Page 146 - Çevre Şehir ve İklim Dergisi İngilizce - Özel Sayı

DETERMINATION OF EROSION STATISTICS BY
LAND USE TYPE AT NATIONAL SCALE WITH THE

DYNAMIC EROSION MODEL AND MONITORING
SYSTEM (DEMMS)

İskender DEMİRTAŞ - Günay ERPUL

ABSTRACT
Soil erosion is a major environmental problem in Türkiye, as it is all over the world.
In order to quickly assess erosion and develop policies, the Dynamic Erosion
Model and Monitoring System (DEMMS) has become a supportive planning
tool. Accordingly, it has been set up to monitor erosion in 25 river basins based
on RUSLE technology and technically reinforced by RS and GIS. DEMMS has
successfully produced erosion statistics not only for all river basins but also for
all provinces of Türkiye, taking into account different land use types. In addition,
the statistical results produced by DEMMS show maps of the distribution of
erosion levels on which detailed action plans to combat soil erosion at the micro-
catchment level can be easily im-plemented. The soil loss calculated on the basis
of the statistical results and estimates of DEMMS amounts to about 642 million
tons ha-1 y-1 in Türkiye. Assessing the extent of water erosion in Türkiye by severity,
the results show that 79.4% of the total area is under the influence of very low or
low severity erosion, while 20.6% of the total area is affected by moderate, severe
and very severe erosion. When the extent of severe and very severe erosion is
classified according to the type of land use, it is established that severe erosion
occurs in agricultural and pasture areas. Setting down the eficiency of the model
parameters on the amount of soil erosion; LS, which represents the combined
effect of slope length and steepness on runoff and erosion processes, stood
out in rational eficiency with a value of 47.55%, while C, R, and K were ranked at
34.82%, 14.26% and 3.36%, respectively. At the catchment level, sediment yield
per unit area was the highest in the Çoruh basin at 26 t ha⁻¹ y⁻¹, while sediment
yield was the lowest in the Sakarya basin at 4.2 t ha⁻¹ y⁻¹. Evaluating at the
amount of soil transported by catchment area, the highest sediment transport of
160 million tons was recorded in the Dicle-Fırat basin, while the lowest sediment
yield of 3.6 million tons took place in the Burdur basin.

Keywords: DEMMS, RUSLE, GIS, Soil Erosion, Land Use.

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Special Issue / 2024