ABSTRACT The researches regarding this doctoral dissertation have been focused on the use of modern techniques and technologies of topography for the inventory and record keeping of land reclamation. The proper deployment of the activities of inventory and record keeping of land reclamation objectives requires the existence of an adequate infrastructure with a correspondent geotopographical database and a cartographic base of the land reclamation field, which were considered priority issues in the conduct of this study. Through the directives adopted by the European Commission in 2006 regarding soil protection, the role of land reclamations increased significantly. After 1990, the transition from state ownership to private ownership of the lands occupied and serviced by land reclamations raises serious issues regarding the management, maintenance and operation of these works on the one hand, but also matters related to the design and execution of other works. This doctoral thesis is divided into five chapters, as follows: The first chapter deals with general issues related to global and national land fund, as well as those related to the land reclamations situation. It also focuses on detailing the aspects (history, evolution, researched areas, etc.) connected to the main land reclamation works: irrigation facilities, facilities destined for the control of excessive humidity, facilities destined for soil erosion control, and facilities for the control of landslide phenomena. Chapter two deals with issues related to the general cadastre and the land reclamation cadastre as a subsystem of inventory and record keeping of land reclamations, which is also called a land reclamation informational system. The technical, qualitative and legal aspects of the general cadastre and the land reclamations cadastre are also being approached. Concurrently, this chapter presents aspects of the current state of research on the development of informational systems destined specifically for land reclamation works, both worldwide and nationwide. Chapter three elaborates on general concepts required for the development and use of the Geographical Information Systems (GIS), in a generic way. Detailed concepts of database, geospatial data, database structure, stages of designing a GIS, data collection and spatial analysis methods and techniques are presented herewith. Chapter four describes the development of the informational system used for land reclamation works at the Cojocna Didactic Experimental Station of USAMV Cluj-
Napoca, as a case study of this thesis. An informational application was developed in the studied perimeter for the land reclamations cadastre, using the ArcGIS software, for the graphic and descriptive database, spatial analysis, visualization and database. An informational system specific to land reclamations allows a detailed description of land reclamation works and objectives. This informational system has been shown to improve the speed of information acquisition, data analysis and verification. Database searches become simpler, more accurate and faster. Through its stages of realization, this case study covers the theoretical aspects presented in the first three chapters and can be used as a working tool in the station s management act, and also in research and practical activities with students. Chapter five presents the operation and management of the informational system which has been developed. Thereby, the implementation of the USLE model is being described herewith, as an important application specific to this chapter s objectives. This chapter also presents the queries, reports, graphics, thematic maps and hyperlinks that can be generated with the help of the informational system described in the previous chapter. Additionally, several ideas regarding the prospects of introducing land reclamations cadastre and 3D cadastre in our country are being approached. Fig.1. Map of Cluj County and the studied area.
The 404 ha perimeter of the studied area is a part of the Cojocna Didactic Experimental Station, which is currently being managed by the University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca (Fig. 1). The hydrographical basin of Gădălin-Căian Valley, where the studied area is located, was included in several projects of land reclamations. This basin is affected mainly by surface and depth erosion and excessive humidity. In the perimeter of USAMV s Didactic Experimental Station - Cojocna area land reclamation works were executed after 2001. In the studied area, land reclamations objectives were identified for surface and depth soil erosion control and excessive humidity control. The identified land reclamation works are located in the southern area of the perimeter (terraces and drainage), and in the SE of the perimeter (works for depth soil erosion control). In the initial project documentation (the Gădălin Valley planning project) others land reclamation works were included, such as forest plantation works for the reclamation and protection of terrains affected by landslides, but these have not been done. Thereby, 69 land reclamations objectives have been identified. Works related to surface soil erosion control are represented by classical and bench type terraces, and those related to depth are represented by outlets. Concrete falls, crossing fords, culverts and double gratings were identified on the outlets. The works for excessive humidity control are reflected by absorbing drains, sewers and inspection pits. The topographical measurements required for rising the land reclamations objectives and the studied perimeter boundary were performed using the points from the state geodetic support network and modern technology (GPS receivers and total station). The main objectives of the field phase were: The verification of several points of the state geodetic support network, using the global positioning technology, with different equipments and work methods; The thickening of the support network using the GPS system; Raising the details and land reclamations objectives with the GPS technology and the total station in order to develop an informational system specific to the land reclamations area. The data resulted from GPS and total station measurements were processed using the GNSS SOLUTIONS, TranLT, TranDatRO, Topcon and AutoCad programs. The Geographical Information System for the land reclamations inventory and record keeping was performed using the ArcGIS Desktop 9.3 program, made by ESRI.
