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Research objectives Establishment of scientific grounds for sustainable planning and land use of Da Lat city and its vicinities on the basis of research, exploitation and use of land bas

MINISTRY OF EDUCATION

AND TRAINING

VIETNAM ACADEMY OF SCIENCE AND TECHNOLOGY

GRADUATE UNIVERSITY OF SCIENCE AND TECHNOLOGY

-

NGUYEN THI THUY

STUDY ON GEOGRAPHIC BASIS IN EXPLOITING AND USING LAND FOR SUSTAINABLE PLANNING

IN DA LAT CITY AND ITS VICINITIES

- LAM DONG PROVINCE

Major: Geography of Resource and Environment

Code: 9 44 02 20

THESIS SUMMARY FOR GEOGRAPHY DOCTOR

Hà Nội - 2019

The thesis was completed in:

Graduate University of Science and Technology- Vietnam Academy of Science and Technology

Science instructor 1: Ph.D Nguyen Dinh Ky

Science instructor 2: Prof Ph.D Sc Hoang Van Huay

Thesis can be found in:

- The Library of Graduate University of Science and Technology

- Vietnam’s National Library

INTRODUCTION

1 The necessity of the thesis

Urbanization is an inevitable trend in the history of social development Urban population has now reached 50% of the total world’s population, with rapid urbanization, especially in developing countries Urban concentration has brought greater economic scales to cities and territories, but its downside can lead to negative impacts on resource degradation and environmental pollution To address these challenges, various approaches

in urban and territorial planning have been studied and implemented Located on Lang Biang Plateau, with an average altitude of 1,500m above sea level, Da Lat City is the first-class city of Lam Dong province This is a famous vacation and tourism place of Vietnam However, over

120 years of formation and development, today's landscape of Da Lat has had a great change The city's space has been constantly expanding in terms

of residential land and agricultural production land, narrowing forest land, increasing the density of housing and agricultural production works, concentrating in the central area, which have changed the landscape structure and polluted the city It can be seen that the changes in the land use exploitation structure are the direct reasons that cause Da Lat to be in danger of losing the "proportion of space" in the landscape structure and the decline of the entire ecosystem In order to overcome the problems and develop Da Lat City sustainably, an optimal solution is directed, that is to promote the potential of vicinities with similar climate - soil conditions On that basis, the government approved the "General Plan of Da Lat City and its vicinities until 2030 and vision to 2050" (May 2014) According to the plan, Da Lat city will become a major city, the boundary will be expanded

to vicinities and cover an area of 8.5 times as much as today The urgent problem is that there is a need for comprehensive studies and assessments

of the natural potential, situation and demand of land use, thereby establishing a sustainable land use planning and solution to expand the land use spaces of Da Lat City, resolving the conflicts in exploitation and land use between spaces, and meeting the development orientation of the city in the future

Researching on integrated natural geography is a comprehensive and spatially specific approach, a comprehensive research of natural and socio-economic components in the complex interplay and interaction in a specific territory Since then, the direction and solution of resource use and socio-economic development have been set in accordance with the geographical laws of the territory This is an effective research method for the planning

of rational use of resources and nature protection in the direction of sustainable development for any territory

Stemming from the urgent requirements of Da Lat city, with the desire to

contribute to the city's sustainable development, the thesis: "Study on geographic basis in exploiting and using land for sustainable planning of Da Lat city and its vicinities - Lam Dong province" has been selected to perform

2 Research objectives

Establishment of scientific grounds for sustainable planning and land use of Da Lat city and its vicinities on the basis of research, exploitation and use of land based on geographic approach

3 Research implementions

- Overview of related documents, as a basis for building a theoretical basis and methods, research process of land use exploitation based on geographic approach for sustainable planning and land use of Da Lat City and its vicinities;

- Analyzing characteristics of arising conditions – degeneration of soil and land resources in Da Lat city and its vicinities;

- Identifying causes, process of soil degradation and evaluation of aggregated soil degradation in Da Lat city and its vicinities;

