Conservation Of Groundwater Resources Research Articles

AquMADE: A GIS-based web application to assess groundwater quality by introducing a risk-based irrigation water quality index (RB-IWQI)

Groundwater quality monitoring plays a vital role in effective water management across all groundwater basins. The provision of decision support systems can assist decision-makers in strategic planning and the conservation of groundwater resources. In this study, AquMADE—a user-friendly and comprehensive web application—is developed to integrate GIS and multi-criteria decision-making methods seamlessly for modifying the irrigation water quality index. AquMADE serves multiple functionalities. Firstly, it empowers decision-makers to import, interpolate, and visualize collected data, enabling a holistic view of the information at hand. Secondly, it offers the flexibility for decision-makers to adjust the weights of various parameters through the utilization of the analytical hierarchy process, taking into consideration their risk attitudes during the aggregation process using ordered weighted averaging method. Finally, the incorporation of sensitivity analysis methods allows for the evaluation of the impact of changes in inputs, such as criteria weights and aggregation methods, on the resulting outputs. The system underwent user testing in Khoy City, Iran, where it received positive feedback. The assessment revealed that the system performed satisfactorily in terms of functionality, interactivity, and ease of use.

Evaluating sustainability of Bhuj aquifer system, Western India using nuclear dating techniques

Abstract Increasing population, food demands and climatic stressors pose an imminent threat to groundwater sustainability in regional aquifer systems globally. Limited availability of surface water and erratic/uncertain rainfall necessitates preservation of groundwater resources, which form reliable fresh water reserves in most of the arid regions. Bhuj Sandstone aquifer is one such fresh groundwater systems in Western India catering the domestic/irrigational needs for over 2 million population. Rapid groundwater depletion in this area warranted a mandatory conservation of groundwater resources for future sustainability. Nuclear techniques using 3H and 14C provide estimates of groundwater age that help in planning sustainable groundwater management. In this study, sustainability of deep groundwater was assessed using environmental radioactive isotopes (3H, 14C). Results indicate that 14C activity of the groundwater samples varies from 26 to 73.6 pMC (percent modern carbon). Considering the various biases and uncertainties present, multiple correction models were applied to obtain representative groundwater ages by incorporating stable (13C) isotope and hydrogeochemical data. The corrected and representative ages are found to range from 5.8 to 8.6 ka BP (thousand years before present). From the study it can be inferred that central Bhuj aquifer hosts paleo-groundwater while the western part is recently recharged. Therefore, over-exploitation of deep groundwater in central Bhuj aquifer may further lower the water levels and this would have long-term impact on the socio-economic development of Kutch region.

먹는 샘물에 관한 연구동향 분석

The purpose of this study was to analyze the research trends related to drinking spring water and bottled water in this study and to suggest an expanded interpretation and direction for future research. 695 papers to be analyzed were collected by the Academic Research Information Service (RISS) with the keywords of drinking spring water and bottled water, and 117 final analysis papers were selected. For this, the publication status, research field, and research topic of drinking spring water research by year were analyzed. As a result of analyzing the research trend, it was confirmed that the number of publications of papers on drinking spring water research has gradually increased since the 2010s. The mainly studied fields were divided into business administration, chemistry, and environmental fields, and as a result of confirming the topics by research field, the most frequently addressed in the business administration field was mainly research on the effect of factors such as the selection attribute of drinking spring water and brand image on purchasing behavior. In this chemical field, research was mainly conducted on the characteristics of groundwater, changes in the microbiological quality of drinking spring water, and changes in the quality of drinking spring water, and in the environmental field, topics such as the improvement of the permitted intake of drinking spring water and the development and conservation of groundwater resources were dominated.

