HydroSoil: A 2-D hydrological model to improve simulations of crop-soil water interactions at the spatial domain for agriculture applications

Abstract:

Concerns about food security in the face of climate change have raised the need for evaluation and adaptation of crops to future changes. Using crop modeling may assist in the task of predicting future impacts of climate on crop yield and quality. However, to accurately forecast climate effects on crops, crop models need to better address crop-climate interactions. Soil water is one of the key factors affecting crop yield and quality, particularly in rainfed fields in water-limited regions. Currently, widely-used crop models deal with crop-soil water interactions in a rather simplified way because integrating both, crop and hydrologic models, at the spatial domain is not straightforward. Also, hydrological models require extensive information on soil properties, which are difficult to acquire. These, and other problems, make the integration of hydrologic and crop growth models a challenging task.

We propose a new two-dimensional numerical simulation model of soil water flow (HydroSoil), which will be directly integrated into a crop growth model to better simulate crop-soil water interactions at the spatial domain. Hydrosoil aims to use fewer soil parameters compared to more complex models, yet provide accurate soil water estimations. Using HydroSoil will help us understand crop-soil water interactions under the uncertainties and variabilities of climatic changes. The objectives of our study are to: (1) develop a new free-distributed and easy-to-use two dimensional hydrologic model with basic soil property inputs to simulate soil water dynamics based on grid-cell information of soil texture derived from satellites, (2) test the model with various pedotransfer functions, (3) evaluate the model using field experimental datasets for different scenarios of precipitation and soil characteristics, and (4) compare the performance of HydroSoil with other widely-used hydrologic models in terms of soil water balance and dynamics.