Integrated basin-scale and field-scale modelling as a tool to assess improved water and salinity management

Soil Research ◽  
2004 ◽  
Vol 42 (4) ◽  
pp. 355 ◽  
Author(s):  
M. Torabi ◽  
H. R. Salemi ◽  
P. Droogers ◽  
M. Noshadi
Keyword(s):  
Water Resources ◽  
Scale Model ◽  
Water Quantity ◽  
Irrigation Season ◽  
Baseline Scenario ◽  
Field Scale ◽  
Scenario Analyses ◽  
Basin Scale ◽  
Return Flows ◽  
The Impact

This study was conducted to investigate the impact of changes in water management on water and salinity problems and crop production at field and basin level by analysing several probable scenarios. First, a simplified water and salinity basin model (WSBM) was developed for a quick analysis of river basin processes and was combined with the comprehensive field-scale model, SWAP (soil–water–atmosphere–plant). The WSBM model was calibrated and used for water resources analyses in Zayandeh Rud basin in central Iran. Observed and simulated stream flows were similar, proving that the model could be used for scenario analyses. Yield functions for cotton were developed with SWAP, including the impact of water quantity and quality on crop yields and field water and salinity balances. Three scenarios were considered. The first scenario analysed the effect of more efficient irrigation techniques on the basin water resources, where it was assumed that farmers would not accept lower water allocations if they invested in these more efficient techniques. Therefore, return flows would decrease and less water would be available for downstream users. It was concluded that the effect on the downstream irrigation schemes was dramatic, with a 22% decrease in yield. Obviously, upstream yields would increase. A second scenario was defined where the effect of an increase in water extraction for the town of Esfahan was evaluated. In terms of basin-scale water quantity aspects, this increased extraction was negligible as extractions were relatively low and return flows high. The last scenario was developed to study the additional releases required from the reservoir to provide sufficient water for expansion of the tail-end Rudasht irrigation scheme. If no restriction were imposed on water quality, additional releases from the reservoir would be limited. However, if salinity levels were not to exceed 2�dS/m, mean annual water release requirements from the reservoir would increase from 52 to 64 m3/s, and peak requirements during the irrigation season would increase from 85 to 112 m3/s. In this case, the crop yield would increase from 66% (for the baseline scenario) to 73%. Finally, it was concluded that the methodology and the models developed were useful for a swift and transparent analysis of past, current, and future water and salt resources, and to perform scenario analyses.

scholarly journals Future Climate Change Impact on the Nyabugogo Catchment Water Balance in Rwanda

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3636
Author(s):  
Adeline Umugwaneza ◽  
Xi Chen ◽  
Tie Liu ◽  
Zhengyang Li ◽  
Solange Uwamahoro ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Water Balance ◽  
Surface Runoff ◽  
Hydrological Cycle ◽  
Swat Model ◽  
Global Climate Models ◽  
Future Climate Change ◽  
Baseline Scenario ◽  
The Impact

Droughts and floods are common in tropical regions, including Rwanda, and are likely to be aggravated by climate change. Consequently, assessing the effects of climate change on hydrological systems has become critical. The goal of this study is to analyze the impact of climate change on the water balance in the Nyabugogo catchment by downscaling 10 global climate models (GCMs) from CMIP6 using the inverse distance weighting (IDW) method. To apply climate change signals under the Shared Socioeconomic Pathways (SSPs) (low and high emission) scenarios, the Soil and Water Assessment Tool (SWAT) model was used. For the baseline scenario, the period 1950–2014 was employed, whereas the periods 2020–2050 and 2050–2100 were used for future scenario analysis. The streamflow was projected to decrease by 7.2 and 3.49% under SSP126 in the 2020–2050 and 2050–2100 periods, respectively; under SSP585, it showed a 3.26% increase in 2020–2050 and a 4.53% decrease in 2050–2100. The average annual surface runoff was projected to decrease by 11.66 (4.40)% under SSP126 in the 2020–2050 (2050–2100) period, while an increase of 3.25% in 2020–2050 and a decline of 5.42% in 2050–2100 were expected under SSP585. Climate change is expected to have an impact on the components of the hydrological cycle (such as streamflow and surface runoff). This situation may, therefore, lead to an increase in water stress, calling for the integrated management of available water resources in order to match the increasing water demand in the study area. This study’s findings could be useful for the establishment of adaptation plans to climate change, managing water resources, and water engineering.

