No abstract

TSS (Total Suspended Solid) is one of the optical parameters that can be used for turbidity key indicator to assess water quality. The rapid development of remote sensing technology in the field of mapping has resulted in various methods for estimating TSS concentrations. The spatial, spectral, and temporal characteristics of PlanetScope data have the potential to estimate TSS concentrations. This study aims to determine the best method for estimating TSS concentrations and mapping the spatial distribution of TSS at a depth of 0 – 0.2 m using PlanetScope data. There are 4 single bands, 12 band ratio combinations, and 4 PC-bands in TSS mapping. Single bands, band ratio combinations, and PC-band which able to pass the significance limit of r value on the number of samples (n) are used in empirical modeling of PlanetScope data with field data using regression tests. The results show that: 1) 4 band ratio combinations (B1/B4, B2/B4, B3/B4, B4/B3) and one PC-band (PC-2) significantly correlated with TSS (mg/l), 2) PC-2 is the best spectral transformation in estimating TSS concentrations in Menjer Lake, indicated by the SE value of 3.47 mg/l with maximum accuracy produced at 78.62%, 3) all models that significantly correlated are over-estimated, indicated by the variations in model plots are below the 1:1 plot line, 4) high TSS concentrations are in the north, west, and south around the edge of the lake because of the inlets and the floating net cages, while the low concentration is in the middle of the lake.

Diatom is classified as algae within the Division of Bacillariophyta. They are unicellular eukaryotic organisms characterized by siliceous cell walls that can be long preserved in sediments. Therefore, diatom analysis in sediment records is a potential water quality indicator for present or paleo studies. The current knowledge on the distribution and diversity of diatoms in the sediment in the urban pond is poorly known. This study aimed to identify the distribution and diversity of diatoms from the sediments of the pond. We expect to obtain a primary database of a variety of diatoms. The sediment samples were taken from Cibuntu and Cilalay Ponds in Cibinong Botanical Garden. Sediments were digested using HCL and H2O2. The resulting diatom solution was dried and transferred onto glass coverslip, which subsequently mounted onto microscope slides using Naphrax (Refraction index 1.7). Diatom identification was examined using a light microscope at 1,000x magnification. Diatom communities in Cibuntu Pond were dominated by species Aulacoseria ambigua, Eunotia bilunaris, Cymbopleura sp, Discostella stelligera, and Rossithidium sp with diversity index of 2.4 and species evenness of 0.8. Whereas, species Fragilaria sp, Eunotia monodon, Navicymbula pusilla, Eunotia bilunaris, and Pinnularia viridis were predominant in Cilalay Pond with diversity index of 1.6 and species evenness of 0.5. Based on the diatom community, Cibuntu Pond is eutrophic indicated by the occurrence of Aulacoseria ambigua, whereas Cilalay Pond is meso-eutrophic indicated by the dominance of Fragillaria. This exploratory survey provides the first inventory of diatom assemblage in Cibuntu and Cilalay Ponds for roughly inferring the environmental changes in a shallow lake ecosystem.

No abstract

The organic matter content of lake sediments provides a variety of indicators, or proxies that can be used to reconstruct paleoenvironments of lakes and their watersheds. Particularly, in this study it will provide information that is important to interpretations of both natural and human-induced changes in lake ecosystems. The abundance of organic matter in sediments is described from the total organic carbon (TOC) because it’s a primary parameter. Moreover, Algae is the main source of organic carbon in the eutrophic lake. Lake Maninjau that located in West Sumatra has been eutrophic due to increasing of lake water utilization for floating fish cages, in recent years Lake Maninjau has faced an algal bloom frequently. Four sediments core were collected in Lake Maninjau from the lowest (near coastal) and deepest part (30 cm long core in average). Total organic matter (TOM) was performed using Lost on Ignition method (LoI) in whole cores, while total organic carbon (TOC) was analyzed using combustion analyzer method in one core that was taken in the deepest part of Lake Maninjau. TOM in Lake Maninjau among the cores varied between 21 to 34% at the surface, then decreased slowly as a depth. The percentage of surface TOM in the near coastal is elevated to the deepest part (21% to 34%). The TOC content in the surface was 9%. According to the Mid-Atlantic Integrated Assessment (MAIA) Estuaries the TOC concentrations in the sediments was in the range of high organic carbon level (>3%). The high value of TOC level in the surface sediment was controlled by algal productivity.