Multi-Criteria Evaluation (MCE) of Groundwater Prospect and Vulnerability Index Mapping from Second-Order Geo-Electric Indices: A Case Study of Coastal Environments

Exploration, management, and conservation of groundwater resources are critical stages toward potable water supply, driven by an expanding populace and the threat of a new norm posed by the distinctive coronavirus (COVID-19) pandemic. An in-depth assessment of the potential of groundwater reserves and susceptibility, using a multi-criteria evaluation, is required to aid in the planning of exploration programs for groundwater well location. Thirty (30) vertical electrical soundings (VES) were collected in Okerenkoko, Warri-Southwest, Delta State, to assess groundwater potential and vulnerability indicators. The VES data were used to obtain the first-order geoelectric variables, which were further exploited to calculate the geo-hydraulic parameters (hydraulic conductivity and transmissivity) and the vulnerability indices of the aquifer. For aquifer vulnerability appraisal, the AVI (aquifer vulnerability index), GOD (groundwater occurrence, overlying lithology, and depth to the aquifer), and GLSI (geoelectric layer susceptibility index) models were used. The groundwater characteristics in the area were evaluated using the aquifer resistivity, thickness, transmissivity and coefficient of anisotropy values of the aquifer layers defined from VES 1-30. The results show that aquifer layers with low resistivity favor more saturation due to immense porosity and therefore have greater groundwater potential than aquifers with high resistivity. The geoelectric structures defined by VES 1, 2 and 4 were consistent in their groundwater potential and yield judging from the multi-criteria assessments. The estimation of AVI, GOD, and GLSI models for aquifer threat assessment was facilitated by the multi-criteria evaluation of vulnerability indices utilizing hydro-geophysical parameters and index-based approaches. The models depend on the symbiotic effects of geologic array and thickness as the basis for the magnitude of conservation imparted to any particular aquifer involved. The AVI model map depicts that most of the VES locations were rated high (C between 1 and 2) to extremely high (C < 1), indicating that the aquifers at these locations are vulnerable to pollution. However, the extent of vulnerability observed in the GOD model is less than in the AVI model, as GOD accords much more inclination to the inherent properties of geologic entities. The GOD model map categorized the vulnerability index ratings in the area as negligible (0.0-0.1), low (0.1-0.3) and moderate (0.3-0.5), with most VES locations ranked low to moderate, which indicates that these locations are susceptible to vulnerability. In the GLSI model, individual overlying layer thicknesses were prioritized. The GLSI model map shows that the vulnerability index ratings in the area are ranked as moderate (2.00-2.99), high (3.00-3.99) and extremely high (≥ 4.00) with most of the VES locations ranked moderate to high with the exception of VES 27, which ranked extremely high in both AVI and GLSI indices. By correlating the results of vulnerability index valuation for the AVI, GOD and GLSI models, more correlation was observed between the AVI and GLSI models. These findings validate the adoption of a multi-criteria evaluation methodology for groundwater potential and aquifer vulnerability studies and are strongly recommended as practical criteria for locating subsurface aquifers and their protective measures for groundwater prospect development planning and management.

Delineation of suitable sites for groundwater recharge based on groundwater potential with RS, GIS, and AHP approach for Mand catchment of Mahanadi Basin

Groundwater management requires a systematic approach since it is crucial to the long-term viability of livelihoods and regional economies all over the world. There is insufficient groundwater management and difficulties in storage plans as a result of increased population, fast urbanisation, and climate change, as well as unpredictability in rainfall frequency and intensity. Groundwater exploration using remote sensing (RS) data and geographic information system (GIS) has become a breakthrough in groundwater research, assisting in the assessment, monitoring, and conservation of groundwater resources. The study region is the Mand catchment of the Mahanadi basin, covering 5332.07 km2 and is located between 21°42′15.525″N and 23°4′19.746″N latitude and 82°50′54.503″E and 83°36′1.295″E longitude in Chhattisgarh, India. The research comprises the generation of thematic maps, delineation of groundwater potential zones and the recommendation of structures for efficiently and successfully recharging groundwater utilising RS and GIS. Groundwater Potential Zones (GPZs) were identified with nine thematic layers using RS, GIS, and the Multi-Criteria Decision Analysis (MCDA) method. Satty's Analytic Hierarchy Process (AHP) was used to rank the nine parameters that were chosen. The generated GPZs map indicated regions with very low, low to medium, medium to high, and very high groundwater potential encompassing 962.44 km2, 2019.92 km2, 969.19 km2, and 1380.42 km2 of the study region, respectively. The GPZs map was found to be very accurate when compared with the groundwater fluctuation map, and it is used to manage groundwater resources in the Mand catchment. The runoff of the study area can be accommodated by the computing subsurface storage capacity, which will raise groundwater levels in the low and low to medium GPZs. According to the study results, various groundwater recharge structures such as farm ponds, check dams and percolation tanks were suggested in appropriate locations of the Mand catchment to boost groundwater conditions and meet the shortage of water resources in agriculture and domestic use. This study demonstrates that the integration of GIS can provide an efficient and effective platform for convergent analysis of various data sets for groundwater management and planning.