- Assessing and classify land in Da Lat city and its vicinities for the main land use types;

- Determining the percentile and norm system, and making a geographic zoning map of the soil of Da Lat city and its vicinities;

- Proposing spatial orientation and solutions for sustainable land use planning in Da Lat city and its vicinities

4 Research area and objects

- Research area: Da Lat city and its vicinities (including Lac Duong, Don Duong, Duc Trong and Lam Ha districts)

- Research objects: Arising geographical factors - degradation and land resources

5 Protected thesic points

- Point 1: The diverse and complex differentiation of the soil cover

reflects the specific geographic laws and the corresponding processes of land generation, development and degradation in the territory of Da Lat city and its vicinities, expressed through a system of land units and geographic zoning units with diverse characteristics and potentials

- Point 2: Integrating results of research on characteristics and directions

of land use and protection of each soil sub-region with results of land classification and soil degradation assessment, creating a reliable scientific basis for the proposal of spatial orientation and solutions for sustainable land use planning of Da Lat city and its vicinities

6 New thesic points of

- Clarifying the regular characteristics and spatial division of soil cover of

Da Lat city and its vicinities, as evidenced by the system of soil geographic zoning units shown on the map at 1: 100,000 scale

- Proposing spatial orientation and solutions for sustainable land use of Da Lat city and its vicinities, based on an integrated analysis of the results of assessment of land classification, integrated soil degradation assessment and soil geographic zoning

7 Scientific and practical contributions

- Scientific contributions: Contribute to supplementing the theoretical basis

and research methods of land use exploitation based on geographic approach for sustainable planning and land use of tropical highland urban areas Enrich the research direction of applied geography in rational planning and protection of natural resources for sustainable development of the territory

- Practical contributions: The research results are a scientific basis for the

locality to refer to territorial organizations, planning and land use planning

in the orientation of sustainable development

8 The structure of the thesis

In addition to the introduction, conclusions and recommendations, references and appendices, the thesis content consists of 4 chapters:

Chapter 1 Theoretical basis and research methods of land use

exploitation with geographic approach for sustainable planning and land use

Chapter 2 Characteristics of arising geographical conditions -

degeneration of soil and land resources in Da Lat city and its vicinities;

Chapter 3 Evaluation, classification of land and general land

degradation in da lat city and its vicinities;

Chapter 4 Proposal of spatial orientation and sustainable land use

solutions for Da Lat city and its vicinities

Chapter 1 THEORETICAL BASIS AND RESEARCH METHODS

APPROACH FOR SUSTAINABLE PLANNING AND LAND USE 1.1 Some used concepts

1.1.1 Soil, land, land resources and environment

1.1.1.1 Soil

From a biological perspective, V.V Docuchaev (1879) gave the

definition: “Soil is a natural entity with its own developmental origin and

history, an entity with complex and diverse processes taking place in it, formed under the mutual influence of basement rocks, topography, climate, organisms, humans and time”

Fertility is a basic property of the soil, defined: “Fertility is the ability

of the soil to provide plants with water, mineral nutrients and other necessary elements (air, temperature, etc) for plants to grow and develop” 1.1.1.2 Land

According to FAO (1976), Land covers all elements of the natural

environment, which affect land use potential, including climate, topography, soil, hydrology, organisms, and results of human activity in the past and present So land is a broader concept than soil

1.1.1.3 Land resources and environment

Land resources: It is understood as the entire crust of the earth in

which organisms and humans can live

Land environment: Is a complex ecosystem, formed through physical,

chemical and biological processes

1.1.2 Land evaluation and soil degradation

1.1.2.1 Land evaluation

Land evaluation is defined as:“Assess the effectiveness of land when

used for a specific purpose, involving the conduct of studies on soil, climate, vegetation and other aspects of land to identify and compare the requirements of specific types of land use and land conditions for the purpose of the evaluation” (FAO, 1976, 2007)

