High-tech agriculture has been developing strongly in developed and developing countries, including Vietnam. The objective of study is to assess the application of high technology criteria for agriculture such as rice and vegetables under specific conditions in Thoai Son and Chau Phu districts, An Giang province. This study used the secondary data, documents relating to high-tech agriculture, legal documents, decrees, circulars, and agricultural policies of high technology for setting up the criteria level 1 and level 2. Methods of household interview, Rapid Rural Appraisal (PRA) and expert’s knowledge were used to synthesize and evaluate the rate of importance of the criteria for high-tech producing of rice and vegetables by using the analytic hierarchy process and multi criteria evaluation method. The results of this study showed that four criteria at level 1 and 22 criteria at level 2 were identified for rice and vegetables in term of high-tech agricultural production and also classified the important role of each criterion for the rice and vegetables production. In four criteria at level 1, technological criteria were classified as the highest important role, and the economic, social and environmental criteria were next, respectively. Regarding to the criteria at level 2, product market was classified as the most important role among the 22 criteria drawn from farmer interviews.

The study aimed at identifying effective practices for irrigation management in rice cultivation in a study area of Nga Nam district, Soc Trang province. The modeling method (an agent-based model) was used to simulate the interaction among water supply capability of canal system, operation of irrigation system, water demand of rice, and human factors involved in the process of water resources management. The results showed that there are several unnecessary steps in irrigation decision, leading to ineffective irrigation management. The irrigated farming pratices such as maintaining the water depths and storing rainfall help to reduce the cost and adapt to saline intrusion in the future.

The study was conducted to identify bio-product that could be used for treatment of biogas effluent at household scale. In the experimental condition, the treatments were arranged in a completely randomized design including the control treatment (without bio-product) and five bio-products including EmTech Green, BioEm, Emc, Jumbo A, and EmTech BKS. The results showed that the treatment efficiency of total suspended solids (TSS), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), total phosphorus (TP), total coliform, and E.coli of the five tested bio-products were in the range of 28 - 97.3%. The treatment efficiency of BioEm and Emc was significantly higher than that of the control and the other bio-products of EmTech Green, Jumbo A, and EmTech BKS. At household scale, BioEm and Emc had treatment efficiency of TSS, COD, TKN, TP, and total coliform from 55.4 to 86.9%.

The study aimed to evaluate the factors and agricultural zones suffered by climate change in 8 land use type including triple rice cropping, double rice cropping, intensive shrimp, rice-shrimp rotation, rice-cash crop rotation, fruit orchard, sugar cane, and intensive cash crop. The data was collected via 192 farmer and expert interviews. The data was analyzed and assessed by multi-critical evaluation and geographic information system. The results showed that saline and flood were the most influencial factors to triple rice cropping, double rice cropping, intensive shrimp, rice-shrimp rotation, rice-cash crop rotation, fruit orchard, sugar cane, and intensive cash crop. The flooding factor was the most influencial factor to the sugar cane and fruit orchard. This study determined 5 vulnerability levels to agricultural production systems including very low, low, medium, high, and very high. The vulnerability areas at medium, high and very high levels tended to increase while the vulnerability areas at very low and low levels showed a decreasing trend in 2016, 2030, and 2050.

Land use allocation is one of the most important steps in land use planning. This paper is aimed to present a new model for supporting land use distribution in agricultural land use planning named Soc Trang Land Use Allocation Model (ST-LUAM). The model was conducted based on Cellular Automata and GAMA platform. The input data was the land use map (from local government in 2010), and it was divided into cells. Each cell showed land use type and was referenced to land unit map. Based on these relations, the cells data values were determined including (i) land suitability, (ii) apparent frequency of each land use type in para-cells, (iii) distance from traffic road and rivers, and (iv) local economic capability. The ST-LUAM model was applied for allocating agricultural land in My Xuyen district, Soc Trang province for the year of 2015 with various scenarios. The all indexes combined scenario showed the best result in comparison with the real land use map in 2015 with the Kappa coefficient of 0.97. Therefore, the ST-LUAM model initially showed its prospect and allowed to broadly apply in agricultural land use distribution in the Mekong Delta.

The study was aimed to evaluate water properties in trench of land use types of Acacia Hybrid and Melaleuca Cajuputi at U Minh Ha zone, Ca Mau province. The study was conducted on two soil types of deep acid sulfate and shallow acid sulfate. For each soil type, water properties were examined at two area levels with over 10 ha and less 10 ha. The study results showed that pH was very low at both land use types of Acacia Hybrid and Melaleuca Cajuputi, EC and DO had not affected yet the environment. On the contrary, COD and BOD5 exceeded the regulations about water surface quality, and COD at land use forest of Acacia Hybrid tended to be higher than that of Melaleuca Cajuputi. They were not different about Fe and Al. The concentration of Fe was always higher than regulations about water surface quality, except Fe in deep acid sulfate soil at land use forest of Acacia Hybrid. H2S was lower than regulations about water surface quality for aquatic animal conservation. But N-NH4+ exceeded the limit, and N-NH4+ at land use forest of Acacia Hybrid was often higher than Melaleuca Cajuputi.

