تخمين شروع همزمان آستانه رواناب و فرسايش با استفاده از مؤلفه هاي مختلف فرسايش

Estimation of runoff and erosion simultaneous threshold using erosion different components

در اﺑﺘﺪاي ﺗﺒﺪﯾﻞ ﺑﺎرش ﺑﻪ رواﻧﺎب، ﻣﻘﺪاري از ﺑﺎرش ﺑﻪ وﺳﯿﻠﻪ ﺧﺎك ﺟﺬب ﺷﺪه ﯾﺎ ﺑﻪ اﻋﻤﺎق زﻣﯿﻦ ﻧﻔﻮذ ﻣﯽﮐﻨﺪ و ﺑﺎﻗﯿﻤﺎﻧﺪه ﺗﺒﺪﯾﻞ ﺑـﻪ رواﻧـﺎب ﺳـﻄﺤﯽ ﻣﯽﺷﻮد ﺑﺎ ﺗﻌﯿﯿﻦ آﺳﺘﺎﻧﻪ ﻫﻤﺰﻣﺎن رواﻧﺎب و ﻓﺮﺳﺎﯾﺶ ﻣﯽﺗﻮان ﺑﻪ ﻣﺪﯾﺮﯾﺖ ﺻﺤﯿﺢ ﺣﻮزهﻫﺎي آﺑﺨﯿﺰ ﮐﻤﮏ ﺷﺎﯾﺎﻧﯽ ﮐﺮد. در اﯾﻦ ﺗﺤﻘﯿﻖ ﺑﻪ ﻣﻨﻈﻮر ﺗﻌﯿﯿﻦ ﺷﺮوع ﻫﻤﺰﻣﺎن آﺳﺘﺎﻧﻪ رواﻧﺎب و ﻓﺮﺳﺎﯾﺶ ﺑﺎ اﺳﺘﻔﺎده از ﻣﻮﻟﻔﻪﻫﺎي ﻣﺨﺘﻠﻒ ﻓﺮﺳﺎﯾﺶ در ﮐﺎرﺑﺮيﻫﺎي ﻣﺨﺘﻠﻒ ﺳﺎزﻧﺪ ﮔﭽﺴﺎران، ﺑﺨﺸـﯽ از ﺣـﻮزه آﺑﺨﯿـﺰ ﮐـﻮه ﮔـﭻ ﺷﻬﺮﺳﺘﺎن اﯾﺬه ﺑﺎ ﻣﺴﺎﺣﺖ 1202 ﻫﮑﺘﺎر اﻧﺘﺨﺎب ﮔﺮدﯾﺪ. در اﯾﻦ ﺗﺤﻘﯿﻖ ﺗﻌﯿﯿﻦ راﺑﻄﻪ ﺑﯿﻦ ﺷﺮوع ﻫﻤﺰﻣﺎن آﺳﺘﺎﻧﻪ رواﻧﺎب و ﻓﺮﺳـﺎﯾﺶ و ﻣﺆﻟﻔـﻪ ﻫـﺎي ﻣﺨﺘﻠـﻒ ﻓﺮﺳﺎﯾﺶ ﻣﺎﻧﻨﺪ ﻣﯿﺰان ﻧﻔﻮذﭘﺬﯾﺮي ﺧﺎك و ﻣﻘﺪار رﺳﻮب و ﻣﯿﺰان رواﻧﺎب در ﮐﺎرﺑﺮيﻫﺎي ﻣﺨﺘﻠﻒ ﺳﺎزﻧﺪ ﮔﭽﺴﺎران ﺑﻪ ﮐﻤﮏ رﮔﺮﺳـﯿﻮن ﭼﻨـﺪ ﻣﺘﻐﯿـﺮه اﻧﺠـﺎم ﮔﺮﻓﺖ. ﺳﭙﺲ ﻧﻤﻮﻧﻪﺑﺮداري ﻣﻮﻟﻔﻪﻫﺎي ﻣﺨﺘﻠﻒ ﻓﺮﺳﺎﯾﺶ در 6 ﻧﻘﻄﻪ و ﺑﺎ 3 ﺗﮑﺮار و در ﺷﺪتﻫﺎي ﻣﺨﺘﻠﻒ ﺑﺎرش 1 ،0/75 و 1/25 ﻣﯿﻠﯽﻣﺘﺮ در دﻗﯿﻘﻪ در ﺳﻪ ﮐﺎرﺑﺮي ﻣﺮﺗﻊ، ﻣﻨﻄﻘﻪ ﻣﺴﮑﻮﻧﯽ و اراﺿﯽ ﮐﺸﺎورزي ﺑﻪ ﮐﻤﮏ دﺳﺘﮕﺎه ﺷﺒﯿﻪ ﺳﺎز ﺑﺎران اﻧﺠﺎم ﺷﺪ. ﺑﻪ ﻣﻨﻈﻮر اﻧﺠﺎم ﺗﺤﻠﯿﻞﻫﺎي آﻣﺎري از ﻧـﺮم اﻓـﺰار SPSS و EXCEL اﺳﺘﻔﺎده ﮔﺮدﯾﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ در ﺗﺨﻤﯿﻦ ﺷﺮوع آﺳﺘﺎﻧﻪ رواﻧﺎب و ﻓﺮﺳﺎﯾﺶ در ﻫﺮ ﺳﻪ ﮐﺎرﺑﺮي، ﻣﻘﺪار رﺳﻮب و ﺳﭙﺲ ﻣﯿﺰان ﻧﻔﻮذﭘﺬﯾﺮي ﺧﺎك ﺑﯿﺸﺘﺮﯾﻦ اﺛﺮ ﮔﺬاري ﻣﺜﺒﺖ و ﻣﻨﻔﯽ را داﺷﺘﻪ اﻧﺪ و ﻣﻘﺪار رواﻧﺎب ﻫﯿﭻ ﻧﻘﺸﯽ در ﻣﺪل ﺳﺎزي ﻧﺪاﺷﺘﻪ اﺳﺖ. اﺛﺮﮔﺬاري ﻣﺜﺒﺖ ﻣﻘﺪار رﺳﻮب ﺑﻪ ﻃﻮر ﮐﻠﯽ در ﻣﯿﺰان ﺷﺮوع رواﻧﺎب و ﻓﺮﺳﺎﯾﺶ ﭘﻨﺞ ﻣﻮرد و اﺛﺮﮔﺬاري ﻣﻨﻔﯽ آن ﻧﯿﺰ در ﺳﻪ ﻣﻮرد ﻣﯽﺑﺎﺷﺪ و اﺛﺮﮔﺬاري ﻣﺜﺒﺖ ﻣﻘﺪار ﻧﻔﻮذﭘﺬﯾﺮي ﺧﺎك در ﻣﺪلﺳﺎزي ﺑﻪﻃـﻮر ﮐﻠـﯽ در ﻣﯿﺰان ﺷﺮوع رواﻧﺎب و ﻓﺮﺳﺎﯾﺶ ﺳﻪ ﻣﻮرد و اﺛﺮﮔﺬاري ﻣﻨﻔﯽ آن ﻧﯿﺰ در ﺳﻪ ﻣﻮرد ﻣﯽﺑﺎﺷﺪ

