Surface Groundwater Research Articles

Impact of Improper Waste Disposal on Surface and Ground Water

Pollution in water occurs when harmful substance (often chemicals or biological) contaminate streams, river, lakes, oceans or other bodies of water, degrading water quality and rendering it unhealthy to humans, animal and the environment. The widespread problem of water pollution is jeopardizing our health. Water pathogens, in form of disease-causing bacteria and viruses from human and animal waste, are a major reason of illness from contaminated drinking water. Owing to the improper treatment facilities, waste is often discharged into the surface and ground water sources. Water bacteria can be limited by recycling used plastic, standard disposal of chemicals, oils or non-biodegradable items and proper collection and transportation of solid waste to a processed disposal site. In addition, waste water should be treated properly to prevent adverse health risk of the user of both surface water and ground water in the aquatic ecosystems.

An Urban Lake Drainage Catena: Influences of Terrain, Soils, and Precipitation

Urban lake drainage systems are heavily impacted by terrain, soil characteristics, and precipitation, which influence water infiltration and groundwater movement. This study focused on the drainage catena around Lake Nokomis in Minneapolis, Minnesota, where local residents have experienced wet basements and yards. The primary goal was to identify the factors contributing to these water-related problems, particularly soil permeability and how it responds to precipitation. By conducting soil borings, using pressure transducers, and measuring saturated hydraulic conductivity (Kfs), the study compared upland and lowland areas. Findings indicated that upland soils, primarily composed of sandy fill, had much higher infiltration rates, with Kfs values ranging from 72.4 cm/hr to 149 cm/hr. In contrast, lowland areas characterized by lacustrine and organic soils exhibited significantly lower Kfs values, ranging from 1 cm/hr to 14.8 cm/hr. Between 2022 and 2024, wet and dry seasons occurred, yet recorded more than 127.5 cm of rain and snow water equivalent, further contributing to groundwater rise and surface water presence in low-lying regions. The study concluded that increased precipitation, coupled with specific hydrogeologic conditions, was the main factor causing elevated groundwater levels and surface saturation in these areas. To address these challenges, Minnesota's water management authorities are encouraged to implement strategies that consider the increasing magnitude and intensity of precipitation events due to climate change. Incorporating hydrogeologic assessments into urban planning is recommended to better manage water infiltration, reduce flood risks, and strengthen the resilience of drainage systems to changing climate patterns.

Understanding Water–Rock Interaction in Crystalline Shield Fluids Using Calcium Isotopes

Calcium isotopes provide a potentially robust tool for understanding the evolution of crystalline shield fluids, but previous applications have focused on near surface groundwaters. The tendency of Ca isotopes to be affected by mass-dependent fractionation during processes such as water–rock interaction provides a powerful tool for studying the evolution and origin of groundwaters hosted in crystalline rocks. We report Ca isotope ratios (δ44/40Ca) of deep fluids (>300m) from across the Canadian Shield and integrate these with Sr and Br isotope values to understand long-term fluid–rock interactions in crystalline shield environments. Ca isotope ratios have a wide range of values from 0.07‰ to 0.86‰. At individual sites, δ44/40Ca values are variable whereas 87Sr/86Sr ratios are relatively constant. Sr isotope ratios (87Sr/86Sr) have a negative relationship with the Ca vs. Na content of the fluid indicating different host-minerals contributing Sr to the fluid. Ca isotope fractionation was caused by metamorphic reactions and by the growth and dissolution of Ca-rich fracture-filling minerals. The δ44/40Ca signatures of these processes are overprinted by radiogenic ingrowth of 40Ca by decay of 40K, which is expected to affect older and more K-rich rocks. At one site, δ44/40Ca and δ81Br variability reflects gas-generating reactions in the fluid and/or water–rock interaction processes. These new results demonstrate the strength of combining multiple isotope analysis to elucidate the sources of groundwater salinity and decipher the complex long-term processes that occur in crystalline shield environments.

Practical Remediation of Hg-Contaminated Groundwater by MoS2: Batch and Column Tests.

