Application of Swat Hydrological Model with GIS Interface to Upper Bernam River Basin

Rising concern over the degradation of the environment due to rapid land development in recent years has created a need for watershed modeling. The Upper Bernam River Basin in South Perak and North Selangor, Malaysia was chosen for this study. This study was carried to evaluate the effectiveness of a GIS interface physically based hydrologic model (SWAT) in predicting surface runoff and sediment load from a basin scale watershed. The effects of land use changes on runoff and sediment loading rate were also studied. The data required for this study is the topographical, hydrometeorological, soil, and the land use data. All of them are integrated in a GIS in tabular, vector and grid formats. The land use data in this study were derived from Landsat TM images. These images were enhanced and classified using a combination of different classification strategies. The classified land use maps compares reasonably well with the map showing broad vegetation types of the river basin with an accuracy of 95%. Due to recent rapid land use changes, the model was run in a short term basis. The results from model application and statistical analysis show that SW AT generally does a good job in predicting both runoff flow and sediment load with a an average gap of 22% and 34% respectively between observed and predicted results. The exception is for those days with very heavy rainfall (> 35 mm/day), SWAT seriously overestimated runoff. Results from historical data, trend analysis, and calculated runoff rate and sediment loading rate due to open area have also shown the close relationship between surface runoff, sediment load and open area downstream of the upper river basin. It is found that the average increment of sediment loading rate for the study area ranges from 1.47 to 2.06 tonnes per millimeter of rainfall for each kilometer-square increase of open areas

Applications of GIS and remote sensing in the hydrological study of the Upper Bernam River Basin, Malaysia

Rising concern over the degradation of the environment, such as erosion and sediment loads, warrants the integration of the complex and dispersed geographical data sets. This paper describes the use of Geographic Information System (GIS) and remote sensing for assessing the impact of land use changes to water turbidity in multiple watersheds. In this study, necessary data sets representing land uses, hydrology, weather, soils, elevation, and surface characteristics were integrated in a GIS in tabular, vector and grid formats. The land use maps that were derived from Landsat-5 TM imagery using a combination of different classification strategies gave an average accuracy of 95 %. Results from data analysis had shown that there exists a close relationship existed between the extent of open area and sedimentation loading rate. However, the sediment loading rates were found to be non-linear ranging from 1.47 to 2.13 tonnes per millimeter of rainfall for each kilometer-square increase of open areas, depending on their location of open areas with respect to factors such as availability of sediment, soil type, slope length, and slope steepness etc

Ecological Sanitation, Sustainable Strategy as an Alternative Urban Water Source

Water supply is one of the basic infrastructure requirements. Water treatment and supply are often granted a much higher priority than wastewater collection and treatment, despite the fact that wastewater deserves a greater emphasis due to the impact of its poor management has on public health. A new commitment to give wastewater the same priority as water supply is a very positive development. A pilot project of greywater ecological treatment is established in Kuching city since 2003. Such treatment facility opens up an opportunity of wastewater reclamation for reuse as secondary sources of water for non-consumptive purposes. This paper aims in exploring the potential of the intended purposes in the newly developed ecological treatment project. By utilizing the Wallingford Software model, InfoWorks WS (Water Supply) is employed to carry out a hydraulic modeling of a hypothetical greywater recycling system as an integrated part of the Kuching urban water supply, where the greywater is treated, recycled and reused in the domestic environment. The modeling efforts had shown water saving of more than 50% from the investigated system reinstating that the system presents an alternative water source worth-investing in an urban environment

Modelling the flood vulnerability of deltaic Kuching City, Malaysia

The main objective of this writing is to present a practical way to envisage the flood vulnerability in deltaic region, particularly on the concern of sea level rise. Kuching city of Malaysia is established on banks of Sarawak River, 30 km from the sea. Therefore, it is subjected to fluvial and tidal floods. Kuching Bay experiences the highest King Tides in Southeast Asia region. These tide magnitudes could be a glimpse of future sea level rise. By means of modelling these tides, it provides an understanding and preparation for the impacts of sea level rise on the flood mitigation infrastructures and the city itself. The modelling efforts had created an illustration that a 10% rise in tide levels would result in increase of flooding areas up to 6% relative to existing tide levels

Applications of GIS and Remote Sensing In The Hydrological Study Of The Upper Bernam River Basin, Malaysia

Rising concern over the degradation of the environment, such as erosion and sediment loads, warrants the integration of the complex and dispersed geographical data sets. This paper describes the use of Geographic Information System (GIS) and remote sensing for assessing the impact of land use changes to water turbidity in multiple watersheds. In this study, necessary data sets representing land uses, hydrology, weather, soils, elevation, and surface characteristics were integrated in a GIS in tabular, vector and grid formats. The land use maps that were derived from Landsat-5 TM imagery using a combination of different classification strategies gave an average accuracy of 95 %. Results from data analysis had shown that there exists a close relationship existed between the extent of open area and sedimentation loading rate. However, the sediment loading rates were found to be non-linear ranging from 1.47 to 2.13 tonnes per millimeter of rainfall for each kilometer-square increase of open areas, depending on their location of open areas with respect to factors such as availability of sediment, soil type, slope length, and slope steepness etc

Applications of two neuro-based metaheuristic techniques in evaluating ground vibration resulting from tunnel blasting