Groundwater Potential Mapping using Geospatial and AHP Techniques in Eastern Province of Rwanda

The article presents an analysis of the potential groundwater recharge zones in the Eastern Province of Rwanda using Geographic Information System (GIS) technology. The groundwater potential zones (GWPZs) in the area are influenced by several factors. To conduct the spatial analysis, seven theme layers were created and integrated, including geology, drainage density, rainfall, slope, soil, land use and land cover (LULC), and normalized difference vegetation index (NDVI). The Analytical Hierarchy Process (AHP), based on multiple criteria, was utilized to assign weights to each layer. By overlaying the theme layers with the prescribed weights, a map of potential groundwater recharge zones was generated. These zones were classified into five categories: poor, fair, medium, good, and excellent, representing 173 km2 (1.9 %), 1002 km2 (11.3%), 5976 km2 (67.2%), 1732 km2 (19.5%), and 12 km2 (0.1%), respectively. The findings revealed that a significant portion of the study area exhibited good to moderate potential zones for groundwater. Among the seven districts in the Eastern Province, Rwamagana district had the highest coverage of good and excellent groundwater potential zones, accounting for 59% and 1% of the area, respectively. The accuracy of the GWPZ map was assessed by comparing it with borehole yield data, demonstrating the reliability of the chosen methodology. These validated results provide valuable support for the sustainable management and strategic utilization of groundwater resources in the study area. The study outcomes can guide decision-makers in making informed choices regarding the conservation of groundwater resources in the research area.

Constructing GRACE-Based 1 km Resolution Groundwater Storage Anomalies in Arid Regions Using an Improved Machine Learning Downscaling Method: A Case Study in Alxa League, China

Using the Gravity Recovery and Climate Experiment (GRACE) satellite to monitor groundwater storage (GWS) anomalies (GWSAs) at the local scale is difficult due to the low spatial resolution of GRACE. Many attempts have been made to downscale GRACE-based GWSAs to a finer resolution using statistical downscaling approaches. However, the time-lag effect of GWSAs relative to environmental variables and optimal model parameters is always ignored, making it challenging to achieve good spatial downscaling, especially for arid regions with longer groundwater infiltration paths. In this paper, we present a novel spatial downscaling method for constructing GRACE-based 1 km-resolution GWSAs by using the back propagation neural network (BPNN) and considering the time-lag effect and the number of hidden neurons in the model. The method was validated in Alxa League, China. The results show that a good simulation performance was achieved by adopting varying lag times (from 0 to 4 months) for the environmental variables and 14 hidden neurons for all the networks, with a mean correlation coefficient (CC) of 0.81 and a mean root-mean-square error (RMSE) of 0.70 cm for each month from April 2002 to December 2020. The downscaled GWSAs were highly consistent with the original data in terms of long-term temporal variations (the decline rate of the GWSAs was about −0.40 ± 0.01 cm/year) and spatial distribution. This study provides a feasible approach for downscaling GRACE data to 1 km resolution in arid regions, thereby assisting with the sustainable management and conservation of groundwater resources at different scales.

Groundwater recharge in typical geomorphic landscapes and different land use types on the loess plateau, China

AbstractLand use significantly affects the rate and amount of groundwater recharge. To understand these patterns, stable isotope analyses (δ2H and δ18O) and hydrochemical methods were employed to study the recharge and evolution of groundwater. MixSIAR Bayesian mixture modelling and statistical regression techniques were utilized to investigate the influence of land‐use type on groundwater recharge and to calculate the contribution of various water sources to different groundwater types. These findings are important for effective management and conservation of groundwater resources. The groundwater in all studied areas displayed a magnesium bicarbonate type with notable cation exchange, and also demonstrated the dissolution of carbonate and weathering of silicate. Results from the Bayesian mixture model indicate that 69.3% of the groundwater in the Loess Plateau region was recharged by precipitation, while 86.9% of the groundwater in the loess hilly‐gully region was recharged from the surface water. Groundwater recharge was more rapid in the loess hilly‐gully region than in the Loess Plateau and was less sensitive to the land use type in the former. Dryland‐moderate coverage grassland was found to be most conducive to groundwater infiltration, whereas monotypic dryland and high‐coverage grassland inhibited infiltration to some degree. To maintain balanced soil erosion control, an increase the area of moderate‐coverage grasslands in the Loess Plateau region is recommended.

