فهرست مطالب alireza zarei ghorkhodi

The purpose of this study is the effects of the formation of water markets on the improvement of water productivity in the Tajen catchment basin. In this research, a mathematical programming model modeling system and profit maximization objective function were used in MATLAB environment. After simulating the formation of the water market, its impact on physical and economic water productivity indicators was evaluated in two groups including: farms without water restrictions group (A) and farms with water restrictions group (B). Based on the results, forming a water market leads to a 13 percent increase in profit in group (A) and 30 percent in group (B). According to the results, the formation of the water market reduces and increases the amount of water consumption in representative farms (A) and (B), respectively. The results of the evaluation of water productivity indicators indicate that in group (A), the availability of water and consequently the increase of the cultivated area, and in group (B), the compensation of the lack of water and the increase of the cultivated area have led to an increase in physical productivity. In the farms of group (A), the sale of water and in the farms of group (B), the allocation of water to products with higher economic value has led to an increase in the economic productivity of water. In general, it can be said that forming a water market leads to an increase in productivity, but alone it does not lead to achieving sustainable agriculture and reducing water consumption at the watershed level. Therefore, the implementation of other policies such as the control of extraction from surface and underground water resources, volume delivery of water based on the pattern of optimal cultivation and allocation of water to products with higher economic value along with the water market approach can improve water productivity in addition to reducing water consumption.

Lack of water resources in Mazandaran province and the volume of effluent produced in different sectors, ‎has caused that in order to reduce the withdrawal of surface and groundwater resources in the province, the ‎use and management of unconventional water resources, much attention is paid. The purpose of the present ‎study is to evaluate the application of unconventional water use scenarios on the amount of runoff and ‎sediment in six stations (including Kordakhil, Garmroud, Varand, Vastan, Parvijabad and Aliabad stations) in ‎the Tejn watershed during the years 2000 to 2017 using the SWAT model. Recalibration and validation of the ‎model using data from 2003 to 2012 and 2013 to 2017 and then to evaluate the scenarios of allocating 30% of ‎the available wastewater for agriculture (scenario one), allocating 30% of unconventional water to feed ‎aquifers in the conditions of applying scenario one (scenario two) and a 20% reduction in the extraction of ‎underground water sources for irrigation and the use of unconventional water sources as alternative sources ‎to meet environmental needs (scenario three).‎‏ ‏Evaluating the efficiency of the model using R2 and NSE ‎coefficients shows the proper performance of the model in simulating these two parameters. The results ‎indicate that the application of scenario one did not affect the amount of runoff and sediment in the basin, but ‎with the application of scenario two, the amount of runoff and sediment decreased by 13.4% and 9.1%, ‎respectively. Applying Scenario three should be 10 to 20% of the annual discharge for the second six months ‎and 30 to 40% of the average annual discharge for the first six months of the year in order to meet the ‎environmental needs. The results obtained from the present research show that the use of non-conventional ‎water, in addition to solving the water shortage, also reduces the problems caused by the flow of runoff and ‎the settling of sediments.‎

Limited water resources and increasing the need for it in the agricultural sector have made the use of strategies to increase physical productivity and improve economic water efficiency in the agricultural sector inevitable. In this regard, water productivity indicators can be considered as one of the main components in the field of national planning. In this research, economic and physical productivity was calculated using Indicators Crop Per Drop (CPD), Benefit Per Drop (BPD) and Net Benefit Per Drop (NBPD) indicators for lands under citrus and paddy in the west and center of Mazandaran province, which were irrigated as a Modern (irrigation and underwater irrigation). the method used in this study is based on field visits and perceptions and including performance estimation, water consumption, net and gross costs. The study area in Mazandaran province was divided into four plains including Ramsar - Chalus, Nor - Noshahr, Amol - Babol and GhaemShahr - Joybar. The results of this study showed that the average economic and physical productivity in lands under citrus culture and paddy for CPD index, 5.8 and 0.76 kg/ m3 per hectare, for BPD index, 261 and 175, 1000 Rials/m3 per hectare for the NBPD index, 209 and 127, 1000 Rials/m3 per hectare. Therefore, citrus and paddy fields in Nor - Noshahr and Ramsar - Chalous areas have the best performance in terms of economic productivity of NBPD index and Nor - Nowshahr and Amol - Babol areas have the best performance in terms of CPD index. According to the results of the present study, water management in the field, the use of modern irrigation methods and changing the pattern of culture due to the climatic. Also, creating the necessary infrastructure to replace malfunctioning machines and incentive and punitive policies can be an effective way to increase water productivity.

Changing rainfall patterns and increasing population in Mazandaran province has caused the correct use of surface water resources in various sectors, especially agriculture is inevitable. Despite appropriate rainfall potential in Mazandaran province, there is no regular plan for the management of surface resources. While using the ab bandan, some of the problems of the water sector in this area can be solved. To evaluate this issue in the present study, the SWAT model was used in the Tajan watershed from 2000 to 2017. First, the efficiency of the model and its results were evaluated as the current situation, then the scenario was implemented without considering the ab bandans. The SUFI2 algorithm in SWAT CUP software was used to analyze the uncertainty, calibration and validation of monthly discharge and sediment at six selected stations. The performance of the model was evaluated by coefficient of determination and Nash Sutcliffe. R2 coefficient in runoff and sediment simulation was obtained in the range of 0.68_ 0.87 and 0.62 _ 0.79, respectively. Also, the NS coefficient for runoff was in the range of 0.52 _ 0.72 and sediment was in the range of 0.58 _ 0.74. The results showed that the model had a satisfactory performance in simulating discharge and sediment. The findings of the scenario show that in the absence of ab bandans, runoff discharge and sediment output will increase by 16.3% and 17.5%, which indicates the inhibition of discharge and sediment by these structures. Also, by examining this scenario, during the floods, these structures had an effective role in flood control by inhibiting 17% of runoff and 27% of sediment. Due to the capacity of ab bandans in controlling discharge and sediment, it can be planned to manage surface water resources control floods by increasing the surface area and volume of these structures.