS) and total nitrogen (TN) the following steps were undertaken:
(1) Depth, velocity and RTK surveyed cross-sectional area data were used to generate a stage-discharge rating curve for each site;
(2) Linear relationships between TSS and TN sample concentrations and coincident turbidity data were derived for all sites (Table 6). Turbidity data was not used when (i) the instrument exceeded the instrument calibration threshold; (ii) turbidity sensor readings were erroneous due to damage or sensor malfunction, or when the sensors were buried. These relationships allowed for estimation of TSS and N from turbidity. When there was no turbidity data (due to sensor issues or instrument burial), TSS and TN concentrations were infilled using sample interpolation.
(3) Total suspended sediment (TSS) and total nitrogen (TN) loads were then generated for each event and each water year (generally Nov to April) by multiplying discharge by concentration.
(4) For all sites flow weighted annual average mean concentrations (FWAAC) were generated by dividing the annual load by annual runoff. This provided a quick visual assessment of the relative change in concentration between sites.
(5) For some sites (i.e. Mt Wickham) event mean concentrations (EMCs) were generated for individual events by dividing the event load by event runoff. This provided a flow weighted mean concentration for each event. The event mean concentration (EMC) value for each event and year was calculated using mass of the sediment (in tonnes) divided by the runoff volume (in ML) during the time interval (T) (after Kim et al., 2004).

Limitations of the Data:
This dataset contains Water Quality monitoring data collected at these gully sites for the three reporting wet seasons spanning June-July 2016-2017, 2017-2018 and 2018-2019. During this study, the project had challenges with (i) sensor malfunctions (ii) sensor burial and re-scour (iii) sensors being damaged by moving objects (iv) green ant nests in sensors and (v) wires chewed by livestock. In addition sampling error or uncertainty in the discharge and load calculations can be high in semi-arid systems (Kuhnert et al., 2012). Consequently, all runoff and loads estimates are considered preliminary and will likely change in subsequent reporting years.

Format:
This data collection consists of 5 zip files (one for each paired gully monitoring site). Zip files are named according to the property on which they are located. Each zip file contains eight to twelve MS Excel spreadsheets representing daily and annual discharge and load estimates for both the Control and Treatment gully sites.

MS Excel files contain tabs representing the following:
SETUP – contains the site specific parameters used to estimate discharge and loads such as catchment size, location of instruments relative to depth sensor or gully cross section, discharge rating curve, and constituent-turbidity relationship
SUMMARY – provides annual totals for rainfall, runoff, and loads, daily rainfall runoff chart, summary tables of rainfall and runoff events.
RUNOFF_LOADS_CHART – chart of timeseries of depth, event depth, TSS or N concentration (as estimate from turbidity) and sample concentration - used to check for issues with depth or turbidity when interpreting annual or daily totals
DAILY_SUMMARY_ALL_DATES – for generating daily rainfall, runoff and load estimates
SAMPLES – list of sample values relevant to loads sheet period for cross checking against turbidity relationship
RUNOFF LADS CALCS ALL TIMESTEP - raw Stream data with associated instantaneous calculations of discharge and loads
RAIN AT GAUGE – rainfall timeseries from site (or closest) gauge
RAIN USED FOR AVERAGING – if catchment is large, a second rain gauge may be used for averaging (not usually for gullies)

Data Dictionary:

Column headings used in the Excel spreadsheets:
Timestamp – time in AEST (+10GMT)
Depth – Depth of flow above depth sensor in millimetres, Depth sensor was level with gully bed at time of installation.
Turbidity or Turb – turbidity in units of NTU
(note that the Turbidity and velocity sensors are mounted above the depth sensor by 100 mm or more).
Rainfall – rainfall in millimetres
Discharge – discharge as either a rate or a total volume of water
Runoff – discharge divided by catchment area
Sample – Sample Number as submitted to Lab
TSS / N = Total Suspended Sediment / Total Nitrogen

Site_Code used for file names is as follows:
MIV = Minnievale
MV = Meadowvale
MW = Mount Wickham
SB = Strathbogie
VP = Virginia Park
- Treatment/Control
Note:
SBT is now the Strathbogie Control site
SBC (to 2018) and SBT2 (after 2018) is now the Strathbogie Treatment site

References:

Bartley, Rebecca; Hawdon, Aaron; Henderson, Anne; Wilkinson, Scott; Goodwin, Nicholas; Abbott, Brett; Baker, Brett; Matthews, Mel; Boadle, David; Jarihani, Ben (Abdollah). (2018) Quantifying the effectiveness of gully remediation on off-site water quality: preliminary results from demonstration sites in the Burdekin catchment (second wet season). RRRC: NESP and CSIRO. csiro:EP184204.