At the beginning of the conversion of precipitation into runoff, some of the precipitation is absorbed by the soil or penetrates deep into the earth and the rest becomes surface runoff. By determining the runoff and erosion simultaneous threshold can help to watersheds proper management. In this study, in order to determine the runoff and erosion simultaneous threshold using erosion different components in different land uses of Gachsaran Formation, a part of the Kuhe Gach watershed of the Izeh city with an area of 1202 hectares was selected. In this study, the relationship between the runoff and erosion simultaneous threshold and erosion different components such as soil permeability and the amount of sediment and runoff in different land uses of Gachsaran Formation was done using multivariate regression. Then, sampling of erosion different components at 6 points with three replicates and at different rainfall intensities of 0.75, 1 and 1.25 mm in min, in 3 land uses of the range, residential area and agricultural lands with the help of the device rain simulator was performed. SPSS and EXCEL software were used for statistical analysis. The results showed that in estimating the runoff and erosion threshold in all three-land uses, the amount of sediment and then the degree of soil permeability had the most positive and negative effects and the amount of runoff had no role in modeling. The positive effect of the amount of sediment in general on the runoff and erosion threshold in five cases and its negative effect in three cases and the positive effect of soil permeability in modeling in general on the runoff and erosion threshold in three cases and affecting its negative is three cases.