1.1.2.2 Soil degradation

As defined by FAO (2002): “Soil degradation is a temporary or

permanent decrease in the productive capacity of soil"

From the perspective of synthetic natural geography, Nguyen Dinh Ky

(1987, 1990) stated that: “In the stage of generation, development, soil

degradation is governed by inherent natural processes called potential degradation Degeneration of each element of soil properties or comprehensive degradation in each time of land use exploitation is considered as current degradation”

1.1.3 Sustainable land use and land use planning, space organization

1.1.3.1 Sustainable land use

Sustainable land use is a form of land use that helps maintain the soil's natural fertility and allows efficient production and regeneration of natural resources on a long-term basis

FAO (1993) developed the definition of specific sustainability in

agriculture: "Sustainable agricultural land use is a type of land use that

can produce enough to meet the needs of current and future residents while preserving and improving land resources to ensure production."

1.1.3.2 Land use planning

FAO/UNEP (1999) gave the definition: "Land use planning is a

systematic evaluation of land and water potentials, land use plans and socio-economic conditions to select and apply the best land use plans." In

other words, land use planning is the key to a sustainable development of a

territory

1.1.3.3 Space Organization

The concept of spatial organization or territorial organization is agreed

to be: The arrangement and coordination of objects in multidisciplinary

relationships in a specific area in order to rationally use natural, labor potentials, socio-economic geographic location and technical facilities have been and will be built to bring about high socio-economic benefits and improve the living standards of the people in that region Spatial/

territorial organizations devise integrated and regional development strategies for each region to achieve the territorial sustainable development goals

1.2 Overview of research works on land evaluation, land classification and soil degradation

1.2.1 The research works on land evaluation and classification

1.2.1.1 In the world

Irrigated land classification (1951) and potential-based land classification (1961) are two evaluation systems built specifically for the condition of the United States based on the constraints of land that interfere with land use;

Evaluate and classify land according to V.V Docuchaev's point of view in Russia and Eastern Europe (1960) by scoring derived factors and soil properties on the basis of an agreed benchmark scale

In order to unify worldwide land evaluation standards, FAO (1976)

developed "Land evaluation framework" Actually, this is a set of

principles and methods, on which the land evaluation systems of any country and at any rate can be built FAO also provided specific guidance

on the detailed application of the "evaluation framework" for specific

subjects such as: Land evaluation for rain-fed agriculture (1983), Land

evaluation for forestry (1984), Land evaluation for irrigated agriculture (1985), Land evaluation for extensive pastures (1991) At the same time,

along with the development of technology and its application in the land evaluation process has contributed to quantification and correction of research results Studies on land evaluation based on FAO's guiding framework and GIS application have become popular in the world, mainly

in the following directions: GIS application and available utilities of GIS; GIS integration and advanced tools (RS, GPS, etc); GIS integration and automated soil evaluation software (ALES)

In addition, FAO has also provided specific guidelines on the land evaluation process in land use planning for sustainable development, such

as: land evaluation for development (1986), guidelines for land use

planning (1993), land evaluation framework for sustainable land management ( FESLM, 1993), planning for sustainable use of land resources (1995) and two latest guidelines on integrated planning for sustainable management of land resources (1999) and land evaluation - towards a revised framework (2007) These guidelines have suggested

considering factors related to sustainability (natural suitability, high economic efficiency, social acceptance and no negative impact on the environment) in the land evaluation process, using the multi-criteria decision analysis (MCDA)

1.2.1.2 In Vietnam

Since the late 1980s, FAO land evaluation studies have been conducted extensively in localities across the country Land evaluation becomes a mandatory rule in land use planning The works are carried out from large ecological regions to provinces, districts and specific research areas, for example: at regional level, there are studies of Vu Cao Thai (1988), Tran

An Phong (1992), Nguyen Van Toan (2005), Vu Nang Dung (2015), etc;

