بررسی علل افزایش و تشدید سیل در ایران با تاکید بر نقش پوشش گیاهی - استان هرمزگان

Inwstigation of watershed cOJ11prl'hensive is a hasis solution for ecosystem managcmcnt. Ihat lu result hetkr natural resourcc prc-.,ervation. land use and climatolog: variabilit: such as !;\cIOrs that errect un natural waleI' cycle in ecosyslem. Ihis stuch providcs an alternati\ c approach to assess thc actual changes in flood response (If a \\atcrshed in an arid tropical region from the ivll1lah catchment's (ca. 1.106 ha) in Ilonnnzgan province. by inwstigation of rainfall and t100d historical time series and land use transt()rmations made in the pasl 2S years and finally used Rain(;lll-runoIT model for simulation of land cover changes efkct on peak !lood Resulls of land use maps comparisnn showed in 1976. about 45 percent of the \\atershed lIrea was covered by rangeland and naiural forest. Due to continued overgrazing. rangeland l:over decreased to R percent in 1002. Therefore had effected on increasing of curve number fmm 74 to SO and peak !lood was simulated to 1 O~(). But in recent years in spite of increasing raintall. runoff did not increase that can related to creating watershed management projects in recent two periods. Also investigation of ratio between rainl;tll count more than I mm. 5 mm. 10 mm. 15 111m .20 mm and flood count and nood volume were direct. It can be concluded that climatic \ariability and land lIse change arc the most irnportant factors affecting the l100d increasing and aggravation of the Minab catchment's. For a 11(10d return period of morc than I () years. (high) rainl~\11 intensity as a climatic faclor is c\1!lslckred dominant l'or a rdurn period of Icss than 1 () years in combination with a low 111)\\ pcrind. land lISl' changl' is the dl\lninanl !actor detcrmining the 110\\ n.:ginH:. An active management strateg: aimed at the c\H1sel"\ation and regeneration of the natural vcgetation is recommended. in order to improve the distribution of \vater throughout thc entire Minah catchment's. during both dry and wet periods. Kcvwords: 1 alld cm r ch~1I1gl'_ chmalil \anahilit~. J11mab \\ali.:rshed. remote sensing. (iiS

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سیلاب ، بوم سازگان ها ، برنامه ریزی ، پوشش گیاهی ، آب پخشان ها