Reservoir water quality deterioration due to deforestation emphasizes the indirect effects of global change

This repository contains the dataset linked to the following publication:

Article title: Reservoir water quality deterioration due to deforestation emphasizes the indirect effects of global change

Journal title: Water Research

Article Number: WR_118721

doi: https://doi.org/10.1016/j.watres.2022.118721

Abstract: Deforestation is currently a widespread phenomenon and a growing environmental concern in the era of rapid climate change. In temperate regions, it is challenging to quantify the impacts of deforestation on the catchment dynamics and downstream aquatic ecosystems such as reservoirs and disentangle these from direct climate change impacts, let alone project future changes to inform management. Here, we tackled this issue by investigating a unique catchment-reservoir system with two reservoirs in distinct trophic states (meso‑ and eutrophic), both of which drain into the largest drinking water reservoir in Germany. Due to the prolonged droughts in 2015–2018, the catchment of the mesotrophic reservoir lost an unprecedented area of forest (exponential increase since 2015 and ca. 17.1% loss in 2020 alone). We coupled catchment nutrient exports (HYPE) and reservoir ecosystem dynamics (GOTM-WET) models using a process-based modeling approach. The coupled model was validated with datasets spanning periods of rapid deforestation, which makes our future projections highly robust. Results show that in a short-term time scale (by 2035), increasing nutrient flux from the catchment due to vast deforestation (80% loss) can turn the mesotrophic reservoir into a eutrophic state as its counterpart. Our results emphasize the more prominent impacts of deforestation than the direct impact of climate warming in impairment of water quality and ecological services to downstream aquatic ecosystems. Therefore, we propose to evaluate the impact of climate change on temperate reservoirs by incorporating a time scale-dependent context, highlighting the indirect impact of deforestation in the short-term scale. In the long-term scale (e.g. to 2100), a guiding hypothesis for future research may be that indirect effects (e.g., as mediated by catchment dynamics) are as important as the direct effects of climate warming on aquatic ecosystems.

Data description
by Xiangzhen Kong ([e-mail]; [e-mail])
2022-06-20

1. Discharge in the streams from 2010 to 2021 at YRZ site, and from 2010 to 2020 at YHZ_Q site.

File name: dat_discharge_stream_YRZ_YHZ_2010_2021_daily.csv

Note: The data is at daily basis but also available at 15-min high frequency basis, which can be requested from the authors.

2. Nitrate concentration in the streams from 2011 to 2019 at both YRZ and YHZ_Q sites.

File name: dat_nitrate_stream_YRZ_YHZ_2011_2019_daily.csv

Note: The data is at daily basis but also available at 15-min high frequency basis, which can be requested from the authors.

3. Water quality data in the inflows from 2010 to 2021 at biweekly basis, from YRZ and YHZ_WQ sites.

File name: dat_waterquality_stream_YRZ_YHZ_2010_2021_biweekly.csv

Note: The data is at biweekly basis, measured at the depth of 0.5m under water surface, from both probe and lab.

4. Water quality data in the predams from 2010 to 2021 at biweekly basis, from YR1 and YH1 sites.

File name: dat_waterquality_predams_YR1_YH1_2010_2021_biweekly.csv

Note: The data is at biweekly basis, measured at the depth of 0.5m under water surface, from both probe and lab.

5. Water quality data in the predams from 2010 to 2015 at biweekely basis, from YR3 and YH3 sites.

File name: dat_waterquality_predams_YR3_YH3_2010_2015_biweekly.csv

Note: The data is at biweekly basis, measured at various water depth, only from lab.

