Your search found 13 records
1 Black, C. A.; Evans, D. D.; Ensminger, L. E.; White, J. L.; Clark, F. E. (Eds.) 1965. Method of soil analysis: part 1 - Physical and mineralogical properties including statistics of measurement and sampling. Madison, WI, USA: American Society of Agronomy. 770p. (Agronomy 9)
Soil analysis ; Measurement ; Sampling ; Chemicophysical properties ; Calibration ; Water content ; Soil water content ; Soil hydraulic properties ; Hydraulic conductivity ; Water intake ; Water table ; Evapotranspiration ; Porosity ; Soil air ; Heat capacity ; Heat transfer ; Radiation ; Particle density ; Bulk density ; Consistency ; Shear strength ; Rupture ; Penetrometers ; Bearing characteristics ; Microscopy ; Photometry ; Infrared spectrophotometry ; X rays ; Chemical composition
(Location: IWMI HQ Call no: 631.4 G000 BLA Record No: H043954)
(0.49 MB)
2 Katic, Pamela; Grafton, Q. 2011. Optimal groundwater extraction under uncertainty: resilience versus economic payoffs. Journal of Hydrology, 406(3-4):215-224. [doi: https://doi.org/10.1016/j.jhydrol.2011.06.01]
Groundwater extraction ; Economic impact ; Aquifers ; Salt water intrusion ; Recharge ; Soil hydraulic properties
(Location: IWMI HQ Call no: e-copy only Record No: H044134)
(0.87 MB)
This paper evaluates the trade-off between resilience and economic payoffs in terms of groundwater extraction where there is a risk of an irreversible and catastrophic event. A dynamic and spatial model is developed that incorporates a stochastic recharge process and the risk of an irreversible catastrophic event (such as saltwater intrusion) that arises when hydraulic heads fall below a given threshold. The results show that if the threshold is uncertain then controlling both the rate and depth of extraction can generate a higher economic return and a lower probability of crossing the threshold than only controlling the rate of extraction. This occurs even if the extraction rate is set optimally and is less than the extraction rate than when two forms of control are used. The model and ndings provide an applied framework to understand and to quantify where there might be ‘win–win’ outcomes, and trade-offs between economic payoffs and resilience in terms of groundwater extraction.
3 Corwin, D. L.; Loague, K. M. (Eds.) 1996. Applications of GIS to the modeling of non-point source pollutants in the Vadose Zone. Madison, WI, USA: Soil Science Society of America (SSSA). 319p. (SSSA Special Publication No. 48)
GIS ; Models ; Information technology ; Pollutants ; Sensitivity analysis ; Surface water ; Water flow ; Groundwater ; Soil hydraulic properties ; Soil salinity ; Pesticides ; Leaching
(Location: IWMI HQ Call no: 526.0285 G000 COR Record No: H045259)
(0.32 MB)
4 Schmugge, T. 2011. Microwave remote sensing of soil hydraulic properties. In Shukla, M. K. (Ed.) Soil hydrology, land use and agriculture: measurement and modelling. Wallingford, UK: CABI. pp.415-426.
(Location: IWMI HQ Call no: e-copy SF Record No: H045791)
5 Chinnasamy, P.; Hubbart, J. A. 2014. Measuring and modeling shallow groundwater flow between a semi-karst border stream and Ozark forested riparian zone in the Central USA. Journal of Scientific Research and Reports, 3(6):844-865.
