Calibration and spatial modelling of daily ET0 in semiarid areas using Hargreaves equation

Castillo, Francisco Gomariz-Castillo; Alonso‐Sarría, Francisco; Cabezas-Calvo-Rubio, Francisco

doi:10.1007/s12145-017-0327-1

Cited by 15 publications

(18 citation statements)

References 44 publications

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“…7) represents the limitation of the available labour for each IZ. The programme used allows estimation of the gross margin generated under different water availability assumptions, as well as derivation of water demand curves and the marginal value of this resource (Griffin, 2006).…”

Section: Socioeconomic Impacts At the Segura River Basin (Srb)mentioning

confidence: 99%

Climate change effects on the hydrology of the headwaters of the Tagus River: implications for the management of the Tagus–Segura transfer

Pellicer-Martínez

Martínez‐Paz²

2018

Hydrol. Earth Syst. Sci.

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Abstract. Currently, climate change is a major concern around the world, especially because of the uncertainty associated with its possible consequences for society. Among them, fluvial alterations can be highlighted in basins whose flows depend on groundwater discharges and snowmelt. This is the case of the headwaters of the Tagus River basin, whose water resources, besides being essential for water uses within this basin, are susceptible to being transferred to the Segura River basin (both basins are in the Iberian Peninsula). This work studies the possible effects that the latest climate change scenarios may have on this transfer, one of the most important ones in southern Europe. In the first place, the possible alterations of the water cycle of the donor basin were estimated. To do this, a hydrological model was calibrated. Then, with this model, three climatic scenarios were simulated, one without climate change and two projections under climate change (Representative Concentration Pathways 4.5 (RCP 4.5) and 8.5 (RCP 8.5)). The results of these three hydrological modelling scenarios were used to determine the possible flows that could be transferred from the Tagus River basin to the Segura River basin, by simulating the water resource exploitation system of the Tagus headwaters. The calibrated hydrological model predicts, for the simulated climate change scenarios, important reductions in the snowfalls and snow covers, the recharge of aquifers, and the available water resources. So, the headwaters of the Tagus River basin would lose part of its natural capacity for regulation. These changes in the water cycle for the climate change scenarios used would imply a reduction of around 70 %–79 % in the possible flows that could be transferred to the Segura basin, with respect to a scenario without climate change. The loss of water resources for the Segura River basin would mean, if no alternative measures were taken, an economic loss of EUR 380–425 million per year, due principally to decreased agricultural production.

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Section: Socioeconomic Impacts At the Segura River Basin (Srb)mentioning

confidence: 99%

Climate change effects on the hydrology of the headwaters of the Tagus River: implications for the management of the Tagus–Segura transfer

Pellicer-Martínez

Martínez‐Paz²

2018

Hydrol. Earth Syst. Sci.

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“…Water inputs are composed by natural sources (surface and groundwater resources) together with non-conventional sources (interbasin transfers, desalination, and wastewater reuse). Surface and groundwater resources closely depend on (i) rainfall amounts which vary between 1000 mm/year and 1500 mm/year in the northwest, whereas values among 300 mm/year and 400 mm/year are recognized in the south-east; (ii) evaporation and evapotranspiration losses which reach their highest rates in the south-east of this country (an average real evapotranspiration of 335 mm/year is registered in the Segura River basin district [38][39][40]). As a result, the south-east of Spain depicts low levels of natural available water (total runoff in Figure 1a).…”

Section: Study Area and Methodsmentioning

confidence: 99%

Wastewater Treatment and Water Reuse in Spain. Current Situation and Perspectives

Jódar-Abellán

López-Ortiz

Melgarejo

2019

Water

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The issues of wastewater treatment and the reuse of water are of great importance, especially in areas where the shortage of conventional resources is a structural problem, as it is in the case of Spain. Wastewater reuse is a valid mechanism to avoid problems derived from droughts and water scarcity. It allows access to water resources in areas with water restrictions and to prevent futures scenarios, due to it being expected that water consumption will double by 2050 over the world. Thus, the likelihood that this unconventional, strategic resource would become scarce is unquestionable, particularly in cases where water planning and exploitation systems prioritize the preservation, protection, and improvement of water quality, as well as the sustainable and efficient use of natural resources. This paper shows how wastewater treatment and reuse are linked, as the reuse of wastewater is associated with a previous regeneration, and both of them are essential tools for maximizing environmental outcomes, as called for in the European Union Directives.

