4/25/2017 VIC-CropSyst Sep 16, 2011 Template I-Grey curve

Outline Overview Modeling Approach Data and parameterization Challenges ahead

Overview

VIC-CropSyst VIC CropSyst Hydrology Cropping Systems Liang et al, 1994 Stockle and Nelson 1994

Overview of Framework

Modeling Approach – specific to VIC-CropSyst

VIC-CropSyst Model VIC CropSyst 1. Weather (D) 2. Soil Sow date Soil layer depths Soil water content 3. Water flux (D) Infiltrated water 4. Crop type Irrigation water = Crop Water Demand /irrigation efficiency Sow date Crop interception capacity Crop phenology Crop uptake (D) Water stress (D) Current biomass (D) Crop Water demand (D) Harvest day Crop Yield D – communicated daily

VIC-CropSyst : Coupling Approach T – Transpiration IP – Interception capacity I – Infiltration Ir – irrigation Wd- Water demand Q – Runoff Q01 – Drainage from 0 to 1 Q02 – Drainage from 0 to 2 Qb – Baseflow W0 – water content in 0 W1 – water content in 1 W2 - water content in 2 Tmin, Tmax – daily minimum and maximum temperature Ws – wind speed RH – Relative humidity SR – Solar radiation Qb Q12 T IP Redistribute I, W0, W1 and W2 to CropSyst layers Q Q01 W0,W1, W2 T0, T1, T2, IP, Wd I CropSyst VIC Ir Daily Tmin, Tmax, Ws, RH, SR, I VIC – CropSyst interactions The main difference in the subsurface structure between the two models is the number of subsurface layers. Although VIC is capable of having many layers, it traditionally run with 3 layers (0, 1 and 2). CropSyst has many more subsurface layers that increase with depth. VIC to CropSyst -The transpiration amount returned by the CropSyst model is used to update the soil water content of the VIC layers -Infiltration, surface runoff, drainage between layers, and base flow are estimated by VIC at daily time scale -The weather data, infiltrated water are passed daily -soil water contents and soil structure (layer depths) are passed once at the beginning of the season The CropSyst model finds an appropriate day for sowing the crop and starts simulating the crop growth. At daily time step it returns the water transpired by the crop, the interception capacity, current biomass, water stress and the water demand of the crop. Based on the water demand, VIC adds the irrigation water, which depends on the water availability when running under reduced irrigation scenario. CropSyst also finds the appropriate day after maturity to harvest the crop and returns the crop yield on that day.

Invoking CropSyst within VIC gridcell CropSyst is invoked Crop 2 CropSyst is invoked Crop 1 Non-Crop Vegetation This illustrates an example of land cover distribution within a VIC grid cell. Sub-grid variability in land cover is handled statistically (i.e., each land cover within a grid cell is assigned a percentage of the area occupied by that grid cell.) When the VIC-Cropsyst model is executed, the CropSyst model is invoked only for the sub-grids that are occupied by a crop. The non-crop type land covers are handled by the non-coupled VIC model. VIC grid cell (resolution=1/16° ~ 33 km2 ) Within the cell, VIC does not identify the geographical locations of the crops

VIC-CropSyst integration - Time view Total yield, Biomass etc Crop 1 At the beginning of each daily time step To CropSyst Weather condition Irrigation- add 20mm if the need ≥ 20 mm Crop type, Soil texture Start looking for sow day Crop harvest date VIC grid cell Crop emerges Time This gives a time series view of how the integration works. The text boxes are also surrogates for actual programming interfaces. When the land cover type is identified as a crop, we prepare CropSyst at the beginning of the time loop (this can be actually done anytime before the growing of the crop) by telling it what type of crop is being grown and also give the soil characteristics. Depending on the management parameter-sowing date, we will ask CropSyst to start the plant dynamics. From this date onwards, we will tell CropSyst at the beginning of each time step, the soil water content, weather condition, CO2 concentration, reference evap. And at the end of the time step, CropSyst returns the updated soil water content, Irrigation need and transpiration. When it is time for harvesting, we ask CropSyst to harvest and return the total yield, biomass etc. At the end of each daily time step From CropSyst Irrigation need Transpiration

Time view Crop type 2, Soil texture At the beginning of each daily time step To CropSyst Weather Irrigation if needed Sow date- Start crop growing Crop harvest date Total yield, Biomass etc Crop 2 Crop 1 At the beginning of each daily time step To CropSyst Weather Irrigation if needed Sow date- Start crop growing Crop harvest date Total yield, Biomass etc Crop type 1, Soil texture First clipping Second clipping The crop parameters both physical and management can change between crops within the same VIC grid cell. This is to show that the management options like sowing date, irrigation practices and harvesting date can change between crops and in theory crop 1 and crop 2 can be the same3 crop but have different management practices. This is also a good time to emphasize the spatial variability of Crop parameters. We may have to mention that as a first step, while the parameterization is still going on, we are building a model that grows only one crop with spatially homogenous parameters.

