Analysis of Evolution Trend of Water Resources Based on Spearman and R/S methods:A Case Study of Agricultural Water Source in Jinghui Irrigation Area

Based on the monitoring data of precipitation and runoff series from 1953 to 2013 and groundwater exploitation from 1977 to 2013 in Jinghui Irrigation Area,especially the evolution of water resources during the growth period of main crops,the trend test of precipitation and runoff series was carried out by using Spearman rank correlation test and R/S analysis.The results showed that the annual mean precipitation and runoff and the growth period of main crops showed a downward trend,and the changes in the future were similar to those in the past;the amount of groundwater exploitation has not changed much,which is about 150 million m^3.The research results can provide scientific basis for efficient utilization and reasonable allocation of water resources in irrigation area,and provide technical support for the development of modern agriculture.

Evaluation of the Impact of the Ongoing Water Resource Management Plans on Nitrate Concentration in Gaza Coastal Aquifer Using Modeling Approach

Groundwater crisis in Gaza includes two major folds: shortage of water supply and contamination. The groundwater pollution by nitrates increased rapidly as a result of wastewater leakage, sewage sludge, animal manure and N-fertilizers. The aims of this study are to obtain the impacts of implementing the Gaza Emergency Technical Assistance Programme (GETAP) on the nitrate concentration in groundwater in Gaza Strip using modeling approach. A flow and transport model using a three dimensional, finite difference simulation model (VMODFLOW Pro.) was applied to simulate the Gaza coastal aquifer (GCA). The approach for selecting the management scenarios was carried out depending on the GETAP projects and focuses into the aquifer system during the next 24 years. It was estimated that work as usual scenario will raise the average nitrate concentration by 8.15 mg/l annually, while upgrade and maintain pipe work scenario will reduce the rising of average nitrate concentration by 4.51 mg/l annually. This means that the average nitrate concentration will increase by only 3.63 mg/l annually. Also, it was estimated that scenarios imported water from Israel, construction of short term low volume desalination plant (STLV), Construction of two regional desalination plant and Reuse of treated wastewater in addition to decrease N-fertilizer will annually increase the average nitrate concentration by only (4.67, 2.78, 3.87, 2.15) mg/l, respectively. The results show that applying all the scenarios together will decrease the average nitrate concentration by 2.44 mg/l annually. Regionally, the best scenario to solve the increasing of nitrate concentration problem is a combination of those scenarios. In domestic areas, the best scenarios is STLV and upgrading and maintaining pipe work. In Agriculture areas, the best scenario and the only one that has significant effect is the reuse of treated wastewater in addition to decrease N-fertilizer.

Effective groundwater level recovery from mining reduction: Case study of Baoding and Shijiazhuang Plain area

The effective recovery of water level is a crucial measure of the success of comprehensive groundwater over-exploitation management actions in North China.However,traditional evaluation method do not directly capture the relationship between mining and other equilibrium elements.This study presents an innovative evaluation method to assess the water level recovery resulting from mining reduction based on the relationship between variation in exploitation and recharge.Firstly,the recharge variability of source and sink terms for both the base year and evaluation year is calculated and the coefficient of recharge variationβis introduced,which is then used to calculate the effective mining reduction and solve the water level recovery value caused by the effective mining reduction,and finally the water level recovery contribution by mining reduction is calculated by combining with the actual volume of mining reduction in the evaluation area.This research focuses on Baoding and Shijiazhuang Plain area,which share similar hydrogeological conditions but vary in groundwater exploitation and utilization.As the effect of groundwater level recovery with mining reduction was evaluated in these two areas as case study.In 2018,the results showed an effective water level recovery of 0.17 m and 0.13 m in the shallow groundwater of Shijiazhuang and Baoding Plain areas,respectively.The contributions of recovery from mining reduction were 76%and 57.98%for these two areas,respectively.It was notable that the water level recovery was most prominent in the foothill plain regions.From the evaluation results,it is evident that water level recovery depends not only on the intensity of groundwater mining reduction,but also on its effectiveness.The value of water level recovery alone cannot accurately indicate the intensity of mining reduction,as recharge variation significantly influences water level changes.Therefore,in practice,it is crucial to comprehensively assess the impact of mining reduction on water level recovery by combining the coefficient of recharge variation with the contribution of water level recovery from mining reduction.This integrated approach provide a more reasonable and scientifically supported basis,offering essential data support for groundwater management and conservation.To improve the accuracy and reliability of evaluation results,future work will focus on the standardizing and normalizing raw data processing.

