Water quality index assessment for the Skudai watershed and its tributaries

It is very important to develop a rehabilitation plan for the watersheds that have been degraded because of increased development activities and high urbanization. Identifying the most vulnerable parts of a watershed is challenging and can be done if water quality in the river was determined in different sections from the upstream to the downstream of a watershed. In this study, we delineated the Skudai watershed into 25 sub-watersheds using ArcGIS technique. Later, we identified tributaries in each sub-watershed. The sub-watersheds were grouped into three main categories, i.e. natural, semi-urban, and urban sub-watersheds. Water quality samples were collected at different tributaries from all three categories of sub-watersheds. The paper presents water quality analysis results. The Skudai River (natural part) was classified into natural sub-watershed. The Senai and Kempas rivers were classified into sub-urban watersheds while Melana and Danga rivers were classified into urban watersheds. The water quality index (WQI) for the Skudai River (Natural) was 95.2 and falls in class I category, i.e. clean. The Senai River had WQI of 84.5 and Class II category, i.e. slightly polluted. However, Kempas River which was also in the sub-urban watershed had calculated WQI of 54.4, in Class III and polluted. Melana River had was also polluted river with WQI of 68.8 (Class III). The Danga River was also polluted river with WQI value as 55.2

Soil erodibility for water pollution management of Melaka watershed in Peninsular Malaysia

The relationships between surface runoffand soil erodibility are significant in water pollution and watershed management practices. Land use pattern, soil series and slope percentage are also major factors to develop the relationships. Daily rainfall data were collected and analyzed for variations in precipitation for calculating the surface runoff of these watersheds and surface runoff map was produced by GIS tools. Tew equation was utilized to predict soil erodibility of watershed soils.Results indicated that the weighted curve number varies from 82 to 85 and monthly runoff 23% to 30% among the five watersheds. Soil erodibility varies from 0.038 to 0.06 ton/ha (MJ.mm/ha/h). Linau-Telok-Local Alluvium, Malacca-Munchong, Munchong-Malacca-Serdang and Malacca-Munchong-Tavy are the dominant soil series of this region having the average soil erodibility of about 0.042 ton/ha (MJ.mm/ha/h). The main focus of this study is to provide the information of soil erodibility to reduce the water pollution of a watershed

Ranking of Skudai river sub-watersheds from sustainability indices - application of promethee method

In this study, ranking of sub-watersheds in the Skudai River watershed was developed from the sustainability index. The watershed sustainability index (WSI) was developed by considering two important parameters such as potential flood damages (PFD) and potential water quality deterioration (PWQD) parameters. Preference Ranking Organization Method (PROMETHEE), a multicriteria decision making (MCDM) method, was used and WSI scores for 25 Skudai River sub-watersheds were produced. Based on the WSI score, a ranking of sub-watersheds was developed to locate the more problematic areas in the Skudai River watershed. The middle and lower parts of the Skudai River watershed were found to have considerably low sustainability score which suggested the degradation of sub-watersheds from water quality and flood damage parameters. The ranking of sub-watersheds in this study will assist planners and decision makers to identify the problematic areas within the watershed so that priority interventions can be built before the problem gets worse and affects other areas of the Skudai River watershed

Farmers' preferences on water allocation criteria : a multi-criteria approach in water allocation

Water allocation based on multiple criteria (attributes) has the potential to maximize the possible benefits to be gained from the use of a unit amount of this scarce commodity. However most multi criteria methods inherently include a considerable degree of subjectivity. In this study, opinions on the importance of a number of water allocation criteria were sought from a large number of irrigation farmers. The opinion survey data were analysed using the traditional conjoint analysis method which is widely used to analyse marketing surveys. The analysis allowed objective determination of the relative importance of five water allocation attributes (for example, net farm income, percent of family working on the farm, amount paid to irrigation agency for canal water share). Part-worths (utilities) for attribute levels were also estimated from the preferences for the five water allocation attributes obtained in face-to-face interviews. The survey was completed in selected parts of Sanghar and Shaheed Benazir Abad districts (Lower Indus River of Pakistan). The conjoint survey results revealed that the respondents prefer that ‘annual net farm income’ be the most important attribute in water allocation decisions. ‘Groundwater quality beneath the farm’ was the second most important attribute of water allocation. As would be expected the vast majority of the respondents overwhelmingly placed the ‘water price’ charged by the local irrigation agency in the last position

Identification of major problems with urban water supply in selected areas of Johor Bahru, Malaysia

In this paper the survey results of 836 households located in three local authorities of Johor Bahru District are presented. A questionnaire consisted of some demographic, water supply, water usage and some opinion questions were administered to a randomly selected respondents based on housing type, settlement type and some socio-economic criteria in face-to-face interviews. The survey data were analyzed using descriptive and inferential statistical techniques. The major focus of the questionnaire were on water usage and water issues such as water quality, interrupted or continuous water supply, response to pipe leakage problems, water pressure in the supply line, and water utility bill payments encountered by the households. The survey results reveal that the quality of domestic water in the surveyed area was realistically good except for few places where some complaints regarding high chlorine contents and silt presence were recorded. Besides that, water pricing was also identified as one of the major issues where some residents complained about current water price that is unaffordable. This paper will be of interest to policy makers, regulators, water company professionals and other researchers for enhancing water management in terms of strategies, policy and programs formulation and initiatives towards technological and infrastructural innovations

Proritization of farmlands in a multicriteria irrigation water allocation: promethee and gaia applications

