Source: UNIVERSITY OF CALIFORNIA, RIVERSIDE submitted to NRP
UNDERSTANDING SURFACE WATER-GROUNDWATER INTERACTIONS AT LARGE CATCHMENT SCALES
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1013324
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Jul 8, 2017
Project End Date
May 31, 2022
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIVERSITY OF CALIFORNIA, RIVERSIDE
(N/A)
RIVERSIDE,CA 92521
Performing Department
Environmental Sciences
Non Technical Summary
Sustainable management of water resources requires detailed characterization of land surface and subsurface hydrologic processes that control stream flow, evapotranspiration, and groundwater dynamics. This understanding will be achieved through analysis of in-situ and satellite based observations and implementation and development of numerical models to understand temporal and spatial variability of land surface and subsurface fluxes and states. In addition, by consideration of natural (climate, vegetation, soil) and anthropogenic factors (changes in land use, irrigation type, groundwater pumping rates) in the hydrologic prediction systems, the impact of management practices on future water availability will be explored. Development of process-based, computationally efficient modeling tools and their implementation across variety of landscapes provide valuable means for water resources assessment at large scale. Results of this project provides improved understanding of plant water use using novel measurement techniques in different settings and provides valuable information for water management in irrigated agriculture systems.
Animal Health Component
20%
Research Effort Categories
Basic
50%
Applied
20%
Developmental
30%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1120210205060%
1020320205020%
1320210205020%
Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 112 - Watershed Protection and Management; 132 - Weather and Climate;

Subject Of Investigation
0320 - Watersheds; 0210 - Water resources;

