Drainage System of Tegalsari Polder for Handling Flood and Tide in Tegal City Indonesia

Although in 2019 the local government of Tegal city Indonesia had constructed a retention basin at drainage system of Siwatu, Tegal Barat, Tegal city with a catchment area of 226 ha, the areas around the system still experienced flood and inundation. This study belonged to a descriptive qualitative research aimed to evaluate the performances of Siwatu drainage system and Tegalsari retention basin. Data of the study included field data and technical data from institutions. Based on the 15-year rainfall data (2014 – 2018) from Pemali - Comal PSDA Office, Central Java Province, Indonesia, the statistical parameters of Cs: 0.0027, Ck: 1.904, Sd: 15.91, Cv: 0.144 were obtained and so Gumbel method distribution was applied in the study, the return period rainfall of 10 years was 138 mm, the flood discharge for Qr.10 years was 9.63 m3/sec., the addition of long storage was 8×2,50×500 m, and the combination of pump addition was of 1 m3/sec. with the long storage of 8×2.00×500 m. By implementing one of the alternative choices, either flood or inundation could be resolved.

Organic Removal Treatment Using Microbubble Generator (MBG) in Eutrophic Disorder Condition

The Techno Park basin, built as an extension of a small tributary of the Code River primarily acts as a retention basin for runoff during the rainy season. It improves the quality of water that has been degraded by domestic wastewater discharge from the surrounding community. Therefore, this study aims to assess the extent to which water quality of the basin can be improved with aeration technology. The aeration technology is a Microbubble Generator (MBG) built using a 100 Watts submersible pump with three horizontal nozzles at a depth of 40 cm from the water surface. Furthermore, the profiles of dissolved oxygen (DO) concentration were measured at the basin’s inlet and outlet, as well as the depths of 1 m below surface water and the bottom of the basin. Diurnal DO was measured to investigate the causes of supersaturation. The aeration performance was also determined from the COD parameters at the inlet and outlet. Discharge measurements were then conducted on the tributary/drainage channel to the inlet basin. The result showed that the DO supersaturation concentration has been attributed to the contribution of photosynthesis from phytoplankton such as algae. Furthermore, no change in DO concentration was observed in a range of 1 m depth from the surface of the water to the bottom (0.3 - 0.14 mg-DO/l). In this eutrophic state, DO increased exponentially during the daytime hours and then decreased during the night. The daily measurement showed an increase in the average DO of 2.31 mg/l (standard deviation of 1.56 mg/l), with average CODinlet fluctuations of 18.79 mg/l (standard deviation of 13.56 mg/l) and average CODoutlet of 14.38 mg/l (standard deviation 2.94 mg/l). Due to additional DO concentration coming from eutrophication during daylight, it was not possible to make a precise assessment of the effectiveness of the MBG aerator.

Reviving Opportunities through Socio-Spatial Parameters for Community Interaction:

Within urbanized areas, the importance of neighborhood ponds should be assessed and investigated with its socio-spatial parameters (access and linkage, sociability, uses and activities, comfort and image etc) since such water bodies act as retention basin during floods, reservoir for lean period and responsive socializing agent to measure community interaction which are generally been neglected by city government, threatened by developers but taken care by neighborhood people in Old Dhaka. Most of the inner city small neighborhoods ponds have been encroached and filled up upon demand on land as the pond were not integrated in the city planning. The main objective of this research is to assess the significance of such water bodies and revive the spatial relationship of neighborhood ponds with its nearby residents. Therefore a socio-environmental survey (quantitative and qualitative) is held on neglected and threatened small neighborhood ponds of Old Dhaka with direct observation, in-depth interviews of the residents to compare the environmental, ecological and social contexts and explore the opportunities. An integrated assessment for enhancing sustainability and creating opportunities through community participation has been suggested to rejuvenate the ponds with attention for wetland preservation and to integrate into community development programs or planning.