The study was conducted to determine the status and management of surface water resources in agriculture and aquaculture in My Xuyen district, Soc Trang province. Household interviews (local farmers and officials) based on the Integrated Environmental Assessment in the Driver forces - Pressure - State - Impact - Response framework, were applied to collect the data with the objectives (i) to determine the current state of the use of surface water resources; and (ii) to analyze the strengths and weaknesses of local residents in the use of surface water for agriculture and aquaculture during dry season. The results showed that surface water resources were mostly influenced by the development of agriculture (rice cultivation and aquaculture) which caused surface water resources changing and manifested by the reduction of water supply for agriculture due to the effects of drought and salinity intrusion in dry season. The change of surface water resources had caused difficulties for local resident because of the lack of fresh water for agriculture and the occurrence of diseases on crops leading to reduction of agricultural productivity. Therefore, local government has introduced solutions to limit difficulties for local resident including policies to support losses in agriculture, repairing and upgrading irrigation system. These solutions are supposedly effective, meeting the demands for production activities of the locals.

The aim of study was to determine species composition and distribution on the different habitats of soil animal communities in Lung Ngoc Hoang nature reserve from October 2015 to October 2016. There were 3 habitats concerned including: (1) habitat of agriculture, (2) habitat of agroforestry, and (3) habitat of Melaleuca forest with 35 sampling stations. The study recorded 59 species belonging to 30 genera under 18 families and 6 classes including Arachnida, Chilopoda, Diplopoda, Entognatha, Insecta, Oligochaeta within 2 Phylum (Annelida and Arthropoda). The findings showed that soil animals differently distributed according to natural habitats and seasons. In addition, they had tight correlation with litter, (correlation coefficients: r = 0.81 in the rainy season and r = 0.83 in dry season).

The study was carried out to assess groundwater (GW) dynamics affected by the exploitation and usage of GW in the period of 2000-2015, and to understand the hydrogeological characteristics in Can Tho city. The results of this research will be the basis for the input data to calculate and set up GW flow simulation model (Modflow) for further research. Following steps were (i) collecting and synthestizing secondary data (2000-2015) on current status of GW exploitation and monitoring data, (ii) analyzing the collected data to evaluate GW dynamics, and (iii) using geographic information system application to digitize background maps to display information of GW observation wells. The results showed that the Pleistocene aquifer (qp2-3) has currently been exploited, and has the largest number of boreholes in Can Tho city. GW level of Pleistocene aquifer (2000-2015) was decreased from 1.89 m to 4.5 m (average of 3.2 m). The GW level of this aquifer varies at the monitoring sites. The results of this study also provide useful information for development planning in water resources field.

Leachate often contains many organic compounds, inorganic substances, and heavy metals, which require appropriate treatment technology solutions to enhance treatment efficiency and cost saving. The electrocoagulation process combined with Fenton-ozone was studied as a pretreatment for landfill leachate of Phuoc Thoi - O Mon to determine suitable operating parameters. Firstly, the electrocoagulation process (electrode area of 486 cm2, current density of A = 0.522 A /m2, inclination of electrode of 45o, retention time of 1.66 h) was applied with removal efficiency of turbidity (58.16%), color (65.73%), COD (55.1%), SS (71.92%), BOD5 (33.04%), TP (68.42%), Fe (55.16%), Cr6+ (76.13%), and TKN (11.9%). Next, leachate was treated with Fenton - ozone process (at pH 3, retention times of 70 minutes and H2O2 : Fe2+ ratio of 4 : 1). The removal efficiency of turbidity, color, SS, COD, BOD5, and TKN was found at 43,89%, 65.81%, 26.26%, 69.64%, 29.63%, and 7.9%, respectively, and none of Cr6+, TP, and PO43- was detected. The BOD5/COD ratio after electrocoagulation and Fenton-ozone processes was enhanced from 0.19 ± 0.02 to 0.58 ± 0.04 which is suitable for next biological treatment steps.

This study was conducted in order to choose the weight of rice straw and water hyacinth for batch biogas production. The experiment involved the use of a single factor completely randomized design in 120 mL reactors with 5 different rice straw and water hyacinth weight [10, 15, 20, 25 and 30 gVS. L-1aresimilar to 1.0, 1.5, 2.0, 2.5, 3.0% VS], with 5 replications during 45 days at 35oC in the laboratory condition. The results showed that rice straw at loading rate ranging from 15 to 20 gVS. L-1 produced the highest biogas productivity (66-70.4 mL.gVS-1) (p

The experiment was conducted to assess the capability of biogas effluent in supplying ammonium and nitrate for soils. The experiment was designed with 4 treatments: soil added 100% distilled water (control treatment), soil added 50% biogas effluent and 50% distilled water, soil added 75% biogas effluent and 25% distilled water, and soil added 100% biogas effluent. The results showed that N-NH4+and N-NO3- concentrations significantly increased in biogas effluent-supplying treatments in comparison to the treatment without biogas effluent addition. The concentrations of N-NH4+and N-NO3- were 171±5.45 mg/kg and 78.9±3.08 mg/kg, respectively, in the soil added 100% biogas effluent. The nitrogen-supplying capability increased proportionately to soil microbial respiration, which was showed by the highest accumulated CO2concentration in the soil added 100% biogas effluent (855 mgCO2/kg). The result also showed that mineralized nitrogen concentration positively correlated with CO2 accumulation in soil, indicating that soil microbial activity increased in line with increasing added-biogas effluent volume and amount of soil mineralized nitrogen.

