Identification of Waters Incorporated in Laguna Lake, Republic of the Philippines, Based on Oxygen and Hydrogen Isotopic Ratios

Abstract

Abstract:We examined the oxygen and hydrogen isotopic ratios of surface waters and groundwaters in the catchment of Laguna Lake, Republic of the Philippines, to identify the types of water that combine and control these ratios in the lake water. The oxygen and hydrogen isotopic ratios of water samples collected from rivers, lakes, springs, and irrigation canals were determined using cavity ring-down spectroscopy. The lake water data deviated from the meteoric line of the Philippines by between −13.5‰ and −10‰, and between −11.5‰ and −1.5‰ in the dry and wet seasons, respectively. The values for the groundwaters and surface waters were mainly between −8‰ and 3‰ throughout the year. In addition to rainwater, evaporative concentration, which may have an almost constant effect throughout the year, was the main control on the oxygen and hydrogen isotopic properties of Laguna Lake. The contributions of the surface waters and groundwaters to the oxygen and hydrogen isotopic ratios of the lake were relatively constant. Based on their isotopic properties, the waters within the water catchment area of Laguna Lake can be roughly divided into lake water with heavier isotopic ratios, and groundwater and surface water with lighter isotopic ratios.

Isotopes in Hydrology and Hydrogeology

“…Nine articles [3][4][5][6][7][8][9][10][11] look at the start of the hydrological cycle and its processes (including lake water balance), and at the origin of rainfall and its selection in groundwater recharge using characteristic, naturally occurring δ 2 H and δ 18 O signatures. Spatial and temporal modifications in hydrogen and oxygen isotopic compositions (δ 2 H and δ 18 O) could be associated to equilibrium exchanges occurring at all phase transitions and kinetic isotopic fractionation during the transformation from the ocean surface to the atmosphere, small rainfall amounts when raindrops fall below the cloud [3].…”

“…The chloride mass balance inferred that groundwater currently contributes more than 90% of the annual chloride loading to the lake, which is likely four times greater than the earlier period (1981-2000) with a lower groundwater input. Maruyama and Kato [9] examined the oxygen and hydrogen isotopic ratios of surface and groundwater in the catchment of Laguna Lake, Republic of the Philippines, to identify the types of water that combine and control these ratios in the lake water.…”

Identification of inrush water recharge sources using hydrochemistry and stable isotopes: A case study of Mindong No. 1 coal mine in north-east Inner Mongolia, China

“…The meteoric water line reveals the relationship between D and 18 O in rain and is regarded as a reference for the evaluation of relative enrichment or depletion in isotopic content, including evaporation, condensation and the mixing of two or more water bodies with different isotopes (Chen et al 2015;Maruyama and Kato 2017). In 1961, by analysing the isotopic data of global precipitation samples, Craig (1961) obtained the 'Global Meteoric Water Line' (GMWL).…”

“…The environmental isotope technique, especially stable isotopes (dD and d 18 O), has good performance in analysing the origin and formation of groundwater in the main aquifer (AQ). It can not only determine the interconnection between groundwater, precipitation and surface water, but also analyse the supply sources and mixture ratio of groundwater (Jiao et al 2014;Guo et al 2015;Maruyama and Kato 2017;Chafouq et al 2018;Joshi et al 2018;Xu et al 2018;Yi et al 2018). However, compared with the hydrogeochemistry method, isotope analysis is less used in coal mine enterprises independently due to its high cost, especially when there are more sample data.…”

Chlorophyll-a Concentration Retrieval Using Convolutional Neural Networks in Laguna Lake, Philippines

“…Field data collection campaigns were conducted by the Multi-platform and Cross-sensor Water Quality Monitoring (MCWQM) Project in seven different days starting from November 2018 to April 2019, covering wet season from June to November and dry season of other months (Maruyama, 2017). The Laguna Lake is divided into three regions, west, center, and east, covering west bay, central bay, and south & east bays, respectively, since it is impossible to cover the whole water bodies in only one campaign.…”