Assessment of the potential impacts of climate change on the hydrology at catchment scale: modelling approach including prediction of future drought events using drought indices

Abstract: In this study, the Distributed Catchment-Scale Model, DiCaSM, was used to study the impact of climate change on the hydrology of the Eden catchment, north east of Scotland. As a first step, the model was successfully calibrated and validated for a 42 years period. The DiCaSM model was then used to study the impact of climate change on the water availability. Data from the UKCP09 Climate change scenarios for the 2010–2039, 2040–2069 and 2070–2099 periods, considering three gas emission scenarios (low, medium and high), were applied. The results indicated that the greatest decrease in streamflow and groundwater recharge was projected to happen under the high emission scenarios towards the end of the century, i.e. between 2070 and 2099. This would mainly be due to the summers becoming drier. Meanwhile, the projected increase in winter precipitation did not contribute much towards groundwater recharge due the projected increases in evapotranspiration and soil moisture deficit. The following drought indices were calculated and were found to be effective in predicting different types of droughts: the Standardized Precipitation Index, SPI, and the Standardized Precipitation Evaporation Index, SPEI, the Reconnaissance Drought Index, RDI, the modified adjusted RDI, the Soil Moisture Deficit, SMD and the Wetness Index, WI. The findings of the study have broader implications in water resources management considering the future changes in climate

Algunas consideraciones éticas acerca de la medicalización de la mutilación/corte genital femenina (circuncisión femenina).

According to each society’s condition the ethical attitude of the individual may be colored by the attitude of the society. It is therefore not surprising to find what is ethical in one society might not be ethical in another. Female Genital Cutting, as an example, is seen in some societies as a must and something good for the whole community in general and for girls in particular, while in others, it is seen as mutilation and violation of human rights. The practice of female genital cutting is a complex issue that ties the traditional gender roles, superstition, local concepts on health and sexuality, as well as several other social relations. Worldwide, an estimated 130 million girls and women have undergone FGC. The current paper examines medicalization of female genital cutting from ethical point of view. The paper discusses the issue in the following themes: definition of the practice, the justifications of the practice, the complications and lastly the ethical reflections. The paper argues that laws that prohibit the practice would not work, without wide socio-cultural change; any effort to eradicate the practice would not succeedDe acuerdo a las condiciones sociales la actitud ética del individuo puede ser matizada por la actitud de la sociedad. Por lo tanto no es sorprendente encontrar, que algo que es ético en una sociedad no lo sea para otra sociedad. La mutilación genital femenina, es un ejemplo de esto, ésta mutilación es vista en algunas sociedades como lo debido y algo bueno para toda la comunidad en general y para las niñas en particular; mientras que en otras sociedades, esto es visto como mutilación y violación de los derechos humanos. Esta práctica, es un aspecto complejo que ata los roles tradicionales de género, la superstición, los conceptos locales en cuanto a sexualidad, salud, así como otras relaciones sociales. En el mundo se tiene un estimado de 130 millones de niñas y mujeres que han sido sometidas a la mutilación genital femenina (FGC) El presente artículo examina la medicalización de ésta práctica, desde un punto de vista ético. Este documento discute el tópico en los siguientes temas : definición de la práctica, justificación de la misma, sus complicaciones y finalmente las reflexiones éticas. Este artículo argumenta que las leyes que prohiben esta práctica no funcionarían sin un amplio cambio sociocultural; cualquier esfuerzo para erradicar dicha práctica no será exitos

Improving water resources management using different irrigation strategies and water qualities: Field and modelling study

The aim of this study was to investigate the effects of two different irrigation strategies, regulated deficit irrigation, RDI and partial root drying, PRD using surface freshwater (SW) and brackish treated wastewater (TWW) for maize and potato crops. The SALTMED model has been applied using the field measurements of two cropping seasons 2013 and 2014 at the Canale Emiliano Romagnolo, CER’s experimental farm located in Mezzolara di Budrio (Bologna, Italy). In 2013, PRD irrigated potato received 17% less irrigation water than RDI but produced nearly the same yield as under RDI. The water productivity, o naverage, was 11% higher for PRD compared with RDI. For maize 2014 season, the PRD strategy received almost 15% less irrigation water, but produced a yield only 6% lower than that of RDI and gave equal water productivity to RDI. Given that the two strategies received the same amount of rainfall the results favour the PRD over RDI. Had the site not received above average rainfall (258 mm in 2013 and 259 mm during the 2014 growing seasons), PRD might have produced higher yield and water productivity than RDI. In terms of model simulations, overall, the model showed a strong relationship between the observed and the simulated soil moisture and salinity profiles, total dry mater and final yields. This illustrates SALTMED model’s ability to simulate the dry matter and yield of C3 and C4 crops as well as to simulated different water qualities and different water application strategies. Therefore, the model can run with “what if” scenarios depicting several water qualities, crops and irrigation systems and strategies without the need to try them all in the field. This will reduce costs of labour and investment

Evaluation of the SALTMED model for tomato crop production in unheated greenhouses

