A STUDY ON QUALITY OF LIFE OF MIDDLE-INCOME GROUP ALONG URBAN CANAL WATERFRONTS

In most of the cases, canal network in Greater Colombo region work as the drainage system of the urban area and as the backyard of the city. Therefore, there is a lack of attention to the canal waterfronts by the government and by the public. Hence, this research was to find out and evaluate the factors, which will affect the quality of life of people along urban canal waterfronts. It has been discussed in terms of liveability through a series of carefully selected indicators. Liveability surveys were conducted along five canal waterfronts and the participants’ perceptions were taken. Every canal waterfront was assigned a rating of over 25 qualitative and quantitative factors (set of indicators) across six broad categories (dimensions): safety, comfort, health and wellbeing, mobility, environment, and socio-cultural factors. Each qualitative factor was given a rating from 1(tolerable)-5(intolerable). Qualitative factors were then combined with quantitative factors through a series of equations to form the liveability index. According to the proposed liveability index, transport dimension index is ideal (100), while the health and well-being dimension is the lowest (27). This will help for the creation of government policies, plans, rules and regulations and when implementing projects along urban canal waterfronts.

Calcium Transport along the Axial Canal in Acropora

In Acropora, the complex canals in a coral colony connect all polyps into a holistic network to collaborate in performing biological processes. There are various types of canals, including calice, axial canals, and other internal canals, with structures that are dynamically altered during different coral growth states due to internal calcium transport. However, few studies have considered the regulation of calcium transport in Acropora. In this study, we investigated the morphological changes of the axial canal in six Acropora muricata samples by high resolution micro-computed tomography, observing the patterns of the axial canal during the processes of new branch formation and truncated branch rebuilding. We visualized the formation of a new branch from a calice and deposition of the iconic hexactin skeletons in the axial canal. Furthermore, the diameter and volume changes of the axial canal in truncated branches during rebuilding processes were calculated, revealing that the volume ratio of calcareous deposits in the axial canal exhibit significant increases within the first three weeks, returning to levels in the initial state in the following week. This work indicates that the axial canal can transport calcium to form hexactin skeletons in a new branch and rebuild the tip of a truncated branch. The calcium transport along canal network regulates various growth processes, including budding, branching, skeleton forming, and self-rebuilding of an Acropora colony. Understanding the changes in canal function under normal and extreme conditions will provide theoretical guidance for restoration and protection of coral reefs.

Livestock and Small-Scale Irrigation Scheme Interactions as a Key Source for Sedimentation during the Irrigation Season: Four Case Studies from South-West Shoa, Ethiopia

Small-scale irrigation (SSI) development can play a major role in Ethiopia’s economic development, but sedimentation is a major threat to its sustainability. The focus of the dominant discourse around the sedimentation of SSI schemes lies in upstream catchment protection during the rainy season, neglecting both protection against erosion through overland flow along the margins of the canal network and sedimentation caused by livestock disturbances. Remedies against the latter causes of sedimentation during the irrigation season have been ineffective due to erroneous assumptions regarding its cause. This study aimed to identify the sources and extent of sedimentation in SSI schemes. The accumulated sediment in the canal pre-irrigation season was measured from four SSI schemes and suspended sediment samples during irrigation season were collected from one SSI scheme. The accumulated sediment in the canal pre-irrigation season was measured from four SSI and suspended sediment samples during irrigation season were collected from one SSI scheme. The extent of sedimentation in the canals during the pre-irrigation season in relation to canal capacity was 100% of lined and unlined canals in abandoned, 68% in a lined, and 84% unlined canals in heavily sedimented and 38% in a lined and 46% of unlined canals lightly sedimented schemes. Livestock interactions with the SSI schemes were found to be the major sediment source before and during the irrigation, hence, attention should be given to integrating livestock as a part of the system.