Impact on Water Resources in a Mountainous Basin under the Climate Change Transient Scenario (UKTR)

The impact of climate change on the hydrological regime and water resources in the basin of Venetikos river, in Greece is assessed. A monthly conceptual water balance model was calibrated in this basin using historical hydro meteorological data. This calibrated model was used to estimate runoff under a transient scenario (UKTR) referring to year 2080. The results show that the mean annual runoff, mean winter and summer runoff values, annual maximum and minimum values, as well as, monthly maximum and minimum, will be reduced. Additionally, an increase of potential and actual evapotranspiration was noticed due to temperature increase.

Assessment of Climate Change Impacts on the Water Resources of Megech River Catchment, Abbay Basin, Ethiopia

This study was aimed to assess the impact of climate change on the water resource of Megech river catchment. In this study, large scale regional climate model (REMO) output was downscaled statistically to metrological variables at a daily resolution using SDSM model version 5.11. We noticed that statistical downscaling smooth out the bias between REMO output and observed data. According to the projected climate data, the maximum temperature is likely to have an increasing trend +0.57°C while the minimum temperature shows a decreasing trends ﹣0.61°C. There is no clear trend for precipitation, both increasing and decreasing trend observed in the catchment. The HBV-Light hydrological model was successfully calibrated (1991-1995) and validated (1998-2000) using current climatic inputs and observed river flows. The overall performances of the model was good at monthly time scale both on calibration (NSE = 0.91) and validation (NSE = 0.86). Future discharge (2015-2050) was simulated using statistically downscaled 20 ensembles climate scenario data for both A1B and B1 scenarios. HBV-Light model simulation results showed a reduction of the peak discharge in August and September.

Development and Forecasting Drought Indices Using SPI (Standardized Precipitation Index) for Local Level Agricultural Water Management

Drought is primarily an agricultural phenomenon that refers to conditions where plants are responsive to certain levels of moisture stress that affect both the vegetative growth and yield of crops. It occurs when supply of moisture stored in the soil is insufficient to meet the optimum need of a particular type of crop. Causes of drought in Bangladesh are related to climate variability and non-availability of surface water resources. While it may be possible to indicate the immediate cause of a drought in a particular location, it often is not possible to identify an underlying cause. Therefore, to improve all these services in favour of enhancing agricultural production and reducing food insecurity in Bangladesh, it is mandatory to develop an effective way for disseminating the SPI data indicating drought indices to farmers, and enhance drought and climate resilience. To develop future plan and policy in agricultural sector of Bangladesh, it is vital to understand the previous droughts events with accurate indicators. Since this study will contribute to the agricultural development of Bangladesh therefore there is an obvious need to understand the change of drought frequency all over Bangladesh using a standardized drought index. The main intention of this project is to prepare a proper baseline for forecasting drought indices using SPI data. So, the final outcome of this project would be a knowledge base where a proper forecasting tools and dissemination networks can be updated/developed for farmers.

Impact of Domestic Solid Waste Management on Wet Land Water Quality: Case of Abomey-Calavi Municipality in Benin Republic

The waste management is a major environmental challenge in all the countries. In the Republic of Benin, in absence of controlled landfill, the wetlands are filling in by solid household waste to set up housing environments. This study aimed at identifying the various forms of wetlands water pollutions originated by this practice. Physico-chemical parameters of sampling water were determined by using Ionic chromatography and spectrometry of atomic absorption. The microorganisms indicating fecal peril were identified by the conventional techniques of microbiology. Water quality of a witness well was also used to assess the general water quality of the backfilled wetland. The results revealed the water samples collected from backefilled wetlands were mineralized (898.32 ± 6.13 μs/cm), rich in chlorinate (237.80 ± 4.23 mg/L) and nitrates ions (224.10 ± 3.42 mg/L). They are more colored (399.23 ± 3.01 Pt/Co) and more turbid (62.5 ± 2.48 NTU) than those of the unfilled wetlands. The results of microbiological analysis shown the presence of the cysts of Giardia lamblia (590/100 L) and cysts of Entamoeba histolytica (13/100 L) in all water, except those of witness well. The frequency of water contamination by bacteria indicating general degradation is 86.4%. The embankment of the wetlands by the solid household waste leads to the water pollution.

