High precipitation rate usually give an impact on soil instability and streamflow volume that lead to hazard such as landslide, soil erosion and flood. However, such hazard might happen as a result of various factors including types of soil, soil structure, land used, human activities and surface and subsurface water flow. The major changes on flow rate might change the soil structure and flow direction due to high volume of precipitation with uneven dispersion, especially in hilly topography. The research on Streamflow Generating Process (SGP) has been advancing in order to understand the formation of stream resulting from both surface and subsurface flow comprising Infiltration Excess Overland Flow (IEOF), Saturation Excess Overland Flow (SEOF), Shallow Subsurface Flow (SSF), Direct Precipitation onto Stream Surface (DPOSS), percolation, evapotranspiration and ground water (GW). This paper will only focus on one of the process which is IEOF. Despite the apparent important of IEOF in determining changes in environment, relatively little is understood in the processes that occurred behind. The review aims to minimize the misconception on the terms that regularly used in IEOF studies such as overland flow, surface runoff, urban runoff and stormwater. The term used can make the meaning become misleading and give confusion to the readers. A numerous of terms used to explain the process in Hydrology does not pose problems for Hydrologist but effect the understanding of those who are from different field of background. Besides, this study also discussed on the current model that used in IEOF studies and the trend of integrated hydrological and Geographic Information System (GIS) model in solving IEOF problems. In addition, this paper also concentrates on one of the environmental issues that give impact to IEOF which is global warming.
Slope stability evaluation is an essential element in assessing landslide hazards and ensuring the safe design of structures and infrastructure. There has been increased awareness of the need to give greater attention to these phenomena. However, there is no general rule for classifying safety factors of the slope. The factor of safety (FOS) is used globally to determine slope stability by identifying shear strength and shear stress. However, the FOS cannot become the only assessment to evaluate slope stability. This research focuses more on the infiltration of soil-water that reduces the strength of slopes based on the danger level (DL). DL is divided into four categories: low, moderate, high, and very high. To estimate slope stability, four main locations are set on the slope: P1 (highest point), P2, P3 and P4 (lowest point). The DL value is determined using FOS, a rainfall threshold, soil-water infiltration, and soil classification. The DL value for P1 is 0.567 (moderate risk), while the DL values for P2, P3, and P4 are 0.116, 0.073, and 0.095 (very high risk), respectively, indicating that this slope is hazardous. Determining hazardous slope points will be easier, as DL has classified specific slope locations with exact risk values.
This is an Open Access article distributed under the terms of the Creative Commons Attribution-Noncommercial 4.0 Unported License, permitting all non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.