Assesment of Badlands Stabilization Methods in Sefid Rud Watershed

Effective factors on degradation of watersheds. particularly arid and Semiarid watersheds generally present their signs in terms of gradual vegetal cover decrease, presence of accelerated soil erosion . variation ot hydrological manor and deterioration of ecological balance on a watershed . Presence and domination of the above mentioned characteristics in any given watershed mean degradation and deterioration of the existing balance between soil, water and plants which tends to expansion and acceleration ofdesertilication factors and their effects itt arid watershed. Zanjan province is located on the Northwest of Iran . the geographical characteristics of this province are; 47,10 to 50.10 east longitude 30°,25`to 370.10 north latitude. About 21059.37 square kilometres oftotal geographical area of this province is part of Sefid Rud watershed with 5.60 million hectares of total area . The average amount of sediment yield of this watershed is estimated to be about 50.00 million tons per year . This amount of sediment has been caused and still is causing lots of problems to the Sefid Rud Dam and the area development as well . Due to sever soil erosion problem and tremendous amount of sediment yield , the application of soil. erosion control projects have been and still is imperative in this watershed. According to the studies about 10 percent of geographical area of this watershed is occupied by Neogen Marl formation which is source of 75 percent of annual sediment . Therefore. in order to find the applicable and workable method(s) for soil and water conservation and control of different types of soil erosion as well as reduction of sediment yield from the areas covered by Neogen Marl fomtation and marine soils , a research study project using five different treatments were used for 7 years as follow 1- Mixed straw mulch 2- Watering by fence and rice straw 3- Applying cationic mulch 4- Applying anionic mulch 5- Control plot All five treatments were used by construction of research plots having the size of 2 * 10 meters on the south aspect of selected area which is located in the down stream of Zanjan Rud River so called Sarcham area. * In order to measure depth , intensity and duration of rainfall a automatic rain gage recorder was use and data were collected . The amount of run off and sediment were measured by using storage tanks having a volume of 220 litters in down slopes of each" plots right of each rainfall event . All collected data during seven years of study starting from 6 Dec. 1988 to 20 Feb. 1995 were analysed by using variance analysing method. compression between mean ofyielded sediment for each treatment _ " by four replication for each one were done by using Duncan Test Method. The least Significant Range (LSR.) was calculated and the result were analysed . The results of this study were shown that the intensity of effective rain is the most effective factor for generation of run-off and soil erosion as well as sediment and the application of watering has most influence in stabilisation of the marine soil and minimising the amount of sediment yield from Neogenous marl formation in compression to the otherused treatments.