Simulation supported scenario analysis for water resources planning: a case study in Northern Italy

2005 ◽  
Vol 51 (3-4) ◽  
pp. 11-18 ◽  
Author(s):  
A. Facchi ◽  
C. Gandolfi ◽  
B. Ortuani ◽  
D. Maggi
Keyword(s):  
Land Use ◽  
Water Availability ◽  
Irrigation Water ◽  
Irrigation System ◽  
Groundwater Resources ◽  
Northern Italy ◽  
Irrigation District ◽  
Zone Model ◽  
Crop Water ◽  
The Impact

The work presents the results of a comprehensive modelling study of surface and groundwater resources in the Muzza–Bassa Lodigiana irrigation district, in Northern Italy. It assesses the impact of changes in land use and irrigation water availability on the distribution of crop water consumption in space and time, as well as on the groundwater resources. A distributed, integrated surface water-groundwater simulation system was implemented and applied to the study area. The system is based on the coupling of a conceptual vadose zone model with the groundwater model MODFLOW. To assess the impact of land use and irrigation water availability on water deficit for crops as well as on groundwater system in the area, a number of management scenarios were identified and compared with a base scenario, reflecting the present conditions. Changes in land use may alter significantly both total crop water requirement and aquifer recharge. Water supply is sufficient to meet demand under present conditions and, from the crop water use viewpoint, a reduction of water availability has a positive effect on the overall irrigation system efficiency; however, evapotranspiration deficit increases, concentrated in July and August, when it may be critical for maize crops.

scholarly journals Afforestation of Degraded Croplands as a Water-Saving Option in Irrigated Region of the Aral Sea Basin

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1433
Author(s):  
Navneet Kumar ◽  
Asia Khamzina ◽  
Patrick Knöfel ◽  
John P. A. Lamers ◽  
Bernhard Tischbein
Keyword(s):  
Land Use ◽  
Water Balance ◽  
Water Supply ◽  
Water Availability ◽  
Irrigation Water ◽  
Water Saving ◽  
Aral Sea ◽  
Water Balance Components ◽  
Study Region ◽  
Trade Offs

Climate change is likely to decrease surface water availability in Central Asia, thereby necessitating land use adaptations in irrigated regions. The introduction of trees to marginally productive croplands with shallow groundwater was suggested for irrigation water-saving and improving the land’s productivity. Considering the possible trade-offs with water availability in large-scale afforestation, our study predicted the impacts on water balance components in the lower reaches of the Amudarya River to facilitate afforestation planning using the Soil and Water Assessment Tool (SWAT). The land-use scenarios used for modeling analysis considered the afforestation of 62% and 100% of marginally productive croplands under average and low irrigation water supply identified from historical land-use maps. The results indicate a dramatic decrease in the examined water balance components in all afforestation scenarios based largely on the reduced irrigation demand of trees compared to the main crops. Specifically, replacing current crops (mostly cotton) with trees on all marginal land (approximately 663 km2) in the study region with an average water availability would save 1037 mln m3 of gross irrigation input within the study region and lower the annual drainage discharge by 504 mln m3. These effects have a considerable potential to support irrigation water management and enhance drainage functions in adapting to future water supply limitations.

scholarly journals A unique vadose zone model for shallow aquifers: the Hetao irrigation district, China

2019 ◽  
Vol 23 (7) ◽  
pp. 3097-3115 ◽  
Author(s):  
Zhongyi Liu ◽  
Xingwang Wang ◽  
Zailin Huo ◽  
Tammo Siert Steenhuis
Keyword(s):  
Field Experiment ◽  
Irrigation Water ◽  
Yellow River ◽  
Shallow Groundwater ◽  
Groundwater Table ◽  
Irrigation District ◽  
Zone Model ◽  
Calibration And Validation ◽  
Irrigation Water Use ◽  
Hetao Irrigation District