Trace mercury contamination in groundwater poses a serious threat to ecological systems and human health. The kinetics and isotherms of MoS2 (MS) for Hg removal were studied in batch tests under an unfavorable high salinity and low mercury environment. Flower-like MS with nanosheets can effectively remove Hg in the groundwater matrix, with a shorter equilibrium time (3 h), superior removal efficiency (94.26%), excellent distribution coefficient (5.69 × 106 mL g-1), and higher maximum adsorption capacity (926.10 ± 165.25 mg g-1). Furthermore, the Adams-Bohart model (R2 = 0.9052-0.9416) can accurately describe the dynamic interception process of the initial stage (≤40 PVs), and the Yan model (R2 = 0.9765-0.9941) depicts the whole process (140 PVs) of MS in a fixed column well. A higher dosage of m, but lower C0 and νp facilitate the interception efficiency in column tests. Based on the characterizations of X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), which were used to simultaneously consider the species of Hg and the groundwater matrix, surface complexation, electrostatic attraction, ion exchange, and precipitation is a plausible interfacial adsorption mechanism of MS for mercury. The excellent performance demonstrates that MS with nanosheets is a promising candidate for the PRB remediation of trace Hg in saline groundwater.

Growth Increase of Gelam (Melaleuca Leucadendron) Burnt Peatland Through the Provision of Soil Conditioner (Study in Londerang Peat Protection Forest)

The protected forest of Londerang Jambi is an area of hydrological unity with a surface area of 12.484 ha that is located in the district of Tanjung Timur and Muaro Jambi, which is surrounded by palm plantations and forest of industrial crops and 10 villages in the Districts of Tanjung Jabung Timur and Jambi. Based on the results of the Landsat 8 OLI image analysis and the SPOT 7 image interpretation by WWF Indonesia in 2015 that the Londerang Forest Protection Area (HLG) has an area of 12.848 Ha, currently the steep vegetation cover that canopies closely on the HLG Londerang remains only less than 10% of the area of HLG londerang due to forest fires in 2015. An attempt to overcome the situation has been made, one of them in the HLG Londerang being made an of the Hydrological Union of Mendahara-Sungai Batanghari which has been intervened by the Badan Restorasi Gambut (BRG). This effort was also carried out by the KIFC (Korea Indonesia Forest Center) by revegetating the blocks of land that had been burned in HLG Londerang. The planting has been carried out from the beginning of 2022 to December 2022. The species of plants planted among them are Pulai Rawa (Alstonia scholaris), Balangeran (Shorea balangeran), Gelam (Melaleuca leucadendron). In order to support the success of the revegetation, intensive maintenance is required, including the provision of soil fertilizers such as dolomite and NPK fertilizer. The research was conducted for seven months from May to December 2023 at HLG Londerang. Measuring fields are made with group random designs (RAK). The clustering is based on the difference in the height of the groundwater surface

Historical patterns of well drilling and groundwater depth in Arizona considering groundwater regulation and surface water access

Historical patterns of well drilling and groundwater depth in Arizona considering groundwater regulation and surface water access

Comprehensive, Multi‐Scale Evaluation of Field Methods for Assessing Stream–Aquifer Interactions Along Channelised Lowland Streams

