5. CONCLUSIONS
This
study analyzed the impacts of three factors on soil erosion and sediment
yield in the Kuye River watershed by applying the SEDD model. The
process of land use changes showed that arable land and bare land
transformed into vegetation cover and construction land from 1987 to
2016, while arable land and bare land were the main sources of sediment
yield in 1987. As of 2011, 306 key dams had been built in the Kuye River
watershed, with a total storage capacity of 316.64
Mm3. According to the classification of soil erosion
and sediment yield, we found that under the influence of three factors,
high erosion areas were consistently transformed into low erosion areas.
Hot spot analysis showed that the high-risk regions of soil erosion and
sediment yield were mainly concentrated in the middle reaches of the
watershed, and the hot spots decreased with time. The average value of
SDR for the whole watershed showed a declining trend with increasing
time. The simulation results showed that the check dams were the
dominant factor, reducing total soil erosion by 70.95% in 2006 and
57.78% in 2016. Check dams reduced total sediment load by 53.77% in
2006, which were still the dominant factor. From 1987 to 2016, the
contribution of these three factors to sediment load reduction was
29.10%, 40.09% and 30.81%, respectively, which indicated that all of
them had significant influence on sediment load in 2016.