Modeling the Effects of Land Use Change on Surface Runoff in the Watershed of Khorramabad Using RS and GIS Integration Model and L- THIA

land use change, mainly socio-economic benefits to follow. However, these changes have negative effects on the natural environment. Due to the high volume of runoff from a lack of permeability in the city and Non-use of certain areas or any structure in addition to the problem of flooding in low-lying areas for water infiltration in several studies to develop models with simulation approach to land use changes have taken place. In this study, L-THIA model for estimating runoff from land use changes in the area of Khorramabad is used. The Model of L-THIA, a model to assess long-term effects land use change on water resources using simple and availability data Such as long-term climate data, land use map and soil map applicable.  

This study was conducted in a period of 10 years and in the period of 2004-2014. Landsat images from the site the US Geological Survey has been downloaded and various corrections have been made. Land use maps were prepared and used using Landsat 7 satellite images of ETM sensors and Landsat 8 images of OLI sensors related to 2004 and 2014, respectively. Precipitation data are provided by the Regional Water Authority. After sorting, they are prepared for future analysis. By combining land use map and soil texture map in GIS software, the soil hydrological group is produced. Finally, the prepared maps are given to the L-THIA model and the effect of land use change on surface runoff is investigated.

The results of modeling using L-THIA, increased annual runoff in ten years shows that this increased volume of runoff and the need for control over land use change in the region. User modifications to increase mainly in residential areas and loss of woodland and grassland.

As the results of this study show, the L-THIA model has a good ability to express the effect of land use change on the volume and depth of runoff. Also, using the results of the study, it is possible to prepare control programs for land use changes to prevent runoff in the area.