To assess diversity and identify factors that affected the diversity indexes, the research surveyed vascular plant diversity with three types of characteristics of soils including acid sulfidicpeat soil (SPS), active acid sulfate soil with sulfuric materials present near layer (0-50 cm) (SSN), and depth in soil (>50 cm) (SSD), in opened depression of flood plain in An Giang province. On texture, all three types of soils had higher clay composition than silt and sand composition. pHKCl ranged from 3.98 ± 0.09 to 4.62 ± 0.06 and EC from 353.33±5.23 μS/cm to 531.50±53.01 μS/cm (p>0.05). Organic matter was the highest in the SPS (11.74 ± 0.46 %OM). The content of Ca2+ and Mg2+ in SPS was lower than the other soils (8.76±1.37 meq Ca2+/100g and 1.36±0.19 meq Mg2+/100g) (p

This study aimed to define the optimum hydraulic retention time to treatsugar-cane processing wastewater on the aerobicmoving bed biofilm reactor (MBBR). The   processing wastewater was first treated by the electroflotation tank, then transfered to the MBBR with various hydraulic retention time (HRT) of 10 hours, 8 hours, and 6 hours. Operating the MBBR to treat the wastewater from sugar-cane processing (SS = 331 mg/L, COD = 5362 mg/L, TKN = 17 mg/L, TP = 8 mg/L) with the 3 suggested HRT, the treatment efficiencies were SS 43%, 45%, -4%; COD 97%, 97%, 97%; TKN 46%, 33%, 29%; and TP 80%, 40%, 29%. At all the studied HRT, the parameters of pH, SS, BOD5, COD, TKN, and TP of wastewater after treated by MBBR reached the national standard of QCVN 40:2011/BTNMT (column B).

This study was conducted to analyze economic and environmental aspects among cropping systems aimed to assess the effect of agriculture activities within a full-dyke system in Cho Moi district, An Giang province. Structured interview (90 famers and 3 local officers) and descriptive statistics were used to assess economic and environmental effects of different agricultural cropping systems such as rice (3 crops), vegetable, and fruit in the study area. The results showed that there was a trend of land-use change from rice farming with low profit to fruit garden with better profit. About environmental aspect, intensive farming in areas with a full-dyke system (without inflow from flood) to increase crop yield in the long term could decrease the sediment loads that keep rice field fertile. Moreover, in the areas with a full-dyke system, pest and disease were likely to be exacerbated by extreme weather such as high temperature or prolonged rain. That led to increase cost of production models because of higher level of fertilizer and pesticide application. This application, in turn, could cause severe pollution to surface water in research area.

This research was aimed to build up the scientific basis of land resources to help managers orient the use of agricultural land in a sustainable and effective manner and promote the land potential of the district. The data on physical condition, socio-economic and environmental factors were collected by farmer interview and PRA method. The land evaluation methods of FAO (1976 and 2007) were used to define the land suitability zones of district. The results showed that having 5 land characteristics of the district, 13 land units and 3 land suitabitlity zones were determined. Based on the land suitability to the natural and economic conditions and the level of impact of social and environmental factors, sustainability land use model was proposed.

Soc Trang is one of the coastal provinces, where rice cultivation provides the most important production in the Mekong Delta. However, saline intrusion under climate change impact becomes a big issue which affects rice cultivation in Soc Trang. This research was aimed to evaluate the impact of climate change, specifically saline intrusion on rice cultivation areas in Soc Trang following two climate change scenarios in 2004 and 2030. In this research, time series vegetation index based MODIS data (MOD09Q1) with 250 m of spatial resolution from 31st July 2014 to 31st July 2015 combined with LANDSAT 8 was used to map the rice cropping systems in Soc Trang. The results showed that there were three main rice crops system including triple rice crop (99,182.2 ha, accounting for 30.3% total area), double rice crop (69,484.2 ha, accounting for 21.2% total area) and rice-shrimp rotation crop (69,484.2 ha, accounting for 4.3% total area). The overall accuracy of classification was calculated by using 100 sites of field survey, result of Kappa coefficient was 78%. The impact of saline intrusion following two climate change senarios in 2004 and 2030 to rice cropping system in Soc Trang is mainly distributed to three districts including My Xuyen, Long Phu, and Tran De. By comparing scenarios of climate change in 2004 and in 2030, the affected area of rice-shrimp rotation crop in My Xuyen increased by 14.7 ha; the affected areas of double rice crop in Tran De and those of triple rice crop in Long Phu decreased by 155.5 ha and 35.5 ha, respectively.

