Effects of Land Use Land Cover and Slope Gradients on Soil Fertility at Kori Sub-Watershed, East Wollega, Ethiopia

BackgroundThe complex nature of the relationship and interaction between LULC and slope gradients resulted in the decline of soil fertility parameters, which aggravate the reduction of sustainable productivity in Ethiopia in general and the study area in particular. This study was aimed to determine the effects of land use land cover and slope gradients on the physicochemical properties of soil in study area A total of 27 composite soil samples were collected from 0-20cm depth under three dominant adjacent LULC across three slope with three replications. The collected soil samples were analyzed for selected soil physicochemical properties. Two-way ANOVA was used to test the mean differences of the soil fertility parameters. ResultThe mean values of soil physicochemical parameters showed that, SOC, TN, AvP, CEC, exchangeable bases (Ca2+ Mg2+, K+, and Na+), PBS, and percentage of clay contents of cultivated land and steep slope gradient (15-30%) were low and significantly different at (P≤0.05) than forest and grad grassland of the same slope gradient.. The gentle slope (3-8%) gradients of the forest lands had the lowest BD and high TP as compared to the others.ConclusionThe overall soil fertility status of the steep slope gradient (15-30%) of cultivated lands is lower than others and cultivating the steep slope is the cause for productivity loss in the study sub-watershed. Therefore, proper land-use planning and the use of integrated soil fertility management strategy give better production and keep the soil fertility status to a better level.

ANÁLISIS LOCACIONAL DEL YACIMIENTO PALEOLÍTICO DE COVA EIRÓS (TRIACASTELA, LUGO)

In this paper, we deal with the locational analysis of the Cova Eirós site (Triacastela, Lugo), occupied from the Middle Palaeolithic to the present. From GIS and statistics, we intend to approach those environmental factors that define its importance as a place of occupation over time and on a recurring basis. Once we have analysed the variables that characterize the site’s patterns of use, we have verified that Cova Eirós is an important, prominent and strategic point. The place is very close to the potential transit routes and has great visibility. It is also protected and set on a steep slope. Moreover, the site has hunting resources and raw materials sources nearby. So it is a settlement that presents ideal living conditions for hunter-gatherer groups.

Synantropijne stanowisko Erysimum wittmannii Zaw. (Brassicaceae) w BeSkidzie Sądeckim

A new local population of a Carpathian endemic plant species, Erysimum wittmannii, was found in Szczawnica in concrete-filled crevices between large stones on a steep slope falling to the Dunajec River, slightly downstream from the stream Grajcarek, when walking from Krościenko. This is certainly its largest, although anthropogenic, local population in the Polish Carpathians. On 14 July 2020, it included 45 fruiting individuals and two flowering ones.

Flash Flood Characteristics of Ciberang River, Its Impact and Mitigation

Flash flood is a deadly natural disaster that develops at space and time scales caused by high rainfall intensities and frequently occurs. It occurs in mountainous regions with steep slope relief and often causes a loss of economy, society, and environment and threatens human lives. The Ciberang river is located at Lebak district, Banten Province, and has been experiencing a significant flash flood from December 31, 2019 to January 01, 2020, which contributed to various damages, including households nearby the river. In this study, the impact areas were identified with the HEC-RAS model and satellite image data. The impact area was damage on eight sub-districts, including agriculture (77.86 Ha), buildings (0.80 Ha), roads (2.5 km), and nine bridges. In addition, this study tried to build Sabo Dam upstream of Banjar Irigasi sub-districts to respond to the flash flood occurrence. The results have reduced the discharge to around 40 m3/s, and the travel time was delayed about 53 min. The results of this study help the community and decision-makers be ready for further flash flood disasters.

Morphodynamics of Gully Development on the Platform–Slope System of Spoil Dumps under Platform Concentrated Flow

Severe gully erosion on spoil dumps, caused by dense concentrated flow derived from platforms, poses a significant threat to the land management of mining areas. However, little is known about the development processes and mechanisms of gullies on spoil dumps. A flow scouring experiment was conducted on an established platform–slope system under 3.6–5.04 m3 h−1. The soils of the system consisted of a surface sandy loam A layer and anunderlying clay loam B layer. The results showed that the platform exhibited a gully development process of headcut-incision–headcut-expansion–stabilization and the steep slope experienced gully development of A-layer incision–A-layer expansion–B-layer incision–stabilization. The results showed 88.97–100% of Froude Number (Fr) decrement and 47.90–88.97% of Darcy–Weisbach roughness coefficient increment finished in the two incision stages on the steep slope. Gully depth has the most sensitive response to flow hydraulics. A significant linear correlation exists between gully depth and shear stress, runoff power, Fr, and Reynolds Number (R2 > 0.337). Overall, the optimal hydraulic indicator varies within different stages for describing the gully morphology development, illustrating the different action mechanism between flow hydraulics and gully morphology. Our findings provide a theoretical support for future mechanistic studies of gully erosion and the land management on spoil dump.