The SALTMED model is one of the few available generic models that can be used to simulate crop growth with an integrated approach considering water, crop, soil and field management. It is a physically based model using the well-known water and solute transport, evapotranspiration, and water uptake equations. The possibility of using models able to simulate crop growth with this integrated approach can be very useful for farmers as a decision support tool, helping with decisions such as: what crop/variety to use, when to plant and harvest, when and how much to irrigate, what yield to expect under a specific irrigation system or strategy, when using a certain water quality, and also to allow increasing water use efficiency and crops productivity. The SALTMED model has been calibrated and validated for several field crops, in several parts of the world, including field tomato. However, the greenhouse environment has specific conditions that are not always easy to simulate with generic crop growth models. The objective of this work was to evaluate SALTMED model for a tomato crop grown in unheated greenhouse conditions. Climatic data and crop parameters were recorded during two years, in two greenhouses with different ventilation management, and three different sets of data were used to calibrate and to validate the model. The results showed that the model can accurately simulate soil grown tomato crop yield under Mediterranean unheated greenhouse conditions

Drought Risk and You (DRY): case study catchments – physical characteristics and functioning

This report was produced by the Centre for Ecology & Hydrology as part of the 'Developing a drought narrative resource as a multi-stakeholder decision making utility in drought risk management' ('Drought Risk and You'; DRY) project, funded under the Research Councils UK 'UK Droughts & Water Scarcity' programme (Natural Environment Research Council grant ref. NE/L010291/1). A Work Package 3 deliverable

Simplicity versus complexity in modelling groundwater recharge in Chalk catchments

Models of varying complexity are available to provide estimates of recharge in headwater Chalk catchments. Some measure of how estimates vary between different models can help guide the choice of model for a particular application. This paper compares recharge estimates derived from four models employing input data at varying spatial resolutions for a Chalk headwater catchment (River Pang, UK) over a four-year period (1992-1995) that includes a range of climatic conditions. One model was validated against river flow data to provide a measure of their relative performance. Each model gave similar total recharge for the crucial winter recharge period when evaporation is low. However, the simple models produced relatively lower estimates of the summer and early autumn recharge due to the way in which processes governing recharge especially evaporation and infiltration are represented. The relative uniformity of land use, soil types and rainfall across headwater, drift-free Chalk catchments suggests that complex, distributed models offer limited benefits for recharge estimates at the catchment scale compared to simple models. Nonetheless, distributed models would be justified for studies where the pattern and amount of recharge need to be known in greater detail and to provide more reliable estimates of recharge during years with low rainfall.</p> <p style='line-height: 20px;'><b>Keywords:</b> Chalk, modelling, groundwater recharge</p

How do climate and land use changes affect the water cycle? Modelling study including future drought events prediction using reliable drought indices

To investigate the impacts of climate and land use changes on hydrology, the Don catchment in Yorkshire, UK, was selected. A physically based distributed catchment-scale (DiCaSM) model was applied. The model simulates surface runoff, groundwater recharge and drought indicators such as soil moisture deficit SMD, wetness index WI and reconnaissance drought index RDI. The model's goodness of fit using the Nash–Sutcliffe efficiency factor was >91% for the calibration period (2011–2012) and 83% for the validation period(1966–2012). Under different climate change scenarios, the greatest decrease in stream flow and groundwater recharge was projected under medium- and high-emission scenarios. Climate change scenarios projected an increase in evapotranspiration and SMD, especially in the latter half of the current century. Increasing the woodland area had the most significant impact, reducing stream flow by 17% and groundwater recharge by 22%. Urbanization could lead to increase in stream flow and groundwater recharge. The climate change impact on stream flow and groundwater recharge was more significant than land use change. Drought indices SMD, WI and RDI projected an increase in the severity and frequency of drought events under future climatic change, especially under high-emission scenarios

The benefit of using drainage water of fish farms for irrigation: field and modelling study using the SALTMED model

This study investigated the suitability and benefits of using drainage water of fish farms (DWFF), instead of canal fresh water (IW), for wheat irrigation. Two water qualities, DWFF and IW, and four levels of N-fertigation rates [100% N (192 kg N ha−1 season−1), 80% N, 60% N and 40% N] were tested. The results showed a positive impact when increasing N-fertigation rate on the yield using both DWFF and IW. However, the yield under DWFF was higher than the yield under the IW treatment by between 11 and 51% in 2014 and between 8 and 38% in 2015. This is due to the additional amount of dissolved biological nitrogen and other nutrients inherent in DWFF. The SALTMED model simulated reasonably well the soil moisture and nitrogen content of all soil layers as well as wheat dry matter, yield and water productivity for all treatments, with R2 of 0.99, 0.97 and 0.96, respectively. It was concluded that the use of drainage water of fish farms instead of fresh water for irrigation of wheat could help to achieve higher yields while using less irrigation water and less chemical fertilizers. Additional benefits are less drainage to the drainage network and higher income for farmers

Effect of fertigation frequency and duration on yield and water productivity of wheat: field and modelling study using the Saltmed model

This study investigated the impact of fertigation frequency and fertigation time on wheat production. The field experiment included nine treatments over two seasons, 2014/2015 and 2015/2016. The same amount of water and nitrogen fertilizer was given for all treatments, either over 1 day, divided over 2 days or over 3 days. Three fertigation times (FT, period of injecting fertilizers in irrigation water) as a fraction of the irrigation period were also applied. In FT strategies, nitrogen is given either during the same period of the irrigation from the start to the end, at the last three‐quarters of the irrigation period or at the second half of the irrigation period, IT [FT = IT, FT = 0.75IT and FT = 0.5IT]. The observed and simulated nitrogen uptake and grain nitrogen content showed an increasing trend when fertigation frequencies increased and fertigation time decreased.The field and modelling results indicated that increasing fertigation frequencies and decreasing fertigation time have benefits particularly for sandy soils, including higher yields and less pollution. In conclusion, the use of the fertigation frequency of 3 days and fertilizer injection in the second half of the irrigation period is a good fertigation strategy for sandy soils