At the detailed level, there are studies of Nguyen Khang (2001), Tran An

Phong (2002, 2004), Luu The Anh (2003), etc

At the same time, along with the technological development of the world, current studies on land evaluation in our country are applying GIS,

in addition to combining with RS, GPS and automated soil evaluation software and multi-criteria decision analysis Some typical works by: Tran

An Phong (2001), Nhu Thi Xuan (2006), Le Canh Dinh (2011), Vu Nang Dung (2014), Nguyen Thanh Tuan (2015), etc

1.2.2 The research works on soil degradation assessment

1.2.2.1 In the world

Researching on soil degradation is gradually opened as a research direction in soil science for effective planning and sustainable land use

From 1987-1990, the project “Global Assessment of Human-induced Soil

Degradation (GLASOD)” developed by UNEP and ISRIC to produce a

map of global soil degradation status at 1: 10,000,000 scale

In addition to global-scale studies, soil degradation has also been studied in detail for regions, countries and territories, including the

following typical works: Project on Assessment of Soil Degradation in

South and Southeast Asia (ASSOD) (FAO and ISRIC, 1994-1997); Project

on Assessment of Soil Degradation in Central and Eastern Europe (SOVEUR) (FAO and ISRIC, 1997-2000); Project on Assessment of Soil Degradation in dry areas (LADA) in 6 countries: Argentina, China, Cuba, Senegal, South Africa and Tunisia (FAO and GEF, 2002-2008); Assessment of Soil Degradation in Togo ( ORSTOM, 1991 - 1994); Soil degradation research in India (NBSS, 1992); Global Soil degradation Mapping (Gibbs HK, et al, 2015)

1.2.2.2 In Vietnam

The studies of soil degradation in our country began in the late 1960s and gradually became a research branch of soil science, focusing on the following directions:

Studies on soil degradation according to types of degradation: typical studies on soil degradation due to erosion by Nguyen Quang My (1980, 2005), Nguyen Trong Ha (1996), etc; Studies on land degradation according to types of degradation (with application of ASSOD system) of

Vo Quang Minh (2003), Nguyen Xuan Thanh (2009), Center for Surveying and Assessing Land Resources - Ministry of Natural Resources and Environment (2009-2012)

Studies on land degradation based on the aggregated natural geographic point of view of Nguyen Dinh Ky et al (1987, 1990, 1998, 2007, 2012, 2015);

Studies on land degradation, and rehabilitation and restoration measures of Nguyen Tu Siem and Thai Phien (1998, 1999, 2002);

In addition, studies applying other methods of soil degradation assessment have been implemented, such as those of Nguyen Quang Viet (2014); Nguyen Thi Thuy (2016)

1.2.3 The research works in Da Lat city and its vicinities

1.2.3.1 Studies on land evaluation and classification

From 1995 to 2010, the People's Committee of Lam Dong Province

conducted the program "Evaluation of agricultural land in Lam Dong",

conducted by the Southern Soils and Fertilizers Research Institute - SFRI Based on FAO (1976) guidelines, assessment of agricultural land for communes at 1/10,000 scale maps, districts/cities at 1/25,000 scale to assess land quality, proposed land use and crop intensive measures From

2009 to 2012, Center for Surveying and Assessing Land Resources -

Vietnam General Department of Land Administration conducted Land

evaluation for agricultural production land in Lam Dong province at 1/100,000 scale From 2011-2015, National Institute of Agricultural

Planning and Projection conducted Land evaluation and proposing

solutions for sustainable development of industrial crops and food crops in Lam Dong at 1/ 100,000 scale

In addition, there are detailed land evaluation studies in districts, such

as those of Le Canh Dinh and Pham Quang Khanh, (2005); Vo Thi Phuong Thuy and Le Canh Dinh (2011); ect

1.2.3.2 Studies on soil degradation

In 1998, in a cooperation program between the Institute of Geography and the French National Research Institute for Sustainable Development