This study was conducted to evaluate the impacts of surface water quality resources on agricultural practices in the full-dyke system of Cho Moi district, An Giang province. Structured interviews method, random selection (60 farmers and 02 local officers) and descriptive statistics were used to assess the impacts of the surface water quality changes on agricultural activities (including: rice farming, upland crop, and orchard). According to farmers’ perceptions, the reduction of surface water quality and sediment loaded affected financial benefit of agricultural production. A full-dyke system decreased the sediment load supplemented to field and fertility added to the soil. Therefore, enhancement of using chemical fertilizers and pesticides leaded to rising farming cost and decreasing net benefit. Local residents tended to convert from rice and upland crop to orchard to adapt to decreasing surface water quality and sediment load.

ISCST3 and AERMOD are two atmospheric dispersion models developed and recommended by United States Environmental Protection Agency. These two models have been used in many parts of the world and give relatively consistent results in estimating concentration of air pollutants for environmentalists. ISCST3 and AERMOD are also used in some projects of Vietnam related to air pollution assessment. This research was conducted to compare the difference of the results between ISCST3 and AERMOD models for simulating the dispersion of SO2 and TSP from Hiep Phuoc industrial park. The total number of industrial sources used for this simulation is 40-point sources, and the operating period of the models is in 2016. This research has shown that AERMOD is more suitable than ISCST3 for simulating air pollution dispersion in Hiep Phuoc industrial park. Besides, it has also pointed out the spatial distributions of SO2 and TSP in Hiep Phuoc industrial park, providing the basis for setting out the reasonable solutions to reduce air pollution in this area.

This study aimed to assess the shift of agricultural structure in an upstream region of the Vietnamese Mekong Delta with the case of Cho Moi district, An Giang province. Household interviews and literature review based on the DPSIR framework (Driving Forces-Pressure-State-Impact-Response) to identify factors of changes in agriculture. The results showed that in the period of 2012 - 2016, local residents tended to narrow down the ineffective cultivation area of rice to vegetable and orchard, which were more economically effective. In addition, growing corn in combination with cow raising were potential for economic development in the study area. The main determinant of the transformation of the agricultural structure was the socio-economic factors including the economic efficiency from farming system, the market demand, and general conversion trend of local resident. The transition process helped develop the local economy and improve the living standards of the local residents. The transition process helps develop the local economy and improve living standards of local residents. However, farmers had difficulties in cultivation techniques, harvest, and investment costs when shifting to a new farming system.

This study analyzed the impacts of drought and saline intrusion in the canal network to agricultural farming systems in My Xuyen district, Soc Trang province. The key informant panel and household interview approaches were used to collect primary data. In total, four experts who work in agriculture field and 61 households were interviewed. Descriptive statistics were applied to analyze the influences of soil properties, tidal-induced floods, salt water intrusion, and weather factors on agricultural practices and to determine possible solutions to adapt to changes of them. The results showed that two typical land use types in My Xuyen (double rice crop and shrimp-rice farming systems) were seriously damaged in the dry period of 2015-2016. The saline intrusion in the canal network, acid sulphate soil, drought, and irregular rainfall affected both rice and shrimp cultivation. In the future, if the extreme events of saline intrusion and drought continue, 54% of local farmers will break one crop of the farming; 19% of farmers will remain as the current farming, but they will specially pay attention to the happenings of the weather to avoid the damage; and 27% of farmers will convert to new farming models, in which intensive shrimp will be the main model. This research helps assess the effects of drought and salt water intrusion to the agricultural production and plan suitable cropping calendar in My Xuyen.

The objective of this study is to assess groundwater (GW) exploitation status and GW level declines and land subsidence relationship for case studies in Can Tho city and Tra Vinh province. Firstly, GW exploitation for different purposes was compiled and evaluated; GW level declines in upper-middle Pleistocene (qp2-3) at monitoring wells were examined. The land subsidence was calculated using the expression for 1D consolidation of compressible porous media for vertical compaction rates. The results showed that the GW in Pleistocene layer has been the most popular GW exploitation aquifers, for domestic and industrial purposes, and also for agricultural usage. Consequently, GW level in this layer has been found to decline significantly (3.98 m (2001-2014) and 4.06 m (2004-2015) at QT16 (Can Tho), Q217020 (Tra Vinh), respectively). The compaction-based subsidence at these two locations, respectively are 4.383cm and 27.854 cm. It is noticed that the preliminary calculation of compaction-based subsidence from this study inherits hydrogeological parameters from previous studies, and only upper-middle Pleistocene aquifer was considered.

The aim of study was to evaluate adaptive capacity to annual floods (in the present and future context) by local residents at a full-dyke system area of the Mekong Delta, the case study of Cho Moi district, An Giang province. Household interviews (local farmers and officials) and descriptive statistics were applied to evaluate the farmers and government’s strategies to flood. The results showed that existing the full-dyke systems and other irrigation constructions leaded to the ignorance of local residents about flood and flood hazards; therefore, the prepareration of local residents for flood events was limited. In short, the majority of farmers believed that the full-dyke system can mitigate negative flood impacts, so local residents have little concerns about the flood progress and adaptation.