Morphological and molecular characters of Cherax quadricarinatus (von Martens, 1868) from Sermo Reservoir and Tambakboyo Retention Basin, Daerah Istimewa Yogyakarta, Indonesia

The Australian red claw freshwater crayfish, Cherax quadricarinatus is one of the most widely distributed and cultivated freshwater crayfish due to its high tolerance towards various environmental conditions. Native to North Australia and South Papua New Guinea, this crayfish was found in Tambakboyo Retention Basin in 2016 and Sermo Reservoir in 2019. This research was aimed to identify the morphological and molecular characters of C. quadricarinatus collected from Sermo Reservoir and Tambakboyo Retention Basin, Yogyakarta. The genetic information of the samples was compared to Australian red claw freshwater crayfish currently available. The methodology used for this research are morphological, morphometrical, meristic identification, and molecular identification using the PCR method. The primer used to be 1471 primers as the forward primer and 1472 primers as the reverse primer. In conclusion, all six specimens obtained were identified to be C. quadricarinatus. Morphological analysis using UPGMA showed that all specimens were formed one big cluster and has the highest similarity index (1.00). Molecular analysis using BLAST showed that specimen from Sermo Reservoir was 98.96% identical to C. quadricarinatus and specimen from Tambakboyo Retention Basin was 100% identical to C. quadricarinatus. Thus concluding that based on their morphological and molecular character, all samples of this study were C. quadricarinatus. This finding also contributes to the distribution information of C. quadricarinatus in Daerah Istimewa Yogyakarta

SIMULASI POLA OPERASI EMBUNG SERBAGUNA TAMBAKSARI KABUPATEN CILACAP DENGAN METODE STANDARD OPERATING RULE (SOR)

Human survival depends on water availability as water is a basic needs. As population increases, water becomes more limited. One of the ways to prevent draught is collecting water in retention basin. Tambaksari Multipurpose Retention Basin serves to provide basic water demand and irrigation water for the local community. Water availability and water demand should be equal, so a simulation of the operating patter of the retention basin is necessary to distribute water equally and determining the failure level of the retention basin in performing its task. In the present study, the retention basin operating pattern was simulated using Standard Operating Rule (SOR) method. The present study used secondary data, including population data, rainfall data, climatological data and technical data of the retention basin. The size of DAS Tambaksari is 0.41 km² while the size of the irrigated land is 12 Ha. The rainfall data was from 2008-2018 obtained from two rain stations, population data of Tambaksari Village was from 2008-2019, and the climatological data was from 2014-2019. The simulation result of the retention basin operating pattern using SOR method showed that the final collection wasn’t under minimum collection and failure happened in the operation of the retention basin for one year. . The optimal ability of the target release is 70.83% for the reliability of irrigation needs and the level of reliability for raw water needs of 58.33%. Population projection analysis to determine the population in 20 years showed that the future population of 4044 required 3.861 l/person/s of water. Irrigation demands for rice-rice-palawija planting pattern showed that irrigation intake was 11.89 l/s. Water balance determined the balance between inflow and outflow. The value for average water availability was 0.021 m³/s while total average water demand was 0.016 m³/s. therefore, the water availability in partial intake wasn’t able to meet the irrigation and basic water demands. Keywords: discharge, retention basin operation simulation, SOR

Evaluasi dan Analisis Kolam Retensi Pengendalian Banjir: Studi Kasus Kolam Retensi Brimob Kota Palembang

Brimob retention basin located within the Sekanak Sub-watershed system, which is a flood-prone point. Administratively, the Brimob retention basin area is a part of the Sub-district of Ilir Barat I. The research method used is computer modeling. The steps taken are: data collection, hydrological analysis, cross-sectional analysis, hydrological and hydraulic modeling using pumps. The Brimob retention basin can accommodate a volume of water up to 115,103.73 m3, up to an elevation of the embankment of + 4.30 m. The magnitude of designed rainfall is R2 = 118.78 mm, R5 = 144.78 mm, R10 = 161.99 mm and R25 = 183.73 mm. The peak discharge of each return period is Q2 = 6.30 m3 / s, Q5 = 7.67 m3/s, Q10 = 8.59 m3/s and Q25 = 9.74 m3/s. To assess the effectiveness of pump operation, 2 (two) pumping capacities are simulated, namely: 250 l / sec and 500 l / sec, each used 2 (two) pump units. The simulation used a pump with a capacity of 500 l / sec, and the amount of discharge (inflow) for each return period is as input. The conclusion is that the use of a pump with a capacity of 500 l / sec can overcome excess water volume and avoid runoff and effective in dealing with the excess water in the Brimob retention basin.