Field Of Science
2050 - Hydrology;
Goals / Objectives
This research proposal pursues four fundamental topics (1) Understanding and characterizing feedback processes between the subsurface and land-atmosphere from local to regional scales; (2) Integrating spatially explicit data such as remotely sensed observations for hydrologic model evaluation and prediction, (3) Examining the role of vegetation on land-atmosphere interactions, and (4) Developing computationally efficient approaches for large scale watershed simulations.(1) Understanding and characterizing feedback processes between the subsurface and land-atmosphere using numerical models and observations The extent of land surface-subsurface coupling in variety of settings and in response to climatic and anthropogenic factors are poorly understood. For instance, not enough is known about how recharge rates might be altered by climate change and groundwater pumping in arid and semi-arid mountainous catchments. The lack of a groundwater monitoring network in mountainous catchments hinders understanding of recharge rates and groundwater flow paths from mountains to valley aquifers. Precipitation (snow and rain) in the Sierra Nevada mountain range is the dominant recharge mechanism for the aquifer system in California's Central Valley, one of the nation's most important agricultural regions. Recurrent droughts and record low snowpacks in the Sierra Nevada are expected to decrease recharge, posing significant challenges to sustainable groundwater management. Lack of understanding about this key hydrological process of mountainous catchments in Sierra Nevada and Basin and Range province will render assessments of the climate variability impacts incomplete and possibly inaccurate.Irrigation return flow is another major source of recharge in many arid and semi-arid aquifer systems (Jiménez-Martínez et al., 2010). However, it is not clear how changes in crop water demand and implementation of more efficient irrigation technologies impact overall return flows in agricultural ecosystems. Therefore, there is a need to understand and characterize groundwater recharge processes and identify how different recharge pathways will be altered as a result of climate variability and human water management practices. Conversely, it is also important to characterize how groundwater dynamics impact streamflow and evapotranspiration processes at the land surface particularly in response to groundwater pumping and changes in land use.(2) Integrating spatially explicit data such as remotely sensed observations for hydrologic model evaluation and predictionEvaluation of distributed hydrologic models is often made using stream flow time series at a few locations in a given catchment. With a growing number of remotely sensed products, spatially explicit data obtained from remotely sensed observations provide a valuable resource for hydrologic model evaluation and can be used to improve prediction. These datasets allow multi-criteria evaluation of hydrologic prediction systems to perform model diagnostics and improve predictions (e.g. streamflow, evapotranspiration and groundwater levels). This requires developing benchmarks for assessing performance of distributed hydrologic models.(3) Examining the role of vegetation on land-atmosphere interactions Evapotranspiration constitutes a major component of the water budget in many arid and semi-arid basins, and vegetation communities have great impact on partitioning of water and energy balances at the land surface. However, simplified approaches have been implemented to represent vegetation processes in hydrologic models. Proper representation of dynamic vegetation in hydrologic models is an important step in characterizing and understanding feedback processes between hydrology and ecology on the land surface under climate variability and increases in CO2 concentrations. Moreover, partitioning of ecosystem?scale evapotranspiration fluxes between soil/canopy evaporation and plant transpiration is not well understood (Wang et al., 2010) particularly in irrigated agriculture systems. Therefore, an improved understanding of how much water is transpired by crops relative to the amount lost due to evaporation under various irrigation scenarios and for different crops is required. Recent advances in field deployable laser based water isotope analysers has provided a promising tool for partitioning transpiration and evaporation in the field with high temporal resolution.(4) Developing computationally efficient approaches for large scale watershed simulationsIn recent years, a large number of complex hydrologic models have been developed that simulate terrestrial hydrologic processes from subsurface to the atmosphere. However, their applications at large scales or for uncertainty assessment are limited due to the enormous computational requirements these commonly pose to modelers. Recently, a new semi-distributed hydrologic modeling framework has been developed to reduce computational time for large scale catchment simulations. The Soil Moisture and Runoff simulation Toolkit (SMART) is written in MATLAB (Ajami et al., 2016, Environmental Modelling and Software) and performs all the geospatial data processing and model simulations behind a user friendly interface. SMART has a modular framework and it simulates lateral flow and soil moisture dynamics using a 2-dimensional Richards' equation-based hydrologic model and has multiple tools for delineating 2-dimensional cross sections. The SMART modeling toolkit offers unique computation advantages that no other model can offer at the moment. However, there is a need to apply this framework across multiple catchments with various topography, soil and vegetation types to assess its performance. Moreover, future enhancements are required to include additional modules for river routing, groundwater and dynamic vegetation simulation, and make SMART platform independent.
Project Methods
