Pamekasan coastal area is the center of salt production concentrated in the Pademawu subdistrict with the ponds area of 740.96 ha. The sufficiently close distance of salt ponds to settlement areas ...allows several issues, such as shallow groundwater salinization. This study aimed to determine the salt pond’s degradation over five years (2015-2020) and its influence on the salinization issue in Pademawu. We compare groundwater quality parameters (conductivity, TDS, the depth of shallow surface groundwater, and salinity) surveyed in 2015 and 2020, correlated to salt pond area alterations. Over five years of measurement, it was found that conductivity declined, reaching 2779.94 µS/cm. Based on TDS deterioration, groundwater transformed from brackish to freshwater in 2020. By contrast, the depth of shallow groundwater-surface increased by almost one meter. The freshwater area also increased by 22% over five years based on conductivity classification. Groundwater quality dynamics are related to the alteration of the salt pond area. On the other hand, the significant increase in rainfall intensity, which is not beneficial for salt agriculture, results in the salt pond area deterioration, thereby declining surface groundwater salinity in Pademawu due to the less interaction between Cl and groundwater within aquifers. Although the groundwater pollution induced by seawater intrusion and salinization declined in 2020, re-organizing the distance between salt ponds and the settlement area in Pademawu is crucial to minimize further groundwater pollution.
Keywords : Dynamics; pollution; groundwater; salt agriculture; Pademawu
Copyright (c) 2022 Geosfera Indonesia and Department of Geography Education, University of Jember
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Land utilization changes of the natural resources conservation area of Pangandaran coastal area, that have been utilized as a marine tourism area, which affect many kinds of environmental degradation ...threats. Updating the condition of Pangandaran waters is essential due to its condition impacted by anthropogenic activities. Water condition monitoring was done by measuring nutrients as an indicator to assess the water fertility and pollution. Fourty five observation points were selected and divided into three locations, representing the condition of river, estuary/mangrove area, and open sea. Nutrients were analyzed by employing Standard Methods for The Examination of Water and Wastewater 22nd Edition 2012 (SMEWW). Currents and tides were measured for 15 days, used as the basis input of hydrodynamic model. The results showed that the highest of average value of nitrate was found in the estuary/mangrove forest which reached 0.998 mg.L-1. While, the highest phosphate content was observed in the river which reached 0.928 mg.L-1. The highest ammonia concentration was observed in the sea which reached 0.027 mg.L-1. N:P ratios in the study area are categorized <16, which showed that Pangandaran waters are in the condition of N-limitation. These conditions trigger blooming of phytoplankton due to the high concentration of nitrate. The higher nutrient concentration indicates that anthropogenic activities take place. Tidal current has an important role transporting nutrient in the estuary, triggering nutrient deposition and blooming tendency. Restrictions on residential areas and the utilization of coastal areas are an appropriate step to reduce the pollution level in Pangandaran waters.
The capital coastline city of Padang is intensively developed to enhance tourism attractions and protect the coastline from natural hazards and disasters. Massive urban developments applied in the ...coastal area have not gone well, and several regions have been eroded and unstable. This study aimed to determine the significant change in Padang city's coastline due to rapid urban development in the coastal area. Spatial analyses are employed to determine the coastline changes and coastal vulnerability, such as a DSAS (Digital Shoreline Analysis System) and Smartline-associated CVI (coastal vulnerability index) approach. A hydrodynamic and coastal model is also used to illustrate the transport mechanism and predict the level of abrasion. The result shows that substantial coastal changes and vulnerability have occurred. Of particular concern, 66 % of Padang's coastline is eroded with a rate of 0.21 - 49.4 m/year, 1% stable, and the rest, 34% experiencing accretion. More than 9% of coastal areas are categorized as highly vulnerable. The numerical model confirms the abrasion in several significant areas in Padang City, proven by the relatively high value of bed-level change (ranging from 0.39 up to -4 m) and considerable variability of seasonal sediment transport and suspended materials. The erratic hydrodynamics and ineffective coastal building are the primary factors triggering Padang City's coastal instability.
Mandeh Bay is threatened by sedimentation issue caused by the rapid development of marine tourism area which strongly impacts to the environmental degradation. Due to the semi-enclosed area of Mandeh ...Bay, the tidal current has a significant role in triggering vertical and horizontal transports within the bay. This study aimed to determine the characteristic of tidal current during the southwest monsoon. We developed a hydrodynamic model based on Navier-Stokes equations using a flexible mesh and tidal forecast in which the validation is performed by ADCP data. The simulation results will be used as the basic data to develop a model which depicts the elliptical pattern of tidal current constituents. Offshore rotary tidal currents which are originally semidiurnal reiterate the elliptical pattern every 6 hours and 12 minutes. The strongest semidiurnal current speeds are observed in the bay mouth ranged from 0.1-0.5 m.s-1. The tidal constituent ellipses are oriented more meridionally and in several areas oriented zonally. The current speed of is the highest at all which the speed is averagely one third of magnitude. While, the two main diurnal tidal constituents ( and ) have the maximum speeds approximately one fifth of magnitude. Thus, the domination of semidiurnal constituents may trigger sediment distribution and accumulation within the bay because of its twice tidal oscillations entering the bay.