scholarly journals Multi-Scale Hydrologic Sensitivity to Climatic and Anthropogenic Changes in Northern Morocco

Geosciences ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 13 ◽  
Author(s):  
Adam Milewski ◽  
Wondwosen M. Seyoum ◽  
Racha Elkadiri ◽  
Michael Durham
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Groundwater Resources ◽  
Water Storage ◽  
Scale Model ◽  
Climate Projections ◽  
Monitoring Networks ◽  
Total Water ◽  
Anthropogenic Changes ◽  
The Impact

Natural and human-induced impacts on water resources across the globe continue to negatively impact water resources. Characterizing the hydrologic sensitivity to climatic and anthropogenic changes is problematic given the lack of monitoring networks and global-scale model uncertainties. This study presents an integrated methodology combining satellite remote sensing (e.g., GRACE, TRMM), hydrologic modeling (e.g., SWAT), and climate projections (IPCC AR5), to evaluate the impact of climatic and man-made changes on groundwater and surface water resources. The approach was carried out on two scales: regional (Morocco) and watershed (Souss Basin, Morocco) to capture the recent climatic changes in precipitation and total water storage, examine current and projected impacts on total water resources (surface and groundwater), and investigate the link between climate change and groundwater resources. Simulated (1979–2014) potential renewable groundwater resources obtained from SWAT are ~4.3 × 108 m3/yr. GRACE data (2002–2016) indicates a decline in total water storage anomaly of ~0.019m/yr., while precipitation remains relatively constant through the same time period (2002–2016), suggesting human interactions as the major underlying cause of depleting groundwater reserves. Results highlight the need for further conservation of diminishing groundwater resources and a more complete understanding of the links and impacts of climate change on groundwater resources.

scholarly journals Ten fundamental questions for water resources development in the Ganges: myths and realities

Water Policy ◽  
2013 ◽  
Vol 15 (S1) ◽  
pp. 147-164 ◽  
Author(s):  
Claudia Sadoff ◽  
Nagaraja Rao Harshadeep ◽  
Donald Blackmore ◽  
Xun Wu ◽  
Anna O'Donnell ◽  
...  
Keyword(s):  
Water Resources ◽  
Policy Makers ◽  
Ganges Basin ◽  
Systems Perspective ◽  
Low Flows ◽  
Basin Scale ◽  
Modelling Techniques ◽  
The Ganges ◽  
The Impact ◽  
Resources Planning

This paper summarizes the results of the Ganges Strategic Basin Assessment (SBA), a 3-year, multi-disciplinary effort undertaken by a World Bank team in cooperation with several leading regional research institutions in South Asia. It begins to fill a crucial knowledge gap, providing an initial integrated systems perspective on the major water resources planning issues facing the Ganges basin today, including some of the most important infrastructure options that have been proposed for future development. The SBA developed a set of hydrological and economic models for the Ganges system, using modern data sources and modelling techniques to assess the impact of existing and potential new hydraulic structures on flooding, hydropower, low flows, water quality and irrigation supplies at the basin scale. It also involved repeated exchanges with policy makers and opinion makers in the basin, during which perceptions of the basin could be discussed and examined. The study's findings highlight the scale and complexity of the Ganges basin. In particular, they refute the broadly held view that upstream water storage, such as reservoirs in Nepal, can fully control basin-wide flooding. In addition, the findings suggest that such dams could potentially double low flows in the dry months. The value of doing so, however, is surprisingly unclear and similar storage volumes could likely be attained through better groundwater management. Hydropower development and trade are confirmed to hold real promise (subject to rigorous project level assessment with particular attention to sediment and seismic risks) and, in the near to medium term, create few significant tradeoffs among competing water uses. Significant uncertainties – including climate change – persist, and better data would allow the models and their results to be further refined.

scholarly journals Investigating the Impact of Climate Change on Future Runoff of River Satluj

