Data for Climate change could increase sediment and nutrient loading in downstream coastal areas of a regional watershed

Description of the data and file structure This dataset contains the data required to replicate figures and tables and analyze outputs from Gay et al. (forthcoming), which assessed the effect of changing climate on water quality and quantity in the Cape Fear River Basin. Data is comprised of spatial and tabular data. Spatial data includes the boundary and stream network from SWAT watershed delineation and physiographic regions of the Southeast, USA. Tabular data is comprised of hydrologic outputs from the SWAT model scenarios and climate files. All scenarios, sources, and methodologies are detailed in Gay et al. (forthcoming). Files and variables Description: To access data, download the respective folder and unzip. Data is structed in two main folders: clean_outputs and spatial_data. File structure is as follows: output_files clean_outputs precip_temp This folder contains CSV files summarizing baseline (2000-2020) and projected future (2040-2060) precipitation and temperature under two climate scenarios (CNRM and IPSL) used in the Cape Fear SWAT model. Data are provided at both the watershed scale and at individual subbasins. mean_annual_precip_values_cnrm.csv – Mean annual precipitation (mm) for baseline and future periods across the entire Cape Fear watershed under the CNRM scenario. Columns include: id – used to count number of records year – year of simulation cnrm_se – standard error of summarized precipitation values (mm) cnrm_sd – standard deviation of summarized precipitation values (mm) cnrm_mean – mean annual precipitation across the entire watershed. mean_annual_precip_values_ipsl.csv – Mean annual precipitation (mm) for baseline and future periods across the entire Cape Fear watershed under the IPSL scenario. Columns include: id – used to count number of records year – year of simulation ipsl_se – standard error of summarized precipitation values (mm) ipsl_sd – standard deviation of summarized precipitation values (mm) ipsl_mean – mean annual precipitation across the entire watershed. mean_cnrm_precip_allsubs.csv – Mean annual precipitation (mm) for baseline and future periods, summarized by subbasin, under the CNRM scenario. Columns include: SUB – subbasin within the Cape Fear watershed cnrm_base_sd – standard deviation of summarized precipitation values during the baseline scenario cnrm_base_mean – mean annual precipitation within the specified subbasin during the baseline scenario cnrm_fut_sd – standard deviation of summarized precipitation values during the future scenario. cnrm_fut_mean – mean annual precipitation within the specified subbasin during the future scenario. mean_cnrm_temp_allsubs.csv – Annual mean, maximum, and minimum temperature (°C) for baseline and future periods, summarized by subbasin, under the CNRM scenario. Columns include: Subbasin – subbasin within the Cape Fear watershed base_mean_sd – standard deviation of the summarized daily average baseline temperature within the subbasin. base_mean – daily mean temperature across all years in the subbasin during the baseline period. base_max_sd – standard deviation of the summarized daily maximum baseline temperature within the subbasin base_max – average daily maximum temperature across all years in the subbasin during the baseline period. base_min_sd – standard deviation of the summarized daily minimum baseline temperature within the subbasin base_min – average daily minimum temperature across all years in the subbasin during the baseline period. fut_mean_sd – standard deviation of the summarized daily average future temperature within the subbasin. fut_mean – daily mean temperature across all years in the subbasin during the future period. fut_max_sd – standard deviation of the summarized daily maximum future temperature within the subbasin fut_max – average daily maximum temperature across all years in the subbasin during the future period. fut_min_sd – standard deviation of the summarized daily minimum future temperature within the subbasin fut_min – average daily minimum temperature across all years in the subbasin during the future period. mean_ipsl_precip_allsubs.csv – Mean annual precipitation (mm) for baseline and future