The experiement for determination LC50-96 of Iprobenfos on climbing perch (Anabas testudineus) fingerlings was carried out with five treatments of Iprobenfos concentrations (at 4, 7, 9, 14, and 17 mg/L), with 10 individuals (4.39±0.09 g) in 60 L composite tanks. The effect of Iprobenfos on the cholinesterase enzyme and growth of climbing perch was conducted by randomly design in 300 L tanks with 30 fishes at four levels of Iprobenfos (0.083, 0.167, 0.83, and 2.07 mg/L) and the control. The result showed that Iprobenfos was toxic at the concentration ranged from 4 to 17 mg/L and LC50-96 hours was 8.28 mg/L. The longer time the climbing perch was exposed to Iprobenfos, the more inhibition of cholinesterase enzyme activity and the highest inhibition level was recorded at 45.5% at 2.07 mg/L of Iprobenfos after 36 hours. The lowest observed effect concentration of Iprobenfos on ChE in this experiment was 0.083 mg/L. The feed intake was not affected by Iprobenfos. Feed conversion ratio, specific growth rate, survival rate and the weight of climbing perch were affected by Iprobenfos at 2.07 mg/L.

The objective of the study was to assess the soil fertility degradation for the period of 2012-2016 and to show the changes in chemical properties in terms of spatial distribution and land use types. It also helped managers to propose effective measures to reduce and improve soil fertility degradation having been happening in the area. The study used a set of properties from background data to assess the degree and extent of soil fertility degradation on the basis of comparison with the soil samples analysis results at the same site or the same soils that are nearest to the location such as soil pH, organic matter (OM), cation exchange capacity (CEC), total nitrogen (N), total potassium (K), and total phosphorus (P). The result showed that the total area of the province had 112,321.38 hectares of soil with degraded fertility, occupied 40.21% of the surveyed area, and the land area without degraded fertility was 167,025 hectares, occupied 59.79% of surveyed area. In general, the soil fertility degradation in the province was light, but the soil chemical properties had significantly decreased in cultivated areas such as intensive rice cultivation in dike areas, short term crops growing areas, and forest soil in the low mountainous with have steep slope.

This study was executed from Deccember 2015 to October 2016. The objective of study was to provide the information regarding the species composition and macrofungi distribution at Lung Ngoc Hoang natural reserve. The result showed that there were 57 species founded belonging to 39 genera, 24 families, 12 orders and 5 classes of 3 divisions which were Basidiomycota, Myxomycota, and Ascomycota. Accordingly, Basidiomycota was the most diverse phylum with 53 species; Agaricales and Polyporales were the second and the third in terms of biodiversity with 20 species and 18 species, respectively. In addition, the level of macrofungi diversity in all 4 surveyed habitats was low (forest, cultivated and riparian) and very low (agricultural land).

The objective of this study was to determine the effects of plant density on growth and the uptake of nitrogen and phosphorus which were added in wastewater from intensive catfish of Hymenachne grass (Hymenachne acutigluma). There were four plant densities of 10, 20, 30, 40 shoots/m2 and control treatment (without plant). The experiment was arranged in completely randomized design with twelve replications. The growth of H. acutigluma and water quality were evaluated every two weeks for eight weeks. Harvested dry biomass of H. acutigluma planted at 40 shoots/m2 was higher than that at 10 shoots/m2. Plant density did not affect nitrogen and phosphorus content in the shoots and roots tissues, but did affect nitrogen and phosphorus uptake of H. acutigluma. However, there was no significant difference among plant densities for total nitrogen and total phosphorus removal efficiency which was 80-84.8% and 93.3-95.6%, respectively, and higher than the unplanted treatment. The results indicated that Hymenachne planted at density of 20-40 shoot/m2 had a better growth, nitrogen and phosphurs uptake.

Full-dyke systems has been established in many provinces in the Mekong Delta, especially in An Giang provinice, and it has prevented sedimental deposition annually in the land of the full-dyke. The study on quantity and quality of sediment in full-dyke and semi-dyke systems had been conducted for 3 years (2013 - 2016) in four districts of An Giang (Chau Phu, Phu Tan, Cho Moi, and Thoai Son). In each district, 30 sediment traps, made by nylon fabric materials with 1m2 pertrap, were installed continuously for three years, including 15 in full-dyke and 15 in semi-dyke area. The traps were placed on the ground before flooding (August) at fixed positions which were located by GPS. After flooding (December), sediment in each trap was collected and analyzed for nutrient composition. The results showed that average weight of sediment in semi-dyke area (22.5 tons/ha) was five times higher (4.4 tons/ha) than that in the full-dyke area. Total phosphorus and organic matter of sediment in the full-dyke were higher than those in the semi-dyke. Total nitrogen of sediment in the full-dyke was lower than that in the semi-dyke (0.33% N and 0.65% N, respectively), and the total potassium in the full-dyke (1.42% K2O) and semi-dyke (1.44% K2O) was not different. The annual flood discharging into the full-dyke of Phu Tan district (2015) showed that the total sedimental deposition was 4.7 tons/ha, and it provided 8.73%, 9.43%, and 82.7% of nitrogen, phosphorus, and potassium demand, respectively.