Study on leakage recharge mechanism of confined fresh water aquifer with semi-permeable membrane in Tianjin plain area

The Group Ⅱ fresh groundwater bearing aquifers in the eastern plain of Tianjin underwent long term exploitation. This study shows that the area with greater water-level declining is associated with more rapid stratigraphic compaction and consolidation. In the study area, the salty groundwater in the un-exploited overlying aquifers have the same dynamic characteristic of synchronization but different amplitude with the Group Ⅱ aquifers, showing that they have a close relationship. Cross-sectional study indicated that surface water, salty groundwater and underlying fresh groundwater belong to an integral water resources system. The compacted clay layers have the feature of semi-permeable membrane under alkaline condition. The infiltration of surface water is driven by the differences of osmotic pressure of salty water in each layer. When the water level difference between the Group Ⅱ aquifers and overlying salty aquifers is greater than osmotic water pressure difference, the salt water layer will desalinate downward and eventually, decreasing the water level of the upper aquifers, turning phreatic water amount supposed to evaporate to leakage recharge. Therefore, stopping mining groundwater in the Group Ⅱ aquifer will lead to other new environmental geology disaster.

Evaluation of Actual Evapotranspiration and Crop Coefficient in Carrot by Remote Sensing Methodology Using Drainage and River Water to Overcome Reduced Water Availability

Searching for alternative methods for traditional irrigation is World trend at days due to a reduction in water and increased of drought due to climate changes therefore farmers need use modern methods of scheduling water and minimizing water losses while also increasing yield. To meet the future increasing demands water and food there is a need to utilize alternative methods to reduce evaporation, transpiration and deep percolation of water. Any countries use recycled water (drain and sewage) and desalination water from the sea or drains to irrigate crops plus computing actual crop evapotranspiration (ETc) so as to calculate the amount of water to apply to a crop. The paper aims to assess the actual evaporation and evaporation coefficient of carrots, by planting carrots in a field and the crop was exposed to several sources of water (DW and RW) and comparing ETc, Kc and production among plots of three sites (A, B and C). The study used two types of irrigation water (drain water (DW) and river water (RW)). The results were to monthly rate and accumulated actual evapotranspiration to C (irrigation by RW only) more than A (67% RW and 33% DW) and B (17% RW and 83% DW) via 7% and 58%, respectively. The yield to C more than A and B by 17% and 75%, respectively. In conclusion the use of DW can cause a reduction in crop consumptive of carrot crops also causes a reduction in yield, crop length, root length, root size, canopy of crop, number of leaves and biomass of the plant therefore, the drainage water needs to treated before irrigating crops And making use of it to irrigate the fields and fill the shortfall in the amount of water from the river. The drain water helped on filling the water shortage due to climate changes and giving production of carrot crop but less than river water.

Evaluating Water Scarcity Indices for Cultivation Region in Sadat Al-Hindya, Babylon, Iraq: A Case Study

The study evaluated the Water Scarcity Indices for Cultivation Region in Sadat Al-Hindya, Babylon, Iraq. It calculated the reference evapotranspiration, actual evapotranspiration, and amount of precipitation with effective rainfall to estimate the droughts indicators which are the Standard Precipitation Index (SPI), the Standard Precipitation and Evaporation Rain Index (SPEI) and Reconnaissance Drought Index RDI. The study indicated that the greatest decrease in river flow occurred from 2019-2021 to 2020-2021 due to increasing temperature in summer and decreasing precipitation in winter. This research evaluated a wet and drought indicating for planning and management of water resources to face changes in climate of future. The research showed the last years were years of drought according to the three indicators. SPI ranged from 0.5 to 1.5 in the rainy years, but it was -0.5 to -1 as moderately dry because in the middle of Iraq while in the south of Iraq was severely dry or extremely dry. SPEI of the study area ranged from -1.5 to -2.5 which means severely dry. The SPEI measures are negative values meaning the months and years were drier. RDi ranged from 0 to -1 was dry and moderately dry while some months and years are positive and will be wet through rainfall for ten years (2014-2023). From indices showed that the region was a drying study area due to the impact of climate change because of the reduction of precipitation and increase in temperature which caused a rise of evapotranspiration during the last few years.