2016 ◽  
Vol 8 (1) ◽  
pp. 10-21
Author(s):  
Narayan P Gautam ◽  
Manohar Arora ◽  
N.K. Goel ◽  
A.R.S. Kumar
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
General Circulation ◽  
Circulation Model ◽  
Climate Change Scenarios ◽  
Impact Of Climate Change ◽  
Basin Scale ◽  
The Future ◽  
Future Climatic Condition ◽  
The Impact

Climate change has been emerging as one of the challenges in the global environment. Information of predicted climatic changes in basin scale is highly useful to know the future climatic condition in the basin that ultimately becomes helpful to carry out planning and management of the water resources available in the basin. Climatic scenario is a plausible and often simplified representation of the future climate, based on an internally consistent set of climatological relationships that has been constructed for explicit use in investigating the potential consequences of anthropogenic climate change. This study based on statistical downscaling, provide good example focusing on predicting the rainfall and runoff patterns, using the coarse general circulation model (GCM) outputs. The outputs of the GCMs are utilized to study the impact of climate change on water resources. The present study has been taken up to identify the climate change scenarios for Satluj river basin, India.Journal of Hydrology and Meteorology, Vol. 8(1) p.10-21

scholarly journals Hydrologic Analysis of an Intensively Irrigated Area in Southern Peru Using a Crop-Field Scale Framework

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 318
Author(s):  
Xiaolu Wei ◽  
Pablo Garcia-Chevesich ◽  
Francisco Alejo ◽  
Vilma García ◽  
Gisella Martínez ◽  
...  
Keyword(s):  
Water Resources ◽  
Decision Makers ◽  
Scale Model ◽  
Substantial Contribution ◽  
Return Flow ◽  
Climate Change Scenarios ◽  
Field Scale ◽  
Southern Peru ◽  
Stream Discharge ◽  
Crop Field

Majes is one of the largest agricultural areas in the Arequipa region (southern Peru). Low seasonal precipitation and increasing water demands for agricultural irrigation, industry, and human consumption have made water supply projections a major concern. Agricultural development is becoming more extensive in this dry, sunny climate where crops can be grown year-round. However, because this type of project usually involves significant perturbations to the regional water cycle, understanding the effects of irrigation on local hydrology is crucial. Based on the watershed-scale Soil and Water Assessment Tool (SWAT), this investigation focuses on the impacts of intensive irrigation on hydrological responses in the Majes region. This study is unique because we allow for crop-field scale input within our regional-scale model to provide information at this smaller scale, which is important to inform local stakeholders and decision makers. Each hydrologic response unit (HRU) was generated to represent an individual crop field, so that management practices could be applied according to real-world scenarios. The management file of each HRU was modified to include different operation schedules for crop rotation, irrigation, harvest, and tillage. The model was calibrated and validated against monthly observed stream discharge during the 2009–2020 period. Additionally, evapotranspiration, irrigation water volume, and daily stream discharge downstream of the local river (Siguas) were used to verify the model performance. A total of 49 sub-basins and 4222 HRUs were created, with 3000 HRUs designated to represent individual crop fields. The simulation results revealed that infiltration from agricultural activities in Majes represents the majority of annual groundwater return flow, which makes a substantial contribution to streamflow downstream of the Siguas River. Simulations also suggested that groundwater flow processes and the interactions between surface and groundwater have a major impact on the water balance of the study area. Additionally, climate variability had a higher impact on surface runoff than on groundwater return flow, illustrating that the groundwater component in the study area is important for future water resources resiliency under expected climate change scenarios. Finally, there is a need to perform a follow-up implementation to provide a guideline for decision-makers to assess future sustainable water resources management under varying climatic conditions for this arid irrigated system.

scholarly journals Modeling Pesticide Runoff from Small Watersheds through Field-Scale Management Practices: Minnesota Watershed Case Study with Chlorpyrifos

2016 ◽  
Vol 9 ◽  
pp. ASWR.S32777 ◽  
Author(s):  
Rohith K. Gali ◽  
Steven A. Cryer ◽  
Nicholas N. Poletika ◽  
Praveen K. Dande
Keyword(s):  
Surface Runoff ◽  
Management Practices ◽  
The United States ◽  
Scale Model ◽  
Zone Model ◽  
Watershed Scale ◽  
Field Scale ◽  
Filter Strip ◽  
Pesticide Runoff ◽  
The Impact