The research was aimed to assess the impacts of saline intrusion on groundwater resources management in the coastal area of the Vietnamese Mekong Delta, with the case studies of Long Phu and Tran De districts, Soc Trang province. Structured and semi-structured interviews with stakeholders (120 farmers and 4 local officers) were done to collect primary data. Descriptive statistics were used to evaluate the impacts of saline intrusion on local groundwater resources management. The results showed that, during salt-influenced period (especially in dry season of 2016), saline intrusion caused certain difficulties in groundwater resources management (mainly in Tran De district), particularly in the control of the extraction and use of groundwater. In aquaculture areas, shrimp farmers extracted groundwater increasingly to decline salinity concentration of surface water. In contrast, towards rice farmers (mainly in Long Phu district), saline intrusion had no impact on the demand of use and extracting groundwater. The reasearch results had great sense in supporting decision making on integrated water management towards local area connectivity.

The study on evaluation and comparison of soil quality inside and outside the full-dyke systems had been conducted continuously for 3 years (2013 - 2016) in four districts of An Giang provinice (Chau Phu, Phu Tan, Cho Moi and Thoai Son). In each district, 15 sampling sites for each inside and outside of the full-dyke systems were selected. Soil samples were collected after the flooding season. The results showed that physical parameters of soil (pH, density, bulk density, porosity, and soil texture) were not different between soils inside and outside the full-dyke systems, except EC value and soil handness. Chemical parameters of soil inside the full-dyke were higher than that outside the full-dyke system and different significantly, this difference of total nitrogen (%N), phosphorus (P2O5) and organic matter (%C) varied 0.26% and 0.20%, 0.16% and 0.13%, 6.93% and 4.70%, respectively. The total potassium (K2O) was not different between soils inside and outside the full-dyke, which was 1.45% and 1.42%, respectively. On both of the research sites, soil quality were quite high.

The objective of study was to build the equation for biomass and CO2 absorption of Acacia hybrid in U Minh Ha zone, Ca Mau province. The experiment was arranged at the Kenh Dung experiment station of Tay Nam Bo Forestry Research Experimental Center, located at U Minh Ha, Ca Mau. The research was carried out on 3 standard plots of the three age levels including: 4, 5 and 6 years. The HARTIG method was used for data collection and correlation equation of biomass, tree height (Hvn), tree volume, and diameter at breast height (D1,3). The results of the study showed that 27 biomass equation were done for 3 age level of Acacia hybrid having a high correlation coefficient (0,86 < r

The study was aimed to identify the impacts of climate change on public health in Giao Thuy district, Nam Dinh province and propose suitable adaptation measures. This study analyzed the evolution of some climate change-related diseases by using the single, linear regression model. The data including temperature, precipitation, humidity, and some epidemics were collected from the statistics in Giao Thuy district, Nam Dinh province from 2010 to 2015. The results showed that the evolution of some diseases correlated with weather changes. Specifically, diarrhea was associated with humidity in 2010, with temperature in 2012, and with rainfall in 2015. The flu was related to all three weather factors in 2012, while malaria was related to temperature and humidity in 2013. This proved that climate change had had impacts on the public health in Giao Thuy district, Nam Dinh province.

The study was carried out following the method of ground water (GW) pumping test in Tra Noc industrial zone, Can Tho city to determine the initial change of water level in the observation wells over time, and then determine the basic hydro-geological parameters of the upper Pleistocene aquifer (qp2-3) such as permeability coefficient (K), transmissivity coefficient (T), storativity coefficient (S), depth of aquifer (D). The following steps were taken to (i) collect secondary data consists of location map, geological-hydrogeological map, and information of wells (aquifer, depth) and (ii) design experimental pumping test to measure GW level of the observation wells during the pumping time. The results determined the hydro-geological parameters (K, T, S and D) in the study area by Theis method, and was a database to set up GW dynamic simulation model for management and prediction of GW exploitation. The results revealed that K is of 3.465 m/h, S is of 0.003, T is of 242,6 m2/d, and D is of 70 m. The results of this research are also the basis to compare and correct secondary hydro-goelogical data, and prepare reliable data for GW flow simulation.

This research was carried out to determine the appropriate operating parameters of the coagulation-flocculation process combined with Fenton process to treat printing factory wastewater. The experiments implemented in coagulation-flocculation reactor and Fenton reactor at lab scale condition. The results showed that optimum operation parameters of coagulation-flocculation process were PAC dosage of 150 mg/L, 67.5 mg/L CaCO3, but no auxiliary coagulant needed adding. The optimum operation parameters for Fenton process included reaction time of 45 minutes, H2O2 dosage of 100 mg/L, and Fe2+ dosage of 80 mg/L. By running the Fenton reactor with the optimum parameters, the treatment efficiency of COD was 81.5%. The COD value of the effluent reached the discharge standard that satisfy the Vietnamese standard of industrial wastewater discharge QCVN 40:2011/BTNMT (column B).