Geospatial Variability of Cholera Cases in Malawi Based on Climatic and Socioeconomic Influences

Cholera remains a public health threat in most developing countries in Asia and Africa including Malawi with seasonal recurrent outbreaks. Malawi’s recent Cholera outbreak in 2022 and 2023, exhibited higher morbidity and mortality rates than the past two decades. Lack of spatiotemporal-based technology and variability assessment tools in Malawi’s Cholera monitoring and management, limit our understanding of the disease’s epidemiology. The present work developed a spatiotemporal variability model for Cholera disease at district level and its relationship to socioeconomic and climatic factors based on cumulative confirmed Cholera cases in Malawi from March 2022 to July 2023 using Z-score statistic and multiscale geographically weighted regression (MGWR) in a Geographical Information System (GIS). We found out that socioeconomic factors such as access to safe drinking water, population density and poverty level, and climatic factors including temperature and rainfall strongly influenced Cholera prevalence in a complex and multifaceted manner. The model shows that Lilongwe, Mangochi, Blantyre and Balaka districts were highly vulnerable to Cholera disease followed by lakeshore districts of Salima, Nkhotakota, Nkhata-Bay and Karonga than other districts. We recommend strategic measures such as Water, Sanitation, and Hygiene (WASH) interventions, community awareness on proper water storage, Cholera case management, vaccination campaigns and spatial-based surveillance systems in the most affected districts. This research has shown that MGWR, as a surveillance system, has the potential of providing insights on the disease’s spatial patterns for public health authorities to identify high-risk districts and implement early response interventions to reduce the spread of the disease.

Protection Planning for Rural Centralized Drinking Water Source Areas in Chongqing

Protection planning is made for rural centralized drinking water source areas according to current situations of rural drinking water and existing problems of centralized drinking water source areas in Chongqing,and in combination with survey,analysis and evaluation of urban-rural drinking water source areas in whole city.There are engineering measures and non-engineering measures,to guarantee drinking water security of rural residents,improve rural ecological environment,realize sustainable use of water resource,and promote sustainable development of society.Engineering measures include conservation and protection of water resource,ecological restoration,isolation,and comprehensive control of pointsource and area-source pollution.Non-engineering measures include construction of monitoring system for drinking water source area,construction of security information system for rural centralized drinking water source area,and construction of emergency mechanism for water pollution accidents in rural water source areas.

Integrating water use systems and soil and water conservation measures into a hydrological model of an Iranian Wadi system

Water resources are precious in arid and semi-arid areas such as the Wadis of Iran. To sustainably manage these limited water resources, the residents of the Iranian Wadis have been traditionally using several water use systems(WUSs) which affect natural hydrological processes. In this study, WUSs and soil and water conservation measures(SWCMs) were integrated in a hydrological model of the Halilrood Basin in Iran. The Soil and Water Assessment Tool(SWAT) model was used to simulate the hydrological processes between 1993 and 2009 at daily time scale. To assess the importance of WUSs and SWCMs, we compared a model setup without WUSs and SWCMs(Default model) with a model setup with WUSs and SWCMs(WUS-SWCM model). When compared to the observed daily stream flow, the number of acceptable calibration runs as defined by the performance thresholds(Nash-Sutcliffe efficiency(NSE)≥0.68, –25%≤percent bias(PBIAS)≤25% and ratio of standard deviation(RSR)≤0.56) is 177 for the Default model and 1945 for the WUS-SWCM model. Also, the average Kling–Gupta efficiency(KGE) of acceptable calibration runs for the WUS-SWCM model is higher in both calibration and validation periods. When WUSs and SWCMs are implemented, surface runoff(between 30% and 99%) and water yield(between 0 and 18%) decreased in all sub-basins. Moreover, SWCMs lead to a higher contribution of groundwater flow to the channel and compensate for the extracted water by WUSs from the shallow aquifer. In summary, implementing WUSs and SWCMs in the SWAT model enhances model plausibility significantly.

