scholarly journals Irrigation and crop water requirement estimation for oil palms using soil moisture balance model in Peninsular Malaysia

2020 ◽  
Vol 1 (3) ◽  
pp. 1-8
Keyword(s):  
Soil Moisture ◽  
Oil Palm ◽  
Water Requirement ◽  
Balance Model ◽  
Rainfall Runoff ◽  
Crop Water ◽  
Hydrologic Models ◽  
Irrigation Demand ◽  
Moisture Balance ◽  
Soil Moisture Balance

This study presents the irrigation and crop water estimation in a Malaysian oil palm plantation for effective irrigation water management during water years 2013 and 2014. The study area was divided into four plots: 2000, 2002, 2006 and 2010, indicating years of peat swamp forest conversion to oil palm plantation. Hydrologic Engineering Centre-Hydrologic Modeling System (HEC-HMS) and Soil moisture balance hydrologic models were used to model the rainfall-runoff in the basin. Statistical analysis using coefficient of determination (R2) and Nash–Sutcliffe efficiency coefficient (NSE) were used to evaluate the performance and correlation of the two hydrologic models. The result showed that R2 and NSE were 0.94 and 0.90 respectively for calibration and 0.92 and 0.54 respectively, for monthly validation. This showed that the models performed well for simulation of the peatland hydrology. With the modelling of rainfall-runoff satisfied, the irrigation demand of the study plots was determined using the same soil moisture balance model. The irrigation demand ranged from 0.893 to 1.6 million cubic meters (MCM) in 2010 and 2000 study plots respectively. Irrigation demand is observed to be site specific which depends on the soil moisture deficit, readily available water in the oil palm root zone and oil palm rooting depth. Estimation of a future oil palm water requirement using the soil moisture balance model would be recommended for further studies for use as an advisory manual for the oil palm managers to enhance adequate water resources planning for oil palm productivity.

scholarly journals Simple water balance model and crop water demand at different spatial and temporal scales in Periya Pallam catchment of upper Bhavani basin, Tamilnadu

2021 ◽  
pp. 217-224
Author(s):  
A. Raviraj ◽  
Ramachandran J ◽  
Nitin Kaushal ◽  
Arjit Mishra
Keyword(s):  
Water Balance ◽  
Water Use ◽  
Water Demand ◽  
Water Requirement ◽  
Water Balance Model ◽  
Balance Model ◽  
Effective Rainfall ◽  
Rainfall Runoff ◽  
Crop Water ◽  
Crop Water Demand

Reduction in agricultural water use and increasing the sustainability of water resources can be achieved by studying the water balance of the area and crop water demand. In this paper, by using a simple water balance model, Evapotranspiration, Rainfall, Runoff, Water Demand and Water Requirement different crops are estimated. The crop water requirement and crop water demand for different crops grown in the Periya Pallam Catchment of Upper Bhavani Basin, Tamilnadu, was estimated. Water balance estimation of the area reveals that out of the annual rainfall, runoff is estimated to be 129 mm, effective rainfall is 252 mm, and deep percolation is about 67 mm. The demand for water for agriculture in the study area is about 61 million cubic meters (MCM), but only 19 MCM of water is available through precipitation in the form of effective rainfall. Hence, the remaining 43 MCM of water is supplied through groundwater and other sources. The results will pave the way for sustainable crop water use planning and would achieve water security in the basin.

scholarly journals Linking soil moisture balance and source-responsive models to estimate diffuse and preferential components of groundwater recharge

2012 ◽  
Vol 9 (7) ◽  
pp. 8455-8492
Author(s):  
M. O. Cuthbert ◽  
R. Mackay ◽  
J. R. Nimmo
Keyword(s):  
Soil Moisture ◽  
Groundwater Recharge ◽  
Water Table ◽  
Preferential Flow ◽  
Numerical Models ◽  
Balance Model ◽  
Shallow Water Table ◽  
Soil Matrix ◽  
Moisture Balance ◽  
Soil Moisture Balance