Peak particle velocity (PPV) caused by blasting is an unfavorable environmental issue that can damage neighboring structures or equipment. Hence, a reliable prediction and minimization of PPV are essential for a blasting site. To estimate PPV caused by tunnel blasting, this paper proposes two neuro-based metaheuristic models: neuro-imperialism and neuro-swarm. The prediction was made based on extensive observation and data collecting from a tunnelling project that was concerned about the presence of a temple near the blasting operations and tunnel site. A detailed modeling procedure was conducted to estimate PPV values using both empirical methods and intelligence techniques. As a fair comparison, a base model considered a benchmark in intelligent modeling, artificial neural network (ANN), was also built to predict the same output. The developed models were evaluated using several calculated statistical indices, such as variance account for (VAF) and a-20 index. The empirical equation findings revealed that there is still room for improvement by implementing other techniques. This paper demonstrated this improvement by proposing the neuro-swarm, neuro-imperialism, and ANN models. The neuro-swarm model outperforms the others in terms of accuracy. VAF values of 90.318% and 90.606% and a-20 index values of 0.374 and 0.355 for training and testing sets, respectively, were obtained for the neuro-swarm model to predict PPV induced by blasting. The proposed neuro-based metaheuristic models in this investigation can be utilized to predict PPV values with an acceptable level of accuracy within the site conditions and input ranges used in this study

A study of hydraulic characteristics for flow in equatorial rivers

This paper presents the results obtained from field measurements taken in several frequently flooded equitorial rivers, including velocity distributions,stage discharge relationships, roughness behaviours and discharge estimation. These have illustrated the large difference in velocity between the mainchannel and floodplain under flood conditions, and the effects of momentum transfer between deep and shallow flow, which include reduction in mainchannel velocity and discharge capacity, leading to a reduction in compound section capacity at depth above bankfull. Another significant characteristicthat has been found is that the floodplain regions behave as storage reservoirs (V=0 m/s) in most cases due to high resistance of long and thick grassesalong the flood plains (n=0.07−0.1). Flow resistance relationships have been presented in terms of Manning’s coefficient and Darcy-Weisbachfriction factor, showing the complex nature of flow resistance in the rivers and further explaining the danger inherent in the conventional practicesofextrapolating inbank data for the analysis of overbank flows. Results for discharge estimation have been shown for comparison with actual data, theerrors incurred by applying empirical methods to compound channel flows have been quantified and found to depend on the particular method use

ENVIRONMENTAL ASSESSMENT OF STORMPAV GREEN PAVEMENT FOR STORMWATER MANAGEMENT

This study evaluates the stormwater management potential of a green pavement technology for permeable road pavement with subsurface micro-detention storage (StormPav) from a water quality perspective. The system provides integration of permeable pavement with hollow spaces to attenuate peak discharge with design installation using precast products. The environmental assessment was gathered from field experiments to assess the water quality, mosquito breeding capability and infiltration rate in the StormPav. The water quality parameters were determined to assess environmental benefits, which are one of the components of sustainable development. The parameters consist of total suspended solids, pH and alkalinity and they showed identical results to other permeable pavement types. Larvae development was found as early as eight days in stagnant water in the cylindrical hollow section of StormPav. However, the StormPav showed a high permeability rate within 122.45 mm/hr to 168.12 mm/hr at subgrade soil of HSG A soils group with no stagnant water retained in the void section in less than two hours, which nullified the required retention time for larvae development. Hence, StormPav displayed a significant benefit in terms of environmental concern for a sustainable design invention in stormwater management with the presence of subsurface detention storage

Modeling climate-smart decision support system (CSDSS) for analyzing water demand of a large-scale rice irrigation scheme

Climate projection at local scale is one of the crucial challenges that affects the development of water management-related mitigation plans. Moreover, the currently available climate models do not directly simulate some of the hydro-climatic parameters (e.g., effective rainfall, reference evapotranspiration, irrigation requirements), which are of interest in irrigation sector. Modeling crop-water demands under changing climate involves several step-by-step approaches that are tedious and time-consuming for many water users. This study developed a water management tool, hereafter called Climate-Smart Decision-Support System (CSDSS), for modeling water demand of rice irrigation schemes under climate change impacts. The CSDSS is a user-friendly interactive program consisting of three main modules integrated in MATLAB and a graphical user interface development environment (GUIDE). The model runs with ten Global Climate Models (GCMs) and three emission scenarios (RCP 4.5, 6.0 and 8.5). It can generate several hydro-climatic parameters based on a daily water balance model, with input data from GCMs projections, crop, soil and field conditions. The model allows water managers to make fast decision for paddy water management. The generated outputs can be obtained through individual GCMs as well as through multi-models (ensemble) projection and can be converted into excel format for further analysis. The model was applied to evaluate the impacts of climate change on irrigation water demand and other key hydro-climatic parameters in Tanjung Karang Rice Irrigation Scheme in Malaysia for the period 2010–2099 with reference to the baseline period of 1976–2005. The results show that irrigation water demand will increase during the off-season (January–June) but decrease during the main season (July–December) due to significant contribution from effective rainfall in the latter season. The CSDSS tool can be used for managing water resources under changing climate and would, therefore, be helpful in promoting appropriate adaptation and mitigation strategies that can lead to more sustainable water use at farm level. Some future improvements of the tool, due to methodological limitations of the study, will however improve its performance