Specific AIM 1: To better understand and characterize surface water-groundwater exchange across mountainous and agricultural catchments, we rely on observational networks established by federal and state water agencies and critical zone observatories. When possible, we collect precipitation, surface water and groundwater samples for stable water isotope analysis to infer groundwater flow paths and determine recharge seasonality. We implement and calibrate a range of hydrologic models suitable for simulating hydrologic processes in mountain catchments including the integrated groundwater-land surface model, ParFlow.CLM (Ashby and Falgout, 1996; Jones and Woodward, 2001; Kollet and Maxwell, 2006), and the semi-distributed hydrological model called hillslope storage Boussinesq-Soil Moisture (hsB-SM) model (Troch et al., 2003). The modeling effort will allow quantification of recharge and evapotranspiration fluxes at large scale, characterizing feedback processes between the land surface and subsurface, and projecting future changes in water availability based on global climate model projections (CMIP5 datasets) and changes in groundwater pumping rates.In agricultural ecosystems, numerical models such as Soil and Water Assessment Tool (SWAT) and ParFlow.CLM will be used to assess the impacts of management decisions on surface water and groundwater resources. In addition, we plan to couple these hydrologic models with water allocations modules to optimize demands based on priorities and constraints using surface water-groundwater interaction information obtained from hydrologic models.Specific AIM 2: While variety of satellite products are available to monitor the status of vegetation, snow, soil moisture and groundwater storage, applications of these products at catchment scale are often limited by their coarse spatial and temporal resolutions. In this project, remotely sensed products will be used for evaluating models developed in aims 1 and 4 while considering inherent uncertainty in these products. In addition, the use of unmanned aerial vehicle systems (UAVs) in monitoring and developing earth system products at high temporal and spatial resolutions that are suitable for water resources assessment will be explored. We will develop multi-criteria indices and benchmarks for evaluating integrated hydrologic models.Specific AIM 3: Understanding the role of vegetation dynamics will be achieved by analyzing time series derived from satellite vegetation products. These changes in vegetation dynamics will be used to better parameterize integrated hydrologic models for long term hydrologic predictions. In addition, state-of-the-art liquid and water vapor isotope analyzers will be used to quantify the partitioning of evaporation and transpiration by a variety of vegetation types. These observations will be supplemented with additional monitoring networks suitable for quantifying evapotranspiration and assessing water use efficiency of various irrigation practices on crop water use and yield. Information obtained from field scale investigations will be used to parameterize ecohydrologic models to explore evapotranspiration dynamics at large scale.Specific AIM 4: We plan to extend this research area further by developing alternative distributed modeling platforms using GIS based tools, and present new developments in this space that have the potential for increasing computational efficiency over time while accounting for important hydrological and ecological processes that impact catchment water balance. This will be achieved by including additional processes in the SMART modeling framework including runoff routing, groundwater component and vegetation dynamics. This investigation also requires detail model evaluation in experimental watersheds and will use methodology and datasets developed in aims 2 and 3.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:The target audience includes hydrologists, civil and environmental engineers, federal/state water resource agencies and general public. Results of the research is disseminated through: • 3 refereed journal articles related to groundwater recharge processes in drylands as a fucntion of climate and vegetation changes, developing a new ecohydrologic module for the computationally efficient semi-distributed hydrologic model, assessing changes in hydrologic response as a fucntion of changes in precipitation, temperature and CO2 concentration • Published 2 book chapters for the Encyclopedia of Geology 2nd Edition • Presentations at 11 national and international conferences. • 1 invited public presentation as part of the Salton Sea summit regarding water resources management in the Salton Sea • Taught 1 upper division undergraduate course in spatial analysis and remote sensing for environmental sciences (4 units) and co-developed and co-taught a new graduate course in integrated hydrologic modeling at UC Riverside. • Served as the Chair of 1 MS thesis committee and participated in 12 PhD qualifying exams • Served as an Associate Editor for California Agriculture, Hydrological Sciences Journal and Journal of Hydrology Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project has provided training opportunity for 1 undergraduate student, 2 graduate students and 2 postdocs at UC Riverside. I also co-adivsied a post doctoral fellow at the University of New South Wales on implementing SMART for large catchment scale simulations. How have the results been disseminated to communities of interest?I gave 1 public presentation to farmers and water agencies in the Imperial Valley What do you plan to do during the next reporting period to accomplish the goals?• Improving mountain system recharge predictions in the Sierra Nevada California using a data-based approach • Improving cropland parameterization in integrated hydrologic models • Quantifying the impacts of California drought on groundwater response in the Central Valley aquifer system • Assessing the impacts of changes in agricultural water management on lake-groundwater interactions

Impacts
What was accomplished under these goals? • Assessed the impacts of uncertainty in meteorological forcings (precipitation and temperature) on the water budgets of a mountain catchment in the Sierra Nevada • Assessed the impacts of climate and vegetation changes on mountain front recharge processes • Quantified groundwater lag time and recovery time to droughts across the continental US. • Assessed the role of CO2 concentration in addition to changes in precipitation and temperature on catchment scale hydrologic response using an ecohydrologic model • Developed an ecohydrologic module for the SMART modeling framework using remotely sensed vegetation products

Publications

  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Schreiner-McGraw, A., E.R. Vivoni, H. Ajami, O.E. Sala, H.L. Throop, D.P.C. Peters.2020. Woody Plant Encroachment has a Larger Impact than Climate Change on Dryland Water Budgets, Scientific Reports, https://doi.org/10.1038/s41598- 020-65094-x
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Stephens, C. M., L.A. Marshall, F.M. Johnson, L. Lin, L.E. Band, and H. Ajami. 2020. Is Past Variability a Suitable Proxy for Future Change? A Virtual Catchment Experiment, Water Resources Research, 56, https://doi.org/10.1029/2019WR026275
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Kim, S., H. Ajami, A. Sharma. 2020. Using Remotely Sensed Information to Improve Vegetation Parameterization in a Semi-distributed Hydrological Model (SMART) for Upland Catchments in Australia, Remote Sensing, http://dx.doi.org/10.3390/rs12183051
  • Type: Book Chapters Status: Awaiting Publication Year Published: 2021 Citation: Ajami, H. 2021. Geohydrology: Global Hydrological Cycle, In: Alderton, David; Elias, Scott A. (eds.) Encyclopedia of Geology, 2nd edition, vol.[6], pp. 393-398. United Kingdom: Academic Press, https://doi.org/10.1016/B978-0-12-409548- 9.12387-5
  • Type: Books Status: Awaiting Publication Year Published: 2021 Citation: Ajami, H.2021. Geohydrology: Groundwater, In: Alderton, David; Elias, Scott A. (eds.) Encyclopedia of Geology, 2nd edition, vol.[6], pp. 408-415. United Kingdom: Academic Press, https://doi.org/10.1016/B978-0-12-409548-9.12388-7


Progress 10/01/18 to 09/30/19

Outputs
Target Audience:The target audience includes hydrologist, federal/state water resource agencies and general public. Results of this project were disseminated through 3 refereed journal articles, 5invited presentations, and 6international conferences. I taught 2upper division undergraduate course regarding principles of Groundwater science (4 units), and Spatial analysis and remote sensing for environmental sciences (4 units). I served on 1MSThesis committee and 1PhD qualifying exams. I served as Associate Editor of California Agriculture and Hydrological Sciences Journals. I always aim to integrate my latest research in classroom activities as well. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?2 undergraduate students, 2 graduate students, 1 postdoc How have the results been disseminated to communities of interest?Yes. Two public lectures have been given as part of Agriculture Summit at UC Riverside and Cadiz project at Pitzer college. What do you plan to do during the next reporting period to accomplish the goals?(1) Simulate groundwater dynamics in response to short-term and long term droughts (2) Characterizing mountain system recharge processes in the Kaweah basin and validate against streamflow and remotely sensed data (3) Improve representation of vegetation processes in hydrologic models

Impacts
What was accomplished under these goals? Goal 1: Published a journal article on assessing climate change impacts on mountain front recharge processes; Work is under progress on development of an integrated groundwater-land surface model for the Kaweahbasin inCentral Valley California; Goal 2: Published a paper on qunatifying uncertainty of remotely sensed vegetation products for calibration of ecohydrologic models Goal 3: Improving vegetation dynamics in SMART model using remotely sensed leaf area index product and precipitation Goal 4:Performing multi-objective assessment of SMART simulations across a range of catchments in Australia using dischargeand remotely sensed products

Publications

  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Fan, Y., M. Clark, D. M. Lawrence, S. Swenson, L. E. Band, S. L. Brantley, P. D. Brooks, W. E. Dietrich, A. Flores, G. Grant, J. W. Kirchner, D. S. Mackay, J. J. McDonnell, P. C. D. Milly, P. L. Sullivan, C. Tague, H. Ajami, N. Chaney, A. Hartmann, P. Hazenberg, J. McNamara, J. Pelletier, J. Perket, E. Rouholahnejad-Freund, T. Wagener, X. Zeng, E. Beighley, J. Buzan, M Huang, B. Livneh, B. P. Mohanty, B. Nijssen, M. Safeeq, C. Shen, W. van Verseveld, J. Volk, D Yamazaki. 2019. Hillslope Hydrology in Global Change Research and Earth System Modeling, Water Resources Research, https://doi.org/10.1029/2018WR023903
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Tang, Y., L. Marshall, A. Sharma, H. Ajami, D.J. Nott. 2019. Ecohydrologic Error Models for Improved Bayesian Inference in Remotely Sensed Catchments, Water Resources Research, https://doi.org/10.1029/2019WR025055
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Schreiner-McGraw, A., H. Ajami, E. Vivoni.2019. Extreme Weather Events and Transmission Losses in Arid Streams, Environmental Research Letters, doi: 10.1088/1748-9326/ab2949


