Comparison between different infiltration models to describe the infiltration of permeable brick pavement system via lab-scale experiment

Permeable brick pavement system (PBPs) is one of a widely used low impact development (LID) measures to alleviate runoff volume and pollution caused by urbanization. The performance of PBPs on decreasing runoff volume is decided by its permeability, and it was general described by hydraulic conductivity based on Darcy's law. But there is large error when using hydraulic conductivity to describe the infiltration of PBPs, and which infiltration process is not following to the Darcy's law, so it is important to found a more accurate infiltration models to describe the infiltration of PBPs. The Horton, Philip, Green-Ampt, and Kostiakov infiltration models were selected to found an optimal model to investigate infiltration performance of PBPs via lab-scale experiment, and the maximum absolute error (MAE), Bias, and coefficient of determination (R2) were selected to evaluate the models' errors via fitting with experiment data. The results showed that the fitting accuracy of Kostiakov, Philip, and Green-Ampt models was significantly affected by the monitoring area and hydraulic gradients. Meanwhile, Horton model is fitting well (MAE = 0.25–0.32 cm/h, Bias = 0.07–0.11 cm/h, and R2 = 0.98–0.99) with the experiment data, and the parameters of Horton model often can be achieved by monitoring, such as the maximum infiltration rate and the stable infiltration rate. Therefore, the Horton model is an optimal model to describe the infiltration performance of PBPs, which can also be adopt to evaluate hydrological characterization of PBPs.

Analisis Laju Infiltrasi Dengan Metode Penggenangan (Fooding) dan Karakteristik Tanah di Kabupaten Sampang, Madura

Pertumbuhan ekonomi yang sangat pesat akan menyebabkan kepada perubahan tata guna lahan serta tutupan lahan pada area pembangunan infrastruktur. Akibatnya dapat menigkatnya volume air hujan menjadi aliran permukaan (surface run off) yang tidak terinfiltrasi ke dalam tanah. Penelitian ini dilaksanakan untuk menganalisis laju infiltrasi dengan perhitungan Model Horton, Model Holtan dan Model Phillip serta mengetahui genangan yang terjadi dan mengetahui karakteristik tanah. Kajian ini dilakukan pada 10 titik tinjau dengan 10 desa berbeda di Kabupaten Sampang. Pada setiap titik dilakukan pembacaan laju infiltrasi menggunakan alat Turf-Tech Infiltrometer dan pengambilan sampel tanah berjarak sekitar 5-10 meter dari titik pembacaan infiltrasi. Pengujian karakteristik tanah dilakukan di Laboraturium Tanah dan Air Tanah (Teknik Pengairan). Data curah hujan yang digunakan pada penelitian ini berasal dari Penakar hujan Sampang, Penakar Hujan Omben, Penakar Hujan Robatal, Penakar hujan Kedundung dan Penakar Hujan Karangpenang. Dari hasil analisis, Model Horton dianggap lebih cocok pada penelitian ini dari segi kemudahan dalam proses perhitungan serta dianggap tepat diterapkan berdasarkan dari perbandingan kurva laju infiltrasi lapangan. 6 dari 10 titik tinjau terjadi genangan. Hasil karakteristik tanah memiliki jenis tanah lempung pada 2 titik, lempung liat berdebu 2 titik dan lempung berdebu pada 6 titik.

LAJU INFILTRASI PADA BERBAGAI NAUNGAN DI KEBUN KOPI RAKYAT SUMBERMANJING WETAN

Climate change in coffee cultivation is very influential and can disrupt the hydrological cycle, so shade planting is required. Planting vegetation on coffee fields can affect the infiltration rate. The infiltration rate is the amount of water per unit time that enters the soil surface. The purpose of this study was to determine the infiltration rate with various shading, namely mixed shade (sengon, teak, pepper, and coconut), sengon shade, and monoculture coffee land and to determine the relationship between soil physical properties and infiltration rate on people's land. The measurement of the infiltration rate was done with a double ring infiltrometer and the Horton model. Infiltration rate can be influenced by a variety of soil properties such as bulk density, soil pore distribution, soil aggregate stability, soil texture, soil organic matter content, and land use. The analysis used correlation, linear regression, multiple linear regression, and t-test. Differences in shade and soil properties affect the infiltration rate, especially micropores and soil porosity. Soil with a lot of micro-pore soil, low porosity and clay texture has a slow infiltration rate. The results of the t-test between the actual infiltration rate and the infiltration rate of the Horton model showed no significant difference; therefore, the Horton method approach can be used in estimating the actual infiltration rate in coffee fields.

