Conversion trends of rangelands to dry farming and its effects on erosion and sediment yield in Kardeh drainage basin

Authors

1 *, W. N. A. B. Sulaiman2, F. Saeidian2

2 M. Yasouri1*, W. N. A. B. Sulaiman2, F. Saeidian2

Abstract

Converting rangelands to arable land such as dry farming is widely practiced in many places in Iran. This activity could possibly contribute to the increase in downstream sedimentation. The effects of this activity on downstream watersheds are not well documented for many strategic areas in the country. One such area which is proposed for this study is the Kardeh drainage basin, located in the north east of Iran, having a catchment area of 570.9 km2. In this study, an attempt was made to quantify the changes in land use, and the sediment yield of the basin, and to identify significant contributing factors that could possibly contribute to the increased downstream sedimentation between the years of 1970 and 2007. Available satellite images and aerial photos were analyzed for the extent of land use changes and an empirical model, Erosion Potential Method (EPM) was validated and applied to quantify the annual total sediment yield of the basin. Step-wise multiple regressions were used to justify that the changes in sediment yield is due to the increased dry farming activities. The results showed a drastic change in land use between these periods where dry farming area has remarkably increased to 91%, while there was a reduction in rangeland area of about 13%. The effect of increased dry farming activities is reflected on the two fold increase in annual total sediment yield of the basin. Statistically, about 95% of the changes in sediment yield is due to the effect of increased dry land farming area in the basin (R2= 0.95, ? < 0.05).

Keywords


Ahmadi, H. (2008) Applied geomorphology, Volume 1 (water erosion), Second Edition, Tehran University Publications, 668 pp.
 
Arnaez, J., Lasanta, T. (2006) Factors affecting runoff and erosion under simulated rainfall in Mediterranean vineyards. Soil & Tillage Research, 83: 321-336.
 
Begueria, S., Vicente, S.M. (2006) Mapping the hazard of extreme rainfall by Peaks-over-threshold extreme value analysis and spatial regression techniques. Journal of Applied Meteorolgy, 45: 108-124.
 
Casasnovas, J.A.M., Bosch, I.S. (2000) Impact assessment of changes in land use/conservation practices on soil erosion in the Penedes-Anoia vineyard region (NE Spain). Soil & Tillage Research, 57: 101-106.
 
Cocos, A.,O, Cocos and Sarbu, I. (2011), Patterns of flow evolution in the central area of the Romanian plain, Caspian Journal of Environmental Sciences, 9: 81-95.. Gaya, U,I, Audu, A, A. (2005) Effect of Irrigation on Soil Properties in Jakara Kano, Nigeria, Caspian Journal of Environmental Sciences, 3(2) 2 99 – 106.
 
Globevnik, L., A. Sovnic, H. Wheater,, Kirby. C. (2006) Impact of catchment land use change on river flows. Proceeding of the British Hydrological Society International Conference, Yasouri et al., 271Hydrology in changing environment, 1:525-533.
 
Goldman, S.J., K. Jakson, and T.A. Bursztynsky, (2004) Erosion and Sediment Control Handbook, Mc Graw-Hill Book Co. New York.
 
Kasa, M., Marutani, T., Reid, L. (2001) Estimation of temporally averaged sediment delivery ratio using aggradational terraces in headwater catchments of the Waipaoa River, North Island, New Zealand. Journal of Earth Surface Processes and Land forms,26: 1-16.
 
Kim, Y., Engel, B. A. (2002) Runoff impacts of land-use change in Indian River Lagoon Watershed. Journal of Hydrologic Engineering, 7: 245-251.
 
Lu, X.X. and Higgitt, D.L. (2005) Sediment delivery to the Three Gorges, Journal of Geomorphology, 91:157-169.
 
Lyon, J., (2006) GIS for Water Resources and Watersheds management. Taylor & Francis, London. Mahdavi, M. (2007) Applied hydrology, volume 2, seventh edition, Tehran University Publications, 401 pp.
 
Mirabolghasemi, H., Morid, S (1999) Investigation of hydrological approaches in estimation of rivers suspended loads, magazine of water development resources, water affairs seasonal paper, power ministry, fourth year, 3: 54-67.
 
Mirzaii, M. (2007) Comparing the statistical approaches in estimation of rivers suspended loads, watershed management M.Sc Thesis, Natural Resources Faculty, Tehran University, 182 pp. National Resources Conservation System (2003) A Method for Estimating Volume and Rate of Runoff in Small Watersheds, Technical paper No. 149, USDA-NRCS, Washington, D.C, USA.
Van Ramapaey, A., Govers J., Puttemans, C, (2002) Modelling land use changes and their impact on soil erosion and sediment supply to rivers. Journal of Earth Surface Processes and Landforms, 27:481-494. Jafarian Jeloudar,
 
Z., Arzani, H., Jafari, M., Kavian, A., Zahedi, Gh., Azarnivand, H. (2010) Vegetation community in relation to the soil characteratics of Rineh rangeland, Caspian Journal of Environmental Sciences, 8: 141-150