Progress 10/01/17 to 09/30/18

Outputs
Target Audience:The target audience includes hydrologist, federal/state water resource agencies and general public. Results of this project were disseminated through 4 refereed journal articles, 3 invited presentations, and 5 international conferences. I taught 2 upper division undergraduate course regarding principles of Groundwater science (4 units), and Spatial analysis and remote sensing for environmental sciences (4 units). I served on 2 PhD dissertation committee and 2 PhD qualifying exams. I also served as Associate Editor of California Agriculture and Hydrological Sciences Journals.I always aim to integrate my latest research in classroom activities as well. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project is training a postdoctoral fellow. 1 undergraduate student was trained to work on the SMART model application How have the results been disseminated to communities of interest?Yes. 4 Journal articles have been published. Wrote the hydrologic assessment section of California's Fourth Climate Change Assessment report for the Desert inlands region (http://www.climateassessment.ca.gov/regions/docs/20180827-InlandDeserts.pdf) 3 invited public presentations as part of California's Fourth Climate Change Assessment report and Riverside County Ag Expo What do you plan to do during the next reporting period to accomplish the goals?Continue on development of the SMART model Complete the work on development of an integrated hydrologic model for the Tulare lake basin Understanding surface water-groundwater exchange and food-water-energy nexus dynamics in the Salton Sea basin in Southern California Assessing the impacts of droughts on groundwater resources

Impacts
What was accomplished under these goals? Goal 1:work is under progress on development of an integrated groundwater-land surface model for the Tulare Lake basin in Central Valley California;work is under progress on assessing the impacts of climate change on groundwater recharge; published a paper on mountain system recharge estimation in Chile Goal 2:Published a paper on using remotely sensed vegetation products for multiobjective calibration of ecohydrologic models Goal 3: Nothing to report Goal 4: Extended the functionality of the semi-distributed model (SMART) model to the catchment scale Developed a new approach for disaggregating sub-basin scale soil moisture to fine resolution Performing multi-objective assessment of SMART simulations across a range of catchments in Australia using discharge and remotely sensed evapotranspiration and soil moisture products, in collaboration with Ashish Sharma University of New South Wales

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Ajami, H., A. Sharma. 2018. Disaggregating Soil Moisture to Finer Spatial Resolutions - A Comparison of Alternatives, Water Resources Research, https://doi.org/10.1029/2018WR022575
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Khan, U., H. Ajami, N.K. Tuteja, A. Sharma, S. Kim. 2018. Catchment Scale Simulations of Soil Moisture Dynamics Using an Equivalent Cross-Section based Hydrological Modelling Approach, Journal of Hydrology, 564: 944-966, https://doi.org/10.1016/j.jhydrol.2018.07.066
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Sandoval, E., G. Baldo, N., N��ez, J., Oyarz�n, J.P. Fairley, H. Ajami, J.L. Arum�, E. Aguirre, H. Maturana, R. Oyarz�n. A Simple Approach for Groundwater Recharge Assessment in a Rural, Arid, Mid-mountain Basin in North-Central Chile, Hydrological Sciences Journal, https://doi.org/10.1080/02626667.2018.1545095
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Tang, Y., L. Marshall, A. Sharma, H. Ajami. 2018. Modelling Precipitation Uncertainties in a Multi-objective Bayesian Ecohydrological Setting, Advances in Water Resources, https://doi.org/10.1016/j.advwatres.2018.10.015


