The decline in water resources and the occurrence of various hydrological disasters in the Citarum watershed indicate the need to restructure the components inside the watershed, especially land cover in the upper watershed area. This study aims to determine the effect of forest land cover on the hydrological parameters of the upstream Citarum watershed through simulations of the SWAT (Soil and Water Assessment Tool) model. The results showed that the forest cover in the Citarum watershed was only 15.96% of the watershed area and only 4.94% was located in the Upper area. The Flow Rate Coefficient of the upstream Citarum watershed is 31.4, the annual average surface flow and annual erosion are 933.03 mm and 517.9 tons/ha respectively. The simulation from several scenarios shows that a decreasing in forest area can increase discharge and surface runoff, whereas an increase in forest area will increase soil infiltration and evapotranspiration. Decreasing forest area by 10% from existing conditions caused 58% of rainwater to become surface runoff. The large number of discrepancies between the existing conditions and the directions in the RTRWP will require a long time and large costs to adjust so that the short-term alternative that can be done is to convert dryland agricultural cover to the forest to reach forest cover of at least 45% of the land area in the upstream area and can optimize the hydrological function of the watershed.
AbstrakPerubahan penggunaan lahan dari hutan ke penggunaan lainnya seringkali diikuti oleh penurunan fungsi tanah sebagai pengatur tata air. Penelitian ini bertujuan untuk mempelajari pengaruh tutupan mangrove terhadap perubahan garis pantai dan intrusi air laut pada hilir DAS. Penelitian difokuskan pada penentuan jenis penggunaan lahan pantai melalui interpretasi citra satelit dan pengecekan lapangan, analisis kondisi fisik tanah, pengamatan intrusi air laut, dan analisis perubahan garis pantai akibat abrasi atau ekresi. Hasil penelitian menunjukkan pada periode tahun 1989 hingga 2013, tambak yang ditanami mangrove di Kabupaten Subang mengalami penurunan luas dari 3402,6 ha menjadi 2384,9 ha, sebaliknya terjadi peningkatan luas tambak tanpa mangrove dari 5745 ha menjadi 8741,5 ha. Analisis perubahan garis pantai menunjukkan adanya abrasi di Ujung Pamanukan dan Teluk Ciasem mencapai 1,2 km ke arah daratan. Akresi dijumpai di Teluk Blanakan dan Muara Cipunagara mencapai 1,3 km dalam kurun waktu 1989 -2013, sedangkan di Muara Sungai Cipunagara mencapai 1,7 km. Air tanah di Desa Muara dan Desa Legon Wetan termasuk air agak payau karena memiliki nilai DHL yang lebih besar dari 1500 µS/cm dan TDS di Legon Wetan > 1000 ppm, sedangkan di Muara TDS nya mendekati 1000 ppm. Perbandingan konsentrasi khlorida-bikarbonat di Desa Muara dan Desa Legon Wetan menunjukkan angka R > 1 sehingga tingginya kadar garam pada air tanah diakibatkan oleh intrusi air laut. Hal sebaliknya terjadi di Desa Tegalurung yang penggunaan pantainya didominasi tambak bermangrove memiliki nilai DHL dan TDS air tanah yang masuk dalam klasifikasi air tawar.Kata kunci: abrasi, akresi, garis pantai, intrusi air laut, mangrove. Abstract Changes in land use from forest to other uses are often followed by a decrease in soil functions as a regulator of the water system. This research aimed to study the effect of mangrove cover to a change of a coastline and sea water intrusion
High rainfall and soil tillage without application of soil conservation have led to higher run off and erosion that washed away top soil that is rich in nutrients. This study was aimed to determine ABSTRAKCurah hujan yang tinggi dan pengolahan lahan tanpa menerapkan teknik-teknik konservasi tanah menyebabkan tingginya aliran permukaan dan erosi yang menghanyutkan top soil yang kaya unsur hara. Penelitian ini bertujuan untuk memperoleh informasi tentang besarnya pengaruh aplikasi teknik konservasi tanah dan air (rorak) terhadap pertumbuhan tanaman Gmelina arborea Roxb. Lokasi penelitian adalah Kawasan Hutan Dengan Tujuan Khusus (KHDTK) Carita. Rancangan yang digunakan adalah Rancangan Acak Kelompok dengan tiga perlakuan, yaitu P 5 = G. arborea + rorak jarak 5 m; P 10 = G. arborea + rorak jarak 10 m; dan P 0 = G. arborea + tanpa rorak (kontrol). Analisis data tinggi dan diameter tanaman menggunakan ANOVA, dan untuk parameter lain dianalisis secara deskriptif. Hasil penelitian menunjukkan pertumbuhan terbaik tanaman G. arborea dicapai pada P 5 dengan rata-rata tinggi dan diameter masingmasing 10,07 m dan 13,21 cm. Pada saat tanaman mencapai umur 3 tahun, pada perlakuan P 5 dan P 10 berpengaruh nyata terhadap pertumbuhan tinggi tanaman sedangkan pertumbuhan diameter hanya dipengaruhi oleh P 5 . Perlakuan P 5 juga mampu menekan aliran permukaan dan erosi sebesar 2,07% dan 13,56% dari plot kontrol. Kehilangan unsur hara melalui erosi lebih besar jika dibandingkan melalui aliran permukaan, dan P 5 mengalami kehilangan unsur hara paling kecil jika dibandingkan P 10 dan P 0 .
