Understanding Water-Food-Energy Nexus and their Management for the Utilization of the Existing Water Resources

 Due to climate change that is happening, the security of water and food in Iran has caused many worries, which include small towns like Boroujerd. A comprehensive assessment is necessary as well as the productivity of water resources, because it can provide information for government agencies and the public to develop appropriate patterns. The aim of this study is the use and productivity of water resources in Borujerd city, the aim of this study to utilize appropriately the existing water resources in the city of Boroujerd and it is based on recycling and reusing water resources and reduced harvesting of ground water. So the potential of water saving and return to the cycle has been evaluated, and the results can be used as a potential solution for water shortage in Boroujerd in the future.

 Water, energy, and food security globally are achieved through a communication approach, an approach that integrates governance and management into all over sectors and scales. A communication approach can support the transition to a green economy which aims instead, among other things, the use of resources and policy coherence. Given the increasing communication between sectors in space and time, reducing economic, social and adverse environmental concerns can increase overall resource efficiency, more benefits and provide human rights for water and food. Therefore in a relationship-based approach, common policy and decision making an approach which reduces the composition and creates collaboration among sectors is in need.Currently, the most reliable tool to produce climate scenarios is the paired 3D Atmosphere-Oceans General Circulation Models which called AOGCM in this paper. AOGCM is based on the physical relationships that are presented by mathematical relations. In formulating its AR5 synthesis report, the IPCC has made use of new RCP scenarios of greenhouse gas (GHG) emissions. The IPCC society has used new scenarios as trajectory representatives of various concentrations of greenhouse gases. New scenarios have four key trajectories called RCP2.6, RCP4.5, RCP6.0 and RCP8.5 that are based on their radiative stimulus in 2100 and different specifications of the technology level, social and economic situation and future policies.LARS-WG is a random weather generator that can be used to simulate atmospheric data at a station under current and future climate conditions. The first version developed in Budapest in 1990 as part of an agricultural risk assessment in Hungary, then reviewed and moderated by Semenov in 1998. This model produces a daily time series of minimum and maximum temperature, rainfall and solar radiation.

 Concerning precipitation variations, it can be concluded that changes in winter months from January to March in RCP2.6 will decrease by 20%. Rainfall variations in the spring are the same and have equal status with the base time. In summer, two scenarios experience a 40% reduction, in fall, RCP2.6 shows a 20% increase in rainfall and the scenario RCP8.5 shows about 10% precipitation reduction. The two scenarios show at least 1.5 degrees Celsius increase and the highest increases are in fall, and in October, a rise of 2.5 degrees has seen. Maximum temperature changes which indicate the temperature increase to 2 degrees at least in both scenarios. In scenario RCP8.5, in winter and fall, the maximum temperature is increased to 2.5 and 3 degrees, respectively. Boroujerdʼs water and sewage company harvests 22 hm3 (MCM) water annually for its population of 240,654 people. If the necessary measures are taken for gray and black water purification, Boroujerdʼs daily city sewage that is 35416/6 m3 daily, can return to the water cycle. The city's total wastewater is 12,750,000 m3 per year and it is possible to prevent underground water harvesting with purification. Rainfall is another important resource never utilized in Boroujerd. The gable roof and those with more than 15 degrees gradient can be used to collect the rainwater in the high rainfall season. The total roofs are 136.13 ha and according to the average rainfall 0/454m, it can be the maximum use of this resource. The annual volume of precipitation for this city is 612612/45m3 which is significant. Supposedly, it could provide 3.6% of fresh water. Also, if the volume of sewage is considered for purification, the amount of available water source reaches 13362612/45m3 which can meet 60/74% of current water demand.

 Rainwater is not used as a natural resource in Borujerd city and flows into seasonal rivers as runoff. It can be said that harvesting rainwater is an opportunity to reduce water shortage in the future. Rainwater system transferred through the water pipelines and sewage system. It is possible to store rainfall and water remained after snow melts for dry seasons and its surplus can be used to supply. Also due to climate changes and agriculture in Borujerd city, a plan should be provided to reduce the use of water in the summer which is expected to be implemented shortly.