ABSTRACTStream–aquifer interactions (SAIs) play a critical role in effective groundwater management, yet their complex dynamics remain poorly understood in channelized lowland perennial streams. This study presents a multi‐scale, multi‐technique investigation of SAIs along two long‐stream reaches in Tennessee, United States. The goal is to define a suitable methodology for characterising SAIs in this specific hydrological setting, serving as a starting point for developing a more standardised and replicable approach. The methodology includes an initial evaluation of various field techniques, followed by extensive surveys using potentiomanometers, electromagnetic induction (EMI), vertical temperature profilers (VTPs) and complementary methods such as seepage meters, bank tests and well‐data analyses. Results reveal distinct hydrogeomorphic behaviours across and along the streams, challenging the SAI‐homogeneity notions typically assumed in groundwater models. Nonconnah Creek exhibited streambed colmation and negligible hydraulic gradients, resulting in disconnection from the aquifer during low flows, except for a 300‐m losing reach with high downward gradients. In contrast, the Loosahatchie River displayed relatively homogeneous streambed properties and small, upward hydraulic gradients, suggesting uniform SAIs along the surveyed reaches. EMI proved highly effective for mapping streambed sediments quickly, while potentiomanometers accurately measured small head differences critical for understanding SAI dynamics. VTPs were less practical due to the extended data‐collection times required and their vulnerability to flooding. This study emphasises the importance of multi‐scale investigations using diverse techniques to accurately characterise SAIs in lowland streams, highlighting the confounding influences of geological formations, anthropogenic alterations and depositional processes on groundwater–surface water interactions. The findings contribute to refining local water balances, informing groundwater management strategies and underscoring the need for incorporating local‐scale field data into regional groundwater models. The proposed methodology serves as a foundation for developing a standardised approach for characterising SAIs in lowland channelized perennial streams, adaptable for similar stream systems worldwide.

The Effect of Chicken Bones Powder Adsorbent Mass and its Contact Time on Reducing Color Concentration in Peat Water Treatment

Peat water is surface water or ground water which is found abundantly in tidal, swampy and lowland areas. It has a reddish-brown color, with an acerbic taste (high acidity), and has a high organic content. Peat water can be treated using the adsorption method. Adsorption is a physical phenomenon in which the molecules of the adsorbed material are attracted to a solid surface, which acts as an adsorbent. In this study, the authors used the adsorption method to reduce the color concentration of peat water using activated chicken bones powder as an adsorbent and observing the changes that occur when mass of powder to the amount of 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, 1.5 and 2.0 grams were added to 50 ml of peat water with contact time that varied from 20, 30, 40, 50 and 60 minutes. From this study, we conclude that the optimum yield was obtained when the mass and contact time were at 0.5 grams and 40 minutes, which yield a percentage of reduction of 95.59%, wherein the initial color concentration of peat water at 337.816 was reduced to 14.89 Pt-Co, which is in line with the standard color for clean water as specified in a Regulation by the Minister of Health of the Republic of Indonesia No. 492/MENKES/PER/IV/2010, which state the standard color for clean water is 15 Pt-Co.

Uranium isotopes and several heavy elements in selected waters in Quang Nam-Da Nang provinces, Central Vietnam

238U and 234U concentrations, 238U/234U ratios and Na, Ca, Mg, K, Al, As, Cd concentrations were measured in selected surface waters (streams, rivers and lakes), ground waters (dug wells) and underground waters (drill wells and thermal waters) in Quang Nam and Da Nang provinces, Central Vietnam. The mineralization was < 500 mg L−1 and Al, As, Cd contents were a few tenths of µg L−1. 234U and 238U activities were between 0.47–27.6 mBq L−1 and 0.6–15.0 mBq L−1 respectively, these values are lower than WHO recommended limits. Uranium contents trended as Urivers < Ustreams < Ulakes < Udig wells < Uthermal water < Udrill wells. The 234U/238U ratio ranged from 0.69 to 2.31 with 1.26 on average. For groundwaters, the ratio scattered around one. Effects of Nong Son uranium deposit located in Quang Nam region were not observed.

Optimisation of open pit slope design considering groundwater effects using particle swarm optimisation and scaled boundary finite element method

Slopes are a crucial structures in open pit mines. Their design has implications on the economic, safety and environmental operation of the mining industry. Designing stable slopes can be challenging due to the complexities introduced by the stratigraphy and hydrology of the strata. With rising commodity costs and inflation rates, mining operating costs are increasing. Reducing operational costs is necessary for mining industries to remain competitive. While steepening the pit slope can decrease stripping materials and save money, it also increases the risk associated with slope surges. Therefore, optimising slopes is crucial for both financial and safety reasons. Numerical models such as the finite element method experience challenges in mesh generation of heterogeneous systems characterised by varying material properties and stratigraphies. Moreover, the need for repetitive geometry update necessitates recursive mesh regeneration that increases the computational burden. Moreover, previous slope optimisation studies focus solely on dry conditions. To consider the complex condition of hydrology along with heterogeneity in the soil stratigraphy, this study develops an optimisation procedure by combining the particle swarm optimisation algorithm and the scaled boundary finite element with an image-based meshing technique to optimise slopes with groundwater and achieve the desired factor of safety (FoS). The method changes the slope design parameters and the phreatic surface of groundwater simultaneously, considering user-defined parameters while iteratively re-meshing the optimisation processes. Several cases are presented, demonstrating the optimisation of bench width, bench angle, backfill parameters, and groundwater pumping levels.

