I Wayan Nuarsa
Jurusan/Prodi Agroekoteknologi Fakultas Pertanian Universitas Udayana

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Monitoring Total Suspended Solid Distribution In Coastal Bali Area Using MODIS Satellite Data Ippah, Imro’atul; Osawa, Takahiro; Nuarsa, I Wayan
International Journal of Environment and Geosciences Vol 5 No 1 (2024): International Journal of Environment and Geosciences
Publisher : Graduate Study of Environmental Sciences, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/ijeg.2024.v05.i01.p04

Abstract

Total Suspended Solid (TSS) is one important parameter for water quality. This research aims to analyze MODIS feasibility for identifying TSS, to identify TSS monthly patterns and annual patterns variability, and to analyze the TSS distribution patterns around Bali coastal area. Observation data of the wet season was observed in Benoa Bay on 2nd October 2013 and the dry season was observed in Perancak from July on 28th to July 31st, 2009. The comparison between observation data and satellite data was used to establish a new modification algorithm for suitable conditions around Bali coastal area. Based on research analysis, the feasibility of MODIS was different in each season. In the wet season, the coefficient correlation was (r) = 0.55 and in the dry season, it was (r) = 0.68. poor correlation in the wet season indicated the bottom effect of the area which has a shallow and heterogeneous depth. The TSS average in the wet season was 75.55 mg/l and 55.97 mg/l in the dry season. The highest value was analyzed in November (82.74 mg/l) and the lowest value in June (46.41 mg/l). During wet season, the stream volume and the stream flow rate increase and bring the TSS into coastal areas through the runoff process. The mapping patterns showed that the southern coastal area and western coastal area of Bali had a high value every month. The northern coastal had a high value only in the wet season. The characteristic of Bali river area, which is perennial and intermittent rivers caused this phenomenon. The population and Bali land-use area also affected the high TSS in these areas. Yearly patterns of TSS from 2009 to 2013 around Bali coastal areas were different every year. The highest TSS distribution observed in 2013 wet season is 87.75 mg/l. The lowest TSS distribution occurred in 2009 dry season with a value of 52.2 mg/l. The TSS tends to increase every year due to the changing in Bali land use. TSS patterns from 2009 to 2013 were dynamic every year. The El Nina and La Nino events also gave impact on the patterns. The MODIS feasibility in different locations was different depending on the characteristic of the physical property of water. The shallow and small area causes misinterpretation of the satellite reflectance. The TSS monthly patterns depended on the season and the mapping can be used to describe the sources of TSS pollution, the distribution, and the quantity of TSS in the coastal area.
Assessing lake shoreline change and prediction for 2030 by physical drivers: A Case Study from Lake Batur, Batur UNESCO Global Geopark, Bali Utama, I Putu Wira; Arthana, I Wayan; Nuarsa, I Wayan
International Journal of Environment and Geosciences Vol 5 No 1 (2024): International Journal of Environment and Geosciences
Publisher : Graduate Study of Environmental Sciences, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/ijeg.2024.v05.i01.p02

Abstract

Over ten years, the water level of Lake Batur has increased. Agriculture area and settlements around Lake Batur are threatened by rising water level. This study aims to analyze the shoreline change of Lake Batur, located in the Batur UNESCO Global Geopark (BUGG), during the period of 2007 – 2018 and design a prediction for 2030. Understanding the shoreline change is very important for lake management and planning. Shoreline changes were analyzed in Geographic Information System (GIS) application. The data were obtained based on Remote Sensing (RS) data, Landsat ETM+ imagery on September 24, 2007, and Landsat OLI imagery on October 24th, 2018. Predictions of lake shoreline in 2030 result from modelling by integrating ASTER-GDEM V2 data, lake water level data for 2007–2018, annual average rainfall data for 2007–2018, and bathymetry data for 2013 and 2015. The results of the satellite imagery analysis show that there has been a change in the length of the shoreline, which has increased from 20.47 km in 2007 to 21.28 km (3.96%) in 2018. The lake surface area changed from 15.34 km2 in 2007 to 16.16 km2 in 2018 (5.35%). The prediction of lake shoreline changes in 2030 showed that Lake Batur will increase to 26.90 km (26.41%), and lake surface area is predicted to increase by 17.67 km2 (9.34%) from 2018. This is because of the morphological change of Lake Bottom.
MODEL SISTEM DINAMIK UNTUK KEBERLANJUTAN DANAU BATUR, BATUR UNESCO GLOBAL GEOPARK, BALI Utama, I Putu Wira; Arthana, I Wayan; Nuarsa, I Wayan; Suryawan Wiranatha, Agung
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 18 No 1 (2024)
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/EJES.2024.v18.i01.p01