Spatiotemporal Analysis of Groundwater Resources in the Saïss Aquifer, Morocco

In recent decades, the Saïss plain, in the northwest of Morocco, has experienced a noticeable increase in water demand due to a very significant population growth and economic development, as well as the climate change effects. With the aim of reaching optimal and dynamic management of these water resources, it is essential to have comprehensive and reliable information on the state of the aquifer systems in the region. To achieve this, we assessed a geostatistical analysis of groundwater level data, and created a multivariate regression model. Indeed, in this study, a spatiotemporal analysis of groundwater depth based on piezometric measurements of 45 wells was carried out for the period from 2005 to 2020. It compares and evaluates eight geostatistical interpolation methods and solves the problem of data gaps of the piezometric measurement by completing the chronological series of the groundwater level between 2005 and 2020 using the ARIMA model. The results demonstrate that the variation in the groundwater level between 2005 and 2020 indicates that the water table level is decreased in certain areas, but it has improved or remained constant in other areas. These results emphasize an urgent need for a dynamic management for the conservation of groundwater resources in certain areas of the region under this study.

Assessment of morphometric characteristics and decadal fluctuation of groundwater level of Kali River basin and its link with climate change, West Uttar Pradesh, India Using Geographical Information System

The Kali River is a sixth-order tributary of the Ganga River. It originates near Khatoli town in Muzaffarnagar and confluences with the Ganga River at Kanauj District, Uttar Pradesh. In this study, drainage morphometry, temporal groundwater level observations and precipitation data are used to examine surface and subsurface hydrological conditions. Survey of India topographic maps has been used to identify the basin characteristics based on their 1:50,000 scale. The groundwater and precipitation data were obtained from the Indian Meteorological Department and the Indian Water Resources Society. The basin area was calculated about 11,470 sq. km with an NW-SE sloping. In addition, it is elongated-shaped with a dendritic pattern. The bifurcation ratio (5.06), drainage density (0.65), stream frequency (0.24) and ruggedness number (0.09) show strongly permeable alluvium, low relief, high infiltration rate, least erodible and high permeability. The basin reflects a relationship between spatio-temporal groundwater level and rainfall (~21 years: 1996 to 2017). According to this study, the water level declined at a rate of 124.7 meters per year as a result of excessive groundwater use and climate changes such as a decrease in precipitation rates around the area. Therefore, it is recommended to conservation of groundwater resources in the future.

Use of Digital Elevation Models to Map Out The Groundwater Resources Base Of Kuje Area to Federal Capital Territory, Abuja, Nigeria


 
 
 This research work examined the use of digital elevation model in the evaluation of groundwater resources in Kuje Area, Nigeria. This was achieved through the acquisition of topographic maps, Digitization of the topographic maps which were glued and interpolated to generate Digital Elevation Models (DEM) and Mapping of groundwater potential areas using ArcGIS 9.2 and ArcView 3.2a software. Findings from this research show that the study area have elevations ranging from 333 m to 429 m above sea level with a moderate groundwater potential in areas with elevation ranging from 286 m and 333 m above sea level. Some areas also have ground water problem, these areas were classified as mountainous areas and are located at very high elevations. The rocky nature of the high elevated environment makes these areas have very little hope of assessing groundwater. It was suggested that government should properly monitor groundwater, inhabitants should be made to accept laws which will help them in the conservation of ground water resources and efforts should also be made by the government towards creating incentives that will encourage people to obey these laws, Conservation methods such as retardation of surface runoff, control of vegetation and groundwater withdrawal rates should be employed.
 