Model simplification to simulate groundwater recharge from a perched gravel-bed river

Gravel-bed rivers are an important source of groundwater recharge in some regions of the world. Their interactions with groundwater are complex and highly variable in space and time, with considerable water storage in the riverbed sediments. In losing river sections, where most of the groundwater recharge occurs, the river can be separated from the regional groundwater system by an unsaturated zone (i.e., perched). The complexity of groundwater–surface water interactions in these environments calls for the use of 3D fully integrated hydrological models to represent them, but their computational intensity limits their practicality for parameter inference, uncertainty quantification and regional scale problems. On the other hand, the simple groundwater–surface water exchange functions currently implemented in regional scale groundwater models are not suited to represent complex gravel-bed river systems such as braided rivers. There is therefore a need for developing groundwater–surface water exchange functions tailored to gravel-bed rivers that can be used in regional scale models.To address this issue, we developed a model simplification framework that combines a 3D integrated surface and subsurface hydrological model, a 2D cross-sectional river-aquifer model and a 1D conductance-based analytical model. We aim at broadly simplifying the 3D model while ensuring the appropriate simulation of groundwater recharge. We demonstrate our modelling approach on the Selwyn River (New Zealand) using piezometric data and groundwater recharge estimates derived from field observations and satellite imagery.Our results indicates that groundwater recharge from this river can be simulated using a simple 1D analytical model, which can easily be implemented in regional groundwater models (e.g., MODFLOW models). However, to represent properly the time variability of groundwater recharge, it is essential to use the groundwater level in the shallow aquifer associated with the river as input to the regional groundwater model. Our approach is generally transferable to other gravel-bed rivers but requires some observations of river losses for proper calibration.

Numerical modeling of transient water table in shallow unconfined aquifers: A hyperbolic theory and well-balanced finite volume scheme

We present a new methodology capable of modeling transient motion of shallow phreatic surface of groundwater in unconfined aquifers. This methodology is founded on a new and comprehensive theory for water table motion and a corresponding efficient numerical scheme. In the theoretical aspect, we derived a new set of governing equations constituted by a depth-averaged continuity equation and momentum equations based on unsteady Darcy’s law. The derived governing equations are of the hyperbolic type and possess stiff terms in the momentum equations due to the inertia motion in a characteristic time scale that is relatively shorter than the time scale of seepage motion. To effectively solve the derived hyperbolic system with stiff terms, in the numerical aspect, we utilize f-wave propagation algorithm, an explicit finite volume method, that can ensure numerical convergence and well-balancing solutions when momentum is rapidly relaxing to an equilibrium of steady state. Verification is successfully performed by comparing the results with analytic solutions to the classic problem of multidimensional spreading of a groundwater mound. This study demonstrates that the proposed methodology can accurately and satisfactorily simulate the spatiotemporal distribution of shallow water table and its wetting front in unconfined aquifers.

Megacity solid waste disposal suitability mapping in Dhaka, Bangladesh: an integrated approach using remote sensing, GIS and statistics.