Abstract. Results are presented of a detailed study into the vadose zone and shallow water table hydrodynamics of a field site in Shropshire, UK. A conceptual model is developed and tested using a range of numerical models, including a modified soil moisture balance model (SMBM) for estimating groundwater recharge in the presence of both diffuse and preferential flow components. Tensiometry reveals that the loamy sand topsoil wets up via macropore flow and subsequent redistribution of moisture into the soil matrix. Recharge does not occur until near-positive pressures are achieved at the top of the sandy glaciofluvial outwash material that underlies the topsoil, about 1 m above the water table. Once this occurs, very rapid water table rises follow. This threshold behaviour is attributed to the vertical discontinuity in the macropore system due to seasonal ploughing of the topsoil, and a lower permeability plough/iron pan restricting matrix flow between the topsoil and the lower outwash deposits. Although the wetting process in the topsoil is complex, a SMBM is shown to be effective in predicting the initiation of preferential flow from the base of the topsoil into the lower outwash horizon. The rapidity of the response at the water table and a water table rise during the summer period while flow gradients in the unsaturated profile were upward suggest that preferential flow is also occurring within the outwash deposits below the topsoil. A variation of the source-responsive model proposed by Nimmo (2010) is shown to reproduce the observed water table dynamics well in the lower outwash horizon when linked to a SMBM that quantifies the potential recharge from the topsoil. The results reveal new insights into preferential flow processes in cultivated soils and provide a useful and practical approach to accounting for preferential flow in studies of groundwater recharge estimation.

scholarly journals A daily water balance model for representing streamflow generation process following land use change

2005 ◽  
Vol 2 (3) ◽  
pp. 821-861
Author(s):  
M. A. Bari ◽  
K. R. J. Smettem
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
Land Use Change ◽  
Water Balance ◽  
Water Balance Model ◽  
Groundwater Depth ◽  
Balance Model ◽  
Streamflow Generation ◽  
Moisture Balance ◽  
Soil Moisture Balance

Abstract. A simple conceptual water balance model representing the streamflow generation processes on a daily time step following land use change is presented. The model consists of five stores: (i) Dry, Wet and Subsurface Stores for vertical and lateral water flow, (ii) a transient Stream zone Store (iii) a saturated Goundwater Store. The soil moisture balance in the top soil Dry and Wet Stores are the most important component of the model and characterize the dynamically varying saturated areas responsible for surface runoff, interflow and deep percolation. The Subsurface Store describes the unsaturated soil moisture balance, extraction of percolated water by vegetation and groundwater recharge. The Groundwater Store controls the baseflow to stream (if any) and the groundwater contribution to the stream zone saturated areas. The daily model was developed following a "downward approach" from an earlier monthly model and performed very well in simulating daily flow generation processes observed at Ernies (control) and Lemon (53% cleared) catchments in Western Australia. Most of the model parameters were incorporated a priori from catchment attributes such as surface slope, soil depth, porosity, stream length and initial groundwater depth, and some were calibrated by matching the observed and predicted hydrographs. The predicted groundwater depth, and streamflow volumes across all time steps from daily to monthly to annual were in close agreement with observations for both catchments.

scholarly journals A conceptual model of daily water balance following partial clearing from forest to pasture

2006 ◽  
Vol 10 (3) ◽  
pp. 321-337 ◽  
Author(s):  
M. A. Bari ◽  
K. R. J. Smettem
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Soil Depth ◽  
Groundwater Depth ◽  
Balance Model ◽  
Model Parameters ◽  
Stream Length ◽  
Time Step ◽  
Moisture Balance ◽  
Soil Moisture Balance