Groundwater flow ; Flow discharge ; Ecosystems ; Forests ; Riparian zones ; Hydrology ; Models ; Soil hydraulic properties ; Stream flow / USA / Missouri
(Location: IWMI HQ Call no: e-copy only Record No: H046360)
http://www.sciencedomain.org/download.php?f=Chinnasamy362013JSRR7711_1.pdf&aid=3574
https://vlibrary.iwmi.org/pdf/H046360.pdf
https://vlibrary.iwmi.org/pdf/H046360.pdf
(0.52 MB)
Aims: Quantitative information is limited pertaining to riparian forest and stream shallow groundwater interactions particularly in karst hydro-ecosystems. Study Design, Place and Duration: Spatiotemporal variability of shallow groundwater flow was monitored along two stream reaches in a riparian Ozark border forest of central Missouri, United States. Each reach was equipped with twelve piezometers and two stream-gauging stations during the 2011 water year (WY). Methodology: High-resolution (i.e. 15 minute) time-series data were analyzed indicating average groundwater flow per unit stream length was -3 x 10-5 m3 s-1 m-1 (losing stream) for the entire study reach (total reach length = 830m) during the 2011 WY. The HYDRUS – 1D groundwater flow model was forced with observed data and outputs were assessed to improve model end user confidence in karst hydrogeologic systems. Results and Discussion: Results indicate rapid groundwater response to rainfall events within two to 24 hours nine meters from the stream. Analyses indicated average stream flow loss of 28% and 7% total volume to groundwater during winter and spring seasons, respectively. During the dry season (June-September), the stream was gaining 95% of the time. During the wet season (March-June), the stream was losing 70% of the time. Based on established assessment criteria, shallow groundwater modeling performance with HYDRUS – 1D was deemed very good (NS = 0.95, r2 = 0.99, RMSE = 2.38 cm and MD =1.3 cm). Conclusion: Results supply greatly needed baseline information necessary for improved understanding of riparian forest management and shallow groundwater transport and storage processes in semi-karst forest ecosystems.
6 Bawain, A. M. A. 2006. Impact of sedimentation on recharge to groundwater at Sahalnoot dam. Thesis. Thesis submitted to the Department of Soils, Water and Agricultural Engineering, College of Agricultural and Marine Sciences, Sultan Qaboos University, Oman, in partial fulfillment of the requirement for the Degree of Master of Science in Soil and Water Management. 93p.
Sedimentation ; Groundwater ; Artificial recharge ; Dams ; Infiltration ; Hydrogeology ; Models ; Gulf states ; Soil hydraulic properties ; Rain ; Flooding / Oman / Kuwait / Salalah / Sahalnoot Dam
(Location: IWMI HQ Call no: D 553.79 G728 BAW Record No: H046499)
(0.09 MB)
7 Meshgi, A.; Schmitter, P.; Babovic, V.; Chui, T. F. M. 2014. An empirical method for approximating stream baseflow time series using groundwater table fluctuations. Journal of Hydrology, 519:1031-1041. [doi: https://doi.org/10.1016/j.jhydrol.2014.08.033]
Stream flow ; Time series analysis ; Hydrology ; Models ; Simulation ; Water resources ; Groundwater table ; Catchment areas ; River basins ; Rain ; Soil hydraulic properties ; Case studies / Singapore / USA / Kent Ridge Catchment / Beaver River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H046591)
(1.73 MB)
Developing reliable methods to estimate stream baseflow has been a subject of interest due to its importance in catchment response and sustainable watershed management. However, to date, in the absence of complex numerical models, baseflow is most commonly estimated using statistically derived empirical approaches that do not directly incorporate physically-meaningful information. On the other hand, Artificial Intelligence (AI) tools such as Genetic Programming (GP) offer unique capabilities to reduce the complexities of hydrological systems without losing relevant physical information. This study presents a simple-to-use empirical equation to estimate baseflow time series using GP so that minimal data is required and physical information is preserved. A groundwater numerical model was first adopted to simulate baseflow for a small semi-urban catchment (0.043 km2) located in Singapore. GP was then used to derive an empirical equation relating baseflow time series to time series of groundwater table fluctuations, which are relatively easily measured and are physically related to baseflow generation. The equation was then generalized for approximating baseflow in other catchments and validated for a larger vegetation-dominated basin located in the US (24 km2). Overall, this study used GP to propose a simple-to-use equation to predict baseflow time series based on only three parameters: minimum daily baseflow of the entire period, area of the catchment and groundwater table fluctuations. It serves as an alternative approach for baseflow estimation in un-gauged systems when only groundwater table and soil information is available, and is thus complementary to other methods that require discharge measurements.