Selecting suitable Megacity Solid Waste Disposal (MSWD) sites is a challenging task in densely populated deltas of developing countries, exacerbated by limited public awareness about waste management. One of the major environmental concerns in Dhaka City, the world's densest megacity, is the presence of dumps close to surface water bodies resources. This study employed the Geographic Information System (GIS)-Analytic Hierarchy Process (AHP) framework to integrate geomorphological (slope and flow accumulation), geological (lithological and lineament), hydrogeological (depth to groundwater table and surface waterbody), socioeconomic (Land use land cover, distance to settlement, road, and airport), and climatological (wind direction) determinants, coupled by land-use and hydro-environmental analyses, to map optimal dumps (MSWDO) sites. The resulting preliminary (MSWDP) map revealed 15 potential landfill areas, covering approximately 5237 hectares (ha). Combining statistical analysis of restricted areas (settlements, water bodies, land use) with AHP-based ratings, the MSWDO map revealed two optimal locations (2285ha). Additionally, the hydro-environmental analysis confirmed the unsuitability of northern sites due to shallow groundwater (< 5.43m) and thin clay, leaving 11 options excluded. Sites 12 (Zone A, 2255ha) and 15 (Zone B, 30ha), with deeper groundwater tables and thicker clay layers, emerged as optimal choices for minimizing environmental risks and ensuring effective long-term waste disposal. This study successfully integrates remote sensing, geospatial data, and GIS-AHP modeling to facilitate the development of sustainable landfill strategies in similar South Asian delta megacities. Such an approach provides valuable insights for policymakers to implement cost-effective and sustainable waste management plans, potentially minimizing the environmental risks to achieve Sustainable Development Goals (SDGs) 6, 11, 13, and 15.

Climate change induced salinization and quality deterioration of groundwater resources in Pakistan; Current scenario and future prospects

Climate change has triggered various catastrophic events including groundwater salinization resulted in quality deterioration worldwide leading to the environmental degradation and posed threat to natural ecosystems. Pakistan is among the countries severely affected by the climate change. Most of the Pakistani depends on groundwater resources for drinking and irrigation purposes but no clear policy exists regarding judicious extraction and usage of groundwater. Over extraction and exploitation of groundwater along with climate change events have deteriorated the quality of groundwater in Pakistan and most of the part is salinized and has excess of soluble salts and other chemical, physical and biological contaminants. This paper reviews the impacts of climate change on salinization and groundwater quality and possible remedies and solution for this problem especially with the perspective of Pakistan. It is the need of the hour of the time to introduce climate smart agricultural practices at farmer level to stop overexploitation of natural resources and to reduce the agriculture share to climate change. Policies should be developed and existing policies should be strictly implemented for the judicious use of surface water and ground water resources to avoid the risks of water scarcity in near future.

Synthesizing vulnerability indices within a diverse lithological context: Corollaries for groundwater quality assurance and surface layer corrosiveness of Lokoja Geomaterials, Nigeria

ABSTRACT This study provides prototypical evaluation of groundwater vulnerability to contamination and soil corrosivity in Lokoja region, central Nigeria. By combining the aquifer vulnerability index, integrated electrical conductivity, groundwater confinement overlying strata depth to water table (GOD), and electrical anisotropy coefficient (λ) derived from lithological composition, resistivity, and layer thickness; the study identifies substantial vulnerabilities in the groundwater resources. Findings indicate that over 70% of the region is moderately to very highly vulnerable to groundwater pollution, especially in the eastern and southern parts, highlighting the need for tailored groundwater management strategies in highly vulnerable areas, covering 40% of the region. Corrosion potential varies spatially, with 80% of the upper layer being minimally corrosive and around 45% of the lower moisture-rich layer showing moderate to significant corrosiveness, emphasizing risks in central and northern zones associated with lithological compositions and moisture content. These accentuate the necessity of rigorous monitoring programs and strict land use regulations to protect aquifers and infrastructure. This research underscores the value of proactive management for safeguarding groundwater resources, providing an invaluable framework for decision-making and resource allocation to tackle contamination and corrosion risks. Importantly, the research addresses a significant research gap in a region with limited scientific exploration.

