Environmental Flow Assessment Using Water-Sediment Approach at the Sekampung River, Indonesia

Endro Prasetyo Wahono,Djoko Legono,&Nbsp Istiarto,Bambang Yulistiyanto

doi:10.4236/ojmh.2014.44016

Abstract

Environmental issue has been considered more significant in many aspects of engineering decision-making process particularly in river management. There is an increasing effort to conserve functioning of rivers for human use as well as nature, therefore environmental flow assessment has been widely developed. This paper discusses on environmental flow assessment of the Sekampung River, particularly on its middle reach. A new analytical approach based on water-sediment equations was introduced in order to determine a minimum environmental flow at the certain cross section of a river. The result of the new method was then compared with a minimum environmental flow provided by using two hydrological based methods, namely, Tennant and Flow Duration Curve Analysis (FDCA) method. The result shows that the concerned discharge provided by the water-sediment method (3.5 m3/s) is the smallest compare with a minimum environmental flow that is provided by both Tennant (5.7 m3/s) and FDCA method (4.5 m3/s). It is promising that the water-sediment method can be used as a simple approach on preliminary state of environmental flow assessment. The method involves not only water discharge but also its related sediment flow of the river in order to mitigate further ecological and morphological risks.

Highlights

In the recent years, environmental issue has been considered more significant in many aspects of engineeringHow to cite this paper: Wahono, E.P., Legono, D., Istiarto and Yulistiyanto, B. (2014) Environmental Flow Assessment Using Water-Sediment Approach at the Sekampung River, Indonesia
The intention of this paper is to introduce relation between magnitude and frequency of the discharge, morphological aspect and their corresponding environmental flow, in addition, comparison was provided to have an overview what will be the reasonable discharge range of environmental flow for the Sekampung River, on its middle reach
Data used for the environmental flow analysis of this research were collected from the discharge measurement stations (AWLR) at the downstream of the Argoguruh Weir as the measurement is conducted by the technical implementation unit (UPTD Balai Pengelola Sumber Daya Air) of the Sekampung River at Metro

Summary

Introduction

Environmental issue has been considered more significant in many aspects of engineering. The scarceness of riverine environmental data makes it difficult to use such methods as habitat simulation methods [7] [8], holistic methods [9] [10] and combined methods [11] Hydrological methods, such as the Tennant method [12] and Texas method [13], have the advantages of simple computation and easy handling, it is appropriate for preliminary stage of the environmental flow assessment on the basin level. They often oversimplify the actual situation of a river, and fail to consider biological parameters and their interactions [14]. Typical cross section of the river has 30 m of main channel width and about 250 m of floodplain length [16]

General

Data Acquisition and Location

Result and Discussion

Findings

Sediment transport predictor:

Conclusions