 

Assessment of Groundwater Quality beneath Agriculturally Advanced Region of Northern Alluvial Plain, India

In the present study, groundwater suitability for domestic and irrigation purposes was analyzed in the alluvial aquifers of the Bist-Doab region of Punjab, India, using various indices such as WQI, WAWQI, MCDA, RSC, SAR, PI, %Na, KR, MH, PS, K, and Ka. Since it is difficult to assess the suitability of groundwater for irrigation based on various indices individually, a composite groundwater quality index for irrigation (CGQII) was used in the study which transforms nine indices to a single value for each sample. Results reveal that the groundwater of a few blocks was found unsuitable for domestic use due to chemical leaching from fertilizers, pesticides, and agricultural and industrial wastes. Whereas, the groundwater of mainly southwestern parts was found unsuitable for irrigation due to long-term water accumulation in aquifers and continuous use of sodium-ion-rich groundwater. The findings conclude that anthropogenic activities have played a significant role in making groundwater unfit for domestic and irrigation purposes in the study area. The present study also emphasizes continuous monitoring and evaluation of groundwater quality, which will help in strategic planning and management for the conservation of groundwater resources in the region.

ANFIS-MOA models for the assessment of groundwater contamination vulnerability in a nitrate contaminated area

The enhanced assessment of groundwater contamination vulnerability is necessary for the management and conservation of groundwater resources because groundwater contamination has been much increased continuously in the world by anthropogenic origin. The purpose of this study is to determine the best model among three ANFIS-MOA models (the adaptive neuro-fuzzy inference system (ANFIS) combined with metaheuristic optimization algorithms (MOAs) such as genetic algorithm (GA), differential evolution algorithm (DE) and particle swarm optimization (PSO)) in assessing groundwater contamination vulnerability at a nitrate contaminated area. The Miryang City of South Korea was selected as the study area because the nitrate contamination was widespread in the city with two functions of urban and rural activities. Eight parameters (depth to water, net recharge, topographic slope, aquifer type, impact to vadose zone, hydraulic conductivity and landuse) were classified into the numerical ratings on basis of modified DRASTIC method (MDM) for the input variables of ANFIS-MOA models. The Original ANFIS, and 3 combined models of ANFIS-PSO, ANFIS-DE and, ANFIS-GA used 95 adjusted vulnerability indices (AVI) as the target data of training (70% data) and testing (30% data) processing. The performance of 4 models was evaluated by mean absolute errors (MAE), root mean square errors (RMSE), correlation coefficients (R), ROC/AUC curves and predicted AVI (PAVI) maps. The statistical results, spatial vulnerability maps and correlation coefficients between PAVIs and nitrate concentrations revealed that the order of model excellence was ANFIS-PSO, ANFIS-DE, ANFIS-GA, and Original ANFIS, and that ANFIS-PSO showed the highest performance in training and testing processing. The performance rates of ANFIS-MOA models were also compared with 10 recent popular worldwide models using the correlation coefficients between PVI and nitrate concentrations, and they were superior to other recent popular models. ANFIS-MOA models were also useful for resolving the subjectivity of physical and hydrogeological parameters in original DRASTIC method (ODM) and MDM. It is expected that ANFIS-PSO models will produce the excellent results in assessing groundwater contamination vulnerability and that they can greatly contribute to the groundwater security in other areas of the world as well as Miryang City of South Korea.

Spatial behavior of the Dar-Zarrouk parameters for exploration and differentiation of water bodies aquifers in parts of Konkan coast of Maharashtra, India

Demarcation of aquifer boundaries and hydro-geologic characterization can help in proper management and conservation of groundwater resources of a coastal region. The objective of the present study is to identify and delineate the groundwater-bearing zones and protection of freshwater aquifers from saltwater ingress in the northern parts of Sindhudurg district, western Maharashtra, India. A total of 86 vertical electrical soundings (VES) were carried out by Schlumberger electrode arrangement to infer the sub-surface lithology around Kankavali, Vijaydurg, and Malvan. The Dar-Zarrouk parameters were computed to generate the spatial variation maps of transverse resistance (T), longitudinal conductance (S), transverse resistivity (ρt), and longitudinal resistivity (ρl), to decipher the resistivity contrast of fresh water and salt water-bearing formations. The results demonstrate that these parameters provide a better resolution in delineating the seawater intrusion in coastal aquifers. The overburden aquifer protective capacity computed from the longitudinal conductance suggests that 59% of the area has poor aquifer protection, while 23% has weak, 11% has moderate and 7% falls in good protective capacity rating. This parameter reveals the infiltration of contaminants and the health of the aquifer. The electrical anisotropy (λ) value ranges from 0.9 to 5.1, suggesting an increase from SW to NE and also from SE to NW. The fracture porosity (φf) ranges from 10−6 to 0.65, which corroborates with the high and low λ values, reflecting that fracturing is due to anisotropy and significant reserves of groundwater could be exploited in this coastal region.