Mandeh Bay is a semi-enclosed water area that there are two main estuaries, Mandeh and Nyalo River estuary. Sedimentation issue has been gotten worse due to the massive development in coastal area. ...This study aims to determine the sediment accumulation within Mandeh bay and its distribution patterns. The measurement of sedimentation rate applied in the Mandeh and Nyalo Estuaries. Oceanography parameters (tides and currents) recorded for 30 days measurement. The thickness of sediment accumulation was predicted by applying single beam echosounder dual frequency. The calculation of sediment volume was done using frustum formula grid 10 x10 meters. Flow model approach was also simulated to depict the distribution pattern of sediment. The thickness of sediment accumulation categorized into five spatial categories that are 0-0,3m, 0,4-0,6m, 0,7-0,9,1-1,2m, and 1,3-1,5m. The sedimentation rate in Mandeh estuary ranged from 60,85 up to 62,16 g.m-2.day-1, while in Nyalo estuary is approximately 48,86 g.m-2.day-1. The tidal current speed that is weak ranged from 0-0,05 m/s induces the sediment accumulation which mainly occurs during the neap tidal conditions. The thickness of sediment accumulation which is more than one meter identified around Mandeh River estuary and several areas near Carocok Tarusan Port where the sediment intake takes place and due to the weak current feature, it causes the increase of sedimentation in this region. Teluk mandeh merupakan kawasan teluk semi tertutup yang mempunyai 2 muara sungai besar yaitu sungai Mandeh dan sungai Nyalo. Masalah sedimentasi menjadi semakin parah karena pengembangan wilayah pesisir yang masif. Tujuan dari penelitian ini adalah untuk mengetahui ketebalan akumulasi sedimen di dalam Teluk Mandeh dan pola distribusinya. Pengukuran laju sedimentasi dilakukan pada dua fokus area yakni muara Sungai Mandeh dan Sungai Nyalo. Pengukuran parameter oseanografi (arus dan pasang surut) dilakukan selama 30 hari pengukuran. Ketebalan akumulasi sedimen diukur menggunakan alat Single Beam Echosounder Dual Frekuensi. Perhitungan volume sedimen dihitung dengan rumus frustum grid 10x10 meter. Simulasi flow model juga dilakukan untuk mengetahui pola distribusi sedimen. Sebaran ketebalan sedimen yang dibagi dalam 5 kategori spasial yakni 0-0,3m, 0,4-0,6m, 0,7-0,9,1-1,2m, dan 1,3-1,5m. Laju sedimentasi di muara Sungai Mandeh berkisar antara 60,85 sampai 62,16 g.m-2.hari-1 dan di muara Sungai Nyalo rata-rata 48,86 g.m-2.hari-1. Kecepatan arus pasang surut yang cukup lemah berkisar antara 0-0,05 m/s menyebabkan potensi akumulasi sedimen akan berlangsung terutama saat kondisi perbani. Sedimen dengan ketebalan lebih dari 1 meter teridentifikasi di sekitar Sungai Mandeh dan beberapa Kawasan Pelabuhan Carocok Tarusan dimana asupan sedimen mendominasi. Karena karakteristik arus yang lemah, sedimentasi meningkat diwilayah ini.
Settlement growth and activity of the population in the Brebes Subdistrict upstream side is also predicted to trigger intrusion and rising sea levels that affect the flow and availability of fresh ...water needed for the survival of life mangrove vegetation, especially in the adult stage. Therefore, identification of the quality of waters in the mangrove areas is needed to determine the status of these waters pollution index. Measurement of physical and chemical parameters of waters in situ using a Water Quality Checker (DKK TOA WQC Type-24) and laboratory testing of some samples to determine the nutrient content of the water is also performed. Insitu value measurement results later are calculated by using a pollution index refers to the Decree of the State Minister of Environment Number 51 The year 2004 on Guidelines for Determination of Water Quality Status. Index of water pollution Brebes District mangrove area is divided into three criteria: pollution index good condition, lightly polluted and heavily polluted. The section near the front mangrove estuary and enter the index criteria lightly polluted.
Ambon Bay waters consist of two parts, Inner Ambon Bay and Outer Ambon Bay separated by a gap that is narrow and shallow. Ambon Bay has a lot of functionality and usability both in transportation, ...conservation, and tourism. The existence of one of the sites SS. Aquila sinking ship that sank since May 27, 1958, became one of the tourist attraction diving in Ambon Bay. Determination of water pollution index Ambon Bay becomes very important to do as support material and development of sea travel. Determining pollution index is done by direct measurement using the sea water quality parameters Water Quality Checker (DKK TOA WQC Type-24), as well as laboratory analysis to determine the chemical parameters of seawater (pH, TSS, salinity, turbidity, oil, grease). The results showed that the waters of the Bay of Ambon Affairs based on some parameters water quality standard for marine tourism is still included in accordance with the standard criteria by Keputusan Menteri Negara Lingkungan Hidup Nomor: 51 Tahun 2004 on Guidelines for Determination of Water Quality Status.