Abstract. Rapid population growth is increasing pressure on the world water resources. Agriculture will require crops to be grown with less water. This is especially the case for the closed Yellow River basin, necessitating a better understanding of the fate of irrigation water in the soil. In this paper, we report on a field experiment and develop a physically based model for the shallow groundwater in the Hetao irrigation district in Inner Mongolia, in the arid middle reaches of the Yellow River. Unlike other approaches, this model recognizes that field capacity is reached when the matric potential is equal to the height above the groundwater table and not by a limiting soil conductivity. The field experiment was carried out in 2016 and 2017. Daily moisture contents at five depths in the top 90 cm and groundwater table depths were measured in two fields with a corn crop. The data collected were used for model calibration and validation. The calibration and validation results show that the model-simulated soil moisture and groundwater depth fitted well. The model can be used in areas with shallow groundwater to optimize irrigation water use and minimize tailwater losses.

scholarly journals A simulation study on the effect of climate change on crop water use and chill unit accumulation

2017 ◽  
Vol 113 (7/8) ◽  
Author(s):  
Abiodun A. Ogundeji ◽  
Henry Jordaan
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Water Use ◽  
Irrigation System ◽  
Future Climate ◽  
Crop Water ◽  
Crop Water Use ◽  
Chill Unit ◽  
The Future ◽  
The Impact

Climate change and its impact on already scarce water resources are of global importance, but even more so for water scarce countries. Apart from the effect of climate change on water supply, the chill unit requirement of deciduous fruit crops is also expected to be affected. Although research on crop water use has been undertaken, researchers have not taken the future climate into consideration. They also have focused on increasing temperatures but failed to relate temperature to chill unit accumulation, especially in South Africa. With a view of helping farmers to adapt to climate change, in this study we provide information that will assist farmers in their decision-making process for adaptation and in the selection of appropriate cultivars of deciduous fruits. Crop water use and chill unit requirements are modelled for the present and future climate. Results show that, irrespective of the irrigation system employed, climate change has led to increases in crop water use. Water use with the drip irrigation system was lower than with sprinkler irrigation as a result of efficiency differences in the irrigation technologies. It was also confirmed that the accumulated chill units will decrease in the future as a consequence of climate change. In order to remain in production, farmers need to adapt to climate change stress by putting in place water resources and crop management plans. Thus, producers must be furnished with a variety of adaptation or management strategies to overcome the impact of climate change.

scholarly journals Impacts of irrigation and nitrate fertilization scenarios on groundwater resources quantity and quality of Almyros Basin, Greece

2021 ◽  
Author(s):  
Aikaterini Lyra ◽  
Athanasios Loukas ◽  
Pantelis Sidiropoulos
Keyword(s):  
Seawater Intrusion ◽  
Irrigation Water ◽  
Crop Yields ◽  
Groundwater Resources ◽  
Water Productivity ◽  
Nitrate Contamination ◽  
Integrated Modelling ◽  
Historical Period ◽  
Crop Water ◽  
Nitrate Fertilization

Abstract Irrigation and nitrate fertilization scenarios were combined and simulated for the crop water irrigation demands and nitrogen applications based on experiments on crop cultivation practices. Two irrigation practices of deficit irrigation and rainfed conditions were applied in the main crop types of the Almyros Basin, a coastal basin located in Thessaly, Greece. The groundwater system of Almyros suffers from progressive water balance deficit, nitrate contamination and seawater intrusion due to the groundwater abstractions for agricultural irrigation to cover crop water demands in the dry season. The impacts of the irrigation and nitrate fertilization scenarios on groundwater resources quantity and quality were simulated with the Integrated Modelling System consisting of models of surface hydrology (UTHBAL), groundwater hydrology (MODFLOW), crop growth/nitrates leaching (REPIC), contaminant transport (MT3DMS), and seawater intrusion (SEAWAT), for the historical period of 1991–2018. The results of the scenarios were evaluated with the indicators of Crop Water Productivity (CWP) for crop yields and irrigation water, Partial Factor Productivity (PFP) for Nitrogen Use Efficiency, and Economic Water Productivity (EWP) for the gross profits of irrigation water.

scholarly journals Impact of a Novel Water-Saving Subsurface Irrigation System on Water Productivity, Photosynthetic Characteristics, Yield, and Fruit Quality of Date Palm under Arid Conditions