Abstract

This research aims to analyze the best scenario for conserving Lake Batur, Batur UNESCO Global Geopark (BUGG), Bali. Using the system dynamics method, key factors in the management of Lake Batur can be identified. Based on modeling results, it is known that the sustainability of Lake Batur is strongly influenced by aspects of land use, the environment, the economy, and the social culture of the community. The main leverage factors in supporting the preservation of Lake Batur are law enforcement and supervision, government assistance, as well as training and outreach to the community. The analysis of the sensitivity value of the optimistic/moderate ratio shows that the optimistic scenario is the best option to reduce the lake pollution index to 0.86 (still below the 1 threshold). Increasing community income per capita in this area in 2045 is estimated to reach Rp87.992.747,76/year, with predictions of 9,312 floating net cage plots owned by 2,592 entrepreneurs. The predicted number of plots is 14.90 ha, which is still below 1% of the area of Lake Batur. Keywords: System Dynamics; Sustainability; Lake Batur; BUGG
ANALISIS KELAYAKAN EKONOMI PENGOPERASIAN SISTEM PENYEDIAAN AIR MINUM (SPAM) DI PULAU NUSA PENIDA - KABUPATEN KLUNGKUNG Ariantana, Ketut; Sudiana Mahendra, Made; Nuarsa, I Wayan; Adnyana, I Wayan Sandi; Kastini Adiputri, Ni Made
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 17 No 2 (2023)
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/EJES.2023.v17.i02.p03

Abstract

Water is the most basic need for living things, it follows population growth and development activities as in Nusa Penida Island. The water supply on this island comes from SPAM Penida and SPAM Guyangan. The Central and Provincial Governments of Bali provide operational subsidies of more than 7 billion on average. Perumda Panca Mahottama’s services also can’t cover all villages on this island. It means SPAM management is not yet economical, and the service is not optimal. The purpose of this economic feasibility analysis is to determine the economic feasibility of SPAM in terms of Full Cost Recovery and appropriate tariffs so that operational costs are proportional to income. To determine the economic feasibility conditions, a study was conducted to evaluate the value of current tariff (2021). The result is Opex value is bigger than the income value. This results in a NCF value of (-Rp.2,610,621,409.00). The operational cost is IDR.7,164,857,259.00/year with total production 1,530,362.88m3/year. The FCR value obtained was IDR.4,681.80/m3. The average production cost is IDR.2,975.92/m3, which means there will still be a loss in 2021 of IDR1,705.99/m3. Analysis was conducted based on the trial error method with calculation period of 15 years, with 3 different tariff systems, alternative 1, tariff with the same value IDR.4,100/m3 from 2023 to 2036, alternative 2 tariff is IDR.3,500 in 2023 to 2027 increase by IDR.1,000/m3 in 2028 to IDR.4,500/m3 until 2036. Alternative 3 tariff is IDR.3,000/m3 in 2023 increase by IDR.500/m3 in 2024 to 2026 and settled at a rate IDR.4,500/m3 until 2036. Keywords: SPAM; feasibility; economy; tariff
PEMETAAN JASA EKOSISTEM PENYEDIA PANGAN DI PROVINSI BALI Wiranatha, I Made Alit; Nuarsa, I Wayan; Sudarma, I Made
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 18 No 1 (2024)
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/EJES.2024.v18.i01.p06

Abstract

Ecosystem services are the benefits that humans obtain from ecosystems. With the growing demand to implement sustainable development, the need for information on ecosystem services is increasing as a consideration in various policies and development planning. In response to this need, the method that is often used is the preparation of ecosystem services maps using an approach obtained from land cover data. Many people think this method works well and saves a lot of time and money, especially for studying places on a global, regional, or national level, where it's easy to get data on land cover. The point of this study is to look at how the results of the 2018 and 2022 food supply ecosystem services maps compare. These maps were made by experts who thought about how ecosystem services could be used in different types of land and ecoregions. The Analytical Hierarchy Process (AHP) with the pairwise comparison method is used to figure out how much ecosystem services are worth in relation to land cover and ecoregions. The island of Bali was used as a study area, and food supply was the type of ecosystem service that was looked at. Ecoregion data results for 2022 with the high class being more dominant and having an area of 385,339.19 ha or the equivalent of 66.67%. Land cover in 2018 produced a dominant high class with an area of 288,931.82 ha or the equivalent of 48.74%. The land cover results in 2022 are predominantly high class with an area of 289,039.25 ha or the equivalent of 50.01% of the total area of the island of Bali. The analysis results from the combination of ecoregion and land cover in 2022 are predominantly high class with an area of 182,039.65 ha or the equivalent of 31.49%. Several factors can explain the connection between ecosystem processes and the benefits they provide, which can get around or lessen the problems with using land cover data. Keywords: Ecosystem Services; Expert Judgement; Ecoregion; Land Use Based Proxy