Selective deficit irrigation - Curtailment cells are identified from the water rights data -Low value crops are curtailed before curtailing the high value crops - Monthly curtailments are disaggregated to grid cell and crop specific reduction in irrigated water For a low value crop selected for curtailment Under full irrigation Under deficit irrigation Month scale

Data and parameterization

Input to VIC-CropSyst VIC-CropSyst Met data CropSyst parameter files Crop specific parameters files Phenology adjusted files Soil parameter files County – gridcell association information CropSyst parameter files VIC-CropSyst Met data VIC parameter files Global control file Veg parameter file Veg library Soil data Snow bands data Crop library Crop parameter file

Crop Land Data Layers WSDA – Washington State Department of Agriculture USDA – US Department of Agriculture

Reconciling USDA and WSDA Crop Code WSDA name USDA name Model name 218 Wheat WinWheat 210 Missing SpgWheat 701 Alfalfa, Hay Alfalfa 1827 Potato Potatoes 204 Corn, Field Corn 1208 Pasture_Grass 1401 Apple Apples 1803 Bean, Dry DryBeans 1804 Bean, Green BeanGreen 1824 Pea, Dry Peas 713 Grass, Hay GrassHay 1814 Corn, Sweet SweetCorn 1206 NLCDPasture_Hay 1503 Bluegrass, Seed BluegrassSeed 703 Alfalfa/Grass, Hay AlfalfaOrGrassHay 1403 Cherry CherryOrchard 1207 OtherHays

Crops Modeled Major Crops Grape, Juice Grape, Wine Pea, Green Pea, Dry Sugarbeet Canola Onions Asparagus Carrots Squash Garlic Spinach Berries Grape, Juice Grass hay Bluegrass Hay Rye grass Oats Bean, green Rye Barley Bean, dry Other Pastures Winter Wheat Spring Wheat Alfalfa Barley Potato Corn Corn, Sweet Pasture Apple Cherry Lentil Mint Hops Caneberry Blueberry Cranberry Pear Peaches Other Tree fruits Lentil/Wheat type Generic Vegetables

Crop specific parameters Each crop has a parameter file [phenology] maturity_significant=true emergence= flowering=850 peak_LAI=800 filling=950 maturity=1500 senescence=1000 tuber_init= resolution=day base_temp=5 cutoff_temp=25 maximum_temp=25 …. [transpiration] ET_crop_coef=1.23 max_water_uptake=13 stomatal_closure_leaf_water_pot=-1300 wilt_leaf_water_pot=-2000 [canopy_cover] initial_cover=0.05 maximum_cover=0.85 mature_green_cover=0.2 mature_total_cover=0.7 …

Phenology parameters adjustments

Phenology parameters adjustments Crop parameter file Downscaled Met data Crop present in the grid cell? Calibration (independent code) New phenology crop parameter file- adjust is specific to the geographic location of the cell. This is a pre-processor and creates “xxx_adjusted” file for each crop

County yield adjustments CropSyst yields are dry yields and cannot be directly compared to the NASS values CropSyst assumes optimum conditions and does not account for losses due to pests, diseases etc Adjusted based on observed data Observed yield data available only at county or State scale Adjustments are currently hard coded

CropSyst soil data Current VIC soil data was too course for CropSyst STATSGO based soil data is used by the CropSyst for estimating the soil properties

Input to VIC-CropSyst Met data VIC-CropSyst CropSyst parameter files Crop specific parameters files Phenology adjusted files Soil parameter files County – gridcell association information CropSyst parameter files Met data VIC-CropSyst VIC parameter files Global control file Veg parameter file Veg library Soil data Snow bands data Crop library Crop parameter file

Veg parameter file Traditional land cover inputs to VIC Vegetation library file Vegetation parameter file 1…. 60.0 … Evergreen Needleleaf 2…. 60.0 … Evergreen Broadleaf … 10.......... 11……. 272002 2 10 0.550000 0.10 0.10 1.00 0.65 0.50 0.25 0.013 0.038 0.038 0.038 0.025 0.562 1.237 1.312 0.325 0.025 0.025 0.025 11 0.450000 0.10 0.10 1.00 0.70 0.50 0.20 0.225 0.262 0.287 0.375 0.712 1.212 0.913 0.600 0.412 0.275 0.225 0.213

New parameter files related to crop distribution Crop library file Crop parameter file 204 Corn 205 CornUnknown 210 SpgWheat 218 WinWheat Alfalfa ….. 315617 6 210 0.017000 60 9 0 218 0.145000 265 9 0 701 0.024390 1 1 1 1401 0.055300 1 20 1 1814 0.012330 60 41 0 1827 0.196400 60 9 0 Crop code Fraction of the cell Day of the crop creation Irrigation identifier Perennial crop identifier

Veg parameter file for VIC-CropSyst 1…. 60.0 … Evergreen Needleleaf … .......... 11……. 204……. Corn 205….. CornUnknown Vegetation library file Vegetation parameter file 272002 2 10 0.550000 0.10 0.10 1.00 0.65 0.50 0.25 0.013 0.038 0.038 0.038 0.025 0.562 1.237 1.312 0.325 0.025 0.025 0.025 ….. 205 0.130000 0.10 0.10 1.00 0.70 0.50 0.20 0.225 0.262 0.287 0.375 0.712 1.212 0.913 0.600 0.412 0.275 0.225 0.213

Challenges ahead

Future work VIC soil data – should be redone Crop land data layer – discrepancies between data sources must be resolved Irrigation data for other States Crop rotation Conveyance loss is currently not modeled Groundwater component Calibration of “VIC-CropSyst”

4/25/2017 THANK YOU!! Template I-Grey curve