The study was conducted to evaluate the effects of five NH4-N:NO3-N ratios (in mol) of 4:0, 3:1, 1:1, 1:3, and 0:4 on the growth of Hymenachne acutigluma. The experiment was arranged in a completely randomized design with 12 replications for each treatment. The growth of H. acutigluma and water quality were determined every 2 weeks for 8 weeks. The results showed that dry weight of H. acutigluma were high in the NH4-N:NO3-N ratio of 1:3 and 0:4. The presence and increment of both nitrogenous forms NH4-N and NO3-N in catfish wastewater helped to enhance NO3-N and NH4-N content and uptake capacity inthe shoots and roots of H. acutigluma. The high NH4-N concentration (NH4-N:NO3-N ratios of 4:0 and 3:1) had negative effect on H. acutigluma root growth. The leaves had senescence and rotting symptoms in the eighth week of the experiment. The results indicated that nitrate is the preferable inorganic nitrogenous form for H. acutigluma’s growth and nitrogen uptake. Therefore, H. acutigluma had high potential use in constructed wetlands for wastewater treatment from intensive catfish pond with high nitrate concentration.

Soc Trang province is one of the major agricultural areas in the Mekong Delta where rice production is the most popular activity. Currently, to respond to the economic goal, choosing appropriate rice production technique is a crucial requirement. However, the selection of rice production model needs to consider both social and environmental aspects, especially in the context of climate change. Therefore, this research was carried out in order to: (i) assess the economic, social and environmental effectiveness of rice production model: large-scale rice field and traditional rice cultivation; and (ii) analyze the strengths, weaknesses, opportunities, and threats of rice production model in Nga Nam district, Soc Trang province. Cost-benefit analysis, data standardization, directive interview, expected cost approach and Likert scale were applied, based on criteria of Food and Agriculture Organization of the United Nations (FAO,2007). The result showed that the large-scale rice field model gave higher effectiveness in comparison with the traditional rice cultivation model, with points of effectiveness being 0.99 and 0.73, respectively. In general, the large-scale rice field model is an advanced rice production method which encourages the agricultural development in Nga Nam district, Soc Trang province.

Cluster Analysis (CA) and Discriminant Analysis (DA) were applied to assess salinity intrusion of groundwater in the Pleistocene aquifer in Tan Thanh district, Ba Ria – Vung Tau province. Groundwater samples were collected from 18 monitoring wells in April 2012. The water quality parameters selected for statistical analysis include pH, hardness, TDS, Cl-, F-, NO3-, SO42-, Cr6+, Cu2+, Ca2+, Mg2+, Na+, K+, HCO3- and Fe2+. CA groups the wells into three distinct clusters related to agricultural activities, industry, and salinization. DA revealed the existence of significant differences between these clusters, built a function discriminant analysis and determined group which causes difference among clusters in the data set. The parameters representing salinity intrusion (TDS, Mg2+, Cl-, Hardness, Na+, K+, Ca2+, and SO42-) accounted for 99.8% of the variance of dependent variables explained by the DA model. The results showed that cluster analysis and discriminant analysis are the effective statistical methods in the clustering of salt intrusion.

Insecticide chlorpyrifos ethyl and fenobucarb were commonly used in rice cultivation in the Mekong Delta of Vietnam. To mix several active ingredients before spraying was common for saving labour cost. Snakehead fish (Channa striata) used to come to rice paddy for spawning in rainy; therefore, this species was at high risk of exposure and effects. This study was aimed to compare effects of using single and mixture insecticide Bascide 50EC and Mondeo 60EC for rice on activity of cholinesterase (ChE) in snakehead fish in ricefield. The results showed that using single Bascide 50EC, Mondeo 60EC or the combination of these insecticides for rice caused significant ChE inhibition for snakehead fish. Less than 30% ChE inhibition was found as applying single Bascide 50EC for rice whereas mortality and served (>70% inhibition) and long ChE inhibition were seen as using single Mondeo 60EC or combination of Bascide 50EC and Mondeo 60EC.

Chromium is toxic for microorganisms as well as human health and environment; however, it is used extensively in tanning industry. Thus, chromium is obligatorily removed from the wastewater stream for applying next biological treatment steps. The coagulation-flocculation process and the advance oxidation by ozone have been studied to apply for crocodile tannery wastewater stream. The result showed that when the chromium containing effluent was treated by coagulation-flocculation (a combination of 500 mg/l FeCl3 and 4 mg/L polymer C at pH 7.5) and advance oxidation of ozone column (heigh of 1.4 m, volume of 17 L, ozone generation of 2 g/h, and retention of 10 minutes), the concentration of Cr3+, Cr6+ and color in the effluent were 0.09 mg/L, 0.00 mg/L, and 36.8 Pt/Co, respectively. These values of chromium (Cr3+, Cr6+) and color were lower than the limit value of national regulation QCVN 40:2011/BTNMT (column A) and were completely non-toxic for biological treatment process. Therefore, the coagulation-flocculation process combined with advance oxidation by ozone can be definitely applied to remove chromium from the wastewater stream as a pretreatment solution for tanning industry.