Abstract. A simple conceptual water balance model representing the streamflow generation processes on a daily time step following land use change is presented. The model consists of five stores: (i) Dry, Wet and Subsurface Stores for vertical and lateral water flow, (ii) a transient Stream zone Store (iii) a saturated Goundwater Store. The soil moisture balance in the top soil Dry and Wet Stores are the most important components of the model and characterize the dynamically varying saturated areas responsible for surface runoff, interflow and deep percolation. The Subsurface Store describes the unsaturated soil moisture balance, extraction of percolated water by vegetation and groundwater recharge. The Groundwater Store controls the baseflow to stream (if any) and the groundwater contribution to the stream zone saturated areas. The daily model was developed following a downward approach by analysing data from Ernies (control) and Lemon (53% cleared) catchments in Western Australia and elaborating a monthly model. The daily model performed very well in simulating daily flow generation processes for both catchments. Most of the model parameters were incorporated a priori from catchment attributes such as surface slope, soil depth, porosity, stream length and initial groundwater depth, and some were calibrated by matching the observed and predicted hydrographs. The predicted groundwater depth, and streamflow volumes across all time steps from daily to monthly to annual were in close agreement with observations for both catchments.

scholarly journals Linking soil moisture balance and source-responsive models to estimate diffuse and preferential components of groundwater recharge

2013 ◽  
Vol 17 (3) ◽  
pp. 1003-1019 ◽  
Author(s):  
M. O. Cuthbert ◽  
R. Mackay ◽  
J. R. Nimmo
Keyword(s):  
Soil Moisture ◽  
Groundwater Recharge ◽  
Water Table ◽  
Preferential Flow ◽  
Numerical Models ◽  
Balance Model ◽  
Shallow Water Table ◽  
Soil Matrix ◽  
Moisture Balance ◽  
Soil Moisture Balance

Abstract. Results are presented of a detailed study into the vadose zone and shallow water table hydrodynamics of a field site in Shropshire, UK. A conceptual model is presented and tested using a range of numerical models, including a modified soil moisture balance model (SMBM) for estimating groundwater recharge in the presence of both diffuse and preferential flow components. Tensiometry reveals that the loamy sand topsoil wets up via preferential flow and subsequent redistribution of moisture into the soil matrix. Recharge does not occur until near-positive pressures are achieved at the top of the sandy glaciofluvial outwash material that underlies the topsoil, about 1 m above the water table. Once this occurs, very rapid water table rises follow. This threshold behaviour is attributed to the vertical discontinuity in preferential flow pathways due to seasonal ploughing of the topsoil and to a lower permeability plough/iron pan restricting matrix flow between the topsoil and the lower outwash deposits. Although the wetting process in the topsoil is complex, a SMBM is shown to be effective in predicting the initiation of preferential flow from the base of the topsoil into the lower outwash horizon. The rapidity of the response at the water table and a water table rise during the summer period while flow gradients in the unsaturated profile were upward suggest that preferential flow is also occurring within the outwash deposits below the topsoil. A variation of the source-responsive model proposed by Nimmo (2010) is shown to reproduce the observed water table dynamics well in the lower outwash horizon when linked to a SMBM that quantifies the potential recharge from the topsoil. The results reveal new insights into preferential flow processes in cultivated soils and provide a useful and practical approach to accounting for preferential flow in studies of groundwater recharge estimation.

Improved large-scale crop water requirement estimation through new high-resolution reanalysis dataset

2020 ◽  
Author(s):  
Matteo Rolle ◽  
Stefania Tamea ◽  
Pierluigi Claps
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Large Scale ◽  
Water Requirement ◽  
Crop Water Requirement ◽  
Balance Model ◽  
Blue Water ◽  
Crop Water ◽  
Water Requirements ◽  
Reanalysis Dataset

