Temporal variation of water suitability for paddy irrigation needs at karst springs influenced by allogenic recharge in Gunungsewu Karst Area, Indonesia

Abstract

Irrigation, a critical element in farming, can fulfill crop water needs and increase agricultural productivity during the dry season, provided that the two necessary factors are met, namely water supply and water quality. Water quality is a principal factor in assessing whether or not a water body is usable as a source of irrigation. Excess or lack of elements in irrigation water may affect irrigated crops and soil. For maximum harvests, studies scrutinizing the suitability of water supply for irrigation become necessary. Beton Spring has a large discharge, which the people of Ponjong District, Gunungkidul Regency, rely on for their irrigation and fish farming practices. Uniquely, this karst spring receives allogenic recharges from outside the karst area. This research was intended to assess the suitability of water quality of Beton Spring for temporal irrigation purposes by Sodium analysis (Na%), Sodium Adsorption Ratio (SAR), USSL, and Wilcox. The elements observed in the analysis were Ca2+, Na+, Mg2+, K+ and electrical conductivity. Based on the overall analysis results of the water quality series—Sodium analysis (the water samples were classified as Excellent), SAR (Excellent), USSL (moderate to good), and Wilcox (Excellent to Good), Beton Spring produces good-quality water that is suitable for irrigation.

Karakteristik Hidrogeokimia dan Kualitas Air pada Mata Air Karst Selonjono Karst Gunungsewu Daerah Istimewa Yogyakarta

“…Hasil metode Schoeller sesuai dan memperkuat hasil klasifikasi piper diagram yang menunjukan Mataair Selonjono termasuk dominan Ca 2+ dan SO4 2-. Hasil diagram Schoeller Baik Mataair Beton dan Gremeng diperoleh pola yang berbeda dengan Mataair Selonjono yaitu didominasi Ca 2+ dan HCO3 - (Cahyadi et al, 2020;2020b;2021a;2021b;Ramadhan et al, 2021). Selain itu, Mataair Guntur memiliki hasil diagram Schoeller yang berbeda juga dengan Mataair Selonjono yaitu bertipe ion dominan Ca 2+ dan HCO3 - (Ramadhan et al, 2021) yang disebabkan akuifer karst pada wilayah tersebut sudah cukup berkembang.…”

“…Salah satu sistem hidrogeologi yang cukup jarang dilakukan kajian hidrogeokimia secara multitemporal adalah Sub Hidrogeologi Ponjong, terkhusus pada mataair yang tidak terpengaruh aliran sungai alogenik. Pada kajian sebelumnya telah dilakukan kajian hidrogeokimia multi-temporal pada mataair yang terpengaruh sistem alogenik misalnya oleh Cahyadi et al, (2020a;2020b;2021adan 2021b dan Tastian et al, (2022), selain itu juga dilakukan kajian hidrogeokimia pada sungai bawah tanah dan gua (Adji et al, 2017b). Kajian hidrogeokimia secara temporal musim penghujan dan kemarau juga cukup jarang dilakukan pada mataair yang tidak disuplai oleh sungai alogenik.…”

Temporal Variation of Phosphate Contamination In Tropical Epikarst Springs, Gunungsewu Karst Area, Indonesia

“…Karst is a landscape with distinctive hydrological systems that play a vital role in clean water provision [1,2]. Another distinguishing feature is the dissolution process that creates conduits (a type of secondary porosity), even though water still oftentimes moves through intergranular pores via diffusion that are developing in soluble rocks [3,4].…”

Hydrogeochemistry of Epikarst Spring During Rainy Seasons in the Ponjong Hydrogeological Subsystem, Gunungsewu Karst Area, Indonesia

“…The Gunungsewu Karst Area is one of the karst landscapes in Indonesia that has a substantial role in the provision of water resources. It is the most studied karst * Corresponding author: aulianisa01@mail.ugm.ac.id region in relation to hydrogeochemical characteristics of water originating in karst aquifers [9,10,11,12].…”

“…However, research on epikarst springs dominated by high diffuse flow is still rare [13]. Most studies in the area are centered on underground rivers and springs with large flow rates that are fed by allogenic rivers [9,10,11,12].…”