Baker, B., Hawdon, A. and Bartley, R., 2016. Gully remediation sites: water quality monitoring procedures, CSIRO Land and Water, Australia.

eAtlas Visualisation
The visualisation presented on the eAtlas maps is a derived product of the summary data found within this data collection. A summary dataset was created using information presented on each spreadsheet [Water-Year, Site, Catchment Area, Rainfall, Runoff, %Runoff, Total TSS Load, Average TSS from time series, Total N Yield, N Loss, Average B from timeseries]. Two additional columns were added to the core information: data infill as referenced in the spreadsheets, has been represented in column 'Contains_Infilled_Data' noting Y or N; column 'Treatment_Control' was added to the summary dataset to aid visual representation, where treatment 'T' and control 'C' sites clearly identified.

Data Location:

This dataset is filed in the eAtlas enduring data repository at: data\nesp2\2.1.4_Gully-remediation-effectiveness

本数据集基于NESP项目2.1.4——《大堡礁牧场沟壑修复对下游水质与农业生产的示范与评估》的监测数据，包含流量与负荷（总悬浮沉积物（Total Suspended Sediment, TSS）、总氮（Total Nitrogen, TN））的初步估算值。

本元数据中收录的数据为更大数据集的一部分，需结合项目整体背景进行解读。如需了解项目更多详情，请查阅其父级元数据记录：《大堡礁牧场沟壑修复对下游水质与农业生产的示范与评估》（NESP TWQ 2.1.4，澳大利亚联邦科学与工业研究组织（CSIRO））。

作为NESP TWQ项目5.9的一部分，上述监测站点的监测工作仍在持续。本数据集的任何时序扩展内容均将通过本记录进行关联。

## 数据估算方法
为估算总悬浮沉积物与总氮负荷，本研究采用如下步骤：
(1) 利用水深、流速与实时动态载波相位差分（Real-time kinematic, RTK）测量的断面面积数据，为每个监测站点构建水位-流量关系曲线；
(2) 为所有站点建立总悬浮沉积物、总氮采样浓度与同步浊度数据之间的线性关系（详见表6）。当出现以下情况时，不使用浊度数据：① 仪器超出校准阈值；② 浊度传感器因损坏、故障或被掩埋而读数异常。通过上述线性关系，可基于浊度数据估算总悬浮沉积物与总氮浓度。若因传感器故障或传感器被掩埋导致无浊度数据，则通过采样插值法补全总悬浮沉积物与总氮浓度；
(3) 针对每场水文事件与每个水文年（通常为11月至次年4月），通过流量与浓度相乘的方式，计算得到总悬浮沉积物与总氮负荷；
(4) 为所有站点计算流量加权年平均浓度（Flow-Weighted Annual Average Concentration, FWAAC），计算方式为年负荷除以年径流量。该指标可快速直观地对比不同站点间的浓度相对变化；
(5) 针对部分站点（如威克汉姆山（Mount Wickham）），通过事件负荷除以事件径流量的方式，计算得到单场水文事件的事件平均浓度（Event Mean Concentration, EMC），即单场事件的流量加权平均浓度。单场事件及对应年份的事件平均浓度值，按照Kim等人2004年的研究方法，以时段（T）内沉积物质量（单位：吨）除以径流量（单位：兆升（Megalitre, ML））计算得到。

## 数据局限性
本数据集收录了上述沟壑监测站点在2016-2017、2017-2018及2018-2019三个报告湿季（每年6-7月为季末）采集的水质监测数据。本研究期间，项目遭遇了诸多挑战：① 传感器故障；② 传感器被掩埋及后续冲刷暴露；③ 传感器被移动物体损坏；④ 传感器内出现绿蚁巢穴；⑤ 线路被牲畜啃咬。此外，半干旱系统中的采样误差或流量与负荷计算不确定性可能较高（Kuhnert等人，2012）。因此，所有径流量与负荷估算值均为初步结果，后续报告年度中可能会进行修正。