Persepsi Pengrajin dalam Pengelolaan Limbah Cair Batik Kabupaten Bojonegoro

Batik waste is waste produced from batik producing activities which can have a negative impact. In general, the process of making batik will channel wastewater into the surrounding air which causes various pollution, including color changes, increased pH, COD, BOD, TSS, odors, changes in the taste of the air, soil and ground air pollution, and the influence of chemicals on the bodies of plants, animals and humans. Craft perceptions relate to batik waste management, including knowledge, awareness and economic limitations. The research method approach applied is to use a quantitative descriptive approach. The research location is in the center of the small and medium batik industry (IKM) in Bojonegoro Regency. There are 10 batik SMEs as a complete sample of the population. The method used to measure craftsmen's perceptions is the Likert Scale. As many as 100% of the community felt the benefits in the form of a source of income, opening up employment opportunities, preserving local culture and so on. The level of public perception regarding the benefits of batik wastewater management was obtained: 80% agreed that wastewater management could reduce surface air, soil, groundwater and air pollution, 70% could expand the product market, and 100% strongly agreed that it could reduce the cost of purchasing candles. The community agrees that managing IPAL requires expensive investment and maintenance costs, as well as skilled human resources. Changes in air color, odor and causing cancer, decreased DO, air surface quality, ground water and soil are also threats if batik wastewater is not managed. The community quite agrees that there will be a decrease in soil fertility, and the killing of air and soil organisms can occur if wastewater pollution occurs. The level of public perception reaches 100%, the need to carry out socialization and training for IPAL operators and inadequate human resources are challenges in managing batik waste. Another aspect to consider is inadequate economic conditions and low awareness of craftsmen.

A distributed modeling approach to water balance implications from changing land cover dynamics in permafrost environments

There is 78 % permafrost and seasonal frozen soil in the Yangtze River’s Source Region (SRYR), which is situated in the middle of the Qinghai-Xizang Plateau. Three distinct scenarios were developed in the Soil and Water Assessment Tool (SWAT) to model the effects of land cover change (LCC) on various water balance components. Discharge and percolation of groundwater have decreased by mid-December. This demonstrates the seasonal contributions of subsurface water, which diminish when soil freezes. During winter, when surface water inputs are low, groundwater storage becomes even more critical to ensure water supply due to this periodic trend. An impermeable layer underneath the active layer thickness decreases GWQ and PERC in LCC + permafrost scenario. The water transport and storage phase reached a critical point in August when precipitation, permafrost thawing, and snowmelt caused LATQ to surge. To prevent waterlogging and save water for dry periods, it is necessary to control this peak flow phase. Hydrological processes, permafrost dynamics, and land cover changes in the SRYR are difficult, according to the data. These interactions enhance water circulation throughout the year, recharge of groundwater supplies, surface runoff, and lateral flow. For the region’s water resource management to be effective in sustaining ecohydrology, ensuring appropriate water storage, and alleviating freshwater scarcity, these dynamics must be considered.

Groundwater drought risk assessment in the semi-arid Kansai river basin, West Bengal, India using SWAT and machine learning models

Increasing concerns over groundwater drought risks, which threaten water availability and adversely impact ecosystems, agriculture, and human activities, underscore the necessity of comprehensive evaluation methods. This research introduces a meticulous approach to evaluating groundwater drought risk (GWDR) in the semi-arid expanse of the Kansai River Basin, West Bengal, India. It intricately amalgamates the Soil and Water Assessment Tool (SWAT) model with three distinct machine learning algorithms namely, Support Vector Machine (SVM), Random Forest (RF), and Neural Networks (NN). The assessment relies on a diverse array of 26 thematic datasets encompassing hydrological, meteorological drought risk, and socioeconomic conditioning variables. The SWAT model has been used to derive hydrological parameters including groundwater recharge, lateral flow, base flow, surface runoff, evapotranspiration, return flow, and soil water content. Simultaneously, a pre-monsoonal water level dataset from 503 well locations is adhered to an impartial sampling strategy, maintaining a 70:30 ratio for training and testing datasets. The ensuing GWDR maps, derived through SVM, RF, and NN models, reveal four discerning risk classes across the study area. High-risk zones conspicuously predominate in upper catchment areas, while low-risk zones find their strategic position in the lower catchment regions. The area under the receiver operating characteristic curve (AUC-ROC) for the RF model, showcases an impressive 91% success rate, surpassing its counterparts SVM and NN models, which attained success rates of 88.4% and 80.7%, respectively. The Mann–Kendall test with Sen's slope analysis confirms a noticeable decline in groundwater levels within high to moderately high GWDR zones, supporting the study's findings. These findings significantly impact water resource management in semi-arid regions, emphasising the need for proactive measures to address evolving groundwater drought risks.