Water pollution has been increasing quickly and complexly for recent years. Water quality forecast to provide prompt and timely information on water pollution is very necessary. In this study, the aim of the study was to compare capability of water quality forecast by the multilayer perceptron neural network method and the grey theory method that emphasized rapid predictability and accuracy, contributing to improving the efficiency of water quality forecast. The data were collected from 23 monitoring stations of Dong Nai river from 2010 to 2014 in Dong Nai and Binh Duong Department of Natural Resources and Environment for forecasting the water quality index. The results showed that both methods had good performance of water quality forecast. The water quality index forecasted by the multilayer perceptron neural network model showed higher accuracy (RMSE = 2.88, R2 = 0.987 and P = 0) than that forecasted by the grey theory model (RMSE = 7.84, R2 = 0.879 and P = 0).

Paddy rice plays a key role in strategy that ensures the balance among local socio-economic development and food security targets. The main objectives of this study were to determine factors effecting possibility of land use scenarios and to propose the solutions to enhance the efficiency of sustainable paddy rice land use planning. The data were collected from technical report, household investigation and local officers on situation of land uses of district period 2010 - 2015 and plan for period 2016 - 2020, land evaluation (FAO, 1976), optimization mathematical model and comparison with present conditions of the planning by government. The results showed that the economic factor groups (benefit, cost) affecting strongly the implementation of paddy rice land were identified, while the social factor groups were less important (techniques, farming practices, labor, and policy) to need considering in building plan in the future.

In recent years, drought and salinity intrusion frequently affect rice cultivation areas in dry season of coastal provinces in the Mekong Delta, especially Soc Trang province. This paper aims to analyze the changes of rice areas in dry season by classifying Landsat images based on decision tree with the normalized difference vegetation index data and to build a simulation model of rice area changes under the impacts of drought and salinity intrusion. The rice maps of Soc Trang in dry season in 2014 and in 2016 are developed, corresponding to the maps in normal temperature and in drought and salinity intrusion conditions. These classified maps are assessed by Kappa coefficient of 0.89 for the map in 2014 and 0.83 for the one in 2016. Then, the model of rice area changes is built based on rainfall data, salinity intrusion into irrigation regions. The simulated result of rice map of dry season in 2016 is compared with the real one with Kappa value of 0.88. This result shows the simulated map can be used to provide a visual assessment of rice area under drought and salinity conditions.

The aims of the study were to investigate effects of saline intrusion and socio-economic factors on the current agricultural land use to propose suitable solutions. The Kriging method was applied in order to edit saline intrusion map in Vung Liem district. Besides, farmer interviews, statistical analysis using SPSS software and map processing by geographic information system. The results showed that there was 03 salinity intrusion areas, in which Trung Thanh Tay and Trung Thanh Dong communes. This had impacted on land use types including vegetables, rice and fruit trees cultivations. Besides, the study determined the impact of socio-economic factors such as gross profit per hectare, agricultural products market, technical training, support policies, farming practices, irrigation water and time of salinity intrusion or fresh water in the year on the agricultural production in Vung Liem. The finding pointed out that it is necessary to propose structural and non-structural solutions to minimize the impact of salinity intrusion on agricultural production.

In order to suitably use acid sulfate soils, it is necessary to survey and determine the genesis, distribution, classification and physio-chemical properties of acid sulfate soils. The research was aimed at describing soil morphology profiles and surveying soil physical and chemical characteristics in some types of acid sulfate soils in Dong Thap Muoi region. Soil samples at the original horizons were taken to determine physical and chemical properties. The soils in Thanh Hoa – Long An province were classified as heavily actual acid sulfate soil (Epi-Orthi-Thionic Fluvisols), which contained the jarosite mottles (2.5Y8/6) below 50 cm depth and sulfidic materials appeared > 75 cm depth. In Tan Thanh – Long An province and Tan Lap – Tien Giang province, the soils were classified as lightly actual acid sulfate soil (Endo-Orthi-Thionic Gleysols and Fluvisols), of which the jarosite mottles (2.5Y8/6) occurred >50 cm depth and sulfidic materials presented > 80 cm depth. The areas in Tan Thanh were surrounded by flood preventing dykes and mainly grown with 3 rice crops all year round. Both areas in Ben Ke and Tan Lap were cultivated with vegetables (Dioscorea alata and pineapple). The pH values within the topsoil layers in all acid sulfate soil profiles in Dong Thap Muoi were low, varying in a range from 2.9 to 4.2. The soils also had medium to high risks of Al, Fe toxicity and low contents of exchangeable cations Na+, K+, Ca2+, and Mg2+. During cultivation, these soils should be applied with organic fertilizers or alkaline fertilizers to neutralize, reduce acidity, and increase soil fertility.