8 Smith, C. J.; Oster, J. D.; Sposito, G. 2015. Potassium and magnesium in irrigation water quality assessment. Agricultural Water Management, 157:59-64. (The Jim Oster Special Issue) [doi: https://doi.org/10.1016/j.agwat.2014.09.003]
Irrigation water ; Wastewater irrigation ; Water quality ; Assessment ; Potassium ; Magnesium ; Sodium ; Soil hydraulic properties ; Hydraulic conductivity / USA / Australia / California
(Location: IWMI HQ Call no: e-copy only Record No: H047500)
(0.51 MB)
There is a growing trend of K replacing Na in wastewaters from agricultural industries to reduce the adverse effects of irrigation with these waters on soil hydraulic properties. However, problems with soil physical properties caused by wastewaters with high concentrations of K have been reported in both Australia and California. A review of the literature dating back to the 1930s supports the general conclusion that the relative order of deleterious effect on soil hydraulic properties of the four common cations in soils is Na >K> Mg > Ca. This paper explores the capabilities of the Cation Ratio of Structural Stability (CROSS), a generalized Sodium Adsorption Ratio incorporating all four cations, as an improved irrigation water quality parameter. This new parameter includes a coefficient for K that accounts for its relative deleterious effect as compared with Na and another coefficient for Mg that accounts for its relative beneficial effect as compared with Ca. Based on optimizing CROSS using threshold electrolyte concentration data for a Sodosol from the Riverina Region of Australia, the deleterious effect of K is estimated to be about one-third of that of Na, while the concentration of Mg needs to be about an order of magnitude larger than Ca to have the same beneficial effect.
9 Erban, L. E.; Gorelick, S. M. 2016. Closing the irrigation deficit in Cambodia: implications for transboundary impacts on groundwater and Mekong River flow. Journal of Hydrology, 535:85-92. [doi: https://doi.org/10.1016/j.jhydrol.2016.01.072]
Irrigation water ; Water requirements ; Water deficit ; International waters ; Groundwater depletion ; Models ; Aquifers ; Pumping ; Rivers ; Stream flow ; Soil hydraulic properties ; Irrigated rice / Cambodia / Vietnam / Mekong River
(Location: IWMI HQ Call no: e-copy only Record No: H047502)
(1.98 MB)
Rice production in Cambodia, essential to food security and exports, is largely limited to the wet season. The vast majority (96%) of land planted with rice during the wet season remains fallow during the dry season. This is in large part due to lack of irrigation capacity, increases in which would entail significant consequences for Cambodia and Vietnam, located downstream on the Mekong River. Here we quantify the extent of the dry season ‘‘deficit” area in the Cambodian Mekong River catchment, using a recent agricultural survey and our analysis of MODIS satellite data. Irrigation of this land for rice production would require a volume of water up to 31% of dry season Mekong River flow to Vietnam. However, the two countries share an aquifer system in the Mekong Delta, where irrigation demand is increasingly met by groundwater. We estimate expansion rates of groundwater-irrigated land to be >10% per year in the Cambodian Delta using LANDSAT satellite data and simulate the effects of future expansion on groundwater levels over a 25-year period. If groundwater irrigation continues to expand at current rates, the water table will drop below the lift limit of suction pump wells, used for domestic supply by >1.5 million people, throughout much of the area within 15 years. Extensive groundwater irrigation jeopardizes access for shallow domestic water supply wells, raises the costs of pumping for all groundwater users, and may exacerbate arsenic contamination and land subsidence that are already widespread hazards in the region.
