ارزیابی عملکرد و شاخص‌های طراحی سامانه زهکش زیرزمینی اجراشده در شبکه آبیاری و زهکشی گمبوعه استان خوزستان

ارزﯾﺎﺑﯽ ﺳﺎﻣﺎﻧﻪ ﻫﺎی زﻫﮑﺸﯽ ﺑﻪ ﻣﺤﻘﻘﺎن و ﺑﺮﻧﺎﻣﻪرﯾﺰان ﮐﻤﮏ ﻣﯽﮐﻨﺪ ﺗﺎ ﻧﻘﺎط ﻗﻮت و ﺿﻌﻒ در اﯾﻦ ﺳﺎﻣﺎﻧﻪ ﻫﺎ را ﺑﺮرﺳﯽ ﮐﺮده و در ﻃﺮح ﻫﺎی آﯾﻨﺪ اﺻﻼح ﮐﻨﻨﺪ. اﯾﻦ ﻣﻮﺿﻮع ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﭘﯿﭽﯿﺪﮔﯽﻫﺎی ﺣﺎﮐﻢ ﺑﺮ ﻃﺮاﺣﯽ ﺳﺎﻣﺎﻧﻪ ﻫﺎی زﻫﮑﺸﯽ و ﺗﻌﯿﯿﻦ ﺷﺎﺧﺺ ﻫﺎی آن از اﻫﻤﯿﺖ زﯾﺎدی ﺑﺮﺧﻮردار اﺳﺖ. ﺑﻪ ﻫﻤﯿﻦ دﻟﯿﻞ، در ﭘﮋوﻫﺶ ﺣﺎﺿﺮ، ﺑﻪ ارزﯾﺎﺑﯽ ﻋﻤﻠﮑﺮد ﺳﺎﻣﺎﻧﻪ زﻫﮑﺸﯽ اﺟﺮاﺷﺪه در ﺷﺒﮑﻪ آﺑﯿﺎری و زﻫﮑﺸﯽ ﮔﻤﺒﻮﻋﻪ، واﻗﻊ در اراﺿﯽ ﮐﺸﺎورزی ﺷﻬﺮﺳﺘﺎن ﺣﻤﯿﺪﯾﻪ ﭘﺮداﺧﺘﻪ ﺷﺪ. ﻣﺴﺎﺣﺖ اﯾﻦ ﺷﺒﮑﻪ ﺑﺎﻟﻎ ﺑﺮ 6000ﻫﮑﺘﺎر اﺳﺖ و آزﻣﺎﯾﺶﻫﺎی ﻣﯿﺪاﻧﯽ در ﺳﺎل 1402 ﻃﯽ ﺳﻪ ﻣﺮﺣﻠﻪ آﺑﯿﺎری درﮐﺸﺖ ﮔﻨﺪم و ﺑﺮای ﺳﻪ ﻣﺰرﻋﻪ ﻫﺮ ﯾﮏ ﺑﻪ ﻣﺴﺎﺣﺖ ﺣﺪود 8 ﻫﮑﺘﺎر، ﺑﺎ ﺗﻌﺪاد ﺧﻄﻮط زﻫﮑﺶ در ﻫﺮ ﻣﺰرﻋﻪ 3 زﻫﮑﺶ و ﺑﺎ ﻓﻮاﺻﻞ زﻫﮑﺶﻫﺎی زﯾﺮزﻣﯿﻨﯽ 75 ،50 و 80 ﻣﺘﺮی، اﻧﺠﺎم ﺷﺪ. در اﯾﻦ ﭘﮋوﻫﺶ ﺑﻪ ﺑﺮرﺳﯽ ﺗﻐﯿﯿﺮات ﺳﻄﺢ اﯾﺴﺘﺎﺑﯽ و ﺧﺮوج ﺷﻮری از ﭘﺮوﻓﯿﻞ ﺧﺎک و اﻧﺪازه ﮔﯿﺮی ﺷﺎﺧﺺ ﻫﺎی ﻃﺮاﺣﯽ زﻫﮑﺶ ﻫﺎی زﯾﺮزﻣﯿﻨﯽ ﭘﺮداﺧﺘﻪ اﺳﺖ. ﺟﻬﺖ ﻗﺮاﺋﺖ ﻧﻮﺳﺎﻧﺎت ﺳﻄﺢ آب اﯾﺴﺘﺎﺑﯽ، ﭼﺎﻫﮏ ﻫﺎی ﻣﺸﺎﻫﺪه ای در ﻓﻮاﺻﻞ 2/5 ،1/5 ،0/8 ،0/3 و 15 ﻣﺘﺮی و وﺳﻂ زﻫﮑﺶ ﻫﺎی زﯾﺮزﻣﯿﻨﯽ ﻧﺼﺐ ﺷﺪﻧﺪ. ﻓﻮاﺻﻞ ﻧﺼﺐ ﭼﺎﻫﮏﻫﺎی ﻣﺸﺎﻫﺪهای ﺑﯿﻦ دو ﺧﻂ زﻫﮑﺶ در ﻓﻮاﺻﻞ 3/4l ،2/4l ،1/4l و 25 ﻣﺘﺮی از ﺧﺮوﺟﯽ زﻫﮑﺶ ﺑﻮد. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﺷﺎﺧﺺ ﻫﺎی ﺣﺎﮐﻢ ﺑﺮ ﻃﺮاﺣﯽ زﻫﮑﺶﻫﺎ، ﺷﺎﻣﻞ ﻫﺪاﯾﺖ ﻫﯿﺪروﻟﯿﮑﯽ و ﺿﺮﯾﺐ زﻫﮑﺸﯽ، ﮐﻤﺘﺮ از ﻣﻘﺪار واﻗﻌﯽ در ﻣﺰرﻋﻪ در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﺷﺪه ﺑﻮدﻧﺪ. ﻣﻘﺪار ﻫﺪاﯾﺖ ﻫﯿﺪروﻟﯿﮑﯽ ﺑﻪ ﻃﻮر ﻣﺘﻮﺳﻂ در ﻣﺰارع ﺑﻪ ﻃﻮر واﻗﻌﯽ 0/95 و در ﺷﺮاﯾﻂ ﻃﺮاﺣﯽ 0/89 ﻣﺘﺮ ﺑﺮ روز و ﻣﻘﺪار ﺿﺮﯾﺐ زﻫﮑﺸﯽ ﺑﻪ ﻃﻮر واﻗﻌﯽ 2/36 و در ﺷﺮاﯾﻂ ﻃﺮاﺣﯽ 2/6 ﻣﯿﻠﯽ ﻣﺘﺮ ﺑﺮ روز در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﺷﺪه ﺑﻮد. اﯾﻦ ﻣﻬﻢ دﻟﯿﻠﯽ ﺑﺮ اﻧﺘﺨﺎب ﮐﻢ ﻓﺎﺻﻠﻪ زﻫﮑﺶﻫﺎ ﺑﻮده ﮐﻪ ﻣﻨﺠﺮ ﺑﻪ اﻓﺰاﯾﺶ ﻫﺰﯾﻨﻪﻫﺎ ﺷﺪه اﺳﺖ. ﻫﻤﭽﻨﯿﻦ، ﺑﺮرﺳﯽ رواﺑﻂ ﭘﯿﺸﻨﻬﺎدی ﺑﺮای ﻃﺮاﺣﯽ ﺳﺎﻣﺎﻧﻪ زﻫﮑﺸﯽ ﻧﺸﺎن داد ﮐﻪ راﺑﻄﻪی دام ﺑﺎﻻﺗﺮﯾﻦ دﻗﺖ و راﺑﻄﻪی وان ﺷﯿﻠﻔﮕﺎرد ﺑﯿﺸﺘﺮﯾﻦ ﺧﻄﺎ را در ﺗﻌﯿﯿﻦ ﺳﻄﺢ اﯾﺴﺘﺎﺑﯽ داﺷﺖ. ﻣﻘﺎﯾﺴﻪی ﺳﻪ ﻣﺰرﻋﻪ ﻣﻮردﻣﻄﺎﻟﻌﻪ ﻧﺸﺎن داد ﮐﻪ ﻋﻤﻠﮑﺮد ﻫﺮ ﺳﻪ ﻣﺰرﻋﻪ ازﻧﻈﺮ ﺷﺎﺧﺺ ﮐﻨﺘﺮل ﻋﻤﻖ ﺳﻄﺢ اﯾﺴﺘﺎﺑﯽ ﺑﯿﻦ 0/82 ﺗﺎ 1/11 و ﺷﺎﺧﺺ ﮐﻨﺘﺮل ﺧﺮوج ﺷﻮری از ﺧﺎک ﺑﯿﻦ 0/3 ﺗﺎ 0/9 ﻗﺎﺑﻞ ﻗﺒﻮل ﺑﻮد. ﺷﺎﺧﺺ ﻋﻤﻠﮑﺮد ﻣﺤﺼﻮل، ﮐﻪ ﻋﻤﻠﮑﺮد ﺳﺎﻣﺎﻧﻪ زﻫﮑﺸﯽ در ﺗﻮﻟﯿﺪ دوره رﺷﺪ ﻣﺤﺼﻮل را ﻧﺸﺎن ﻣﯽدﻫﺪ، در ﻣﺤﺪودهی ﻧﺰدﯾﮏ ﺑﻪ ﯾﮏ )0/78 0/86( ﺑﻪ دﺳﺖ آﻣﺪ. درﻧﺘﯿﺠﻪ ، اﯾﻦ ﺳﺎﻣﺎﻧﻪ ﻋﻤﻠﮑﺮد ﻗﺎﺑﻞ ﻗﺒﻮﻟﯽ داﺷﺖ. ﻧﺘﺎﯾﺞ ﺑﻪ دﺳﺖ آﻣﺪه از اﯾﻦ ﭘﮋوﻫﺶ ﻧﺸﺎن داد ﮐﻪ ﮔﺮﭼﻪ ﺗﻌﯿﯿﻦ ﺣﺪود ﻣﻄﻠﻮب ﺷﺎﺧﺺ ﻫﺎی زﻫﮑﺸﯽ ﻣﯽﺗﻮاﻧﺪ در ﺗﻌﯿﯿﻦ ﻓﺎﺻﻠﻪ زﻫﮑﺶ ﻫﺎ و ﮐﺎﻫﺶ ﻫﺰﯾﻨﻪ ﻫﺎی اﻗﺘﺼﺎدی ﮐﻤﮏ ﺷﺎﯾﺎﻧﯽ ﮐﻨﺪ؛ ﻟﯿﮑﻦ اﺟﺮای اﯾﻦ ﺳﺎﻣﺎﻧﻪ زﻫﮑﺸﯽ ﺳﺒﺐ ﺑﻬﺒﻮد ﺷﺮاﯾﻂ ﻧﺎﺣﯿﻪ رﯾﺸﻪ ﺷﺪه اﺳﺖ. درﻣﺠﻤﻮع، ﭘﺲ از ﭼﻬﺎر ﺳﺎل از اﺟﺮای اﯾﻦ ﺳﺎﻣﺎﻧﻪ زﻫﮑﺸﯽ، ﺑﻬﺮه وری ﺗﻮﻟﯿﺪ ﮔﻨﺪم ﻧﺴﺒﺖ ﺑﻪ ﺷﺮاﯾﻂ ﻓﺎﻗﺪ زﻫﮑﺸﯽ، ﺑﻪ ﻃﻮر ﻣﺘﻮﺳﻂ از 2/55 ﺗﻦ در ﻫﮑﺘﺎر ﺑﻪ 4/1 ﺗﻦ در ﻫﮑﺘﺎر، ﺣﺪود 62 درﺻﺪ اﻓﺰاﯾﺶ ﯾﺎﻓﺖ ﮐﻪ اﯾﻦ ﺳﻬﻢ ﻋﻤﺪﺗﺎً ﻧﺎﺷﯽ از اﺣﺪاث زﻫﮑﺶ ﻫﺎی زﯾﺮزﻣﯿﻨﯽ در ﻣﺰارع ﻣﻮردﺗﺤﻘﯿﻖ ﺑﻮد و ﺳﯿﺴﺘﻢ اﺻﻼﺣﯽ ﺷﺒﮑﻪ آﺑﯿﺎری اﺟﺮاﻧﺸﺪه ﺑﻮد.

evaluation of the performance and design indicators of the underground drainage system implemented in gamboa irrigation and drainage network of khuzestan province.

evaluation of drainage systems helps researchers and planners to examine the strengths and weaknesses of these systems and improve them in future plans.this issue is very important due to the complexities governing the design of drainage systems and determining its indicators. for this reason, in the present study, the performance of the drainage system implemented in the gamboa irrigation and drainage network, located in the agricultural lands of hamidieh city, was evaluated. the area of this network is over 6000 hectares, and field tests were conducted in 1402 during three stages of irrigation in wheat cultivation and for three fields each with an area of about 8 hectares, with the number of drainage lines in each field, 3 drains and with the intervals of underground drains 50, 75 and 80 meters, it was done. in this research, she investigated the changes in water table level and salinity exit from the soil profile and measured the design indicators of underground drains. in order to read the water level fluctuations of the reservoir, observation wells were installed at intervals of 0.3, 0.8, 1.5, 2.5 and 15 meters and in the middle of the underground drains. the installation intervals