Mandeh Bay is threatened by sedimentation issue caused by the rapid development of marine tourism area which strongly impacts to the environmental degradation. Due to the semi-enclosed area of Mandeh ...Bay, the tidal current has a significant role in triggering vertical and horizontal transports within the bay. This study aimed to determine the characteristic of tidal current during the southwest monsoon. We developed a hydrodynamic model based on Navier-Stokes equations using a flexible mesh and tidal forecast in which the validation is performed by ADCP data. The simulation results will be used as the basic data to develop a model which depicts the elliptical pattern of tidal current constituents. Offshore rotary tidal currents which are originally semidiurnal reiterate the elliptical pattern every 6 hours and 12 minutes. The strongest semidiurnal current speeds are observed in the bay mouth ranged from 0.1-0.5 m.s-1. The tidal constituent ellipses are oriented more meridionally and in several areas oriented zonally. The current speed of is the highest at all which the speed is averagely one third of magnitude. While, the two main diurnal tidal constituents ( and ) have the maximum speeds approximately one fifth of magnitude. Thus, the domination of semidiurnal constituents may trigger sediment distribution and accumulation within the bay because of its twice tidal oscillations entering the bay.
ABSTRACTPademawu Sub-District consist of salt ponds reached 740.96 Ha that is the second largest area in Pamekasan. Land-use overlapping problems between salt ponds and settlement influence the ...environmental degradation enhancement. The presence of salt ponds is indicated as the cause of increased salinity in well-water around the settlement so that the well-water is salty. To determine the influence of salt pond on groundwater pollution, the information regarding surface characteristics as well as the profile beneath the surface is essential. The method consisted of a hydro-geology survey, hydrochemistry, and geophysics (Geo-Electricity method). The type of groundwater is predominated by chloride (Na-Cl) and carbonate (Na-HCO3, Ca-HCO3). Based on groundwater chemistry element calculation, it is observed that there is an influence of salt pond infiltration on groundwater aquifer. The conductivity of groundwater ranged from 15,000–50,000 µS/cm (categorized into salty water). The specific resistance value of rocks beneath the surface varied between 0.1–300 that is usual in either coastal or alluvial area. The low value of specific resistance associated with alluvial lithology consisted of either brackish water or salt water expected the result of salt pond filtration. The depth of surface saltwater contaminating the aquifer layer ranged from 5 up to 30 meters. The presence of salt ponds influences the level of contamination of Cl- pollutant in shallow groundwater in Pademawu Sub-District, Madura, so it is necessary to re-arrange the land-use system in the coastal area.Keyword: groundwater pollution, salt pond, Pademawu Sub-District, Specific resistance Geo-ElectricityABSTRAK Kecamatan Pademawu terdiri atas kawasan tambak garam seluas 740,96 Ha yang merupakan wilayah terluas kedua di Pamekasan. Pemasalahan tumpang tindih jenis pemanfaatan lahan tambak garam dengan lahan pemukiman berpengaruh terhadap peningkatan degradasi lingkungan. Keberadaan tambak garam diindikasikan sebagai penyebab meningkatnya kadar salinitas pada air sumur di sekitar pemukiman sehingga air sumur terasa asin. Untuk mengetahui pengaruh keberadaan tambak garam terhadap pencemaran air tanah, dibutuhkan informasi mengenai karakteristik permukaan maupun profil bawah permukaan. Metode penelitian yang dipakai terdiri atas survei hidrogeologi, hidrokimia dan geofisika (metode geolistrik). Tipe air tanah didominasi oleh tipe klorida (Na-Cl) dan karbonat (Na-HCO3,Ca-HCO3), hasil perhitungan rasio unsur kimia air tanah menunjukkan adanya pengaruh infiltrasi air tambak garam kedalam akuifer air tanah. Nilai DHL air tanah daerah penelitian didominasi nilai dengan kisaran 15.000–50.000 µS/cm dan masuk dalam sifat air asin. Nilai tahanan jenis batuan bawah permukaan bervariasi antara 0,1–300 Ωm yang umum dimiliki pada kawasan pesisir atau alluvial. Nilai tahanan jenis rendah berasosiasi dengan litologi alluvial yang terdiri atas air payau atau air asin yang diduga hasil infiltrasi dari air tambak garam. Kedalaman muka air asin yang mencemari lapisan akuifer berada pada kisaran kedalaman 5 hingga 30 m. Keberadaan tambak garam memberi pengaruh terhadap tingkat pencemaran polutan Cl- pada air tanah dangkal yang ada di Kecamatan Pademawu, Madura, sehingga dibutuhkan penataan ulang sistem tata guna lahan di kawasan pesisir tersebut.Kata kunci: pencemaran air tanah, tambak garam, Kecamatan Pademawu, Geolistrik tahanan jenis
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