Experimental studies of pesticide fate in surface runoff offer only a snapshot of the near semi-infinite parameter combinations that can and do occur in the environment, and mechanistic modeling is often used to supplement the often limited number of experimental observations. However, what has been lacking in pesticide surface runoff modeling is the impact of field-scale best management practices (BMPs) on the concentrations of pesticides found at the watershed outlet. A novel application of melding three agricultural models together was used to address field-scale BMPs and off-target pesticide environmental concentrations at the watershed scale resulting from agricultural surface runoff. These models were the pesticide root zone model [PRZM, an edge-of-field runoff and leaching model sanctioned by the US Environmental Protection Agency (USEPA)]; the United States Department of Agriculture-Agricultural Research Service watershed scale model, the soil and water assessment tool (SWAT); and the academic model, the vegetated filter strip model (VFSMOD). Watershed models such as SWAT, using high-resolution local input data, are capable of predicting watershed behavior but are limited when addressing field-scale BMPs. A unique method to approximate a small watershed as a linear combination of sub-basins and fields [hydrologic response units (HRUs)] is presented. Water, sediment, and pesticide runoff for each HRU are simulated using the USEPA field model PRZM. Daily edge-of-field PRZM predictions for pesticides in runoff water and eroded sediment are coupled with VFSMOD to address the effectiveness of a maintained vegetated filter strip (VFS) across the growing season in reducing pesticide loadings and water quality at the watershed outlet. Daily chlorpyrifos (CHP, insecticide) concentrations simulated for the Seven Mile Creek Watershed, MN, using the above modeling approach resulted in a spectrum of concentrations reported by the MN Department of Natural Resources. Simulated VFS effectiveness when used across all pesticide-treated fields ranged between 22% and 100% reductions in CHP mass across all runoff-producing events.

scholarly journals Assessment of nutrient entry pathways and dominating hydrological processes in lowland catchments

2007 ◽  
Vol 11 ◽  
pp. 107-112 ◽  
Author(s):  
B. Schmalz ◽  
F. Tavares ◽  
N. Fohrer
Keyword(s):  
Water Quality ◽  
Water Balance ◽  
Assessment Tool ◽  
Hydrological Processes ◽  
Scale Model ◽  
Basin Scale ◽  
Catchment Areas ◽  
Using Data ◽  
Nested Approach ◽  
The Impact

Abstract. The achievement of a good water quality in all water bodies until 2015 is legally regulated since December 2000 for all European Union member states by the European Water Framework Directive (EU, 2000). The aim of this project is to detect nutrient entry pathways and to assess the dominating hydrological processes in complex mesoscale catchments. The investigated Treene catchment is located in Northern Germany as a part of a lowland area. Sandy, loamy and peat soils are characteristic for this area. Land use is dominated by agriculture and pasture. Drainage changed the natural water balance. In a nested approach we examined two catchment areas: a) Treene catchment 517 km2, b) Kielstau catchment 50 km2. The nested approach assists to improve the process understanding by using data of different scales. Therefore these catchments serve not only as an example but the results are transferable to other lowland catchment areas. In a first step the river basin scale model SWAT (Soil and Water Assessment Tool, Arnold et al., 1998) was used successfully to model the water balance. Furthermore the water quality was analysed to distinguish the impact of point and diffuse sources. The results show that the tributaries in the Kielstau catchment contribute high amounts of nutrients, mainly nitrate and ammonium. For the parameters nitrate, ammonium and phosphorus it was observed as a tendency that the annual loads were increasing along the river profile of the Kielstau.

scholarly journals Impact of Eastern Redcedar Proliferation on Water Resources in the Great Plains USA—Current State of Knowledge

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1768 ◽  
Author(s):  
Chris Zou ◽  
Dirac Twidwell ◽  
Christine Bielski ◽  
Dillon Fogarty ◽  
Aaron Mittelstet ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Resources ◽  
Great Plains ◽  
Surface Runoff ◽  
Water Budget ◽  
Eastern Redcedar ◽  
Aquatic Life ◽  
South Central ◽  
Basin Scale ◽  
The Impact