Assessment of variability of soil Infiltration Characteristics in Forage Cover

In India, very limited knowledge of soil infiltration characteristics in forages are available. In this study, infiltration characteristics of land covered by six forages have been studied with respect to bare land in sandy loam soil. Two empirical (Kostiakov and Horton) and two physically-based (Phillip and Green‒Ampt) models have been employed to estimate infiltration characteristics and compared with observed field infiltration data. The steady-state infiltration rates measured in forages and bare land were significantly (p less than 0.05) different. The highest average steady-state infiltration rate was measured in Panicum maximum (9.00 cm h-1) followed by TSH (7.40 cm h-1) and least was recorded in Cenchrus ciliaris (2.65 cm h-1) whereas the average steady-state infiltration rate recorded for bare land was 1.90 cm h-1. Results showed that the Kostiakov and Phillip model simulated the field infiltration characteristics with higher accuracy than the two other models except for Chrysopogonfulvus and bare land in which the Horton model outperformed other models. Higher steady-state infiltration rates in forages were attributed to more porosity measured in the soils under forages as compared to bare land.

Infiltration Model on Soil Due to the Kostiyacov and Horton Model by using Rainfall Simulator

This research intends to find the best infiltration model between Kostiyacov and Horton that focusing on the infiltration towards soil by using rainfall simulator. The soil is conducted for 3 treatments compacted soil (d1, d2, and d3), however, for every compacted soil has 3 types of slope that are 2 %, 3 %, and 4%. Every trial in the rainfall simulator has the rainfall intensity of 2 l/minute. The result shows that the infiltration rate is very influenced by the compaction and slope. The higher soil compaction and slope cause the smaller infiltration rate. The mean of relative error in Horton Model is 20.365%. It is less than in Kostiyacov Model that is 29.18%. The correlation value in Horton Model is 0.844 and it is more than in Kostiyacov Model that is 0.594. This result shows that the Horton Model is better than the Kostiyacov Model in the research that is conducted with the rainfall simulator

Evaluation of Infiltration Characteristics of Soils Developed on Coastal Plain Sands in Calabar Municipality Local Government Area, Cross River State, Nigeria

Infiltration of water into the soil is an important physical process affecting the fate of water under field conditions, especially the amount of subsurface recharge and surface runoff and hence the hazard of soil erosion. The study was conducted to evaluate the infiltration models of soils developed on coastal plain sands and to select a suitable models as a basis to improve the management of the soil. A total of 16 infiltration runs were made with the double ring infiltrometer. For the purpose of getting best fitting model, the results obtained from various infiltration models were compared with observed field data. The parameters considered for best fitting of model were correlation coefficient and coefficient of variability (CV). Model-predicted cumulative infiltration consistently deviated from field-measured data, that is, the models under-predicted cumulative infiltration by several orders of magnitude for Kostiakov, Green Ampt and Philip model but the model over predicted cumulative infiltration for Horton model. The results of the soil samples analysed revealed that the mean values of 707.50, 208.13 and 84.38 gkg-1 for sand, silt and clay with the textural class of sandy loam. The bulk density, particle density and total porosity had mean values of 1.84 gcm-3, 2.44 gcm-3 and 22.56%. However, there was a fairly good agreement between mean-measured cumulative infiltration (7.30 cm/hr, CV = 32.19%); Philips (1.93 cm/hr, CV = 42.49%); Kostiakov (0.13 cm/hr, CV = 30.77%); Horton (64.49 cm/hr, CV = 22.39%) and Green Ampt model (42.04 cm/hr, CV = 0.57%) respectively. The data however showed that the correlation coefficient for Kostiakov (1.00) was best fitting in predicting the field measured data and this was closely followed by Green Ampt (0.88); while Philip’s model and Horton model showed a negative correlation (r = -0.88 and r = -0.82) with the field measured data. Conservation measures involving mulching, cover cropping and afforestation are recommended to improve the soil structure and infiltration capacity.