10 Sreelash, K.; Buis, S.; Sekhar, M.; Ruiz, L.; Tomer, S. K.; Guerif, M. 2017. Estimation of available water capacity components of two-layered soils using crop model inversion: effect of crop type and water regime. Journal of Hydrology, 546:166-178. [doi: https://doi.org/10.1016/j.jhydrol.2016.12.049]
Water holding capacity ; Water availability ; Estimation ; Soil water content ; Soil hydraulic properties ; Layered soils ; Soil moisture ; Field capacity ; Wilting point ; Water stress ; Crop management ; Models ; Sensitivity analysis ; Leaf Area Index ; Maize ; Sorghum ; Sunflowers ; Turmeric ; Remote sensing ; Catchment areas / South India / Berambadi Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H048041)
(1.43 MB)
Characterization of the soil water reservoir is critical for understanding the interactions between crops and their environment and the impacts of land use and environmental changes on the hydrology of agricultural catchments especially in tropical context. Recent studies have shown that inversion of crop models is a powerful tool for retrieving information on root zone properties. Increasing availability of remotely sensed soil and vegetation observations makes it well suited for large scale applications. The potential of this methodology has however never been properly evaluated on extensive experimental datasets and previous studies suggested that the quality of estimation of soil hydraulic properties may vary depending on agro-environmental situations. The objective of this study was to evaluate this approach on an extensive field experiment. The dataset covered four crops (sunflower, sorghum, turmeric, maize) grown on different soils and several years in South India. The components of AWC (available water capacity) namely soil water content at field capacity and wilting point, and soil depth of two-layered soils were estimated by inversion of the crop model STICS with the GLUE (generalized likelihood uncertainty estimation) approach using observations of surface soil moisture (SSM; typically from 0 to 10 cm deep) and leaf area index (LAI), which are attainable from radar remote sensing in tropical regions with frequent cloudy conditions. The results showed that the quality of parameter estimation largely depends on the hydric regime and its interaction with crop type. A mean relative absolute error of 5% for field capacity of surface layer, 10% for field capacity of root zone, 15% for wilting point of surface layer and root zone, and 20% for soil depth can be obtained in favorable conditions. A few observations of SSM (during wet and dry soil moisture periods) and LAI (within water stress periods) were sufficient to significantly improve the estimation of AWC components. These results show the potential of crop model inversion for estimating the AWC components of two-layered soils and may guide the sampling of representative years and fields to use this technique for mapping soil properties that are relevant for distributed hydrological modelling.
11 Grum, B.; Assefa, D.; Hessel, R.; Woldearegay, K.; Ritsema, C. J.; Aregawi, B.; Geissen, V. 2017. Improving on-site water availability by combining in-situ water harvesting techniques in semi-arid northern Ethiopia. Agricultural Water Management, 193:153-162. [doi: https://doi.org/10.1016/j.agwat.2017.08.009]
Water availability ; Water harvesting ; Techniques ; Straw mulches ; Ridge tillage ; Soil moisture ; Runoff ; Soil hydraulic properties ; Rain ; Hydrometeorology ; Watersheds ; Semiarid zones / Ethiopia / Gule Sub-Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H048375)
(2.78 MB)
Crop production in arid and semi-arid environments is strongly affected by temporal variation of water availability during the growth period. In-situ water harvesting techniques such as tied ridges and mulching improve water availability over time and may improve crop yield. A field experiment was conducted in 2013 and 2014 in the Gule sub-watershed, Northern Ethiopia to study the effect of combining in-situ water harvesting techniques on on-site water regime, i.e., runoff and soil-moisture content. Five treatments with tied ridges, straw mulch, tied ridges and straw mulch together, straw mulch plus effective microorganisms and a combination of tied ridges, straw mulch and effective microorganisms and an untreated control were tested. Combined tied ridges and straw mulch with and without effective microorganisms significantly reduced average runoff per event by 78 and 88%, respectively, compared to the control. Tied ridges alone reduced runoff by 56% and straw mulch with and without effective microorganisms reduced runoff by 49 and 53%, respectively. Average soil-moisture content over the two years was significantly higher (22.4%) in combined tied ridges and straw mulch than the control (19.9%). Tied ridges or straw mulch alone significantly reduced runoff and improved soil-moisture content, but the two combined were more efficient. The findings suggest that combining straw mulch and tied ridges enhance water infiltration into the soil and improve water availability during the growing season, thereby protecting crops from dry periods.
