This study aims to prove the type and abundance of macrozoobenthos are affected by the physico-chemical condition of the habitat so that it can be used as a bioindicator in assessing river water quality with a case study in the Upstream of Citarum River. The method used in this study consists of two stages, namely determining the status of river quality with pollution index and determining the components to see the relationship of the water quality parameters to the abundance of macrozoobenthos with principal component analysis. On the basis of these studies, the results were that at the location of the study status of the river quality is slightly polluted and mildly polluted. For the slightly polluted status Corbicula sp. was used as the dominant macrozoobenthos parameter with the parameters of dissolved oxygen, organic carbon and N-O in the clay-dominated sediments. In turn, for the river areas with mild pollution, Enallagma sp., Tubifex sp., and Chironomous sp. were used as bioindicators and they have a relationship with the parameters of nitrate, TSS, and P-total.

This research aims to develop an assessment tool of ecological status in the upstream area using macrozoobenthic community and its relationship to the physicochemical parameters of water and sediment, in Citarum River. The number of species and abundance of macrozoobenthos in the dry season was higher compared to rainy season. The predominant family (Pachychilidae, Hydropsychidae, Glossiphonidae, and Chironomidae) obtained in both season was significantly correlated with the physicochemical parameter. Based on the Shannon-Wiener index, diversity in upstream area of Citarum River during the dry season (1.68) was similar with the rainy season (1.80) and it showed that the diversity of macrozoobenthic community was moderately diverse in both seasons. The physicochemical parameters that strongly related with the presence and abundance of predominant macrozoobenthic taxa were turbidity, total suspended solid (TSS), total nitrogen, total phosphate, gravel particle, and organic carbon. By considering biological and physicochemical parameters obtained from this study, we developed a modified scoring system to assess the ecological status of upstream area in Citarum River. Based on the scoring system, the ecological status was quite polluted in dry season (2.19) and moderately polluted in rainy season (4.94).

Mendirikan rumah akan mengemisikan CO2 ke udara. Emisi CO2 tersebut berasal dari pembuatan dan pengangkutan bahan bangunan, serta pekerjaan konstruksi. Penelitian ini mencoba memperkirakan besaran emisi CO2 dari pembangunan rumah sederhana. Penelitian diawali dengan pendataan jenis bahan bangunan dan perhitungan kebutuhan bahan bangunan setiap tipe rumah yang merupakan fungsi luas lantai. Kemudian penentuan faktor emisi berbagai bahan bangunan didasarkan pada penelitian terdahulu. Untuk memperoleh gambaran hubungan antara jenis bahan bangunan dan tipe rumah dengan besaran emisi CO2, simulasi dilakukan dengan berbagai skenario yang menyertakan luas rumah dan variasi bahan bangunan sebagai variabel. Hasil simulasi menunjukkan bahwa tipe rumah dan jenis bahan bangunan berperan penting dalam mencapai besaran emisi CO2. Terdapat indikasi bahwa kerumitan pembuatan bahan bangunan dan rumah mempengaruhi besaran emisi CO2. Dengan demikian kesimpulan yang dapat diambil adalah besaran emisi CO2 berbanding lurus dengan luas rumah, jenis dan volume kebutuhan bahan bangunan serta tingkat kerumitan proses konstruksi. Dengan mempertimbangkan variabel tersebut, konstruksi suatu rumah yang rendah emisi CO2 dapat direncanakan.

Increases in coastal pollutants, largely due to human activity on land, have an impact on seagrass ecosystems. The high sedimentation in the waters causes an increase in the concentration of sludge, organic matter, nutrients, and turbidity which reduce the depth that can be reached by sunlight. The condition affects seagrass ecosystems adversely. Changes in water condition can be illustrated by the presence of water organisms. One dominant organism in seagrass ecosystems is periphyton. The existence of periphyton in the waters is determined by physical and chemical conditions of the waters because it has specific limit of tolerance, which causes different community structure. To analyze periphyton response to the changes of environmental quality in seagrass ecosystems, Shannon Winner diversity and Saprobic Indices were measured at Panjang Island, Banten. The results of water quality assessment indicates the status of aquatic seagrass of the island considered as polluted to heavy polluted. It is observed from some physico-chemical parameters that exceeded the standard quality for the life of seagrass ecosystems and marine life. Based on the classification and saprobic coefficient using periphyton biological parameters, the condition of seagrass land ecosystem in the island is classified into β Mesosaprobic to β/α Mesosaprobic phase, which indicates light to medium pollution with pollutants including organic and inorganic materials. Several types of dominant periphyton were discovered during the observations, including Meridion sp, Navicula sp, Nitzschia sp and Synedra sp. This periphyton species belong to Bacillariophyceae class (Family Chrysophyta) that is commonly used to assess the condition of eutrophication and organic pollution on waters.

After the Horton overland flow concept became legend until the early 1960s, new findings then revised this concept for implementation in several catchment area conditions. Runoff processes in tropical regions seem to have specific characteristics such as thick humus on the top layer of the catchment area and non-uniformity of hydraulic conductivity vertically and horizontally across the stream. To overcome the runoff problems in tropical regions, a reasonable model needed to be developed to predict generated runoff. Based on the concept that saturation condition in a catchment generates non-uniformly during the course of a rainfall, and that the storage capability of top layer in intercepting rain-water leads to subsurface and return flow, the water balance in a segment of the catchment area is calculated. The mechanism of flow in the model is that subsurface flow and return flow, which are a function of hydraulic conductivity, and surface runoff on a segment are integrated for the whole areas. The generation of flow using the model seems to indicate that runoff peaks will commence after each segment is saturated starting from the valley bottom. The lag time for initial flow to alter significantly depends on the data on stream-flow before the storm began that indicate the soil moisture and depth of the temporary water table. Generally, though, the model is very flexible, so that data on each segment subject to the wide variety of physical conditions of the catchment area characteristic of tropical regions can easily be implemented.