A decision support model to improve water resources management in agriculture: evaluation of the drip irrigation efficiency in the Ait Ben Yacoub region, East of Morocco

Globally, climate change is projected to exacerbate water scarcity and increase the recurrence and intensity of droughts. These circumstances call for methodologies that can support the design of sustainable water management policies. Improved irrigation efficiency has been cited as an important way to adapt to climate change. This paper illustrates the potential of hydro-economic modeling for integrating the multiple dimensions of water resources, becoming a valuable tool in the empowerment of sustainable water management policies. The modelling framework is used also to analyze the impacts of climate change-induced drought on water uses in the Ait Ben Yacoub region (the East of Morocco). The evaluation of the conversion process from flurrow irrigation systems into drip irrigation by using the model showed that this policy has some positive effects on the agricultural gross margin and contributes to slightly moderating the impact of climate change on farmer’s incomes. Moreover, aoptimal efficiency of drip irrigation will inevitably result in a decrease in the volume of infiltrated water and therefore a very likely drawdown of the groundwater level. This result demonstrates the limitation of this policy and the necessity to accompany this irrigation system by measures of improvement of water supply. It concerns rainwater storage basins that should be covered by the polyethylene geo-membrane as example of promising measures.


Water, agriculture and climate change in the
In Morocco, a semi-arid Mediterranean country acute in the coming years due to: a reduction in water supply demand, accentuated by the population growth as a strategic sector for the country's socioeconomic development. However, this sector faces challenges many management among others.
Therefore, Morocco will have to deal with the additional challenges of climate change that will require the adaptation of economic activities dependent on water resources, such as conditions. Dealing with climate change will require a shift in water management and farming decisions towards more sustainable agricultural production and more efficient water allocation, distribution and use.
The study area named "Ait Ben Yacoub " is located in the east of Morocco and characterized by a semi where water is a limiting factor, thus constituting an unfavorable condition for agriculture. water in this region is thewater from AinLaarais with a flow rate of up to 245 l / s and groundwater exploration through wells and boreholes dug by farmers. The study area has 17 watersheds.  Methodology: a hydro-economic modelling framework.
To respond to the questions and challenges of climate change, we propose a hydro developedmodel integrates: economic, agronomic and hydraulic data. It can simulate the behavior of farmers faced with climate change and can takeinto account Water, agriculture and climate change in the "Ait Ben Yacoub" region country, water resources become increasingly scarce. This scarcity will become a reduction in water supply (as a result of climate change), and increase in growth and the requirements of economic development. Agriculture is regarded socioeconomic development. However, this sector faces challenges many , Morocco will have to deal with the additional challenges of climate change that will require the adaptation of economic activities dependent on water resources, such as irrigated agriculture, to limate change will require a shift in water management and farming decisions towards more sustainable agricultural production and more efficient water allocation, distribution and use.
The study area named "Ait Ben Yacoub " is located in the east of Morocco and characterized by a semi where water is a limiting factor, thus constituting an unfavorable condition for agriculture. Major sources of Irrigation is thewater from AinLaarais with a flow rate of up to 245 l / s and groundwater exploration through wells and boreholes dug by farmers. The study area has 17 watersheds.
Ratios of crops types within the agricultural lands watersheds of Ait Ben Yacoub Region in Ait Ben Yacoub region economic modelling framework.
To respond to the questions and challenges of climate change, we propose a hydro-economic modeling framework. The economic, agronomic and hydraulic data. It can simulate the behavior of farmers faced account the competition for resources.
, water resources become increasingly scarce. This scarcity will become , and increase in water and the requirements of economic development. Agriculture is regarded socioeconomic development. However, this sector faces challenges many; water , Morocco will have to deal with the additional challenges of climate change that will require the agriculture, to the new climatic limate change will require a shift in water management and farming decisions towards more The study area named "Ait Ben Yacoub " is located in the east of Morocco and characterized by a semi-arid climate Major sources of Irrigation is thewater from AinLaarais with a flow rate of up to 245 l / s and groundwater exploration through odeling framework. The economic, agronomic and hydraulic data. It can simulate the behavior of farmers faced The proposed approach is based on nonlinear optimization techniques. It's a hydrological and economic model that uses water resources so as to maximize the profit at the level of the basin while taking into account a set of constraints which are divided into hydrological, agricultural and resource availability constraints. of this model is a detailed disaggregation by spatial units (hydrological units, cropping areas, and grazing land), by agricultural production systems (irrigated and rainfed crops), and by farm sizes.
The Positive Mathematical Programming Method (PMP) approach, as suggested by Howitt [18], has been used to calibrate the models. The fundamental idea of PMP is to reconcile the new optimization of the mathema programming model with the economic and social reality as evidenced in the calibration constraints so that the base solution is close to the lacking strong arguments for other type of functions, a quadratic cost function is often employed (exceptions: [19,20] ). The general version of this variable cost function to be specified is: Results and discussions 1. Simulation 1: climate change The model simulates the assessment of climate change impact on irrigated agriculture. This scenario provides insight the behaviour of farmers in conditions of water scarcity. groundwater recharge and rainfall have been simulated The results of this research show that climate change may region (figure 3). It will reduce considerably the availability of water resources, and will (between 2% and 10 %) and increase irrigation water requirements. The resulting chang and crop competitiveness will drive changes of crop land allocations. The cultivated area will decrease significantly by 45 % under drought conditions.
Model Results also demonstrate also that climate change will produce sig from 6.97 to 6.08 million USD. This reduction in the income concerns all types of farms but the small farms will be more vulnerable to climate change.
The model results highlight the remarkable impact of surface groundwater and the risk of its excessive pricing, pumping cost, and water supply and since it underestimates the overall water scarcity at the basin level (Fig. 1). The detailed results of this simulation are presented in the article [14].
The proposed approach is based on nonlinear optimization techniques. It's a hydrological and economic model that uses water resources so as to maximize the profit at the level of the basin while taking into account a set of constraints nto hydrological, agricultural and resource availability constraints. As a major feature of this model of this model is a detailed disaggregation by spatial units (hydrological units, cropping areas, and grazing land), by rrigated and rainfed crops), and by farm sizes. The Positive Mathematical Programming Method (PMP) approach, as suggested by Howitt [18], has been used to calibrate the models. The fundamental idea of PMP is to reconcile the new optimization of the mathema programming model with the economic and social reality as evidenced in the database set. Essentially, PMP calibration constraints so that the base solution is close to the database set. For reasons of computational simplicity and lacking strong arguments for other type of functions, a quadratic cost function is often employed (exceptions: [19,20] ). The general version of this variable cost function to be specified is:

Simulation 1: climate change
The model simulates the assessment of climate change impact on irrigated agriculture. This scenario provides insight of farmers in conditions of water scarcity. The impact of a reduction of 50% of water allocation, have been simulated at the basin level. The results of this research show that climate change mayseverely impact irrigation systems in the Ait ben Yacoub region (figure 3). It will reduce considerably the availability of water resources, and willalso reduce also crop yields (between 2% and 10 %) and increase irrigation water requirements. The resulting changes of water stress, crop yields and crop competitiveness will drive changes of crop land allocations. The cultivated area will decrease significantly by demonstrate also that climate change will produce significant reductions of the region's income from 6.97 to 6.08 million USD. This reduction in the income concerns all types of farms but the small farms will be the remarkable impact of surface water management on the overexploitation excessivedepletion. A management policy of surface water based on administrative and marginal cost is proven inadequate for a sustainable resource management since it underestimates the overall water scarcity at the basin level (Fig. 1). The detailed results of this simulation are The proposed approach is based on nonlinear optimization techniques. It's a hydrological and economic model that uses water resources so as to maximize the profit at the level of the basin while taking into account a set of constraints As a major feature of this model of this model is a detailed disaggregation by spatial units (hydrological units, cropping areas, and grazing land), by The Positive Mathematical Programming Method (PMP) approach, as suggested by Howitt [18], has been used to calibrate the models. The fundamental idea of PMP is to reconcile the new optimization of the mathematical set. Essentially, PMP added set. For reasons of computational simplicity and lacking strong arguments for other type of functions, a quadratic cost function is often employed (exceptions: [19,20] ). f a quadratic cost calibrated using observed area The model simulates the assessment of climate change impact on irrigated agriculture. This scenario provides insight on impact of a reduction of 50% of water allocation, impact irrigation systems in the Ait ben Yacoub reduce also crop yields es of water stress, crop yields and crop competitiveness will drive changes of crop land allocations. The cultivated area will decrease significantly by nificant reductions of the region's income from 6.97 to 6.08 million USD. This reduction in the income concerns all types of farms but the small farms will be overexploitation of the depletion. A management policy of surface water based on administrative e resource management since it underestimates the overall water scarcity at the basin level (Fig. 1). The detailed results of this simulation are