In this study, we propose irrigation water allocation as a multicriteria problem and demonstrate the potential for application of PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluations), a multicriteria decision making (MCDM) method, for solving a water allocation problem in the lower Indus basin of Pakistan. Five crite-ria were used for allocating irrigation water to 16 farmlands: (1) increasing dependency on agricultural income, (2) gen-erating revenue for improving operational and maintenance capability of the provincial irrigation department (PID), (3) enhancing water allocation efficiency, (4) increasing annual farm income, and (5) supplementing canal water defi-ciencies with fresh groundwater. The relative importance of the five water allocation criteria was determined based on a survey of 62 farmers located in the lower Indus basin of Pakistan. Increasing annual farm income was found to be the most important criterion in water allocations, as the highest weights (37.8%) were attached to this criterion. The survey participants assigned the lowest weight (only 4%) to the “generating revenue for improving operational and maintenance capability of PID” criterion, which makes this the least important criterion to be considered in water allocations. Depend-ing on the performance of these 16 farmlands for the five water allocation criteria, a rank order of the farmlands compet-ing for water allocations was developed using the PROMETHEE method through D-Sight software. Farms 10, 4, and 6 were found to be the first, second, and third most preferred farmlands to which irrigation water should be allocated on priority basis. Farm 15 was identified as the least preferred farmland, as the lowest net flow score (f = -0.544) was calcu-lated for this farmland. We stress that the application of the proposed MCDM water allocation method in larger irrigation systems such as the warabandi system may be difficult, as estimating values for the decision criteria may not be feasible in terms of money, human resources, and time. However, this method could be applied in smaller-scale irrigation schemes and closed watersheds where the estimation of water allocation criteria is economical and consumes relatively less time

A comparison of current and design operational efficiencies of scavenger wells in lower Indus Basin of Pakistan and possibility of upconing problem

Groundwater resources in lower Indus Basin, Pakistan are limited and mostly available in thin layers. Upconging of underlying saline groundwater will occur if overlying fresh groundwater is abstracted extensively. Once quality of fresh water is deteriorated because of upconing of saline groundwater, it is very hard to make it again fit for irrigation usage. Therefore, it is always advised to abstract groundwater without bringing saline groundwater into the fresh water layer. In the early 1990s, the Government of Pakistan installed about 378 scavenger wells in three districts of Sindh Province (Nawabshah, Sanghar, and Mirpur Khas). Out of 378 scavenger wells, 79 were installed on the right side of Jamrao canal to intercept canal seepage and recover fresh water for irrigation and other uses. In this study, we have investigated the performance efficiency of 79 scavenger wells to check whether these wells were performing with the design operational efficiency. We found that a large number of scavenger wells were operating with a maximum of 30 % of the design operational efficiency. The low operational efficiency can cause rise in water table and result in waterlogging in the study area. We also performed a 26-h pumping test on one of the scavenger wells to check whether any chances of upconing were happening and if both pumps (fresh water and saline water) of the selected scavenger well were operational. The pumping test results reveal that chances of upconing were negligible if the pumps are run within the permitted operational factor 0.6 (i.e., 14.4 h/day)

Multicriteria approach for selecting the most vulnerable watershed for developing a management plan/ Użycie wielu kryteriów do wyboru najbardziej wrażliwej zlewni w projektowaniu planu zarządzania

Określenie celów zarządzania zlewnią jest jedną z integralnych części planu zarządzania. W prezentowanej pracy ustalono 18 celów, do których w przyszłości zmierzać będzie zarządzanie zlewniami Malezji. Na podstawie tych celów ustalono ranking priorytetów, stosując wagi względnego znaczenia uzyskane w wyniku ankietowania 29 udziałowców. Dla uzyskania wag zastosowano trzy metody ważenia (SWING, SMART i SMARTER). Stwierdzono, że metoda SMART (Simple Multi-Attribute Rating Technique) była przydatna do ustalenia zestawu wag dla poszczególnych celów zarządzania zlewnią. Wagi ustalone metodą SWING były bardziej przydatne niż ustalone metodą SMARTER. Uporządkowana lista celów zarządzania będzie pomocna zarządcom i decydentom w podejmowaniu decyzji o wykorzystaniu dostępnych zasobów (jakość wody, użytkowanie ziemi, wód podziemnych i innych) w sposób bardziej efektywny i zrównoważony. Efektywne użytkowanie wszystkich zasobów zlewni uchroni je (szczególnie zlewnie zurbanizowane) od dalszego pogorszenia jakości wskutek niekontrolowanego rozwoju infrastruktury w przyszłości

Effectiveness of water quality index for monitoring Malaysian river water quality

The Skudai River has experienced a general decline in water quality over the last several years due to agricultural practices, economic development, and other human activities in the river catchment. The spatial trend of water quality index (WQI) and its sub-indexes are important for determining the locations of major pollutant sources that contribute to water quality depletion in the Skudai and its tributaries. In this study, we have developed WQI for eight sections of the Skudai watershed. Ammonia-nitrogen (NH3-N) was identified as a major pollutant downstream from the Skudai, with the lowest WQI index (i.e. 38). WQI for the Skudai (natural) was 94, i.e., Class I (very clean) category of river water quality. The Senai River has WQI value of 85 and Class II category (slightly polluted). However, the Kempas River, which was in suburban parts of the Skudai watershed, had WQI of 53 (Class III, polluted). The Melana and Danga rivers were also polluted rivers with WQI of 69 and 57, respectively, in Class III (polluted). Overall water quality in the Skudai and its tributaries was downstream of the river. The study also assessed water quality of the Skudai and its tributaries from other water quality parameters such as conductivity, turbidity, temperature, total dissolved solids, total phosphorous, and nitrogen, which were not part of the WQI formula developed by the Department of the Environment (DOE), Malaysia. The study found that Department of Education (DOE) formula for WQI was not effective in water quality assessment as many important parameters such as nutrients, heavy metals, and fecal coliform (or E. Coli) were missing in the WQI formula