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1265
Author(s):  
Maged Elsayed Ahmed Mohammed ◽  
Mohammed Refdan Alhajhoj ◽  
Hassan Muzzamil Ali-Dinar ◽  
Muhammad Munir
Keyword(s):  
Water Use ◽  
Fruit Quality ◽  
Irrigation Water ◽  
Arid Regions ◽  
Date Palm ◽  
Irrigation System ◽  
Water Productivity ◽  
Use Efficiency ◽  
The Impact

Water scarcity is a major constraint in arid and semi-arid regions. Crops that require less irrigation water and those, which are considered drought-tolerant such as date palm (Phoenix dactylifera L.), are dominant in these regions. Despite the tolerance of these crops, the development of technologies that ensure efficient use of irrigation water is imperative. Taking these issues into consideration, the study was conducted to investigate the impact of limited irrigation water using a new subsurface irrigation system (SSI) on gas exchange, chlorophyll content, water use efficiency, water productivity, fruit physicochemical characteristics, and yield of date palm (cv. Sheshi). The impact of the SSI system was compared with two surface irrigation systems, namely, surface drip irrigation (SDI) and surface bubbler irrigation (SBI). The field experiment was carried out during 2018 and 2019 at the Date Palm Research Center of Excellence, King Faisal University, Kingdom of Saudi Arabia. The annual crop evapotranspiration (ETc) was 2544 mm. The applied irrigation water was set at 50%, 75%, and 125% of ETc for SSI, SDI, and SBI, respectively, which were based on the higher crop water productivity recorded in an initial field study. The total annual volume of water applied for SSI, SDI, and SBI was 22.89, 34.34, and 57.24 m3 palm−1, respectively. The crop water productivity (CWP) at the SSI system was significantly higher, with a value of 1.15 kg m−3, compared to the SDI (0.51 kg m−3) and SBI systems (0.37 kg m−3). The photosynthetic water use efficiency (WUE) was 10.09, 9.96, and 9.56 μmol CO2 mmol−1 H2O for SSI, SBI, and SDI, respectively. The maximum chlorophyll content (62.4 SPAD) was observed in SBI, followed by SSI (58.9 SPAD) and SDI (56.9 SPAD). Similarly, net photosynthesis and the transpiration rate were significantly higher in SBI and lowest in SSI. However, the SSI system substantially increased palm yield and enhanced fruit quality. The new SSI system, through its positive impact on the efficiency of irrigation water use and enhancement on fruit yield and fruit quality of date palm, seems quite suitable for the irrigation of palm trees in arid and semi-arid regions.

Evaluation of effectiveness of the water management strategies with the focus on agricultural water use: A case study on Upper-Sakarya River Basin in Turkey

2020 ◽  
Author(s):  
Beyza Özel ◽  
Yasemin Demir ◽  
Oğuz Başkan ◽  
Emre Alp
Keyword(s):  
Land Use ◽  
Water Resources ◽  
River Basin ◽  
Water Availability ◽  
Irrigation Water ◽  
Cropping Pattern ◽  
Management Scenarios ◽  
Efficient Management ◽  
Sakarya River ◽  
Technical Measures

