Assessment of Soil Erosion Hazard in Prambanan District Using RUSLE (Revised Universal Soil Loss Equation)

Prambanan District which located in Daerah Istimewa Yogyakarta Province has the potential for land degradation due to erosion processes. With the characteristics of annual rainfall more than 2000 mm / year, topography with a slope of more than 20% in upland areas, as well as the conversion of upland to dryland agriculture are factors that can trigger the erosion process more quickly. If the rate of erosion speed exceeds the ability of the soil to regenerate the soil body, its productivity will be disrupted and accelerate the formation of critical soil. Therefore, it is necessary to know the estimated rate of erosion, tolerable distribution of erosion, and the potential danger of erosion that occurs. The purpose of this study was to (1) predict the rate of erosion, (2) calculate the permissible erosion value, (3) identify the rate & index of erosion hazard. Data were collected using field surveys and soil sampling using stratified random sampling techniques with land units as the unit of analysis. The value of erosion was predicted using the Revised Universal Soil Loss Equation (RUSLE) method. The RUSLE method is described by the following equation, A=R*K*L*S*C*P, where; A as estimated averages annual loss of soil, R is the rainfall erosivity factor, K is the soil erodibility factor, LS is the slope length factor, C is the cover management factor, & P is the conservation practice factor. The results showed that the erosion value ranged from 0.39 - 268.55 tons/ha/year. Permissible erosion ranges from 8.4 – 15 tons/ha/year for Latosol and 27.4 ton/ha/year for Regosol. The Rate of Erosion Hazard is dominated by moderate erosion, covering an area of 1330.7 ha or 31.8% of the total area. The Erosion Hazard Index is dominated by the low class (<1.0) which is covered over 2703.1 ha or 64.61% of the total area.

Erosion and sedimentation analysis due to land use changes in the Krueng Pase watershed

Human interactions with watershed can have positive and negative impact. The positive impact can improve socio-economic conditions. However, the negative impact is the degradation of the watershed function. For example, it’s continued increase in erosion rate on the land. The purpose of this study is to analyze erosion and sedimentation due to land use changes using the Universal Soil Loss Equation (USLE) and Modified Universal Soil Loss Equation (MUSLE) methods. Data collecting to determine erosion and sedimentation values are rainfall, soil erodibility and soil moisture, land use, and river water samples. The biggest decreased land use changes occurred in forest by 5.87%, followed by agriculture which decreased by 0.65% and water body 0.047%. On the other hand, built-up area increased by 0.65% and land used for agriculture increased by 6.15%. Furthermore, the level of erosion hazard in the Krueng Pase watershed from 2009 to 2019 increased in area, the mild level of erosion hazard increased by 7.9% and the moderate level erosion hazard by 27.4%. The amount of sedimentation obtained using the MUSLE method in 2019 was 6,869,98 tons and in 2009 was 41,692,97 tons. Erosion valuein 2019 is relatively small compared to other years. It’s really depends on the rainfall and the discharge that occurs. Therefore, a good land management system, proper and appropriate technology used, eco-hydrology concept and the monitoring of land use change regularly are needed, so damage that impact the Krueng Pase watershed can be prevented and minimize.

A Study Case on Estimation of Soil Loss and Sediment Yield in Curtin University, Malaysia

Because of human activities, soil erosion has been one of the most concerning issues in Malaysia in the past decades. This study aimed to estimate the amount of soil loss and sediment yield at Curtin University, Malaysia by using the Revised Universal Soil Loss Equation (RUSLE) and the Modified Universal Soil Loss Equation (MUSLE), respectively. The parameters of RUSLE include rainfall erosivity factor (R), soil erodibility factor (K), slope length factor (L), slope steepness factor (S), cover-management factor (C) and support practice factor (P). The rainfall data (10 years) from the Sarawak Meteorological Department was used to determine the R-factor. The K-factor was determined by sieve analysis, hydrometer analysis, the Standard Proctor Test (SPT), and organic content testing. The L-and S-factors were performed by measuring on site and using Google Earth. The C-and P-factors were based on the ground surface cover condition (bare soil in this study). In the MUSLE, the runoff factor comprises V and Qp, while the other parameters are the same as in the RUSLE. The runoff depth, V, is equivalent to the rainfall intensity. Rainfall intensities were recorded by using a rain gauge. The highest rainfall intensity was used for runoff depth. The Rational method has been utilized to calculate Qp. The amount of soil loss estimated was 119.97 tons/ha/year and the sediment yield amount estimated was 0.76 ton/storm event in Curtin University, Malaysia.

