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The 7.4 Mw of tectonic earthquake caused liquefaction in Pasigala on September 28, 2018, happened due to the fault movement of Palu-Koro. It affected the water availability every spring. The research aim is to determine the spatial model of water production every spring after the natural tectonic disaster, especially in Palu and Poboya watersheds-a model built based on the integration between the spatial data overlaying and the statistical regression correlation. The sites are purposively selected at six springs spots and divided into four clusters (Poboya, Uemanje, Ranjuri Beka, Mantikole). The model assessment was generated based on the springs’ performance from x variables (catchment area, land cover, aquifer, free-ground water depth, fault, number of springs users) and the y variable (water discharge). The result shows that Poboya’s performance is bad-disturbed, while Uemanje, Ranjuri, Beka, and the performance of Mantikole are disturbed. The bad performance of springs requires conserving watershed areas through forest and land conservation, tree enrichment planting, wise land management, and good water use.

Tree architecture models and the composition of vegetation types affected surface runoff and erosion rates due to vegetation density and various other morphological and ecological characteristic components. This research purpose was to measure and compare the level of erosion in 3 tree architectural models. The research used the path plots method. The sample pathway was made by cut off contour lines. To measure the erosion rate that occured at the tree architecture model, erosion measuring plots were used in three tree architecture models, namely Attims (Eucalyptus deglupta), Corner (Arenga pinnata), and Rauh (Arthocarpus teysmanii). The results showed that the dominant tree architecture model was the Rauh, Attims, and Corner models. The erosion level which occurred in the three tree architectural models showed that the Attims Eucalyptus deglupta model and Corner Arenga pinnata models were more effective in controlling erosion by 233.55 g/ha/year and 293.10 g/ha/year with rainfall of 493.55 mm compared to Rauh Arthocarpus teysmanii type. The correlation analysis between rainfall and the erosion rate at the three tree architecture models were 80% (very strong) for Attims model, 89% (very strong) for Corner model and 90% (very strong) for Rauh model. To control the erosion the Attims and Corner models are highly recommended as alternatives for rehabilitating the critical land.

One important aspect needed in mangrove forest management was the data and information available regarding structure and associations. However, the structure and association of mangrove forests in the Torue watershed downstream had not been identified. The purpose of this research was to evaluate the structure and association of mangrove forests in the Torue watershed downstream. This research used the plot path method with a path and plot combination. Path placement was done by purposive sampling. The results showed that the mangrove forest structure of the Torue watershed downstream consisted of three canopy layers, i.e., Stratum C, D, and E, which were dominated by seedling and sapling growth rates. Stratum C was dominated by Sonneratia alba type, and Stratum D was dominated by Bruguiera gymnorizha and Bruguiera sexangula types. In contrast, Stratum E was dominated by Rhizophora mucronata and Rhizophora apiculata types. There was no association between mangrove vegetation and all species. However, three pairs of species had a positive association coefficient, namely: Sonneratia alba with Rhizophora apiculata with a coefficient value of 0,42, Rhizophora mucronata with Bruguiera gymnorhiza, and Rhizophora mucronata with Bruguiera sexangula each coefficient value of 0,06, which was not associated with five species, namely Sonneratia alba, Rhizophora mucronata, Rhizophora apiculata, Bruguiera gymnorizha, and Bruguiera sexangula. The results of this study could be the basis of the guidelines for sustainability in mangrove forest management. Keywords: association, mangrove forest, vegetation structure, watershed

Perubahan penggunaan lahan memiliki dampak terhadap sifat fisik tanah maupun proses hidrologi daerah aliran sungai. Penelitian ini bertujuan untuk membandingkan sifat fisik tanah pada penggunaan lahan agroforestri dan hutan lahan kering sekunder di Sub-DAS Wuno, Kabupaten Sigi. Metode penelitian menggunakan metode survei dilanjutkan dengan pengambilan sampel untuk bahan analisis di Laboratorium. Analisis tanah dilakukan di Laboratorium Ilmu Tanah, Fakultas Pertanian, Universitas Tadulako. Penentuan lokasi pengambilan sampel tanah ditentukan secara sengaja untuk mendapatkan 6 titik sampel. Pengambilan sampel tanah dilakukan 3 kali untuk setiap penggunaan lahan. Hasil penelitian menunjukkan bahwa tekstur tanah pada lahan agroforestri memiliki fraksi pasir 79,8%, kemudian fraksi debu 19,1%, dan fraksi liat 1,1%, sedangkan hutan lahan kering sekunder memiliki fraksi pasir 62%, fraksi debu 37,2%, dan fraksi liat 0,8%. Permeabilitas tertinggi pada kedalaman 0-20 cm ditemukan di lahan agroforestri 10,44 cm/jam, dan terendah di hutan lahan kering sekunder adalah 2,29 cm/jam. Bobot isi pada lahan agroforestri adalah 1,41 g/cm3, hutan lahan kering sekunder adalah 1,64 g/cm3. Porositas tanah lahan agroforestri adalah 40,85%, sedangkan hutan lahan kering sekunder adalah 22,90%. Bahan organik tanah pada lahan agroforestri adalah 4,23%, sedangkan hutan lahan kering sekunder adalah 3,81%. Tidak terdapat perbedaan yang cukup siginfikan terhadap parameter sifat fisik tanah diantara kedua penggunaan lahan baik pada tekstur tanah, bobot isi, dan bahan organik, namun demkian nilai porositas tanah dan permeabilitas pada lahan agroforestri lebih tinggi dibandingkan dengan hutan lahan kering sekunder.

