Zoning groundwater potential recharge using remote sensing and GIS technique in the Red river delta plain

The Red River delta plain is the second largest delta in Vietnam and is located in the North of the country with an area of 14,860 km2 and residing more than 22.5 million inhabitants. Groundwater is mainly exploited in Quaternary sedimentary aquifers with a total discharge of about 3 million m3/day. Some localities have shown signs of over-exploitation such as in Hanoi and in Nam Dinh, which may lead to related problems such as depletion, subsidence, saltwater intrusion, and water pollution. In order to be able to sustainably exploit groundwater, the groundwater potential recharge needs to be estimated. There have been many studies using different methods to estimate the groundwater recharge and to zone potential recharge. In the study area, there are several studies for groundwater recharge, but some are still uncertain because of using indirect methods, some are locally estimated in specific areas. Therefore, the objective of this study is to apply remote sensing and GIS to zone the groundwater potential recharge and its verification by using radioactive isotope 3H analysis in the Red River delta plain. Various types of satellite images have been used and interpreted to detect the different thematic layers which concern the groundwater potential recharge. GIS has been applied as a platform for analysis and integration of thematic layers for zonation, finally. Field trip and water sampling for chemical and radioactive 3H analysis were also conducted. Zones with low, moderate, and high groundwater potential recharge have been delineated with good agreement from the direct estimation of groundwater recharge by radioactive isotopes 3H.

APPLICATION OF HIGH-TECH AGRICULTURE BY HOUSEHOLDS IN THE RED RIVER DELTA OF VIETNAM

This study is conducted to model the factors that influence the decision to apply high technology in agricultural production (agricultural production) of farmers in the Red River Delta (RRD), Vietnam. Data used for the study are surveyed in fact 600 households participating in agricultural production in the RRD. The paper uses the Binary Logistic regression analysis method to identify the factors affecting the decision to apply high technology to agricultural production. The research results show that factors such as farm households' education, people's participation in social organizations, the impact of urbanization, capital and market availability all have positive effects extreme decision to apply technology of farmers. Based on the results of the study, the paper proposed policies to be focused on to enhance the application of high technology in agricultural production by farmers. The findings of this study demonstrate that people's application of high technology to agricultural production is improved by enhancing their production capacity.

Vietnam labour policies and its impact on rural wages: an experience from hired farm labourers in the Red River Delta

Purpose. The purpose of this article is to understand how Vietnamese policies for labour impacting on wage of rural labourers in agricultural sector. To do that, the paper particularly pays attention on analyzing wage of hired farm labourers in the Red River Delta region, the rice basket of Vietnam. Methodology / approach. Analyzing the above-mentioned impact of Vietnamese policies was performed by using data surveyed from 150 hired farm labourers in the Red River Delta of Vietnam. The survey on wages of rural labourers was conducted in Bac Ninh, Thai Binh and Hai Duong which are the three typical agricultural production areas in the Red River Delta in 2019. In this survey, the author interviewed 150 people who work as hired labourers in rice cultivation in Bac Ninh, clam farming in Thai Binh and pig raising in Hai Duong. The sample was randomly drawn among farm households which hire labourers in these provinces. This sample was divided into 2 groups of female and male labourers. The main purposes of this survey were to gather both qualitative and quantitative data on hired labourers including: age, gender, education level, money wage, wage in kind and other remunerations that they received from employers. Information relating to their participation in social insurance and vocational training were also collected like: number of years involving in social insurance; money that they used to purchase social insurance; frequency and time spending in vocational training courses. The personal interviews using a standard questionnaire with open and close questions were implemented separately with male and female hired farm labourers. They were interviewed in different places to ensure that their responses do not affect others. After checking for missing values, the author used the following methods: frequency distribution with mean and standard deviation for a description of respondents; cross tabulation and T-test were also used to test for differences in proportions and significant difference between groups; a linear regression model was applied to examine impact of wage regulation, social insurance and vocational training policies on wage of hired labourers in agricultural production (dependent variable was average money wage per month, it was estimated by sum of money wage and other remunerations that a labourer gets each month; independent variables were age, gender, education level and dummy variables which represented labourers’ participation in mentioned labour policies). Results. Among policies relating to agricultural sector, the ones about minimum wage and vocational training statistically impact the most on labour wage. Longer time of vocational training brings an additional 3 USD to a labourer’s monthly wage. Being supported by the policy of minimum wage, labourers can achieve higher wage when negotiating with employers. The author found that wage of a labourer who is aware of this policy is about 5 USD higher than that of others. Meanwhile, social insurance policies do not impact on wage of rural farm labourers. It is stated in the Labour Code that a part of social insurance fee of a contracted labourer is paid by his/her employer. However, hired agricultural labourers usually are excluded, because they mostly work under verbal agreements which are not specified by the Code. This loophole in the Labour Code need to be corrected in the future. Originality / scientific novelty. Despite the fact that industrialization process is rapidly developing in recent years, rural labour force still contributes a remarkable proportion in the Red River Delta region of Vietnam. The transferring skilled and young labourers from farm to off-farm sectors, from rural to urban areas leads to the existence of un-skilled and old-age labourers for agricultural production. This labour force is working in the poor condition with unstable and low wage jobs. However, they are not much concerned by labour policies and there is still a gap in research on their wage. Therefore, this study takes the advance to shed the light on the impact of labour policies on wage of rural farm labourers as well as to propose recommendations to adjust labour policies regarding this issue. Practical value / implications. The author identifies that attending vocational training and understanding of minimum wage will increase the chance for labourers to obtain higher wage.