## 数据格式
本数据集包含5个压缩文件，对应5组成对的沟壑监测站点（每个站点对应一个压缩包）。压缩包以其所在的地块名称命名。每个压缩包内含8至12个Microsoft Excel（MS Excel）工作表，分别对应对照与处理沟壑站点的日度与年度流量及负荷估算数据。

Excel工作表包含以下标签页：
"SETUP"（站点设置）：包含用于流量与负荷估算的站点专属参数，如集水面积、仪器相对于水深传感器或沟壑断面的安装位置、水位-流量关系曲线以及污染物-浊度关系；
"SUMMARY"（汇总统计）：提供降雨、径流量与负荷的年度总量，日降雨-径流量图表，以及降雨与径流事件汇总表；
"RUNOFF_LOADS_CHART"（径流量与负荷时序图）：包含水深、事件水深、总悬浮沉积物/总氮浓度（基于浊度估算）及采样浓度的时序图表，用于在解读年度或日度总量时排查水深或浊度数据异常问题；
"DAILY_SUMMARY_ALL_DATES"（全日期日度汇总）：用于生成日度降雨、径流量与负荷估算值；
"SAMPLES"（采样数据）：列出与负荷工作表时段相关的采样值，用于与浊度关系进行交叉验证；
"RUNOFF LOADS CALCS ALL TIMESTEP"（全时间步长径流量与负荷计算）：包含原始水文流量数据及对应的瞬时流量与负荷计算结果；
"RAIN AT GAUGE"（站点雨量数据）：来自站点（或邻近）雨量计的降雨时序数据；
"RAIN USED FOR AVERAGING"（用于平均的降雨数据）：若集水面积较大，可使用第二台雨量计的数据进行降雨平均（沟壑站点通常无需此操作）。

## 数据字典
Excel工作表中使用的列标题说明如下：
Timestamp（时间戳）：采用澳大利亚东部标准时间（AEST，+10GMT）；
Depth（水深）：水深传感器安装时与沟壑床面齐平，该字段为传感器上方的水流深度，单位为毫米；
Turbidity或Turb（浊度）：浊度值，单位为NTU（散射浊度单位（Nephelometric Turbidity Unit, NTU））。（注：浊度与流速传感器安装位置高于水深传感器100毫米及以上。）；
Rainfall（降雨量）：单位为毫米；
Discharge（流量）：以流量速率或总水量表示；
Runoff（径流量）：流量除以集水面积；
Sample（采样编号）：提交至实验室的采样编号；
TSS/N：总悬浮沉积物/总氮。

用于文件名的站点代码对应关系如下：
MIV = 明尼维尔（Minnievale）
MV = 梅多维尔（Meadowvale）
MW = 威克汉姆山（Mount Wickham）
SB = 斯特拉斯博吉（Strathbogie）
VP = 弗吉尼亚帕克（Virginia Park）
【注：区分处理组与对照组】
备注：SBT现为斯特拉斯博吉对照站点；SBC（截至2018年）与SBT2（2018年之后）现为斯特拉斯博吉处理站点。

## 参考文献
1. Bartley, Rebecca; Hawdon, Aaron; Henderson, Anne; Wilkinson, Scott; Goodwin, Nicholas; Abbott, Brett; Baker, Brett; Matthews, Mel; Boadle, David; Jarihani, Ben (Abdollah). (2018) 量化沟壑修复对下游水质的改善效果：伯德金河集水区示范站点初步结果（第二个湿季）. RRRC: NESP与CSIRO. csiro:EP184204.
2. Baker, B., Hawdon, A. and Bartley, R., 2016. 沟壑修复站点水质监测规程, 澳大利亚联邦科学与工业研究组织土地与水部.

## eAtlas可视化
eAtlas地图中展示的可视化成果为本数据集内汇总数据的衍生产品。汇总数据集基于各工作表中的以下信息构建：[水文年、站点、集水面积、降雨量、径流量、径流量占比、总悬浮沉积物负荷、时序平均总悬浮沉积物浓度、总氮产率、氮流失量、时序平均B浓度]。核心信息中新增了两列：一是在"Contains_Infilled_Data"列中标注"Y"或"N"，以表明是否存在工作表中提及的数据补全操作；二是新增"Treatment_Control"列，用于明确区分处理组（标记为"T"）与对照组（标记为"C"）站点，辅助可视化展示。

## 数据存储位置
本数据集存储于eAtlas永久数据仓库中，路径为：data
esp22.1.4_Gully-remediation-effectiveness