Dampak Perubahan Curah Hujan Terhadap Tingkat Kerentanan Erosi Tanah Di Sub DAS Merawu, Jawa Tengah

This research was held to estimate rainfall and change in soil erosion vulnerability from 2020 to 2050 in Merawu Sub-Watershed, Banjanegara District with RCP 2.6, 4.5 and 8.5. The RCP is an overview of the concentration trends for greenhouse gases, aerosols and land use change created by the climate modeling community. Rainfall prediction was generated from SDSM Software and combined with USLE to predict soil erosion in ArcGIS 10.4. Changes in rainfall intensity are an important factor in changes of soil erosion rates because the kinetic energy of falling rainwater can cause soil erosion.The results showed rainfall in Banjarnegara Station at 2020-2050 with RCP 2.6,4.5 and 8.5 were increasing by +0,26%; +0,60%; +0,52%, while in Kalisapi Station were decreasing by -1,54%; -1,65% dan -2,20%. The change of soil erosion vulnerability prediction showed that soil erosion in Sub-DAS Merawu at 2020-2050 with RCP 2.6,4.5 and 8.5 in very light category were -0,02%;-0,02%;-0,03%, light category were -0,17%;-0,17%;-0,17%, moderate category -0,05%;-0,05%;-0,04%, heavy category -0,26%;-0,35%;-0,37%, and very heavy category were +1,46%;+1,88%;+1,95%. While the average soil erosion prediction at RCP 2.6, 4.5 and 8.5 were +0,86, +1,19% and +1,03%, respectively. Keywords: soil erosion prediction, rainfall prediction, SDSM Software, Sub-DAS Merawu

Linking Soil Erosion Modeling to Landscape Patterns and Geomorphometry: An Application in Crete, Greece

Soil erosion is a severe and continuous environmental problem caused mainly by natural factors, which can be enhanced by anthropogenic activities. The morphological relief with relatively steep slopes, the dense drainage network, and the Mediterranean climate are some of the factors that render the Paleochora region (South Chania, Crete, Greece) particularly prone to soil erosion in cases of intense rainfall events. In this study, we aimed to assess the correlation between soil erosion rates estimated from the Revised Universal Soil Loss Equation (RUSLE) and the landscape patterns and to detect the most erosion-prone sub-basins based on an analysis of morphometric parameters, using geographic information system (GIS) and remote sensing technologies. The assessment of soil erosion rates was conducted using the RUSLE model. The landscape metrics analysis was carried out to correlate soil erosion and landscape patterns. The morphometric analysis helped us to prioritize erosion-prone areas at the sub-basin level. The estimated soil erosion rates were mapped, showing the spatial distribution of the soil loss for the study area in 2020. For instance, the landscape patterns seemed to highly impact the soil erosion rates. The morphometric parameter analysis is considered as a useful tool for delineating areas that are highly vulnerable to soil erosion. The integration of three approaches showed that there is are robust relationships between soil erosion modeling, landscape patterns, and morphometry.

Investigation of the effect of anthropogenic land use on the Pănăzii Lake (Romania) catchment area using Cs-137 and Pb-210 radionuclides

The problem of soil degradation has accentuated over recent decades. Aspects related to soil erosion and its relation to changes in land use as well as anthropogenic influence constitute a topic of great interest. The current study is focused on a soil erosion assessment in relation to land use activities in the Pănăzii Lake catchment area. Fallout radionuclides were used to provide information on soil erosion as well as redistribution rates and patterns. Variations in the sedimentation rate of the lake were also investigated as these reflect periods in which massive erosion events occurred in the lake catchment area. The novelty of this study is the construction of a timescale with regard to the soil erosion events to better understand the relationship between soil erosion and land use activities. In this study, 10 soil profiles and one sediment core from the lake were taken. Soil parameters were determined for each sample. The activities of 210Pb, 137Cs and 226Ra were measured by gamma spectroscopy. For low 210Pb activities, measurements via 210Po using an alpha spectrometer were performed. Soil erosion rates were determined by the 137Cs method and the sedimentation rate calculated by the Constant Rate of Supply (CRS) model. A soil erosion rate of 13.5 t·ha-1·yr-1 was obtained. Three distinct periods could be observed in the evolution of the sedimentation rate. For the first period, between 1880 and 1958, the average deposition rate was 9.2 tons/year, followed by a high deposition period (1960–1991) of 29.6 tons/year and a third period, consisting of the last 30 years, during which the sedimentation rate was 15.7 tons/year. These sedimentation rates fluctuated depending on the main land use activity, which can also be seen in the soil erosion rates that had almost doubled by the time agricultural activities were performed in the area.

Tracing erosion rates in loess landscape of the Trzebnica Hills (Poland) over time using fallout and cosmogenic nuclides

Purpose Loess landscapes are highly susceptible to soil erosion, which affects soil stability and productivity. Erosion is non-linear in time and space and determines whether soils form or degrade. While the spatial variability of erosion is often assessed by either modelling or on-site measurements, temporal trends over decades to millennia are very often lacking. In this study, we determined long- and short-term erosion rates to trace the dynamics of loess deposits in south-western Poland. Materials and methods We quantified long-term (millennial) erosion rates using cosmogenic (in situ 10Be) and short-term (decadal) rates with fallout radionuclides (239+240Pu). Erosion processes were studied in two slope-soil transects (12 soil pits) with variable erosion features. As a reference site, an undisturbed soil profile under natural forest was sampled. Results and discussion The long-term erosion rates ranged between 0.44 and 0.85 t ha−1 year−1, whereas the short-term erosion rates varied from 1.2 to 10.9 t ha−1 year−1 and seem to be reliable. The short-term erosion rates are up to 10 times higher than the long-term rates. The soil erosion rates are quite consistent with the terrain relief, with erosion increasing in the steeper slope sections and decreasing in the lower parts of the slope, while still maintaining high values. Conclusions Soil erosion rates have increased during the last few decades owing to agriculture intensification and probably climate change. The measured values lie far above tolerable erosion rates, and the soils were found to be strongly imbalanced and exhibit a drastic shallowing of the productive soils horizons.

Soil erosion risk assessment: a case study of the Jos Plateau, Nigeria

Soil erosion is a treat to global food security. The objective of this study was to evaluate factors influencing erosion on the arable lands of the Jos Plateau; and to estimate the extent of soil erosion in the area. Universal Soil Loss Equation (USLE) model was used to evaluate soil erosion processes in the study area. This was facilitated with the aid of Geographic Information System Both for Interpolation and Geospatial analysis. Soil data from field survey was the primary source of data for analysis of soil erodibility. Topographic factor was determined from 90-meter elevation data. Rainfall erosivity was determined from rainfall data at 1 kilometer resolution. Whereas vegetation cover factor was determined from Normalized Difference Vegetation Index. Results of the study indicate that rainfall erosivity values were remarkably high and have mean values of 5117MJ.mm/ ha.h.y. Analysis of percent areal coverage indicate that the entire area had 52, 34, 7, and 7% low, moderate, high and very high topographic factors respectively. Further analysis indicate that anthropogenic factors had severely affected vegetation coverage of the Jos plateau, especially on the arable lands. Furthermore, during this research, the mean annual actual and potential soil erosion rates were estimated spatially over the Jos Plateau area. Soil erosion rates were far more than tolerable rates thereby affecting soil fertility and productivity.