Riverbank Filtration – A Potential Water Source Exploitation for the Red River Delta Region

Riverbank filtration technology has been widely applied worldwide because of its high-capacitycollection and good water quality throughout natural purification processes. Infiltration water can beextracted from Holocene (qh) layer or the Pleistocene deep layer (qp), replenished with water from theriver through hydrogeological windows. Hydrodynamic and isotopic signatures were employed todetermine water seepage capacity. The results show that infiltrated water is found in the sand layers alongthe rivers. However, the seepage rate shows a heterogeneously spatial variation ranging from 30 m3/d inthe Dinh Dao river to 33,600 m3/d. Km along the shoreline in the Red River (RRD). Also, the exploitationcapacity of seepage water differs widely in order of large (> 3,000 m3/d), medium (1,000-3,000 m3/d),small (500-1,000 m3/d), and very small capacity (200-500 m3/d). This study indicated that RRD couldapply riverbank filtration techniques to overcome freshwater scarcity in the delta due to increasing surfacepollution and discharge reduction.

Depth Profiles of Microplastics in Sediment Cores from Two Mangrove Forests in Northern Vietnam

Plastics are essential materials that play critical roles in people’s lives in the modern world. However, plastic pollution in the ocean has become a critical environmental problem due to the fact of its durability and long life span. In the present study, we analyze the contamination of microplastics in sediment cores from mangrove forests of the Red River Delta and Tien Yen Bay in Northern Vietnam. The results showed that the concentration of microplastics in sediment cores ranged from 0 to 4941 particles/kg, with four types of microplastics: microfiber, microfragment, microfoam, and microfilm. Microplastics were not observed in sediment samples lower than 65 and 70 cm core depth in sediment cores from the Tien Yen Bay and Red River Delta. The microplastic concentration in sediment cores from the Red River Delta was significantly higher than those of Tien Yen Bay, reflecting the influence of anthropogenic activities on microplastics pollution. The present results highlight that the accumulation of microplastics may have occurred a long time ago and tends to increase in the future. Further investigation on microplastic accumulation rates, sources of microplastics, and reducing plastic pollution is necessary to minimize the impacts of microplastic pollution on aquatic life and the environment.

Spatial distribution of arsenic in groundwater in the northwestern Hanoi

Arsenic contamination in groundwater is commonly found in alluvial plains of major river basins, in which the Red river delta has also been reported to be contaminated with high levels of arsenic. In this study, groundwater from 50 household wells was collected to study the spatial distribution of arsenic in northwestern Hanoi. The results showed that arsenic concentration in groundwater varied in a wide range of less than 5 to 334 μg/l, of which up 62% of the wells exceeded the WHO guideline value of 10 μg/l for arsenic content in drinking water. Arsenic groundwater in this area is unevenly distributed throughout the area, high arsenic concentrations are found in a narrow band between Red river and Day river. This pattern of arsenic distribution is strongly related to the sediment age, sedimentary processes, and it is also modified by local groundwater flow parts and the occurrence of hydraulic connection between aquifers, which are observed in the study area. Arsenic is released into the groundwater during the reductive dissolution of arsenic-bearing minerals under the presence of organic matter.

Policies supporting for agricultural cooperatives in Vietnam: An experience from agricultural cooperatives in the Red River Delta

Agricultural cooperatives have been established in Vietnam since the 1950s. During its development, agricultural cooperatives have made significant contributions to the growth of agricultural sector and to the improvement of farmers' income who are members of the cooperatives. Since Vietnam implemented the "Innovation-Doi moi" in 1986, the Government has continued to issue many policies to support for agricultural cooperatives. However, the impact of these policies on the development of almost all agricultural cooperatives has not been as expected. This paper aims to analyze the implementation of several policies supporting for agricultural cooperatives; to identify advantages and disadvantages of these policies; and to propose solutions for improving policies in the furture. In addition to secondary data from the Vietnam Cooperative Alliance, this paper uses primary data collected from 60 agricultural cooperatives in the Red River Delta to analyze the implementation of policies on cooperative staffs training, cooperative finance supporting, and cooperative land supporting. Bascially, the results show that the policy on training cooperative staff is quite well implemented, it helps to improve the capacity of cooperative managers in all surveyed cooperatives. In contrast, the finance supporting policy has many regulations that make it difficult for agricultural cooperatives to access capital, only nearly 30% of surveyed cooperatives get loans for production. Similarly, the land supporting policy also has unreasonable regulations which prevent agricultural cooperatives from scaling-up production because of the lack of farm-land. Consequently, about 60% of surveyed cooperatives are supported to rent farm-land for expanding agricultural production.