periods, summarized by subbasin, under the IPSL scenario. Columns include: SUB – subbasin within the Cape Fear watershed ipsl_base_sd – standard deviation of summarized precipitation values during the baseline scenario ipsl_base_mean – mean annual precipitation within the specified subbasin during the baseline scenario ipsl_fut_sd – standard deviation of summarized precipitation values during the future scenario. ipsl_fut_mean – mean annual precipitation within the specified subbasin during the future scenario. mean_ipsl_temp_allsubs.csv – Annual mean, maximum, and minimum temperature (°C) for baseline and future periods, summarized by subbasin, under the IPSL scenario. Columns include: Subbasin – subbasin within the Cape Fear watershed base_mean_sd – standard deviation of the summarized daily average baseline temperature within the subbasin. base_mean – daily mean temperature across all years in the subbasin during the baseline period. base_max_sd – standard deviation of the summarized daily maximum baseline temperature within the subbasin base_max – average daily maximum temperature across all years in the subbasin during the baseline period. base_min_sd – standard deviation of the summarized daily minimum baseline temperature within the subbasin base_min – average daily minimum temperature across all years in the subbasin during the baseline period. fut_mean_sd – standard deviation of the summarized daily average future temperature within the subbasin. fut_mean – daily mean temperature across all years in the subbasin during the future period. fut_max_sd – standard deviation of the summarized daily maximum future temperature within the subbasin fut_max – average daily maximum temperature across all years in the subbasin during the future period. fut_min_sd – standard deviation of the summarized daily minimum future temperature within the subbasin fut_min – average daily minimum temperature across all years in the subbasin during the future period. water_quality This folder contains CSV files summarizing baseline (2000-2020) and projected future (2040-2060) water quality metrics two climate scenarios (CNRM and IPSL) from the Cape Fear SWAT model. Data are provided at both the watershed scale and at individual subbasins. annual_concentration cnrm_base_fut_tn.csv – mean annual total nitrogen (TN; mg/L) concentrations for baseline and future periods during the CNRM scenario summarized at each subbasin. Columns include: RCH – subbasin identifier cnrm_base – baseline mean TN concentration cnrm_base_sd – baseline standard deviation of TN cnrm_fut – future mean TN concentration cnrm_fut_sd – future standard deviation of TN tn_pchange – percent change in mean TN concentration from baseline to future. cnrm_base_fut_tp.csv – mean annual total phosphorus (TP; mg/L) concentrations for baseline and future periods during the CNRM scenario summarized at each subbasin. Columns include: RCH – subbasin identifier cnrm_base – baseline mean TP concentration cnrm_base_sd – baseline standard deviation of TP cnrm_fut – future mean TP concentration cnrm_fut_sd – future standard deviation of TP tp_pchange – percent change in mean TP concentration from baseline to future. cnrm_base_fut_tss.csv – mean annual total suspended sediment (TSS; mg/L) concentrations for baseline and future periods during the CNRM scenario summarized at each subbasin. Columns include: RCH – subbasin identifier cnrm_base – baseline mean TSS concentration cnrm_base_sd – baseline standard deviation of TSS cnrm_fut – future mean TSS concentration cnrm_fut_sd – future standard deviation of TSS tss_pchange – percent change in mean TSS concentration from baseline to future. ipsl_base_fut_tn.csv – mean annual total nitrogen (TN; mg/L) concentrations for baseline and future periods during the IPSL scenario summarized at each subbasin. Columns include: RCH – subbasin identifier ipsl_base – baseline mean TN concentration ipsl_base_sd – baseline standard deviation of TN ipsl_fut – future mean TN concentration ipsl_fut_sd – future standard deviation of TN tn_pchange – percent change in mean TN concentration from baseline to future. ipsl_base_fut_tp.csv – mean annual total phosphorus (TP; mg/L) concentrations for baseline and future periods during the IPSL scenario summarized at each subbasin. Columns include: RCH – subbasin identifier ipsl_base – baseline mean TP concentration ipsl_base_sd – baseline standard deviation of TP ipsl_fut – future mean TP concentration ipsl_fut_sd – future standard deviation of TP tp_pchange – percent change in mean TP concentration from baseline to future. ipsl_base_fut_tss.csv – mean annual total suspended sediment (TSS; mg/L) concentrations for baseline and future periods during the IPSL scenario summarized at each subbasin. Columns include: RCH – subbasin identifier ipsl_base – baseline mean TSS concentration ipsl_base_sd – baseline standard deviation of TSS ipsl_fut – future mean TSS concentration ipsl_fut_sd – future standard deviation of TSS tss_pchange – percent change in mean TSS concentration from baseline to future. annual_load cnrm_base_fut_tn.csv – mean annual total nitrogen (TN; kg) loads for baseline and future periods during the CNRM scenario summarized at each subbasin. Columns include: RCH – subbasin identifier cnrm_base – baseline mean TN load cnrm_base_sd – baseline standard deviation of TN cnrm_fut – future mean TN load cnrm_fut_sd – future standard deviation of TN tn_pchange – percent change in mean TN load from baseline to future. cnrm_base_fut_tp.csv – mean annual total phosphorus (TP; kg) loads for baseline and future periods during the CNRM scenario summarized at each subbasin. Columns include: RCH – subbasin identifier cnrm_base – baseline mean TP load cnrm_base_sd – baseline standard deviation of TP cnrm_fut – future mean TP load cnrm_fut_sd – future standard deviation of TP tp_pchange – percent change in mean TP load from baseline to future. cnrm_base_fut_tss.csv – mean annual total suspended sediment (TSS; metric tons) loads for baseline and future periods during the CNRM scenario summarized at each subbasin. Columns include: RCH – subbasin identifier cnrm_base – baseline mean TSS load cnrm_base_sd – baseline standard deviation of TSS cnrm_fut – future mean TSS load cnrm_fut_sd – future standard deviation of TSS tss_pchange – percent change in mean TSS load from baseline to future. ipsl_base_fut_tn.csv – mean annual total nitrogen (TN; kg) loads for baseline and future periods during the IPSL scenario summarized at each subbasin. Columns include: RCH – subbasin identifier ipsl_base – baseline mean TN load ipsl_base_sd – baseline standard deviation of TN ipsl_fut – future mean TN load ipsl_fut_sd – future standard deviation of TN tn_pchange – percent change in mean TN load from baseline to future. ipsl_base_fut_tp.csv – mean annual total phosphorus (TP; kg) loads for baseline and future periods during the IPSL scenario summarized at each subbasin. Columns include: RCH – subbasin identifier ipsl_base – baseline mean TP load ipsl_base_sd – baseline standard deviation of TP ipsl_fut – future mean TP load ipsl_fut_sd – future standard deviation of TP tp_pchange – percent change in mean TP load from baseline to future. ipsl_base_fut_tss.csv – mean annual total suspended sediment (TSS; m tons) loads for baseline and future periods during the IPSL scenario summarized at each subbasin. Columns include: RCH – subbasin identifier ipsl_base – baseline mean TSS load ipsl_base_sd – baseline standard deviation of TSS ipsl_fut – future mean TSS load ipsl_fut_sd – future standard deviation of TSS tss_pchange – percent change in mean TSS load from baseline to future. spatial_data physiographic_regions physiographic_regions.shp – polygon shapefile of the three physiographic regions intersecting the Cape Fear watershed: the Blue Ridge, the Piedmont, and the Coastal Plain. reach_network main_stem.shp – line shapefile of the main stem (Cape Fear River) in the SWAT model. reach.shp – line shapefile of the reach network for the Cape Fear Watershed generated by the SWAT model. watershed_boundary huc8_subwatersheds.shp – polygon shapefile of the HUC-8 level subwatersheds within the Cape Fear Watershed, including the Haw River, Deep River, Upper Cape Fear River, Black River, Northeast Cape Fear River, and Lower Cape Fear River. subasins.shp – shapefile of the subbasins delineated by the SWAT model. watershed_outlet.shp – point shapefile of the watershed outlet for the Cape Fear River watershed. Code/software Any software can be used to view and analyze the data. For the study, we used R Statistical Software.