The upstream part of Wuno Subwatershed in Palu Watershed experiences massive land use change exploitation, causing erosion impact increasingly. An alternative way for reduce the erosion level is by applying conservation farming system. This research aims to examine the conservation farming system with GIS-based agroforestry pattern and its effects to the erosion level reduction perceived by the community living in the Wuno Subwatershed. The method used is image interpretation and field survey to obtain data directly on an object using GPS.The results show that there are four agroforestry patterns in Wuno subwatershed, that is, trees along border, alternate rows, alley cropping and random mixture. The highest erosion level shown by the alley cropping pattern at 5.17 grams/ha and the lowest is trees along border at 0.47 grams/ha, all compared to the total rainfall level of 493.6 mm. The canopy cover of the agroforestry pattern influences the erosion level occurs.

Scrap aluminium is waste aluminium, the result of recycling that can be used as an alternative raw material with consideration of cheap and affordable prices. The use of aluminium scrap has been widely used both on a large scale such as the automotive industry, ships, aircraft, construction, etc., as well as on a small scale such as household appliances. Chloride acid is used in the process of purifying salt, cleaning porcelain, and as a stain remover on kitchen utensils, and sodium chloride, known as salt, is very corrosive due to the presence of chloride ions. The corrosive nature of chloride ions can be influenced by the concentration and duration of immersion, so it is necessary to research changes in the corrosion rate caused by the concentration and time of immersion. This study uses a method of immersion with weight loss where the specimen is immersed in HCl and NaCl with a concentration of 0. 1%; 0. 3%; and 0. 5% with an immersion time of 5 days, 10 days and 15 days. The results showed that the highest corrosion rate of HCl occurred at 15 days immersion with a concentration of 0. 1% at 1542. 314 Mpy, and the smallest corrosion rate at 5 days with a concentration of 0. 5% at 181. 09 Mpy. For the largest NaCl corrosion rate occurred at 15 days immersion with a concentration of 0. 1% from 101. 171 Mpy, and the smallest corrosion rate at 5 days immersion with a concentration of 0. 5% 41. 793 Mpy.

Land use regulation and soil and water conservation techniques need to be intensified to minimize the impact of climate change, especially in controlling floods, erosion and landslides. The purpose of this service is to provide education to the public in efforts to mitigate the impact of climate change through environmentally friendly soil and water conservation technology. The method used in this service is a participatory educational and training method or educational and participatory approach with extension activities, training and technical guidance. The results of the service implementation have been carried out, namely: preparation, introduction of activities, implementation of counseling/training on the material: a) The benefits of increasing land productivity through soil and water conservation techniques and b) Introduction and several soil and water conservation techniques, namely vegetative techniques and terrace construction. the contours of the A frame model, in addition, an evaluation is carried out. Service activities provide benefits in increasing land productivity and assisting in planting arrangements according to contour lines and as a basis for making terraces. [ABSTRACT FROM AUTHOR]

One of the appropriate strategies to evaluate watershed health is by determining peak discharge. The influence of frequent floods and landslides due to forest destruction, and land degradation, especially the upstream, can affect watershed health and the carrying capacity. This study aims to determine the estimated peak discharge the Gumbasa Watershed performance, Central Sulawesi, Indonesia to monitor and evaluate the performance of the main watershed. This was conducted using a rational method with a combined and average flow coefficient approach. The rainfall intensity was calculated based on the concentration-time, which is highly dependent on the characteristics of the flow area. The results showed the flow coefficient in the Palolo and Gumbasa downstream areas was 0.45 and 0.57, which means that 45% (Palolo) and 57% (Gumbasa) of the falling rain will become surface runoff classified as high. Conversely, flow coefficient was low (0.12) for Lindu, meaning that some of the rainwater is flowing on the land surface, thereby causing high peak discharge, especially in the downstream, whereas in the upstream part of the sub watershed Lindu has a high land cover density, which causes a small runoff coefficient. Therefore, it is necessary to conserve and restore land through reforestation and rehabilitation to minimize the flow coefficient and peak discharge. [ABSTRACT FROM AUTHOR]