6. CTD and BBE probe profile data in the predams from 2010 to 2015 at biweekely basis, from YR3 and YH3 sites.

Note: Data stored in the folder "probe_profiles_predam_YR3_YH3_2010_2015_biweekly". The data is at biweekly basis, measured at various water depths. The measurements include water temperature (Celcius), DO (mg/L), Chl-a (mg/m3), bluegreen, green and diatom (all in Chl-a, mg/m3)

本数据集关联以下发表论文：

论文标题：因森林砍伐导致的水库水质恶化凸显全球变化的间接效应

期刊名称：Water Research

论文编号：WR_118721

doi: https://doi.org/10.1016/j.watres.2022.118721

摘要：森林砍伐是当前气候变化快速加剧时代下的全球性现象，且日益引发环境关切。在温带地区，量化森林砍伐对流域动态及下游水库等水生生态系统的影响，并将其与气候变化的直接影响区分剥离，尚且极具挑战，更遑论预测未来变化以指导管理实践。本研究聚焦一个独特的流域-水库系统，该系统包含两个营养状态迥异的水库（中营养与富营养），二者均向德国规模最大的饮用水水库输水。受2015-2018年持续干旱影响，中营养水库所在流域的森林面积出现前所未有的流失：流失规模自2015年起呈指数级增长，仅2020年一年即流失约17.1%。本研究采用过程建模方法，耦合了流域营养盐输出模型（HYPE）与水库生态系统动力学模型（GOTM-WET）。耦合模型通过覆盖快速森林砍伐期的数据集完成验证，使得本研究的未来预测具备高度可靠性。结果显示，在短期时间尺度（至2035年）下，大规模森林砍伐（80%流失）导致的流域营养盐通量增加，可使中营养水库转变为富营养状态，与另一水库现状一致。本研究结果强调，相较于气候变暖的直接影响，森林砍伐对下游水生生态系统的水质损害与生态服务功能的负面影响更为显著。因此，我们建议在评估气候变化对温带水库的影响时，纳入时间尺度依赖的情境，重点突出短期尺度下森林砍伐的间接效应。在长期尺度（例如至2100年）下，未来研究可遵循的指导性假说为：间接效应（如由流域动态介导的效应）与气候变暖对水生生态系统的直接效应同等重要。

数据说明
作者：孔祥振（[e-mail]; [e-mail]）
日期：2022-06-20

1. 2010-2021年YRZ站点、2010-2020年YHZ_Q站点的河道径流量。
文件名：dat_discharge_stream_YRZ_YHZ_2010_2021_daily.csv
注：本数据为日尺度数据集，同时提供15分钟高频数据集，可向作者申请获取。

2. 2011-2019年YRZ与YHZ_Q站点的河道硝酸盐浓度数据。
文件名：dat_nitrate_stream_YRZ_YHZ_2011_2019_daily.csv
注：本数据为日尺度数据集，同时提供15分钟高频数据集，可向作者申请获取。

3. 2010-2021年YRZ与YHZ_WQ站点的入流水质数据，采样频率为双周。
文件名：dat_waterquality_stream_YRZ_YHZ_2010_2021_biweekly.csv
注：本数据为双周尺度，采样深度为水面下0.5m，采用原位探头与实验室两种检测方式。

4. 2010-2021年YR1与YH1站点的前池水质数据，采样频率为双周。
文件名：dat_waterquality_predams_YR1_YH1_2010_2021_biweekly.csv
注：本数据为双周尺度，采样深度为水面下0.5m，采用原位探头与实验室两种检测方式。

5. 2010-2015年YR3与YH3站点的前池水质数据，采样频率为双周。
文件名：dat_waterquality_predams_YR3_YH3_2010_2015_biweekly.csv
注：本数据为双周尺度，采样覆盖全水深范围，仅采用实验室检测方式。

6. 2010-2015年YR3与YH3站点的前池CTD与BBE探头剖面数据，采样频率为双周。
注：数据存储于"probe_profiles_predam_YR3_YH3_2010_2015_biweekly"文件夹中。本数据为双周尺度，采样覆盖全水深范围，检测指标包括水温（摄氏度）、溶解氧（DO，mg/L）、叶绿素a（Chl-a，mg/m³）、蓝藻、绿藻与硅藻（均以叶绿素a计，mg/m³）