<p>Water, energy and food nexus is an integrated framework suggests that the security of one resource is inevitably linked to another’s. Water availability assures healthy food production whereas agriculture is the dominant user of global freshwater. Water stress due to population growth, climate change or malpractices threatens food security. Within the scope of water for food governance, the water efficiency of agricultural irrigation has to be improved to aid sustainable water and agricultural management. The study investigates water availability and withdrawals, evaluates water resources management scenarios in the agricultural sector in the Sakarya River Basin, Turkey’s third-largest river basin. Demand-oriented management scenarios propose a variety of technical measures which include improvements in irrigation technology, shifts in the cropping pattern and water-saving irrigation strategies. The effectiveness of scenarios was evaluated using the Water Evaluation and Planning (WEAP) system developed for the upper sub-basin where significant agricultural activities are held with approximately 1 million ha of total effective arable land. WEAP is an integrated water resources system modeling that operates based on the principle of water balance accounting. A climate data set of precipitation, temperature, relative humidity, and wind speed were applied across each sub-basin, partitioned into land-use classes. A one dimensional, two-bucket model for each land-use class transmits water as surface runoff, interflow, percolation, baseflow and evapotranspiration components. The model was calibrated and validated for observed streamflow, reservoir volume, and irrigation water amount. The mean annual precipitation and evapotranspiration in the upper sub-basin are 387 mm/a and 245 mm/a respectively. Agriculture is the dominant user of both surface water and groundwater resources and accounts for the %88 of total water withdrawals in the upper sub-basin. Impacts of agricultural management on irrigation water supply and flow dynamics of streamflow gauges were evaluated upon each measure. When compared to a historic baseline scenario, efficient management measures can save irrigation water up to %10 by shifting crop patterns from sunflower to safflower, %6 by establishing drip irrigation instead of sprinkler, %4 by applying deficient irrigation on cereal cultivated areas. Furthermore, mean streamflow increases by %8 in June where deficient irrigation strategy is practiced on cereals, by %9 in October where cropping pattern is shifted from sunflower to safflower. After a review of various technical measures related to the efficient management of water resources, the study concluded that sustainable agricultural development is possible by adapting conservative agricultural practices that assure water and food security.</p>

scholarly journals Quantification and Mapping of Satellite Driven Surface Energy Balance Fluxes in Semi-Arid to Arid Inter-Mountain Region

2020 ◽  
Vol 12 (24) ◽  
pp. 4019
Author(s):  
Bibek Acharya ◽  
Vivek Sharma ◽  
James Heitholt ◽  
Daniel Tekiela ◽  
Fabian Nippgen
Keyword(s):  
Land Use ◽  
Energy Balance ◽  
Irrigation System ◽  
Groundwater Resources ◽  
Regional Scale ◽  
Bowen Ratio ◽  
Soil Heat Flux ◽  
Irrigation Districts ◽  
Intermountain Region ◽  
Semi Arid

Crop evapotranspiration (ETc) estimates, on a regional scale, hold enormous potential in managing surface and groundwater resources. This is particularly important for the headwater state of Wyoming, which provides water to found major river basins of the US. In this study, METRIC (Mapping evapotranspiration at high resolution with internalized calibration), a satellite-based image processing model, was used to map and quantify daily, monthly, and seasonal ETc and other energy balance fluxes, i.e., net radiation (Rn), sensible heat (H), and soil heat flux (G) dynamics for different land-use classes. Monthly and seasonal ETc estimated were further used to approximate regional water consumption patterns for different land-use types for nine irrigation districts in semi-arid to arid intermountain region of Big Horn Basin (BHB), Wyoming. The validation of METRIC retrievals against Bowen ratio energy balance system (BREBS) fluxes measured over three vegetative surfaces, viz. sugar beet in 2017, dry bean in 2018, and barley in 2019, indicated high accuracy. The pooled correlation observed between estimated (pooled) and measured instantaneous fluxes had R2 values of 0.91 (RMSE = 0.08 mm h−1, NSE = 0.91), 0.81 (RMSE = 49.6 Wm−2, NSE = 0.67), 0.53 (RMSE = 27.1 Wm−2, NSE = 0.53), and 0.86 (RMSE = 59.2 Wm−2, NSE = 0.84) for ETc, Rn, G, and H, respectively. The biggest discrepancy between measured and estimated monthly ETc values was observed during times when BREBS flux tower footprint was devoid of any crops or the crops at footprint were not actively transpiring. Validation results improved when comparisons were made on monthly scales with METRIC underestimating growing season ETc in the range between 3.2% to 6.0%. Seasonal ETc by land-use type showed significant variation over the study area where crop ETc was 52% higher than natural vegetation ETc. Furthermore, it was found that, in the arid to semi-arid intermountain region of Wyoming, the contribution of irrigation to total seasonal ETc varied in the range of 73–81% in nine irrigation districts that fall within the study area. The high relative contribution of irrigation highlights the importance of identifying and quantifying ETc for improved management in irrigation system design and water allocation.

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