Predicción espacial de la erosión del suelo en zonas áridas mediante teledetección. Estudio de caso: Quebrada del Diablo, Tacna, Perú

La presente investigación trata sobre la evaluación de la erosión hídrica del suelo en una zona árida de la región Tacna al sur de Perú, tomando como caso de estudio la Quebrada del Diablo. Se usaron los modelos USLE (Universal Soil Loss Equation) y RUSLE (Revised Universal Soil Loss Equation) en conexión con sistemas geográficos de información (GIS) y técnicas de teledetección. Los factores R, K, LS, C y P de los modelos fueron calculados a partir de información pluviométrica local registrada en tres estaciones y de datos provenientes de sensores remotos integrados mediante el GIS, obteniendo así una simple y efectiva herramienta para determinar mapas, áreas y tasas de erosión. Los resultados indican que la máxima tasa de erosión hídrica, debido a la precipitación extraordinaria ocurrida el año 2020, calculada mediante ambos modelos, varía de 0 a 50 t/ha/año, variación considerada en el rango bajo, ligero y moderado. Los modelos USLE y RUSLE arrojan un potencial de erosión menor a 10 t/ha/año para el 71,81 % y el 45,27 % del área de estudio, respectivamente; para tazas de erosión mayores a 10 t/ha/año las áreas calculadas con el modelo RUSLE superan a los estimados con el modelo USLE.

Analisis Laju Erosi DAS Citarum dari Hulu Hingga Kawasan Muara Menggunakan Sistem Dinamik

Daerah Aliran Sungai (DAS) Citarum merupakan DAS terbesar yang ada di Jawa Barat. Sedimentasi waduk, dan banjir musiman merupakan permasalahan yang sering terjadi dan merupakan akibat dari erosi dan sedimentasi yang berkepanjangan pada DAS Citarum. Erosi tanah oleh air dapat terjadi akibat tumbukan butiran tanah oleh air dan akibat aliran air permukaan. Tujuan dari tulisan ini adalah memprediksi seberapa besar laju erosi tahunan pada DAS Citarum dengan memanfaatkan pemodelan Power Sim. Sebagai data inputan untuk model digunakan metode Universal Soil Loss Equation (USLE), adapun untuk mengetahui laju erosi tahunan yang dinyatakan dalam ton/km2/tahun, dibutuhkan perhitungan data indeks kemiringan lereng, nilai tata guna tanah, erodibilitas dan erosivitas. Hasil perhitungan prediksi hingga 100 tahun menunjukkan laju erosi terkecil secara garis besar berada pada area muara dengan nilai laju erosi lebih dari 60 ton/km2/tahun, sementara laju erosi lebih besar dari 200 ton/km2/tahun dengan prediksi perhitungan 100 tahun kedepan mendominasi area hulu DAS Citarum.

Pengaruh Penambangan Batu Gamping Terhadap Kondisi Lahan dan Air Tanah Dalam di Desa Bedoyo, Kecamatan Ponjong, Kabupaten Gunung Kidul, Yogyakarta

Potensi batu gamping sangat besar di Desa Bedoyo, Kecamatan Gunung Kidul, Yogyakarta dapat meningkatkan kondisi sosial dan ekonomi bagi masyarakat setempat. Penambangan tersebut juga dapat menimbulkan dampak besar yaitu permukaan lahan pertambangan yang rusak sehingga lebih mudah mengalami erosi, bahkan dampak dari penambangan batu gamping pada air. Tujuan penelitian: (1) Mengetahui tingkat kerusakan lingkungan, berupa laju erosi yang disebabkan oleh penambangan batu gamping di Desa Bedoyo, (2) Mengetahui arahan prioritas konservasi lahan, dan (3) Mengetahui pengaruh kegiatan penambangan batu gamping terhadap kedalaman air tanah di Desa Bedoyo. Metode penelitian pada penelitian ini terdiri dari dua bagian, yaitu: (1) Metode penelitian untuk kerusakan lingkungan menggunakan metode Universal Soil Loss Equation (USLE), faktor yang dibuat dalam perhitungan adalah erosivitas hujan (R), erodibilitas (K), panjang dan kemiringan lereng (LS), vegetasi (C), tindakan konservasi (P), dan (2) Metode penelitian untuk kedalaman air tanah menggunakan metode geolistrik resistivitas konfigurasi Schlumberger. Hasil penelitian tingkat kerusakan lingkungan berdasarkan laju erosi, daerah penelitian di Desa Bedoyo, termasuk dalam kelas bahaya erosi normal, moderat, dan sangat berat, dengan erosi tertinggi sebesar 21.501.849 ton/ha/tahun terdapat pada lahan dekat daerah tambang. Sedangkan pada penelitian geolistrik, konfigurasi Schlumberger diperoleh data titik shounding 2 berada di kedalaman akuifer 0,41–30,32 meter dan titik sounding 3 dengan kedalaman 0,60–31,76 meter.