Comparative Classification of Nebkas at North-Iastern of Sirjan Desert By Using TOPSIS Algorithm

Nebkas are generally appearing in regions that amount of sand is average and sufficient moisture was existed for life of vegetation. Overall، Nebka is self organization reaction of ecosystem against windy erosion stress. In the other word، environmental system is trying to adjust the pressure of windy erosion by the creation of this feature. A wide variety of Nebka landscape is observed in green border of the Sirjan Playa. The aim of this study is comparative grouping of Nebkas in the eastern north of Sirjan Playa، and introduction of the most appropriate type for quicksand stabilization، using analysis of Nebka morphometric parameters، via TOPSIS algorithm. This algorithm is one of the methods of multiple criteria decision making، that it combines the quantitative and qualitative indicators and weights according to importance of each criterion، can help decision makers to choose the best alternative. For this achievement، first، the most important morphometric parameters of 392 Nebkas from Tamarix Macatensis، Seidlitzia Florida، Alhagi Mannifera and Reaumuria Turcestanica type were measured by linear sampling in field. Then، the studied Nebkas were prioritized using comparative evaluation by TOPSIS algorithm. The results show that Tamarix Macatensis Nebka، with weight of 0. 818، has the highest of effect in stabilization of quicksand. Seidlitzia Florida Nebka، with weight of 0. 151، has less important than Tamarix Macatensis Nebka and higher priority than Alhagi Mannifera and Reaumuria Turcestanica Nebkas. In front، Reaumuria Turcestanica and Alhagi Mannifera Nebkas، with weights of 0. 028 and 0. 002، have the lowest of efficiency respectively. Therefore، for implementation of stabilization projects of mobile sands in study area، firstly، development of Tamarix Macatensis Nebka system and in the second stage، development of Seidlitzia Florida Nebka system have the highest of importance and efficiency. The results of this study will be beneficial in systemic management of desert regions and stabilization projects of quicksand.