DrainCAN—A MATLAB Function for Generation of a HEC-RAS-Compatible Drainage Canal Network Model

The dimensioning of canal geometry in a surface drainage network influences the size and functionality of canal structures, reduces flood hazard, and consequently imposes restrictions on land use. Reliable free-surface flow calculation for optimization of the canal network can be challenging because numerous hydraulic structures and canal interactions influence the flow regime. The HEC-RAS software of the US Army Corps of Engineers’ Hydrologic Engineering Center is often used for this purpose as it allows the user to simulate the effect of numerous hydraulic structures on flow regime. This paper presents a MATLAB function, DrainCAN, for generating a HEC-RAS model from standard runoff input data, i.e., topographic data and canal design geometry (profile and slope). The DrainCAN function allows for fast optimization of the network geometry—it generates normal flow depth estimation and observed water levels in critical locations that need to be optimized. Advantages of the DrainCAN function are fast generation of the HEC-RAS hydraulic model files from simple input files, introduction of optimization variables in the model, and automatic adjustment of model geometry for computational junctions. This allows fast iteration of the canal design parameters, namely cross-sectional geometry, invert elevation, and longitudinal slope, and the evaluation of introduced changes on the flow regime.

Introducing winter rice cropping by using non-saline tidal water influx in western basins of South 24 Parganas, India

A population exceeding 3.8 million people in the western region of 24-Parganas (South) is directly or indirectly reliant on agriculture as their primary source of livelihood. The agricultural trend shows a clear lack of multi-cropping with a drop of nearly 30% in rice cultivation during the winter season. Nearly 50% of the region is directly dependent on canals. The introduction of tidal water in the canal network provides an exceptionally economical and highly effective mode of irrigation water supply. The primary aim of the study was to identify the cartographic characteristics and channel hydraulics in the summer season. It was noted that the canals have a wide discharge range of 0.03–540.03 m3/s, average evaporation loss of 9.07 mm/day with a seepage loss ranging from 0.04 to 6.36 m3/s. The tidal water ingress quantity was calculated to be 4.17 Mm3, 5.32 Mm3, 1.88 Mm3 at Diamond Harbour sluice (Sl.), Kulpi Sl. and Kholakhali Sl. respectively. It was denoted that the augmentation of tidal backwater six times monthly would suffice the winter crop water requirement for the majority of the basins. This would result in the production of 172.13 kt which was previously 17.6 kt resulting in an increase of production by 878.01%. The per capita income would also be increased by nearly 978% for the season, resulting in the macro-socioeconomic upliftment of the region.

Very low prevalence of Opisthorchis viverrini s.l. cercariae in Bithynia siamensis siamensis snails from the canal network system in the Bangkok Metropolitan Region, Thailand

The liver fluke Opisthorchis viverrini s.l. is associated with a long-term public health problem in Thailand. However, O. viverrini s.l. infection in Bithynia snails in the canal network system (CNS) in the Bangkok Metropolitan Region (BMR) has never been assessed. This study aimed to investigate the occurrence of B. siamensis siamensis and the prevalence of O. viverrini s.l. infection in this snail in the CNS in BMR along with morphological examination and molecular analyses on O. viverrini s.l. cercariae. The snails were randomly sampled from the CNS in all BMR areas from January 2018 to July 2019. Snail specimens were identified and examined for digenean infection by shedding and dissection. The cercariae were identified using morphology and molecular methods, including PCR with a species-specific primer and a Bayesian phylogenetic analysis of ITS2 sequences. Bithynia siamensis siamensis was found in almost all sampling localities, with different quantities and detected frequencies. From a total of 7473 B. s. siamensis specimens, O. viverrini s.l. infections were detected in the Northern Bangkok, Muang Nakhon Pathom, Krathum Baen, and Lam Luk Ka areas with an overall prevalence of 0.05% (4/7473) and prevalence of 0.22% (1/455), 0.21% (1/469), 0.40% (1/253), and 0.16% (1/614) in individual localities with positive snails, respectively. This study is the first investigation of digenean infection in the canal network system-type habitat in Thailand and revealed extremely low O. viverrini s.l. prevalence.

Canals and Orchards: The Impact of Transport Network Access on Agricultural Productivity in Nineteenth-Century Bangkok

We assess the impact of access to Bangkok’s nineteenth-century canal network on orchard productivity using a new dataset constructed from 1880s orchard land deeds. We find that properties located adjacent to canals, which were built for purposes exogenous to orchard production, had significantly higher labor productivity than those located inland. Gaining direct access to canals led to productivity improvements through better access to markets, which in turn enhanced cultivators’ welfare. We conclude, based on a method developed by Oster (2019), that unobserved selection bias is negligible, allowing for the positive impact of canal access to be interpreted as causal.