(IRD), author Brabant P established "Soil degradation map of Lam Dong

at 1/100,000 scale" on the basis of interpreting satellite images from 1992

to 1998, combined with color aerial photographs and field survey results In 2009-2012, the Center for Surveying and Assessing Land Resources - Vietnam General Department of Land Administration conducted the

assessment of soil degradation status in Lam Dong province at 1/100,000 scale on the basis of applying the ASSOD soil degradation assessment

system In 2011-2015, Luu The Anh, Nguyen Dinh Ky et al established

potential soil degradation, current land degradation and aggregated land degradation maps of Lam Dong province at 1/100,000 scale from the

perspective of aggregated natural geography

1.3 Theory of research on land use exploitation according to geographic approach for sustainable land planning and land use

1.3.1 The nature of geographic approach in the study on rational use and protection of natural resources

Geography is a complete scientific system, studying the natural world

on the earth's surface, development conditions and production distribution characteristics and interaction between human society and geographic environment (Le Ba Thao, 1987) The objects of the study of geoscience are the geographic objects, also known as the geographic integers, in which the geographical crust is the geographic integer at planet scale It is the interdependence and interaction between the geographic components that make up the internal differentiation of the geographical crust, forming geographic integers of different scales

In order to have a basis for selecting the most appropriate territory for different uses, it is necessary to make an overall assessment of natural geographic integers according to ecological adaptation, economic efficiency, environmental and social sustainability

Thus, the geographic basis within the scope of the thesis can be understood simply as the results of the study towards the integrated assessment of natural geographic integers created for various purpose of use, as a basis for proposing orientations for rational use planning and protection of natural resources for sustainable development of a territory

1.3.2 Researching on land use exploitation according to geographic approach for sustainable planning and land use

Soil is a function of all other geographic factors, the most obvious expression of a geographic integer Accordingly, the soil cover as a geographic structure has the structure from the simplest (soil unit) to the most complex (soil cover) In land evaluation, land units are interpreted as soil areas with relatively homogeneous (natural and socio-economic) attributes whereby the boundaries between it and the others can be distinguished Thus, according to the geographic approach, the land units are also the geographic integers (incomplete) and are a structural unit of the soil cover

Accordingly, the integrated research and evaluation of land units to determine the direction of sustainable use and exploitation for specific purposes of the territory is the geographic approach in the study of land use for sustainable planning and land use In other words, it is the study of the arrangement of land use types on land units in a sustainable manner, both in accordance with the arising geographical laws, the development of the soil cover, and promoting the maximum potential of natural land, bringing high economic efficiency and minimizing the negative impacts on land environment resources

Thus, the integration of land classification and soil degradation assessment results with soil geographic zoning will more effectively show the results of land aggregate assessment in the close relationship between soil geographic sub-regions The purpose of this process is to give a direction to the land use space and develop sustainable territories, as a scientific basis in planning and land use of the territory in the direction of sustainable development

1.3.2.1 Land Unit Map

Land Unit Map is the basic maps in the evaluation that completely and objectively reflects the land properties in the relationship and the reciprocal impact with arising geographic factors - soil degradation The Land Unit Mapping method is the overlap of many types of factor maps showing land properties such as: land map, topographic slope, isometric map of rain, temperature, watering ability, etc The results of the construction of the land units are relatively uniform in all criteria, shown on the map as lands with enough characteristics to make a difference with the other land units

1.3.2.2 Evaluation and classification of natural land

Land evaluation and classification are actually the process of comparing the inherent properties of the land units with the land properties that the land use type requires, in order to classify the natural suitability of

a land unit with that land use type Level of suitability is a measure of how well a land unit ensures the needs of the land use type evaluated The land evaluation and classification are determined according to the following

principles, standards and popularity (FAO, 1976, 1983, 1984, 1985):

Evaluation principles: (1) Limitations, (2) Dominant factors; Level of suitability: (1) Very suitable (S1), (2) Medium suitable (S2), (3) Less

suitable (S3), (4) Not suitable (N)