Observations and measurements of mangrove stands were performed using line transect and sample plots method (Line Transect Plot). Substrate and water samples were taken and analyzed in the laboratory. The results showed that the mangrove ecosystem in Subang was dominated by Avicennia sp and Rhizophora sp. Avicennia more adaptive to the shallow water, while Rhizophora more adaptive to an area closer or direct contact with the sea. Water quality conditions at the three locations were quite varied and still within the quality standard range for mangrove waters, except the BOD and DO parameters that need to be recovered because they out of the standard. Fertility conditions (physics and chemistry) of sediment (substrate) were generally in good condition for plant growth.
The utilization of peatlands as agricultural areas that does not pay attention to the sustainability aspects often contributes to climate change and the decline in the peat ecosystem function. For better peatland management and to prevent more severe environmental losses, knowledge of the impacts on chemical and hydro-physical peat characteristics in a specific area is required. This study was aimed to assess the chemical and hydro-physical characteristics of the peat utilized as agricultural land. The study was conducted by field measurements and peat sample analysis in the laboratory. The results indicated that peat managed as agricultural land is categorized as deep inland peat with more than 3 m thickness and dominated by sapric type in the surface layer. Intensive agricultural management significantly changes some peat's chemical characteristics by increasing the pH, phosphor, potassium, calcium, and magnesium contents. Otherwise, the peat management has lowered the hydrological function characterized by increasing water level depth, bulk density, reducing the water content and hydraulic conductivity. Hydrological peat functions on agricultural peatland should be restored by applying appropriate canal blocking. Paludiculture systems should be considered as promising agricultural land management that combines adaptive crops and suitable tree species with high economic value for the community.
Bentuk pengelolaan khas hutan rakyat di Desa Nglanggeran, Kecamatan Patuk, Kabupaten Gunung Kidul, ada tiga macam, yaitu alas (hutan), pekarangan, dan tegalan. Penelitian ini bertujuan untuk mengetahui produksi dan jenis serasah dominan serta menganalisis kandungan nutrisinya sehingga dapat menjadi bahan pertimbangan dalam pemilihan jenis yang dapat menambah unsur hara pada tanah. Hasil penelitian menunjukkan urutan produksi serasah adalah dari HR3 (6,05 ton/ha/6bln), HR2 (5,64 ton/ha/6 bln) dan HR1 (4,61 ton/ha/6 bln). Berat serasah daun sebesar 5,150 ton/ha (77,07%) di HR3, 5,218 ton/ha (76,22%) di HR2 dan 3,816 ton/ha (66,96 %) di HR1. Produksi serasah tersebut jika terdekomposisi sempurna selama 6 bulan akan menambah unsur hara ke tanah HR3 sebesar 80,56 kg/haN; 3,50 kg/ha P; dan 14,73 kg/ha K, HR2 (69,58 kg/ha N; 3,38 kg/ha P; dan 14,28 kg/ha K), dan paling rendah pada HR1 (53,15 kg/ha N; 1,95 kg/ha P dan 7,18 kg/ha K). Untuk memenuhi kebutuhan hara baik tanaman pertanian maupun tanaman hutan (pohon) kandungan hara serasah ini belum mencukupi sehingga perlu dikombinsikan dengan jenis lain seperti legum.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.