3.2. Soil erosion changes p ver
er land co
r each LULC class in the study area. Both in 1992 and 2009 the highest erosion rates were observed in "quarries" class (24 and 26 t/hr respectively). The lowest average soi
Table 2 shows the mean soil erosion pe
l loss was 2.10 t/ha/yr in 1992, 2.16 t/ha/yr in 2009, and it was observed in "protected areas". On the other hand, the "forest" class in 1992 and 2009 are expected to have low erosion rates but the results showed that the erosion rates were 17 and 14 t/ha/yr in 1992 and 2009 respectively. These results can be explained due to poor coverage of trees in the forest classes and the high slopes which increase the soil erosion rates in these areas.
In the study area, there were several changes among the LULC classes. The mean soil loss estimated from each LULC class varies
based on its characteristics like the vegetation coverage and type, slope and ma
nagement practices. Results of LULC mapping (Table 3) showed that the area had important changes. Among these changes was the decrease of "irrigated" areas from 9 % in 1992 to 7.7% in 2009. Also, "rainfed" areas declined with time. One important change was the increase of "urban" areas which nearly doubled between 1992 and 2002. The "open rangeland" increased from 38% in 1992 to 48% in 2009, which indicated that the area was changing from agricultural areas into non-cultivated lands. The major changes in the LULC in the study area were in the "mixed rainfed" areas. The "mixed rainfed" areas have decreased about 40% from 1992 to 2009. This decline could also reflect the frequent drought and rainfall irregularity in the last two decades.