Sustainable Wastewater Treatment and Utilization: A Conceptual Innovative Recycling Solution System for Water Resource Recovery

The global demand for drinking water is increasing day by day. Different methods are used for desalination of water, which can help in the conservation of resources, such as seawater, highly saline, or treated water underground reservoirs. Polluted water can be treated by the utilization of different advanced techniques. In this study, wastewater mixed canal water has been taken into consideration for the utilization of humans and agriculture use as well. A two-stage conceptual methodology has been proposed to deal with the water conservation and utilization process. In the first phase, power has been produced using a Belgian vortex turbine, which is a safe, efficient, and eco-friendly technology working without disturbing waterways. The power produced by the vortex machine will be utilized to operate the water treatment plant to obtain clean water for utilization in the second phase. Since enough energy is produced, and its availability to the water head level base is a natural resource, this energy can be used to fulfill daily water requirements by maximizing the energy-driven treatment process as per WHO Guidelines. Water quality can be monitored at regular intervals, depending upon the selection and installation of a treatment plant. An increase in efficiency comes from nearly exponential patterns depending on water velocity and availability. This technique will not only help in the production of clean water but will also help in the conservation of groundwater resources and the efficient utilization of wastewater.

Modeling aquifer storage and recovery potential for seasonal water storage in the Flemish alluvial plains of Belgium using MODFLOW

The necessity to preserve, reuse, and recycle water is becoming increasingly significant for both environmental and economic sustainability. Conservation of groundwater resources in Belgium is coming under increasing threat due to the variability of climate, rapid urbanization, and population growth. Environmental challenges, as well as rising costs associated with surface water reservoirs, have encouraged water professionals to explore an adequate and sustainable adaptation strategy. Nowadays, aquifer storage and recovery (ASR) is an effective technique and widely applied for seasonal or emergency water storage in an environmentally acceptable, sustainable manner. The work described in this paper explores the potential of ASR to enhance the buffer capacity of water supply systems in pilot sites (Herent Bijlok and Winksele Kastanjebos in Belgium). A conceptual groundwater flow model was developed using the finite-difference code, MODFLOW, for these representative sites. After calibration, the steady-state model was utilized initially for transient simulation, prediction simulation, and later on scenario analysis. The scenario analysis was performed primarily on individual wells and afterward on two multiple wells. The water balance components of the winter and summer stress period showed an increase in groundwater heads during winter months while decreasing throughout the drier periods. Furthermore, among individual ASR wells, one achieved 97% recovery efficiency (RE) while multiple ASR wells attained above 100% RE. Overall, the study indicates that the ASR tool provides an attractive alternative to increasing storage capacity and ensures a sustainable long-term supply of fresh water in the study site of Belgium.

An integrated approach for mapping groundwater potential applying geospatial and MIF techniques in the semiarid region

Geospatial methods play an important role in the identification, monitoring, assessment, and conservation of groundwater resources. An integrated approach combining the geospatial techniques and multi-influencing factors (MIF) was adapted for the determination of potential groundwater zone in the Purulia District of West Bengal, Eastern India. The present groundwater is underexploited for agricultural and other activities. This study would also benefit in identifying the artificial recharge zone for further research and developmental activity in the region. The important parameters including slope, landuse/cover, lineament, drainage, geology, and soil affecting potential groundwater occurrence were generated from Topo Maps, Landsat remote sensing imagery, and various ancillary data. Various thematic layers were allocated a fixed score as weightage using MIF technique. Thereafter, the weighted layers were statistically computed in the overlay analysis to generate the groundwater prospect map. The groundwater potential map demonstrated five zones, viz. very good (13.8%), good (34.9%), moderate (48.3%), poor (2.8%), and very poor (0.2%). The findings of the research study would enable to carry out future research and propose effective planning and management of groundwater development.