1.3.2.3 General land degradation evaluation

The nature of soil degradation is the process of changing the properties

of the soil leading to a reduction or loss of production capacity The causes

of degeneration are very diverse, complicated and associated with the conditions of soil generation, some places are mainly caused by nature and some are caused by humans, which are divided into different types according to the degenerating agent (Nguyen Dinh Ky, 1987, 1990): (1)

Potential soil degradation is the ability of natural fertility degradation of

the soil due to natural processes It is assessed by the soil degradation potential of soil-generated geographic conditions (including: basement rock/ age of basement rock, mantle rock, topographical and climate conditions, local hydrology) assuming no vegetation cover and human

impact; (2) Current soil degradation is the current soil fertility degradation

compared to the natural fertility due to the exploitation and use of humans

It is assessed by the degradation status of soil physicochemical and

biological properties leading to a decrease in soil productivity; (3) General

soil degradation is the result of forecasting the extent of soil degradation

when used for specific purposes It is assessed by the current fluctuation of soil degradation level based on potential soil degradation by space

1.3.2.4 Soil geographic zoning

- Percentile system inherited in the thesis:

The study of natural geographic zoning in general does not have a common percentile system, each country, even each author, based on his/her experience to come up with a percentile system, to contribute a part

to progress towards that common percentile system

According to Vu Tu Lap (2011), each generated land unit bears the mark of the basic natural geographic laws of zonal law and non-zonal law The distribution of each land unit and their spatial combinations, the structure of the soil cover on the territory are necessarily subject to those laws Therefore, when determining the natural geographic zoning units for any natural territory, it is required to analyze in detail and specifically the evolution of these laws

In Vietnam, the percentile system applies to the scale of the Vietnamese territory (1/1,000,000 scale) built by the Vietnam Soil Science Association, including 4 levels: Region - Sub – Region - Area - Zone (Ton That Chieu, 1996) Subsequent soil geographic zoning studies were primarily developed based on the inheritance of the above percentile system and zoning sign for different territories The number of zoning units

may be more or less depending on the size and complexity of the studied territory With small studied territories it is possible to divide the territory into sub-regional units

- Principles of soil geographic zoning:

Include arising, aggregating and dominant factors, relative

homogeneity, sharing the same territory

1.3.3 Scientific grounds for assessing and aggregating land for sustainable planning and land use in Da Lat city and its vicinities

1.3.3.1 Basis for determining research boundaries and scope: Based on

(1) the development history of Da Lat city through periods; (2) Planning to expand Da Lat City to 2030 and a vision to 2050; (3) Characteristics of

- The differentiation of soil cover is diverse and complicated due to the influence of the non-zonal differentiation rules, especially the law of high-belt differentiation and tectonic-geomorphology differentiation, expressed through the system of feralite soils on different types of basement rocks and high belts, creating favorable conditions for the research area to develop a wide variety of agro-forestry crops and form large specialized annual and perennial tree-growing areas on the highlands

- The natural area of the territory is mainly forestry land and agricultural production land However, the current forest cover in mountainous areas has been strongly reduced, which is mainly caused by deforestation to expand agricultural land This is also the main conflict in land use exploitation in the research territory Therefore, the identification

of appropriate space, the arrangement of agricultural and forestry production types in a scientific way, not only resolve conflicts in land use exploitation among territorial spaces and meet the objectives of ensuring food security and economic development (providing raw materials for processing and export industries) but also protect land, water, forest resources and protect the natural environment for sustainable territorial development

- Due to the terrain of the plateau and mountains with high slope, the potential soil degradation processes (erosion, washout, landslides, etc.) are very great, areas that lose their forest cover or agricultural production lacking soil protection measures has led to serious soil degradation

- As an area with diverse and increasing types of non-agricultural land use Therefore, in the orientation of sustainable development of territories,

it is necessary to consider the structure and characteristics of specific types

of non-agricultural land use in each of those territories

1.3.3.3 General land evaluation for spatial orientation and sustainable land use solutions in Da Lat city and its vicinities