Characterization and Mapping of the Potential Area of Oil Palm Using Multi-Criteria Decision Analysis in a Geographic Information Systems Environment

This study presents a GIS-based Multi-Criteria Decision Analysis (MCDA) spatial model to assess land suitability for oil palm (OP) cultivation in rainfed conditions. Initially, twelve parameters, viz., rainfall, number of rainy days, mean temperature, RH, ground water level, soil pH, salinity, soil depth, surface texture, stoniness, slope, and drainage, were selected for assessing OP suitability in one of the states (Kerala). However, subsequent ground verification revealed significant discrepancies, which prompted refining the model by focusing on key parameters with greater accuracy and relevance. Accordingly, only five the most critical parameters affecting OP cultivation under rainfed conditions were selected through the rank sum method, and weights were assigned ac-cording to their significance. This study was aimed at creating a comprehensive tool for informed decision making in agricultural planning. District-level spatial data from reliable sources were utilized for Multi-Criteria Decision Analysis. Thematic rasters, representing key factors influencing land suitability, were created in a GIS. Utilizing MCDA techniques, a digital suitability map was generated in ArcGIS 10.3, delineating three distinct classes over an extensive area of 10.5 million hectares. Further, with an aim to focus on actual locations that can be readily planted with oil palm, the suitable locations identified were restricted to eight selected land use/land cover (LULC) classes. This strategic limitation aimed to facilitate the expansion of OP cultivation exclusively to areas deemed most suitable based on the identified criteria. The validation of this developed model involved comparing the suitability map generated with the performance of existing oil palm plantations across diverse locations. The reasonable similarity between the model’s predictions and real-world plantation outcomes validated the effectiveness of this MCDA spatial model. This model not only helps identify suitable locations for rainfed oil palm cultivation but also serves as a valuable tool for strategic decision making in agricultural land use planning.

Effects of hydraulic conductivity on simulating groundwater–land surface interactions over a typical endorheic river basin

Hydraulic conductivity is the key variable in subsurface configuration that is important in modeling groundwater and its interactions with land surface processes. However, an acquisition of quantitatively distributed hydraulic conductivity is challenging due to limitations on data availability, accuracy and resolution, which inhibits an advanced understanding of hydrologic and energy cycles at the basin scale. This study investigated the role of hydraulic conductivity in simulating groundwater-land surface interactions over a typical endorheic river basin in northwestern China. A 3D variably saturated groundwater model coupled to a land surface model was configured to account for interactions between groundwater dynamics and land energy fluxes. Four scenarios of hydraulic conductivity were tested and inter-compared, adopting both homogeneous and heterogeneous parameterization strategies based on Global Soil Dataset for use in Earth System Models (GSDE) and HYdrogeology MaPS (GLHYMPS). The overall objectives are to diagnose effects of hydraulic conductivity on simulating groundwater–land surface interactions, with a particular focus on differences in spatial distributions and statistical characteristics between scenarios, as well as the dynamics and feedback mechanisms between groundwater and land surface energy fluxes. Comprehensive simulations and analyses were conducted to discern spatial distributions and statistical characteristics of key hydrological variables (streamflow, water table depth, latent heat flux, sensible heat flux) under different scenarios. Results showed that the hydraulic conductivity of the saturated zone had a significant control over water table depth, while the combine hydraulic conductivity in the vadose zone and the saturated zone governed the evolution of streamflow. Moreover, the water table critical range—where the land energy budget is highly sensitive to groundwater table—was 0.1 m–5 m and the area might expand approximately 4.5 % after considering the heterogeneity of hydraulic conductivity. Compared to the homogeneous scenario, the spatial heterogeneity of hydraulic conductivity amplified water table depth variability while diminishing land energy fluxes variability.