Penerapan Model Horton Untuk Kuantifikasi Laju Infiltrasi

[ID] Kapasitas infiltrasi akan semakin menurun bila bidang resapan air semakin berkurang. Dampaknya limpasan air hujan yang menjadi aliran permukaan akan semakin meningkat. Konsep perencanaan yang memperbesar air hujan meresap ke dalam tanah akan mampu mengurangi aliran permukaan. Penelitian ini bertujuan untuk kuantifikasi laju infiltrasi air hujan dengan menerapkan model Horton. Metode yang dilakukan adalah uji sampel di lapangan terhadap laju infiltrasi pada bidang tanah yang tidak ada lubang resapan dan bidang tanah yang diberi lubang resapan. Dimensi lubang resapan adalah diameter (Ø) 3 inchi, 4 inchi, dan 8 inchi dengan kedalaman 1,1 m menggunakan alat ukur double ring infiltrometer. Metode perhitungan menggunakan rumus infiltrasi Horton. Dapat disimpulkan bahwa lubang resapan berpengaruh terhadap peningkatkan laju infiltrasi air hujan ke dalam tanah, sehingga dapat meningkatkan daya resap air ke tanah. Laju infitrasi model Horton pada lubang resapan Ø 3 inchi, Ø 4 inchi, Ø 8 inchi dan tanpa lubang resapan adalah f (t) = 0,55+0,45e-14t ; f (t) = 0,4+1,5e-19,5 t ; f (t) = 2,3+1,8e-46t ; dan f (t) = 0,28+0,72e-10,7t. Nilai laju infiltrasi yang paling besar hingga paling kecil adalah f (0) = 4,1 m/jam (pada Ø 8 inchi); f (0) = 1,9 m/jam (pada Ø 4 inchi); f (0) = 1 m/jam (pada Ø 3 inchi); dan f (0) = 1 m/jam (tanpa lubang resapan). Perbandingan akumulasi waktu laju infiltrasi terhadap lubang resapan Ø 8 inchi adalah 3,8 kali lebih lambat (pada Ø 3 inchi), 3,6 kali lebih lambat (pada Ø 4 inchi), dan 6,63 kali lebih lambat (tanpa lubang resapan). [EN] Infiltration capacity will decrease if the water absorption field decreases. The impact of rainwater runoff which becomes surface runoff will increase. The concept of planning that enlarges rainwater seeps into the ground will be able to reduce surface flow. This study aims to quantify the rate of infiltration of rainwater by applying the Horton model. The method used is a sample test in the field against the infiltration rate in the field of land where there are no infiltration holes and soils are given infiltration holes. The dimensions of infiltration holes are diameter (Ø) 3 inches, 4 inches, and 8 inches with a depth of 1.1 m using a double ring infiltrometer measuring instrument. Calculation method using Horton infiltration formula. It can be concluded that infiltration holes affect the rate of infiltration of rainwater into the soil, so that it can increase the absorption rate of water to the ground. Inflation rate of Horton model in infiltration hole Ø 3 inches, Ø 4 inches, Ø 8 inches and without infiltration hole is f (t) = 0.55 + 0.45e-14t; f (t) = 0.4 + 1.5e-19.5 t; f (t) = 2.3 + 1.8e-46t; and f (t) = 0.28 + 0.72e-10.7t. The value of the largest infiltration rate to the smallest is f (0) = 4.1 m / hour (at Ø 8 inches); f (0) = 1.9 m / hour (at Ø 4 inches); f (0) = 1 m / hour (at Ø 3 inches); and f (0) = 1 m / hour (without infiltration holes). Comparison of accumulated infiltration time to infiltration hole Ø 8 inches is 3.8 times slower (at Ø 3 inches), 3.6 times slower (at Ø 4 inches), and 6.63 times slower (without infiltration holes).