1.1.2. In Vietnam
1.1.2.1. Theoretical base of thematic map and its applications
Research in this area focusing on building up a theoretical basis and applications of thematic maps has widenly developed and contributed to socio-economic development and science research in Vietnam.
1.1.2.2. The methods of assessing soil environment quality
This is a deeply specialized research trend. Researches often use individually criteria in assessing soil environment quality or indirectly evaluate through directive indicators related to soil environment quality. Besides, there exits a number of researches apply the method of FAO in assessing soil capabilities [29], [37].
1.1.2.3. The studies on assessing soil environment quality
In 2000, Pham Ngoc Ho, Hoang Xuan Co et al, Environmental Impacts Assessment in Hoabinh province, initially launched a new method to evaluate SEQ.
In 2009, the General Department of the Environment issued a method to calculate indicators serving evaluating water environment quality. However, this method has not been applied for indicators evaluating other components of environment such as soil, air.
There are 5 main categories of soil in Haiduong, including salinity soil, acid sulphate soil, alluvial soil, gray and barren soil and feralit soil. In which, there are 10 sub-categories, including light salinity soil and intense salinity soil, potential deep and salt acid sulphate soil, neutral and less acidic alluvial soil, silted and sour alluvial soi, glay alluvial soil, alluvial soil with patchy red and yellow, gray soil on ancient alluvial, feralit soil on clay and chalk laid schist, light yellow soil on sandstone, feralit soil changed due to wet rice cultivation. Kinds of soil are distributed unequally in the whole province.
- The SEQ assessment maps were applied by new assessment method - using total indicators TSQI method inherited TEQI method of author Pham Ngoc Ho. This new method reflected an overall picture of SEQ through 11 indicators (for Haiduong province), with 5 SEQ levels in rating scale including good, moderate, poor, bad, very bad corresponding to 5 soil degradation levels: has not yet degraded, starting to degrade, slightly degrade, strongly degrade and extremely degrade. Establishing these maps also helps to develop and finilize technical process of establishing provincal SEQ maps.
- SEQ of land for is generally good with 30.74% of has not yet degraded, 36.25% of starting to degrade, 28.56% of slightly degrade and 4.46% of strongly degraded. The areas with different levels of degradation are not equally distributed in the province of Hai Duong. Increasing waste causing pollution and degrading soil quality has raised new urgent tasks for environment management and protection in Hai Duong.
- The established maps are appropriate and strong tools to support for environment management and protection in local areas. It can be easily to extract data about area of each SEQ level, or statistic by districts to serve soil environment management in Haiduong province. Besides, this process can be applied for other provinces in the whole country. Additionally, the maps illustrated visually and scientifically for an over view of SEQ in the whole province that effectively serve for planning territory development for decision makers as well as to consulting options in mineral exploitation for companies.
2. Recommendation
- The Government State, ministries, departments should research to timely issue technical standards for assessing SEQ by each criterion. Besides, it should be completed technical process min establishing soil environment maps to unify the system of soil environment maps in environment management and protection.
- Employing maps in environment management and protection.
- Developing database on soil environment and national monitoring system of soil and land environment to update every year and monitor changes in soil environment. From that proposing appropriate decisions for development strategies for every local.
Hai Duong Province should clearly identify areas of land for food crops with different level of soil evironment quality to have appropriate plans of soil exploitation and management. Besides, this also help timely detect and rescue areas of strong degradation to sustainably developt.