According to the geographic approach, a general land evaluation based

on the integration of the results of land classification and evaluation and soil degradation assessment by soil geographic zoning will determine the

sustainable land use type for land units in the territory, thereby providing spatial orientation and appropriate land use solutions as a scientific basis for sustainable planning and land use in Da Lat city and its vicinities From the specific characteristics of land use exploitation in the studied territory, the natural land area as well as the conflicts and contradictions in the territory's land use structure mainly belong to agricultural production space and forestry space, the thesis focuses on researching, proposing orientations and solutions for sustainable land use for these two spaces At the same time, analyzing the results of land use orientation for agricultural-forestry-urban production spaces by each soil sub-geographic region to propose priority development space orientations for each territory, aiming

to organize a sustainable space in Da Lat city and its vicinities

1.4 Research views and research methods

1.4.1 Research views: Use of specific research perspectives of the

integrated natural geography including soil biological perspective, ecological perspective, historical perspective, system perspective, integrated perspective and sustainable development perspective

1.4.2 Research Methods: Methods of inheritance and integration;

Methods of survey and investigation; Methods of analyzing soil physical and chemical properties in the laboratory; Expert methods; Methods of assessing economic efficiency of land use types; Mapping and GIS method; Methods of land evaluation and classification; Methods of soil degradation assessment; Methods of soil geographic zoning

1.5 Research procedure

Figure 1.5 Diagram of research steps

Study the geographical basis in land use exploition for sustainable planning in

Da Lat city and its vicinities - Lam Dong province

Define goals and missions

Determine theoretical basis and

research methods

Characteristics of arising geographical conditions - degeneration of soil and land resources in the research area

Geographic zoning for the research area

Land ecaluarion and classification

suitable for agriculture and forestry

production

Assess general soil degradation and determine the degree of degradation

on land units Integrated land evaluation for sustainable land use

Proposing orientations for organizing space for sustainable land use

Chapter 2 CHARACTERISTICS OF ARISING GEOGRAPHICAL CONDITIONS - DEGENERATION OF SOIL AND LAND RESOURCES IN DA LAT CITY AND ITS VICINITIES;

2.1 Arising conditions - soil degradation

2.1.1 Geographical location

The research area is located in the north of Lam Dong province, including the administrative boundaries of Da Lat city and 4 adjacent districts: Lac Duong, Don Duong, Duc Trong and Lam Ha (referred to as

Da Lat and its vicinities) The region has an average altitude above 850m above sea level, with geographical coordinates extending from 11030'27” to

12019'4” North latitude and from 108020'18” to 1080

43'39” East longitude The total natural area is 415,101.9 ha, accounting for 42.4% of the province's total natural area

2.1.2 Geological and mantle rock characteristics

2.1.2.2 Mantle rock characteristics

In the law of forming Mantle rock (VPH) of the humid monsoon tropics, the feralitization process (iron and aluminum accumulation) with laterite and laterite - bauxite formations is a key trend However, due to the natural conditions in which the basement rock and topography play the most important role, the research area has weathered products including:

VPH saprolite, silicite, sialite, sialferite, ferosialite, alferite

2.1.3 Topographic and geomorphological conditions

The topography of the research area consists of mountainous areas (medium mountains, high mountains), highlands and plains The popular terrain orientation is Northeast - Southwest The terrain is clearly

hierarchical, lower from the North to the South, including: High level: is

the average high mountain range (1000 - 1500 m), completely up to the

peaks above 2000m (Chu Yang Sin 2,405 m, Lang Biang 2,163 m); Low

level are strong wavy hill-shaped plateaus, consisting of two different

surfaces of about 500m The above ground surface is 1500m high and the below surface is 850-1000m high

2.1.4 Climate and hydrological characteristics

2.1.4.1 Climate characteristics

The study area is characterized by a tropical monsoon tropical climate, strongly influenced by the monsoon tropical circulation and high belt The differentiate of the terrain has divided into climatic regions with different

characteristics, it can be divided into 2 regions: (1) Climate zone of Da Lat