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“…These areas belong to the Segura river basin district (SE Spain) which presents semiarid climate with irregular and scarce rainfalls (average precipitations of 374 mm/year, showing clear differences from NW mountain areas, around 1,000 mm/year, to coastal areas with less than 300 mm/year), high annual average temperatures (18-10°C), and a large number of hours of sun that generate high potential evapotranspiration rates (average ETP of 993 mm/year) and real evapotranspiration rates (average ETR of 335 mm/year). Detail information can be found in CHS [12], Gomariz-Castillo et al [13] and Ruíz-Álvarez et al [14]. Due to the mentioned climate features, irrigated agriculture developed highly in these areas especially since the 1970s (alongside the start of the Tajo-Segura interbasin transfer) and, nowadays, constitutes great water demands together with high water necessities required from the industrial zones and the extend and densely populated urban areas identified in the south-eastern Spain.…”

Section: Study Areamentioning

confidence: 99%

CALIBRATION AND VALIDATION OF ET₀ THROUGH AN R-CRAN CODE IN AGRICULTURAL LANDS OF SOUTH-EAST SPAIN

Jódar-Abellán

Ruiz-Álvarez

Valdés-Abellán

2019

WIT Transactions on Ecology and the Environment

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Currently, water demands from urban and agricultural use are increasing, especially in arid and semiarid regions, such as the Mediterranean. This situation is expected to become worse with the climate change projections for the region, increasing the pressure, in both quantity and quality, on fresh water resources. Evapotranspiration (ET0) is a hydrologic variable with high uncertainty and considered incorrect in water balance estimations. However, its accurate assessment is essential to obtain the real value of available water to satisfy water demands, especially in extended agricultural areas such as the southeast of Spain. ET0 can be obtained using different equations with different levels of input data requirements, among them the Penman-Monteith option is the one recommended by the FAO (PMFAO), but its input data requirements are high. On the other hand, there are simpler options, such as the Hargreaves equation (ET0,HG), but there is not such a big agreement about its accuracy in the scientific literature. The main objection to the use of PMFAO is the lack of some of the required meteorological variables in most climate stations, forcing the use of simpler alternatives. This paper presents an R-CRAN code where the ET0,HG, parameterized by Samani, is calibrated and validated with the Allen model considering 18 statistical contrasts. Both ET0,HG results (pre-and post-calibrated) are compared with daily, monthly and annual results of the PMFAO. All meteorological data was provided by the CA52 Cartagena La Aljorra weather station, managed by the Agricultural Information System of the Murcia region (SE Spain). The main results show that daily, monthly and annual ET0,HG results after the Allen calibration and validation are similar to the PMFAO. However, a moderate underestimation of ET0,HG compared to PMFAO was identified. To sum up, the presented R-CRAN code provides an alternative to apply the ET0,HG method with few meteorological input requirements and, once calibrated, can be applied to extended data networks in other regions.

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Calibration and spatial modelling of daily ET0 in semiarid areas using Hargreaves equation

Cited by 15 publications

References 44 publications

Climate change effects on the hydrology of the headwaters of the Tagus River: implications for the management of the Tagus–Segura transfer

Climate change effects on the hydrology of the headwaters of the Tagus River: implications for the management of the Tagus–Segura transfer

Wastewater Treatment and Water Reuse in Spain. Current Situation and Perspectives

CALIBRATION AND VALIDATION OF ET₀ THROUGH AN R-CRAN CODE IN AGRICULTURAL LANDS OF SOUTH-EAST SPAIN

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Calibration and spatial modelling of daily ET0 in semiarid areas using Hargreaves equation

Cited by 15 publications

References 44 publications

Climate change effects on the hydrology of the headwaters of the Tagus River: implications for the management of the Tagus–Segura transfer

Climate change effects on the hydrology of the headwaters of the Tagus River: implications for the management of the Tagus–Segura transfer

Wastewater Treatment and Water Reuse in Spain. Current Situation and Perspectives

CALIBRATION AND VALIDATION OF ET0 THROUGH AN R-CRAN CODE IN AGRICULTURAL LANDS OF SOUTH-EAST SPAIN

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CALIBRATION AND VALIDATION OF ET₀ THROUGH AN R-CRAN CODE IN AGRICULTURAL LANDS OF SOUTH-EAST SPAIN