WANG Nan, CHEN Yixian, BAI Leichao, et al. Investigation on Soil Erosion in Small Watersheds Under “7·26” Extreme Rainstorm in Zizhou County, Northern Shaanxi Province[J]. Bulletin of Soiland Water Conservation, 2017, 37(4): 338-344.
DOI:
WANG Nan, CHEN Yixian, BAI Leichao, et al. Investigation on Soil Erosion in Small Watersheds Under “7·26” Extreme Rainstorm in Zizhou County, Northern Shaanxi Province[J]. Bulletin of Soiland Water Conservation, 2017, 37(4): 338-344. DOI: 10.13961/j.cnki.stbctb.2017.04.057.
Investigation on Soil Erosion in Small Watersheds Under “7·26” Extreme Rainstorm in Zizhou County, Northern Shaanxi Province
[Objective] An extreme rainstorm was occurred in Yulin Region of Shaanxi Province in 26 July
2017
resulting in very serious flood hazards and economic losses. The aims of this paper were to figure out the hazards of soil erosion in the rainstorm and provide basis for soil and water conservation and rainstorm hazards defenses.[Methods] Three small watersheds (Qingshuigou
Majiagou and Shejiagou) were selected as key investigation areas in Zizhou County (the devastated area in this rainstorm) in 2-6 August
2017. Soil erosion of slope croplands
forest and grass lands after cropland abandoned
terraces
fields built by filling gullies
check dams and roads were investigated and analyzed.[Results] Rills developed evidently in slope croplands
and even small gullies developed in down slopes. While in forest and grass lands after cropland abandoned in 2000
sheet erosion was dominant and no obvious rills developed. In the new built terraces
the roads connecting two terraces
the field surfaces taking over the runoff from the roads
and the ridge in some sections were washed out seriously
and collapse occurred in the field walls. In fields built by filling gullies
crops and dam bodies were destroyed severely
the roads beside was eclipsed and the cutting walls were collapsed. Check dams were damaged more or less
but block runoff and sediment obviously. The main existing problems were wide spread steep slope farming
lacking storage and drainage systems in small watershed
deficiency in maintenance mechanism of soil and water conservation engineering
lower level of economic development
weak awareness of farmers in soil and water conservation.[Conclusion] Soil erosion under "7·26" extreme rainstorm was still severe
but it is slight in forest and grass lands after cropland abandoned. It suggested that soil and water conservation is still very important. Environmental protection measures should continue to be strengthened
and soil and water conservation
especially steep slope cropland abandonment should be increased in the fragile Loess Plateau of Northern Shaanxi Province. In the meanwhile
it is necessary to design and implement the storage
diversion and drainage network system in small watersheds.