dadvar lotfollahzadeh

The current research was carried out to study the amount of soil erosion and soil moisture storage in cultivation of two species from the Gramineae family . The study area was located 45 km north of Khorramabad in the village of PereskOlia, in the province of Alashatar in the Honam basin. Most of the cultivation in the area is wheat, cultivated on land with a slope of up to 18%, and in rangelands that have been converted to dry farmland. In order to promote the correct principles of crop cultivation and soil tillage, and in order to highlight the effects of land use change on soil condition and water loss, two sites were selected with identical conditions. On the control site wheat, the region’s most common crop, was cultivated and in the treatment site rye (Secalemontanum) was grown. The reason for selection of rye is the natural abundance of this species in the rangelands of the region, its resistance to harsh ecological and climatic conditions, its permanence and the extensive use of this species in the food industry and its several other industrial applications. To determine the amount of soil erosion, special geotextile fabrics were installed at the end of each site. To ensure the accuracy of soil erosion measurements, erosion pins were used in the both sites. Also, soil moisture content from the soil samples with depths of 0-25 centimeters was determined by weighing and drying samples in 20-day intervals during growth period. The three-year results after the implementation of this plan indicated that the amount of rye barley per unit area in the third year was 19.91% higher than the wheat yield in the control site. Soil erosion of the treatment site compared to the control site (wheat) decreased by about 53%, and soil moisture content of the rye site was 91.3% higher than the control site (wheat) in the third year. In addition, the cost of agricultural inputs in the treatment site was reduced to one-fifth in the treatment condition. Along with the scientific and investigative results of this project, its extensional results include the level of participation and interest in this project among farmers. Observing the project accomplish its objectives lead to farmers’ implementation of this plan at a large scale in agricultural fields. Finally, this study increased farmers’ willingness to change the cultivation pattern from wheat to rye in the study area.

The study performed to determine the relationship between landslide and increasing sediment load in Latian dam watershed. Sediment yield of six sub-basins were estimated with by two methods of MPSIAC and hydrometric station . More than 150 landslides were mapped by ETM and Google Earth image processing. Comparing the observed data with MPSIAC output in Lavasanat and Kond-Afjeh sub-catchments, it became clear that Lavasanat has less sediment yield. But, despite of this subject, observed sediment yield in Lavasanat hydrometric station is about two times in Kond–Afjeh, while the landslides area in Lavasanat and Kond–Afjeh sub-basins are 1.8 and 0.7 percent of the area. Based on the estimated sediment yield of MPSIAC model, the weighted average of specific sediment yield for Kond-Afjeh and Garmabdar sub–basins with landslide area of 0.7 and 2.4 percent are 387.02 and 431.39 m3km-2y-1 respectively, which means that increasing the relative percentage of landslide area from 0.7 to 2.4 percent, specific sediment yield increases by 11.5 percent. Based on data analysis in Roodak hydrometric station in Jajrood basin, average sediment discharge of the river in the first nine months of 1383 before Hajyabad landslide was 6.17 tons per day that increased to an average of 16.9 tons per day at nine months after landslide. This amount is equivalent to 170 percent increasing of sediment load in nine months after mentioned event. The interesting point is that this increasing of sediment yield was in the period of about 30% decrease in water debit . This means that not only increasing sediment yield of the river is not related to the water debit, but also, about 30% reduction of water debit is should reduce sediment yield. So, regarding to the area of 20.45 ha of Hajabad landslide zone, each hectare of landslide area could increase more than 8% of the sediment load in the river.