Measurement and Simulation of Soil Water Contents in an Experimental Field in Delta Plain

Abstract

Abstract:Variation in soil water content in the delta plain has its own particularity and is significant for agricultural improvement, the utilization of water resources and flood risk mitigation. In this study, experimental data collected from a plot of farmland located in the Taihu Basin were used to investigate the temporal and vertical variation of soil water content, as well as the effects of individual rainfall on soil water and shallow groundwater and their interaction. The results showed that the variation of soil water content is dependent on the comprehensive influence of soil hydraulic properties, meteorological factors and shallow groundwater and the correlation to the groundwater table is the strongest due to the significant capillary action in the delta plain. A saturated-unsaturated three-dimensional soil water numerical model was developed for the study area in response to rainfall and evapotranspiration. Scenario simulations were performed with different soil depths for soil water content and the error source was analyzed to improve the model. The average RMSE, RE and R 2 values of the soil water content at the five depths between the measured and simulated results were 0.0192 cm 3 ·cm −3 , 2.09% and 0.8119, respectively. The results indicated that the developed model could estimate vertical soil water content and its dynamics over time at the study site at an acceptable level. Moreover, further research and application to other sites in delta plains are necessary to verify and improve the model.

Soil Water Conservation: Dynamics and Impact

“…Novel models are proposed by Ku et al [21], Xiang et al [22] and Hua et al [20]. These contributions allow us to simulate water flow and storage in different environments.…”

“…Finally, Akramkhanov et al [28] involved local stakeholders in Uzbekistan in a transdisciplinary and participatory approach for innovation development. From a methodological point of view, the contributions involve both field [15,16,18,23,24,29] and laboratory [19] experiments, and modeling [20][21][22], survey [17,27,28] and review [25] studies. The Special Issue includes studies carried out at different spatial scales, from field-to regional-scales.…”

“…Three studies address water flow and storage modeling [20][21][22]. Modeling flow processes in unsaturated soils is usually based on the numerical solutions of the Richards equation.…”

“…Variation in soil water content in the delta plain has its own particularity. A three-dimensional numerical model based on the Richards equation was developed by Hua et al [20] to investigate the temporal and vertical variation of soil water content in the Yangtze River Delta (East China). The model was calibrated and validated in an experimental plot.…”

“…The aim of this Special Issue is to enhance our understanding on conservation strategies for effective and sustainable soil and water management. Contributions focus on: recovery of soil hydraulic properties [14][15][16]; erosion risk [17][18][19]; novel modeling [20][21][22], monitoring [23] and experimental [24] approaches for soil hydraulic characterization; improvement of crop yields [25,26]; water availability and food security [27]; and soil salinity [28]. In the following section we resume all the contributions of this Special Issue.…”