Conservation of Groundwater Resources in Arid Lands: A comparative study of NaiGaj Pakistan and WadiDhahban Saudi Arabia

This research was conducted to compare the two research areas NaiGaj, Pakistan and WadiDhahban, Saudi Arabia having Ground Water Potential (GWR). The main objectives of the research was to determine the different parameters that support the ground water availability such as vegetation, nature of slope, Rain Water Rills(RWR), climatic data and land cover area with help of modern techniques. Pakistan and Saudi Arabia emanates under as Arid or Semi-Arid category of land. Both research area have almost same topography, where ground and river water is not found. Growers irrigate land by saline water of different drain canals (in Pakistan) and Rain Water Rills coming from the uplands. A 61 km wide and 326 km long belt is found in slope of Khirthar Mountain in Sindh, Pakistan, this belt is rain shadowarea. Similarly, WadiDhahban has same geographical features, located near the coastal belt of RedSea, where dozens of RWRs are presents and trembled in the Sea.The maps of groundwater potential of both study areas were designed with the help of RS and GIS software.GIS and RS havesignificant role in mapping of ground-water quality and quantity for assessment and monitoring purposes.It was observed through the maps that both areas have ground water potential. Furthermore, the results indicated that NaiGaj has 30.3 % ground water potential and WadiDhahban has 15.8% ground water potential.

Geospatial delineation and mapping of groundwater potential in Embu County, Kenya

Integration of Remote Sensing (RS) and the Geographical Information System (GIS) approaches in the field of groundwater resources management is a breakthrough. The RS and GIS geospatial approaches can enhance the assessment, monitoring, and conservation of groundwater resources. In this study, RS and GIS geospatial techniques were applied with the aim of identifying groundwater potential zones in Embu County, Kenya, based on selected multi influencing factors. Lineament layer was obtained by processing Landsat 8 ETM+ image using Principal Component Analysis in ENVI®4.7 and automatic extraction from Principal Component Image using the LINE module in Geomatica software. The resultant groundwater potential map showed that approximately 78% of the total area ranged from ‘high’ to ‘very high’ zones indicating that almost half of the study area has good groundwater potential. About 20% showed moderate potential while only 2% fell under the low potential zone. The proposed study approach can be used as a new way of modeling geospatial data for identification and mapping of groundwater potential zones. The study findings are useful to first-hand information planners and local authorities for assessment, planning, management and administration of groundwater resources in Embu County.

Crop rotation and N application rate affecting the performance of winter wheat under deficit irrigation

Deficit irrigation to winter wheat is gradually adopted in the North China Plain (NCP) for conservation of groundwater resources. N application to winter wheat should be decided based on the irrigation water availability. Under deficit irrigation, yield of winter wheat was also related to the water use characters of its previous crops. Field studies were conducted from 2013 to 2016 at Luancheng station in the NCP to evaluate the addition of soybean to the conventional annual double cropping system (winter wheat-summer maize) and reducing N input on the performance of winter wheat under deficit irrigation. Summer maize was either replaced by soybean or inter-planted with soybean. The subsequent winter wheat was applied with six nitrogen rates (0, 135, 216, 270, 324 and 405 kg/ha) with one irrigation or two irrigation applications. The results showed that the average seasonal water use of single soybean (SS), intercropping of maize and soybean (IMS) and single maize (SM) was 359.1 mm, 336.3 mm and 309.6 mm from 2013 to 2016, respectively. The inclusion of soybean as single or inter-planted crop increased the water use during the summer rainy season, which was related to the increase in leaf area index. As compared with the SM, the soil water stored in the 2 m soil profile at the summer crops harvesting was reduced by 24.7 mm and 94.7 mm in 2014, 15.9 mm and 95.6 mm in 2015, respectively, for the IMS and SS, respectively. Due to the dependent of winter wheat on the stored soil water before sowing, the reduction in pre-season soil water content significantly decreased the yield by 1005.4–1878.0 kg/ha. Yield of winter wheat didn’t respond to the increase in N application when N rate was over 135 kg/ha. The local N application rate at 270 kg/ha could be reduced up to 50% without apparent effects on crop productivity under deficit irrigation scheduling. The results indicated that for diminishing the reduction in yield of winter wheat under limited water supply, its previous crop with less water use in summer season should be selected. Yield of winter wheat could be maintained with half of its normal N application under limited water supply.