Simulation 2: adaptation measures
Climate change has introduced a number of pressing issues concerning water availability and predictability around the world. Old irrigation practices such as furrow irrigation Several researches have confirmed that the to climate change.
The model evaluates the effect of Drip Irrigation System Implementation as a Climate Change Adaptation Measure on Ait Ben Yacoub region. The evaluation of the conversion process from by using the model showed that, this adaptation measure will help to slightly in terms of profit. It has some positive effects on the agricultural gross margin and contributes to slightly impact of climate change on farmer's incomes.
The farmer will tend to gradually abandon cereal crops and alfalfa to arboriculture. This change in rotation is not very spectacular for this simulation because it is slowed down by an acute water stress recorded on the scale of underground aquifers. Moreover, a better efficiency of drip irrigation will inevitably result in a decrease in the volume of infiltrated water and therefore a very likely drawdown of the groundwater level.
This result demonstrates the limitation of improvement in water supply. It concerns rainwater storage basins that should be covered by the polyethylene geo membrane as example of measures. The success conditioned by the introduction of new crops resistant to new climatic hazards.
ig.4 : Evolution of the volume of water stored in "itzer climate change impact

Simulation 2: adaptation measures (drip irrigation)
Climate change has introduced a number of pressing issues concerning water availability and predictability around the furrow irrigation and imprecise sprinkler irrigation are outdated and confirmed that the adoption of improved irrigation will be important for agricultural adaptation The model evaluates the effect of Drip Irrigation System Implementation as a Climate Change Adaptation Measure on Ait Ben Yacoub region. The evaluation of the conversion process from furrow irrigation systems into drip irrigation that, this adaptation measure will help to slightly reduce the negative effects of the drought in terms of profit. It has some positive effects on the agricultural gross margin and contributes to slightly ncomes. The farmer will tend to gradually abandon cereal crops and alfalfa to grow crops with higher arboriculture. This change in rotation is not very spectacular for this simulation because it is slowed down by an acute recorded on the scale of underground aquifers. Moreover, a better efficiency of drip irrigation will inevitably result in a decrease in the volume of infiltrated water and therefore a very likely drawdown of the of this policy and the necessity to support this irrigation system by measures water supply. It concerns rainwater storage basins that should be covered by the polyethylene geo membrane as example of measures. The success of any agricultural adaptation strategy in the face of climate change is conditioned by the introduction of new crops resistant to new climatic hazards.
: Evolution of the volume of water stored in "itzer-injel" aquifers in million m 3 (reference Year and climate change scenario) Climate change has introduced a number of pressing issues concerning water availability and predictability around the are outdated and inefficient. adoption of improved irrigation will be important for agricultural adaptation The model evaluates the effect of Drip Irrigation System Implementation as a Climate Change Adaptation Measure irrigation systems into drip irrigation the negative effects of the drought in terms of profit. It has some positive effects on the agricultural gross margin and contributes to slightly moderate the water value such as arboriculture. This change in rotation is not very spectacular for this simulation because it is slowed down by an acute recorded on the scale of underground aquifers. Moreover, a better efficiency of drip irrigation will inevitably result in a decrease in the volume of infiltrated water and therefore a very likely drawdown of the this irrigation system by measures water supply. It concerns rainwater storage basins that should be covered by the polyethylene geoof any agricultural adaptation strategy in the face of climate change is (reference Year and climate change scenario)