<p>Estimation of crop water needs is essential to understand the role of agriculture in the water balance modeling at various scales. In turn, this is relevant for water management purposes and for the fulfilling of water-related environmental regulations. In this study, a comprehensive assessment of crop water requirement at large scale is presented, both in terms of rainfall (green water) and irrigation (blue water).</p><p>A water-balance model is built to provide estimates of actual evapotranspiration and accompanying soil moisture by using high space-time resolution data. The new ERA5 reanalysis dataset, published by the ECMWF within the Copernicus monitoring system and obtained from satellite data and ground measurements, provides the precipitation and temperature input variables to the model. Data available at the hourly time scale are all aggregated on a daily scale and used in the water balance model over  a grid of cultivated areas from the MIRCA2000 dataset. Cultivated areas are available for 26 crops for year 2000 at a spatial resolution of 5 arcmin (about 9 km at the Equator). Data from MIRCA2000 are separated between rainfed areas and areas equipped for irrigation and are characterized by specific monthly calendars of the crop growing seasons.</p><p>The model performs the daily soil water balance throughout the whole year, considering all crops at their growth stage and assuming as initial condition at each crop sowing date a monthly average soil moisture. Results quantify the volumes of green and blue water necessary for crop growth and describe the spatial variability of the water requirements of each individual crop. The high spatial and temporal resolution of Copernicus ERA5 data enables a great improvement in the characterization of hydro-climatic forcings with respect to previous assessments and a greater accuracy in the crop water requirement estimates.</p><p>Finally, the knowledge of water requirements is an important step to quantify the irrigation volumes used in agriculture, on which there is a high uncertainty and little spatially distributed information. The model proposed enables the investigation of spatio-temporal variability associated to varying meteorological forcings and of the effects of different irrigation techniques, enabling an improved management of water resources.</p>

scholarly journals Optimisation of Irrigation Regime for Early Potatoes, Late Cauliflower, Early Cabbage and Celery

2013 ◽  
Vol 1 (No. 4) ◽  
pp. 139-152
Author(s):  
Zavadil Josef
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Field Experiments ◽  
Actual Evapotranspiration ◽  
Suction Pressure ◽  
Irrigation Regime ◽  
Marketable Yield ◽  
Moisture Balance ◽  
Seasonal Irrigation ◽  
Soil Moisture Balance

The paper deals with optimisation of threshold suction pressure of soil water on light soils for early potatoes, early cabbage, late cauliflower and celery on the basis of results of small-plot field experiments with differentiated irrigation regime. Experiments were conducted in 2003–2005. Threshold suction pressures of soil water were identical for all crops: 15 kPa in treatment I, 30 kPa in treatment II, 60 kPa in treatment III, and 120 kPa in treatment IV. Precipitation, air temperature and relative humidity, global solar radiation, wind speed and direction were measured by an automated meteorological station. Reference and actual evapotranspiration was determined for the experimental crops according to FAO Paper No. 56 and by means of a biological curve (BC) in 2003–2005. To compare these two methods of calculation of actual evapotranspiration the soil moisture balance was found out. Based on the influence on marketable yield and proportion of the crop quality grades it is possible to determine the optimum threshold suction pressure on light loamy-sand soils in early potatoes, late cauliflower and cabbage 30 kPa and in celery 15 kPa. 80% of available soil water capacity (ASWC) corresponds to the threshold suction pressure 30 kPa, and as much as 96% of ASWC corresponds to 15 kPa. The seasonal irrigation depths determined on the basis of soil moisture balance, in which the crop evapotranspiration (ETc) is calculated either according to FAO 56 or by the BC, are substantially different from the really achieved irriga­tion depths in the treatments where optimal suction pressure is maintained. For potatoes, the really achieved values of seasonal irrigation depths are nearer to the depths calculated by the BC, while for the other vegetables (cauliflower, cabbage and celery) they are more similar to the depths calculated by FAO 56 methodology. The theoretical irrigation depths calculated by the BC method sometimes differ substantially from those based on FAO 56. These differences are at maximum for cauliflower and celery and at minimum for cabbage and decrease with the decreasing irrigation depths.

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