ORDER OF OPERATIONS:
1. Shapefiles of watershed boundaries are delineated/obtained (Shapefiles folder)
2. R scripts are used to obtain PRISM gridded climate data and aggregate/average for each sub basin (PRISM folder)
3. Analyses for Budyko based methods are conducted (BUDYKO folder)
4. Analyses for Human/Climate impacts are conducted (HUMAN CLIMATE IMPACTS folder)


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Data Files:
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SHAPEFILES: This folder contains deliberated subbasins for the Colorado River Basin. 
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- 29 Subbasins: One shapefile related to 29 subbasins
- 29 Subbasins (separate): 29 shapefiles related to each subbasin
- 29 Points: Shapefile of 29 points corresponding to locations where naturalized flow estimates are available.
- An excel file "Coordinates_29_Gages.xlsx" containing the coordinates of all 29 gages


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PRISM: This folder contains input and output files and code relating to summaries of PRISM data.
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- R scripts to download and extract PRISM data: PRISM_DownloadData, PRISM_ExtractData_Precip, PRISM_ExtractData_Temp

1. PRISM_DownloadData: This code downloads raw data from the PRISM website in bulk given user defined period. There is a limitation of 500 locations for getting the data. 
2. PRISM_ExtractData_Precip: This code uses 1- the raw PRISM precipitation files and 2- text files containing PRISM grids of each subbasin to extract the precipitation data of each subbasin and calculate the average precipitation within the subbasin. 
3. PRISM_ExtractData_Temp: This code uses 1- the raw PRISM temperature files and 2- text files containing PRISM grids of each subbasin to extract the temperature data of each subbasin and calculate the average temperature within the subbasin. 

- US PRISM grids with 4km resolution 
- Text files containing PRISM grids of each subbasin
- PrecipBIL: contains raw PRISM files related to precipitation 
- TempBIL: contains raw PRISM files related to temperature
- PRISM_Extracted Precip & Temp folder contains final results of extracting precipitation and temperature from PRISM data


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BUDYKO: This folder contains input and output files and code relating to the determinations of precipitation partitioning, climate elasticity and sensitivity.
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Input Data:
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1. CR_Precip_Int: Time series of precipitation (mm) for each of 29 subbasins within the Colorado River basin. Data were estimated on a monthly basis from PRISM by aggregating over subbasin areas. Each column is defined by the USGS gaging station ID.
2. CR_Temp_Int: Time series of temperature (degrees C) for each of 29 subbasins within the Colorado River basin. Data were estimated on a monthly basis from PRISM by aggregating over subbasin areas. Each column is defined by the USGS gaging station ID.
3. InterveningNaturalFlows: Time series of estimated discharge (acre-feet) on a monthly basis without human consumptive uses from the Bureau of Reclamation https://www.usbr.gov/lc/region/g4000/NaturalFlow/. Each column is defined by the USGS gaging station ID.
4. InterveningSubbasins: Spatial characteristics of each of the 29 Colorado subbasins from GIS. Fields are as defined below for MasterBudyko.

R scripts/code:
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1. BudykoColoradoRiverBasins: This code uses PRISM data, GIS data, and naturalized flow inputs to generate Budyko curves, determine the Budyko parameter, and estimate elasticity and sensitivity to changes in climate for 29 subbasins in the Colorado River basin. Intervening naturalized flow are used to represent each subbasin discretely.
2. BudykoColoradoRiverObservedFlow: This code uses PRISM data, GIS data, and USGS flow data in attempt to generate Budyko curves. Observed flow data were obtained using the USGS dataRetrieval package. Intervening flows were estimated by subtracting observed flows. This oversimplicifican created inconclusive results.
3. BudykoColoradoRiverSubsetBasins: This code uses PRISM data, GIS data, and naturalized flow inputs to generate Budyko curves for select subbasins in the Colorado River basin: the Paria River, the Little Colorado River, and subbasins representative of snowmelt and monsoonal hydrology.

Output Data:
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1. USGSColoradoRiverFlows: Month, water year, and date are listed along with a column of each of the 29 watersheds by USGS gaging station ID. Each cell represents the instantaneous flow in cubic feet per month.

2. MasterBudyko 
Station_ID: USGS gaging station ID
FID: Code assigned in GIS
ID: USGS gage from upstream to downstream
NAME: USGS gaging station name
AREA_MI2: Watershed area in square miles
AREA_KM2: Watershed area in square kilometers
AREA_ACRES: Watershed area in acres
AREA_M2: Watershed area in square meters
MeanT: Average annual mean temperature (degrees C)
AnnualMeanP: Average annual mean precipitation (mm)
AnnualMeanNatQ: Average annual flow using the naturalized flow data (acre-ft)
natQmm: Average annual depth of runoff using naturalized flow data and subbasin area (mm)
ETmm: Average annual depth of evapotranspiration calculated in the code BudykoColoradoRiverBasins (mm)
PET: Average annual depth of potential evapotranspiration calculated in the code BudykoColoradoRiverBasins (mm)
w: Budyko storage  parameter calculated in the code BudykoColoradoRiverBasins. unitless.
Elas: Elasticity (changes in runoff due to changes in precipitation) calculated in the code BudykoColoradoRiverBasins (scalar multiplier)
dQ: Sensitivity (changes in runoff due to changes in temperature) calculated in the code BudykoColoradoRiverBasins (percent change per degree C)
PET_P: Aridity Index (potential evapotranspiration/precipitation) calculated in the code BudykoColoradoRiverBasins (unitless)
ET_P: Evaporative index (actual evapotranspiration/precipitation) calculated in the code BudykoColoradoRiverBasins (unitless)

3. MasterBudyko_Observed : same columns as MasterBudyko, except AnnualMeanNatQ is AnnualMeanObsQ (Average annual flow using the observed flow data) and natQmm is obsQmm (Average depth of runoff using observed flow data). PET_P and ET_P are not calculated because values of w cannot be calculated for each of the basins.


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HUMAN CLIMATE IMPACTS: This folder contains files used to determine breakpoints and estimate shares of human and climate impacts. 
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- R-Code: Double-Mass Curve uses the flow and precipitation data in "R Inputs_DoubleMass.xlsx" as inputs to plot double-mass curve as a method to determine the break points.
- Excel file: "R_Inputs_DoubleMass.xlsx" contains inputs for the R-code.
- Excel file: "Climate_Human_Impacts.xlsx" in which shares of climate change and human impacts are estimated.