12 Waqas, M. M.; Shah, S. H. H.; Awan, Usman Khalid; Waseem, M.; Ahmad, I.; Fahad, M.; Niaz, Y.; Ali, S. 2020. Evaluating the impact of climate change on water productivity of maize in the semi-arid environment of Punjab, Pakistan. Sustainability, 12(9):3905. (Special issue: Climate Resilient Sustainable Agricultural Production Systems) [doi: https://doi.org/10.3390/su12093905]
Climate change ; Impact assessment ; Water productivity ; Crop production ; Maize ; Semiarid zones ; Soil hydraulic properties ; Groundwater recharge ; Irrigation systems ; Precipitation ; Temperature ; Rain ; Models / Pakistan / Punjab / Lower Chenab Canal system
(Location: IWMI HQ Call no: e-copy only Record No: H050210)
(1.37 MB) (1.37 MB)
Impact assessments on climate change are essential for the evaluation and management of irrigation water in farming practices in semi-arid environments. This study was conducted to evaluate climate change impacts on water productivity of maize in farming practices in the Lower Chenab Canal (LCC) system. Two fields of maize were selected and monitored to calibrate and validate the model. A water productivity analysis was performed using the Soil–Water–Atmosphere–Plant (SWAP) model. Baseline climate data (1980–2010) for the study site were acquired from the weather observatory of the Pakistan Meteorological Department (PMD). Future climate change data were acquired from the Hadley Climate model version 3 (HadCM3). Statistical downscaling was performed using the Statistical Downscaling Model (SDSM) for the A2 and B2 scenarios of HadCM3. The water productivity assessment was performed for the midcentury (2040–2069) scenario. The maximum increase in the average maximum temperature (Tmax) and minimum temperature (Tmin) was found in the month of July under the A2 and B2 scenarios. The scenarios show a projected increase of 2.8 C for Tmax and 3.2 C for Tmin under A2 as well as 2.7 C for Tmax and 3.2 C for Tmin under B2 for the midcentury. Similarly, climate change scenarios showed that temperature is projected to decrease, with the average minimum and maximum temperatures of 7.4 and 6.4 C under the A2 scenario and 7.7 and 6.8 C under the B2 scenario in the middle of the century, respectively. However, the highest precipitation will decrease by 56 mm under the A2 and B2 scenarios in the middle of the century for the month of September. The input and output data of the SWAP model were processed in R programming for the easy working of the model. The negative impact of climate change was found under the A2 and B2 scenarios during the midcentury. The maximum decreases in Potential Water Productivity (WPET) and Actual Water Productivity (WPAI) from the baseline period to the midcentury scenario of 1.1 to 0.85 kgm-3 and 0.7 to 0.56 kgm-3 were found under the B2 scenario. Evaluation of irrigation practices directs the water managers in making suitable water management decisions for the improvement of water productivity in the changing climate.
13 Dirwai, T. L.; Senzanje, A.; Mabhaudhi, Tafadzwanashe. 2022. Development and validation of a model for soil wetting geometry under moistube irrigation. Scientific Reports, 12:2737. [doi: https://doi.org/10.1038/s41598-022-06763-x]
Irrigation methods ; Subsurface irrigation ; Wetting front ; Geometry ; Models ; Soil hydraulic properties ; Soil water content ; Soil water movement ; Sandy soils ; Clay loam soils ; Silty soils / South Africa / KwaZulu-Natal
(Location: IWMI HQ Call no: e-copy only Record No: H050970)
(2.13 MB) (2.13 MB)
We developed an empirical soil wetting geometry model for silty clay loam and coarse sand soils under a semi-permeable porous wall line source Moistube Irrigation (MTI) lateral irrigation. The model was developed to simulate vertical and lateral soil water movement using the Buckingham pi (p) theorem. This study was premised on a hypothesis that soil hydraulic properties influence soil water movement under MTI. Two independent, but similar experiments, were conducted to calibrate and validate the model using MTI lateral placed at a depth of 0.2 m below the soil surface in a soil bin with a continuous water supply (150 kPa). Soil water content was measured every 5 min for 100 h using MPS-2 sensors. Model calibration showed that soil texture influenced water movement (p< 0.05) and showed a good ft for wetted widths and depths for both soils (nRMSE = 0.5–10%; NSE = 0.50; and d-index = 0.50. The percentage bias (PBIAS) statistic revealed that the models’ under-estimated wetted depth after 24 h by 21.9% and 3.9% for silty clay loam and sandy soil, respectively. Sensitivity analysis revealed agreeable models’ performance values. This implies the model’s applicability for estimating wetted distances for an MTI lateral placed at 0.2 m and MTI operating pressure of 150 kPa. We concluded that the models are prescriptive and should be used to estimate wetting geometries for conditions under which they were developed. Further experimentation under varying scenarios for which MTI would be used, including feld conditions, is needed to further validate the model and establish robustness. MTI wetting geometry informs placement depth for optimal irrigation water usage.
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