Possibility of using compensatory urban drainage techniques as leisure units to expand public areas into subdivisions

Many housing estates of social interest have not contributed to implementing leisure areas and reducing their environmental and urban quality. This paper aims to propose a leisure unit using a compensatory urban drainage technique in a housing complex of social interest in the city of São José do Rio Preto, São Paulo, Brazil. The characterization of the area, land use and occupation surveys, area sectorization, and catchment division were carried out. Afterwards, proposals for interventions based on surface runoff were presented using calculations of existing runoff and future scenarios. Results related to environmental and social gains for the area are discussed, as well as the possibility of implementing decentralized compensatory techniques. Moreover, 156 rain gardens and 3 ditches were proposed throughout the subdivisions, which enabled a gain of 989m² of contribution area to infiltrate the whole area, and the use of the retention basin as a leisure area. The total storage volume achieved with the sum of all the techniques implemented was approximately 3,000 cubic meters more than that projected for the existing retention basin.

Diversity of cyanobacteria from thermal muds (Balaruc-Les-Bains, France) with the description of Pseudochroococcus coutei gen. nov., sp. nov.

ABSTRACT Cyanobacteria are able to synthesize a high diversity of natural compounds that account for their success in the colonization of a variety of ecological niches. Many of them have beneficial properties. The mud from the thermal baths of Balaruc-Les-Bains, one of the oldest thermal baths in France, has long been recognized as a healing treatment for arthro-rheumatic diseases. To characterize the cyanobacteria living in these muds, several strains were isolated from the water column and biofilms of the retention basin and analyzed using a polyphasic approach. Morphological, ultrastructural and molecular (16S rRNA gene and 16S-23S ITS region sequencing) methods were employed to identify nine cyanobacterial strains belonging to the orders Chroococcales, Synechococcales, Oscillatoriales and Nostocales. The combination of morphological and genetic characteristics supported the description of a new genus and species with the type species as Pseudochroococcus coutei. The taxonomic diversity in the muds from Thermes de Balaruc-Les-Bains appears higher than previously documented, providing new candidate taxa for their observed therapeutic properties.

Characterization of cyanobacteria isolated from thermal muds of Balaruc- Les-Bains (France) and description of a new genus and species Pseudochroococcus couteii

Cyanobacteria are able to synthesize a high diversity of natural compounds that account for their success in the colonization of a variety of ecological niches. Many of them have beneficial properties. The mud from the thermal baths of Balaruc-Les-Bains, one of the oldest thermal baths in France, has long been recognized as a healing treatment for arthro-rheumatic diseases. To characterize the cyanobacteria living in these muds and the metabolites they potentially produce, several strains were isolated from the water column and biofilms of the retention basin and analyzed using a polyphasic approach. Morphological, ultrastructural and molecular (16S rRNA gene and 16S-23S ITS region sequencing) methods were employed to identify nine cyanobacterial strains belonging to the orders Chroococcales, Synechococcales, Oscillatoriales and Nostocales. The combination of morphological and genetic characteristics supported the description of a new genus and species with the type species as Pseudo-chroococcus couteii. The high taxonomic diversity in the muds of the thermal baths of Balaruc-Les-Bains along with literature reports of the potential for bioactive metabolite synthesis of these taxa allowed us to hypothesize that some of the metabolites produced by these strains could contribute to the therapeutic properties of the muds from Thermes de Balaruc-Les-Bains.

Combining Instrumental Monitoring and High-Resolution Topography for Estimating Sediment Yield in a Debris-Flow Catchment

ABSTRACT In mountain basins, long-term instrumental monitoring coupled with high-resolution topographic surveys can provide important information on sediment yield. The Gadria catchment, located in the eastern Italian Alps, typically features several low-magnitude flood episodes and a few debris-flow events per year, from late spring to late summer. Beginning in 2011, sensors devoted to debris-flow detection (geophones, video cameras, flow stage sensors) were installed along the main channel, upstream of a retention basin. In case of debris flows, high-resolution topographical surveys of the retention basin are carried out multiple times per year. Rainfall is measured in the lower part of the catchment and at the headwaters, while passive integrated transponder tracing of bedload was performed in the main channel during spring and summer 2014. In this work, we present the reconstruction of the sediment dynamics at the catchment scale from 2011 to 2017. Results show that (i) coarse sediment yield is dominated by the few debris flows occurring per year; (ii) debris-flow volume estimations may be significantly different—up to 30 percent lower—when performed through a digital elevation model of difference analysis, compared to the time-integration of the debris-flow discharge estimates; (iii) using this latter method, the volumes are affected by significant uncertainties, particularly for small values of flow depth; and (iv) rainfall analysis permits us to characterize debris-flow initiation but also highlights difficulties in discriminating triggering from non-triggering rainstorms if based on rainfall duration and intensity only.