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This research aims to compare precipitation data derived from satellite observation and ground measurements through a dense station network over Central Java, Indonesia. A precipitation estimate from the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) 3B42 Version 7 are compared with precipitation data from interpolated rain gauge stations. Correlation analysis, mean bias error (MBE), and root mean square error (RMSE) were utilized in the analysis for each thee-monthly seasonal statistics. The result shows that the 3B42 products often estimate lower rainfall than observed from weather stations in the peak of the rainy season (DJF). Further, it is revealed that the 3B42 product are less robust in estimating rainfall at high elevation, especially when humid environment, which is typical during the rainy season peak, are involved.

Laundry services are rapidly becoming ubiquitous in rural and urban areas, generating high domestic waste volumes. Their growth has raised concerns about the quality of natural waters, particularly the rivers into which most laundry businesses discharge their wastewater. The research set out to study laundry wastewater characteristics and their relationship with the river water quality as water pollution indicators in Code Watershed (Indonesia). It lies in three administrative units where many human activities take place in the watershed’s upper to the lower reaches. BOD and COD of 25 sampled laundry businesses were analyzed descriptively and compared to the laundry wastewater standards stipulated in Regulation No. 7 of 2016 and the class II water quality standards issued in Governor Regulation No. 20 of 2008. The results showed that the BOD of four laundry businesses and the COD of 18 laundry businesses exceeded the predetermined standards. Overall, rivers in Code Watershed meet the class II river water criteria for BOD at three of the seven sampling points and COD at all points.

Comprehending the characteristics of infiltration is essential for conserving spring recharge areas, particularly on hillslopes of a Quaternary volcanic landscape. Quantitative investigations were carried out to identify soil physical properties and morphological features related to infiltration behavior. We used 15 transects with 70 sampling points in total to collect soil samples, observed morphological characteristics, and measured the infiltration. Data analysis employed statistical methods, including principal component analysis (PCA) and K-means cluster analysis. PCA revealed that infiltration was strongly correlated with slope, slope length, surface curvature, and slope position and that it was a function of soil physical properties, i.e., soil moisture, particle size distribution, and bulk density. The K-means cluster analysis classified the sampling points into four clusters that corresponded to three slope positions, namely upper slope, middle slope, and footslope. The high infiltration rate in the middle slope was caused by the relatively steep slope, sandy soil texture, low soil moisture, and low bulk density. On the contrary, the relatively flat slope, high clay content, high soil moisture, and high bulk density of the footslope created a low infiltration rate. According to these infiltration parameters, the preferred area for spring water catchment conservation was the middle slope. [ABSTRACT FROM AUTHOR]