Assessment of Hydro-Environmental Condition Using Numerical Modeling in Dibawah Lake, Western Sumatra, Indonesia

Abstract

This study investigates the hydro-environmental condition of Dibawah Lake, Province of Western Sumatra, Indonesia, using a finite element model called the Surface-water Modeling System (SMS). The aim is to present the parameters distribution in the existing condition and a year later. Field measurements are carried out to supply data for the domain input, boundary conditions, and model validation. The field measurements are lake-bed elevation, water level, current flow, and contaminant quantity measurements. The contaminant measurements are carried out to collect biochemical oxygen demand (BOD), sulfide, and total suspended sediment (TSS). The existing flow model is validated by current flow and water elevation field data. The validation shows a decent agreement. The result of water quality modeling, using the water quality module of SMS called RMA4, shows that after a year the BOD content is still in an acceptable proportion, which is less than 2 mg/liter. However, it is found that the sulfide content exceeds the limit defined by the government regulation, at over 0.002 mg/liter. In the sedimentation model generated by the module in SMS called SED2D, the maximum bed change obtained is around 15 cm, located at the inlet of two rivers connected to the lake. The proposed mitigation of the current research findings is to control the use of fertilizer around the lake watershed area with the aim of lowering the sulfide content and to maintain the lake bed elevation by routine dredging, particularly in the river inlets.

Tsunami Hazards Along Coastal Area of West Kalimantan Province, Indonesia

“…The module simulates the depth-averaged current velocities. This program has been widely used for a variety of hydrodynamic studies in coastal areas [19], rivers [20], or lakes [21,22].…”

Modeling Salinity Propagation in Cikarang Bekasi Laut Channel, Bekasi Regency, West Java Province, Indonesia

“…The U.S. Army Corps of Engineers coded RMA2 and RMA4. Both modules have been widely used in studies of water quality in water bodies [20][21][22].…”

Land Cover Change Analysis to Sedimentation Rate of Rawapening Lake

“…Ecological pressure on this area is also exacerbated by the poor development of upstream land management systems that have an impact on the area in the form of pollution and sedimentation. In addition to having negative impacts in the form of pollution and sedimentation, hydrological changes due to human activities (development) also have other negative impacts on the region [8]- [11]. To reduce ecological pressure due to land-use change, it is necessary to monitor the progress of land-use change using effective techniques, one of them was used Landsat image.…”