In the Great Plains of the central United States, water resources for human and aquatic life rely primarily on surface runoff and local recharge from rangelands that are under rapid transformation to woodland by the encroachment of Eastern redcedar (redcedar; Juniperus virginiana) trees. In this synthesis, the current understanding and impact of redcedar encroachment on the water budget and water resources available for non-ecosystem use are reviewed. Existing studies concluded that the conversion from herbaceous-dominated rangeland to redcedar woodland increases precipitation loss to canopy interception and vegetation transpiration. The decrease of soil moisture, particularly for the subsurface soil layer, is widely documented. The depletion of soil moisture is directly related to the observed decrease in surface runoff, and the potential of deep recharge for redcedar encroached watersheds. Model simulations suggest that complete conversion of the rangelands to redcedar woodland at the watershed and basin scale in the South-central Great Plains would lead to reduced streamflow throughout the year, with the reductions of streamflow between 20 to 40% depending on the aridity of the climate of the watershed. Recommended topics for future studies include: (i) The spatial dynamics of redcedar proliferation and its impact on water budget across a regional hydrologic network; (ii) the temporal dynamics of precipitation interception by the herbaceous canopy; (iii) the impact of redcedar infilling into deciduous forests such as the Cross Timbers and its impact on water budget and water availability for non-ecosystem use; (iv) land surface and climate interaction and cross-scale hydrological modeling and forecasting; (v) impact of redcedar encroachment on sediment production and water quality; and (vi) assessment and efficacy of different redcedar control measures in restoring hydrological functions of watershed.

scholarly journals Quantifying the impact of climate change on water resources at the basin scale on five continents – a unified approach

2010 ◽  
Vol 7 (5) ◽  
pp. 7485-7519 ◽  
Author(s):  
M. C. Todd ◽  
R. G. Taylor ◽  
T. Osborne ◽  
D. Kingston ◽  
N. W. Arnell ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
River Flow ◽  
Climate Change Impacts ◽  
Global Scale ◽  
Climate Impacts ◽  
Catchment Scale ◽  
Considerable Uncertainty ◽  
Basin Scale ◽  
The Impact

Abstract. This paper presents an overview of the methods and results of an assessment of climate change impacts on catchment scale water resources, conducted under the QUEST-GSI (Global Scale Impacts) programme. The project method involved running simulations of catchment-scale hydrology using a unified set of past and future climate scenarios, to enable a consistent analysis of the climate impacts around the globe. The results from individual basins are presented in other papers in 2010. Overall, the studies indicate that in most basins the models project substantial changes to river flow, beyond that observed in the historical record, but that in many cases there is considerable uncertainty in the magnitude and sign of the projected changes. The implications of this for adaptation activities are discussed.

Application of the Soil and Water Assessment Tool (SWAT) at Field Scale: Categorizing Methods and Review of Applications

2020 ◽  
Vol 63 (2) ◽  
pp. 513-522 ◽  
Author(s):  
Ritesh Karki ◽  
Puneet Srivastava ◽  
Tamie L. Veith
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
Assessment Tool ◽  
Swat Model ◽  
Scale Model ◽  
Future Research ◽  
Field Scale ◽  
Basin Scale ◽  
Water Assessment ◽  
Soil And Water

HighlightsThis review study identified five different ways of setting up a SWAT model for field-scale analysis.Model setup for each field-scale modeling method and examples of application are discussed.Benefits and limitations of each method are discussed.Abstract. Although the Soil and Water Assessment Tool (SWAT) has been widely used as a watershed/basin scale model, recently there has been considerable interest in applying it at the field scale, especially for evaluation of best management practices and for building stakeholder confidence. In this study, a thorough review of the literature on field-scale application of SWAT was conducted. It was determined that there is more than one way of setting up a field-scale SWAT model depending on the spatial scale of the research as well as the research question to be answered. This article provides a detailed review of the methods used for field-scale SWAT modeling along with a summary of applications. This article also discusses the limitations and advantages of each method along with future research needs. The overarching goal of this article is to provide a valuable and time-conserving resource for future researchers interested in field-scale SWAT modeling. Keywords: Arc-SWAT, Field level, Field-scale resolution, Field-scale SWAT, SWAT.

Sign in / Sign up

Export Citation Format

Share Document