Exploring the Influence of Smallholders' Perceptions Regarding Water Availability on Crop Choice and Water Allocation Through Socio‐Hydrological Modeling

Abstract

While it is known that farmers adopt different decision‐making behaviors to cope with stresses, it remains challenging to capture this diversity in formal model frameworks that are used to advance theory and inform policy. Guided by cognitive theory and the theory of bounded rationality, this research develops a novel, socio‐hydrological model framework that can explore how a farmer's perception of water availability impacts crop choice and water allocation. The model is informed by a rich empirical data set at the household level collected during 2013 in Kenya's Upper Ewaso Ng'iro basin that shows that the crop type cultivated is correlated with water availability. The model is able to simulate this pattern and shows that near‐optimal or “satisficing” crop patterns can emerge also when farmers were to make use of simple decision rules and have diverse perceptions on water availability. By focusing on farmer decision making it also captures the rebound effect, i.e., as additional water becomes available through the improvement of crop efficiencies it will be reallocated on the farm instead of flowing downstream, as a farmer will adjust his (her) water allocation and crop pattern to the new water conditions. This study is valuable as it is consistent with the theory of bounded rationality, and thus offers an alternative, descriptive model in addition to normative models. The framework can be used to understand the potential impact of climate change on the socio‐hydrological system, to simulate and test various assumptions regarding farmer behavior and to evaluate policy interventions.

Comment on “Exploring the Influence of Smallholders' Perceptions Regarding Water Availability on Crop Choice and Water Allocation Through Socio‐Hydrological Modeling” by Kuil et al. [Water Resource Research, 54, 2580–2604]

“…In conclusion, some of the assumptions regarding the hydrological aspects of the social‐hydrological model proposed by Kuil et al () are not well justified. Deep percolation of irrigation water was not considered in the water balance equation; and transpiration and evaporation were completely separated for the growing season and the off season.…”

“…Most importantly, the irrigation depth for crop 1 was erroneously estimated by the authors, which proved to have a profound impact on the simulation results. Consequently, the key findings of Kuil et al () might be subjected to large uncertainties, and should be interpreted with much caution. The revised social‐hydrological model is recommended to be used and further improved in the future so as to investigate farmers' behaviors in response to climate change and policy interventions.…”

“…These findings reconfirmed our deduction above, indicating that the incorrect estimation of irrigation depth could have a profound impact on the social‐hydrological simulation. Hence, the key findings of Kuil et al () must be associated with large uncertainties and, therefore, should be interpreted with much caution by the readers.…”

“…I agree with the authors that the social‐hydrological model proposed by them could serve as an important tool to understand the potential impact of climate change on the sociohydrological system, to test various assumptions regarding farmer's behaviors, and to evaluate policy interventions. However, some of the assumptions regarding the hydrological aspects are not well justified; and most importantly, the irrigation depth for crop 1 was erroneously estimated by the authors, which could exert a profound impact on the social‐hydrological simulation and make the findings of Kuil et al () to be questionable and unconvincing. The deficiencies of the social‐hydrological model in estimating water balance, the erroneous parameter values, and the influences of the incorrect estimation of irrigation depth were revealed and discussed in the following sections.…”

“…A paper has been published in Water Resources Research recently, which explored the influence of smallholder's perceptions regarding water availability on crop choice and water allocation through social‐hydrological modeling (Kuil et al, ). The present paper attempts to discuss and comment on that paper.…”