of the observation wells between two drainage lines were 1/4l, 2/4l, 3/4l and 25 meters from the drain outlet. the results showed that the indicators governing the design of drains, including hydraulic conductivity and drainage coefficient, were considered lower than the actual value in the field. the average hydraulic conductivity value in fields was 0.95 in reality and 0.89 m/day in design conditions, and the drainage coefficient value was 2.36 in reality and 2.6 mm/day in design conditions. this is the main reason for selecting the short distance of the drains, which has led to an increase in costs. also, the examination of the proposed relationships for the design of the drainage system showed that damm's relationship had the highest accuracy and van schilfgaard's relationship had the highest error in determining the water level. the comparison of the three studied farms showed that the performance of all three farms was acceptable in terms of the control index of the depth of the water table between 0.82 and 1.11 and the control index of salinity exit from the soil between 0.3 and 0.9. the product performance index, which shows the performance of the drainage system in the production of the product growth period, was obtained in the range of 0.78 0.86. as a result, this system had an acceptable performance. the results obtained from this research showed that although determining the optimal limits of drainage indicators can help in determining the distance of drains and reducing economic costs; but the implementation of this drainage system has improved the conditions of the root area. in total, after four years of the implementation of this drainage system, the productivity of wheat production increased by 62% from 2.55 tons per hectare to 4.1 tons per hectare, compared to the conditions without drainage, which is mainly due to the construction of underground drains in the fields was researched and the improvement system of the irrigation network had not been implemented.