Simulation of Nitrate Contamination in Groundwater Caused by Livestock Industry (Case Study: Rey)

With the economic development of many communities and the growing human population more food is needed. The livestock industry is one of the fastest growing industries in developing countries. The development of the livestock industry and the increase of livestock waste happens as a result of the growth in food production. The wastes are stored in a way that contamination of groundwater and surface water pollution in the environment has a significant impact on environment. This study analyses the environmental impact of livestock facilities and nitrate leaching in groundwater. After site sampling and libratory analysis, calibration of a simulation model with observed data was done to show nitrate contamination in “Rey” groundwater. The movement of nitrate into soil and groundwater was simulated by LEACHN. By defining various scenarios and performing sensitivity analysis, we examined precisely the factors affecting ground water contaminations. Along together with the analysis of different scenarios and comparing them with the measured values, seasonal rainfall conditions have greatest impact on the rate of recharge of nitrate to groundwater. Therefore soil with low rainfall shows 44% reduction of nitrate leakage at a depth of 30 cm of soil conditions. Finally, the modeling results and graphs from different scenarios for purpose of nitrate reduction in groundwater were presented. The good match between model results and observed data showed that the model is calibrated to this area and can be used for prediction purposes and further studies.

General Thinkingon the Management of Blue Algae Outbreak in the Taihu Lake,the Chaohu Lake and the Dianchi Lake

Among the Chinese lakes with the problem of eutrophication, the Taihu Lake, the Chaohu Lake and the Dianchi Lake have the worst cases of blue algae outbreak, which happen every year. Other lakes also have problems of blue algae outbreak at various degrees. However, some lakes don＇t have such problems. Practices have shown that through comprehensive management, the problem can be basically eliminated or significantly alleviated. ＂Water bloom＂ and blue algae outbreak have different connotation. The major factors affecting blue algae outbreak are sources of pollutants and ecological environment. Experiences are summed up and a new thinking on its management is developed： resolving the problem of blue algae is fundamental to lake management and development goals should be clearly set forth so as to eventually build a healthy aquatic ecosys- tem. The problem of blue algae can＇t be fully tackled by solely relying on the management of eutrophication but only by combining efforts of reducing the amount of blue algae and the management of eutrophication. The number of reduced blue algae should be larger than that of naturally prolifera- ted algae so as to alleviate and eliminate the problem of blue algae outbreak. Various engineering and technical measures and relevant protective procedures should be carried out in a scientific and proper manner. The total amount of nitrogen and phosphorous entering the lake either from point-source or non-point source pollution should be substantially reduced. Controlling the source of pollution and intercepting pollutants are the bas- ic measures. Wastewater treatment plant is the largest point source pollution in the future and adequate plants should be built with improved emission standards. Meanwhile, other measures including fishing out blue algae, diverting water, dredging, ecological restoration and expanding reed zone, should be implemented to alleviate the problem of eutrophication and eventually eliminate the problem of blue algae outbreak.

Optimization of Well Position and Sampling Frequency for Groundwater Monitoring and Inverse Identification of Contamination Source Conditions Using Bayes’Theorem

Coupling Bayes’Theorem with a two-dimensional(2D)groundwater solute advection-diffusion transport equation allows an inverse model to be established to identify a set of contamination source parameters including source intensity(M),release location(0 X,0 Y)and release time(0 T),based on monitoring well data.To address the issues of insufficient monitoring wells or weak correlation between monitoring data and model parameters,a monitoring well design optimization approach was developed based on the Bayesian formula and information entropy.To demonstrate how the model works,an exemplar problem with an instantaneous release of a contaminant in a confined groundwater aquifer was employed.The information entropy of the model parameters posterior distribution was used as a criterion to evaluate the monitoring data quantity index.The optimal monitoring well position and monitoring frequency were solved by the two-step Monte Carlo method and differential evolution algorithm given a known well monitoring locations and monitoring events.Based on the optimized monitoring well position and sampling frequency,the contamination source was identified by an improved Metropolis algorithm using the Latin hypercube sampling approach.The case study results show that the following parameters were obtained:1)the optimal monitoring well position(D)is at(445,200);and 2)the optimal monitoring frequency(Δt)is 7,providing that the monitoring events is set as 5 times.Employing the optimized monitoring well position and frequency,the mean errors of inverse modeling results in source parameters(M,X0,Y0,T0)were 9.20%,0.25%,0.0061%,and 0.33%,respectively.The optimized monitoring well position and sampling frequency canIt was also learnt that the improved Metropolis-Hastings algorithm(a Markov chain Monte Carlo method)can make the inverse modeling result independent of the initial sampling points and achieves an overall optimization,which significantly improved the accuracy and numerical stability of the inverse modeling results.