Progress 07/08/17 to 09/30/17

Outputs
Target Audience:The target audience includes hydrologist, federal/state water resource agencies and general public. Results of this project were disseminated through 5 refereed journal articles, 8 invitedpresentations, and 2international conferences. I also taught an upper division undergraduate class in groundwater science in Spring 2017. I always aim tointegrate mylatest research in classroom activities as well. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The PI has contributed to training of a PhD student and a post doc at the University of New South Wales. The PI has also trained one undergraduate student at UC Riverside on the use of SMART model and peforming model sensitivity analysis. How have the results been disseminated to communities of interest?The results of these activities are published in technical journal articles and presented at series of invited talks in California. What do you plan to do during the next reporting period to accomplish the goals?(1) I will continue on developing coupled/integrated surface water-groundwater models in two regions in California. (2) I will continue on inegrating remotely sensed observations including vegetation and soil moisture products for hydrologic model calibration and evaulation. (3) I will continue on developing new modeling schemes to assess the role of vegetation dynamics on catchment water balance and qunaitfy uncertainty in model predictions. (4) I will continue on SMART model evaluation on multiple catchments using in situ and remotely sensed observations as well as adding new schemes to improve representation of hydrologicprocesses in SMART.

Impacts
What was accomplished under these goals? (1) Obtained funding from California Energy Commission to implement an integrated groundwater-land surface model for the Tulare basin in Central Valley, California. The objective of the project is to assess the impacts of climate variability on surface water-groundwater exchanges. In addition, we plan to improvetheirrigation module in the model. The PI has also obtained funding from NSF INFEWS program to develop hydroeconomic models for southern California with colleagues from UC Riverside and in collaboration with Texas A&M University. The coupled modeling framework will provide great understanding of water availability in the Imperial Valley and Salton Sea region. I co-authored 3 journal articles related to this research aim. I contributed to developing an empirical recharge equation in Greece and contributed to the synthesis andassessing the impacts of climate vaiability on groundwater recharge in the Western US aquifers. (2) Co-advised and co-authored a paper with a PhD student at the University of New South Wales. The objective of the paper was to use three remotely sensed vegetation products for multi-objective calibration of a conceptual ecohydrologic model. Results showed that the MODIS Leaf Area Index (LAI) product is the best product for representing LAI and streamflow dynamics in a number of catchments in Australia. (3) Developed a new ecohydrologic catchment classification model and assessed the role of vegetation on annual water balance and non-stationary catchment response. The results of this work is published in Hydrology and Earth System Sciences. (4) Extended the capability of SMART model to the catchment scale and has started implementing the model in two USDA ARS sites (Walnut Gulch and Little Washita catchments). In collaboration with the Boise state university, I added a calibration module to SMART. Additional work is underway to assess the performance of the model in Australian catchments in collaboration with University of New South Wales.

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Naseem, B., Ajami, H., Sharma, A., Liu, Y., Cordery, I. 2016. Multi-objective Assessment of Three Remote Sensing Vegetation Products for Streamflow Prediction in a Conceptual Ecohydrological Model. Journal of Hydrology. Vol. 543: p.686-705. Meixner, T., Manning, A.H., Stonestrom, D.A., Allen, D.M., Blasch, K.W., Brookfield, A.E., Castro, C.L., Clark, J.F., Gochis, D., Flint, A.L., Neff, K., Niraula, R., Rodell, M., Scanlon, B.R., Singha, K., Walvoord, M.A. 2016. Implications of Projected Climate Change for Groundwater Recharge in the Western United States. Journal of Hydrology. p.124-138. Ajami, H., Sharma, A., Band, L., Evans, J., Tuteja, N., Amirthanathan, G., Bari, M. 2017. On the Non-stationarity of Hydrological Response in Anthropogenically Unaffected Catchments: An Australian Perspective. Hydrology and Earth System Sciences. Vol. 21: 14p. doi: 10.5194/hess-21-281-2017. Gemitzi, A., Ajami, H., Richnow, H. 2017. Developing Empirical Monthly Groundwater Recharge Equations based on Modeling and Remote Sensing Data - Modeling Future Groundwater Recharge to Predict Potential Climate Change Impacts. Journal of Hydrology. 13p. doi: 10.1016/j.jhydrol.2017.01.005. Niraula, R., Meixner, T., Ajami, H., Rodell, M., Gochis, D. 2017. Comparing Potential Recharge Estimates From Three Land Surface Models Across the Western US. Journal of Hydrology. Vol. 545: 14p. ic) doi: 10.1016/j.jhydrol.2016.12.028