The design of the GIS project database was executed respecting the specific features described in existing laws and regulations regarding the land reclamations cadastre, as well as other features needed to achieve the other proposed objectives (land fund structure by usage categories, the pedological context, and soil erosion study). Spatial data needed for the development of the Geographical Information System were obtained based on plans, maps, the existing orthophotomap and measurements made in the studied area. The database was realized by creating a Geodatabase in ArcCatalog, which contains the layers required to obtain the digital plans. In order to complete the basic digital cadastral plan the existing cadastral plans were used at a scale of 1:5000, along with the 2010 edition of the orthophotomap and the measurements of perimeter, respecting the usage categories and cadastral numbering (Fig. 2). Fig.2. The basic digital cadastral plan
The attributed database of the digital cadastral plan was created in the same time with the plots digitization and filled out with the following information: usage category, usage subcategory, cadastral number, field number, plot number and surface. The digital plan of land reclamations objectives content has been realized according to the Acts of the Ministry of Agriculture, Forests, Waters and Environment and the Act of the Administration and Internal Ministry concerning the approval of Methodological norms for the preparation of cadastral land reclamations published in the Official Gazette no. 190/2004. This digital plan was derived from the basic digital cadastral plan, previously presented, that has been updated with the 69 identified land reclamations objectives, resulted from the measurements. Fig.3. The map of land reclamation objectives The digital cadastral plan of land reclamations objectives (Fig. 3) were assigned with the following layers: a. the area serviced by land reclamation works, on works categories: areas serviced by draining and drainage works (Sdd); areas serviced by soil erosion control works (Sdc);
b. the area occupied by land reclamation works, on works categories: areas occupied by draining and drainage works (Sod); areas occupied by soil erosion control works (Soc). The cadastral numbering of land reclamations - a specific one, as described in the regulations in force, targeting only areas occupied by land reclamation works (work categories). Within this category of works the following work subcategories were listed: areas occupied with draining and drainage works (Sod); areas occupied with soil erosion control works (Soc). Fig.4. Cadastral numbering Within the two work subcategories every objective was listed, therefore 69 objectives were numbered with Arabic numerals from 1 to 69 preceded by the work subcategory symbol (Sod or Soc), starting from NV to SE (Fig. 4). The Informational system of the Didactic Experimental Station Cojocna designed in this way manages the general cadastre and land reclamations cadastre data and allows database structure modelling and spatial analysis.
The operation of the designed informational system took into account the graphic database composition on the one hand, and the pursued objectives on the other hand, the erosion estimation of this area being one of the objectives. The estimation of the effective erosion was determined based on Universal Soil Loss Equation (USLE) adapted by Moţoc M. et al. in 1975, after Wischmeier et. Smith from 1965, revised up to 2002. This equation uses five major factors in the soil loss calculation. Each factor is a numerical estimation of a condition that affects the soil erosion severity in a certain area. The creation of the GIS model database for USLE modelling was performed in accordance with the proposed objectives, being structured on vectorial and raster layers, according to the structure shown in Table 1: primary: contours, hydrography, soil cover, land usage; derived: soil grid, land cover management grid, digital elevation model (DEM); modelled and raster structures: slope length, amount of eroded soil. Database structure Table 1 No. Name Type Structure Attribute Origin 1 Level curves vector line altitude primary 2 Hydrography vector line name, order, direction primary 3 Soil vector polygon type, texture primary 4 Land usage management vector polygon management type primary 5 Soil raster grid soil erosion factor derived 6 7 Land usage management Climatic aggression factor raster numerica l grid usage management factor derived - - derived 8 DEM raster grid altitude modeled 9 Slope lenght raster grid slope lenght modeled 10 Erosion value raster grid Erosion t/ha/year modeled
The primary database was realized using the 1:25000 topographical map, used in the design of the digital elevation model. The soils database was obtained by digitizing the soil map of the area. The cadastral plans at a scale of 1:5000 represented the land usage database support. Along with the creation of these layers, the database needed for the spatial analysis and soil erosion modelling process was also created. The created database was used in the calculation of the slope length and in the spatial analysis which has been done using the "Spatial Analyst" module from ArcGIS. Due to the changes which occurred during the last 40 years in the Cojocna perimeter in terms of land usage, changes which were also as a result of land reclamations, soil loss estimation will reflect the reality only if the database will be updated, and this operation was performed using the orthophotomap and topographic measurements. Practically speaking, the USLE mathematic model covered two periods: case 1 - before the land reclamations and case 2 following the land reclamations (2010). Using the same calculation relations and coefficients, except the correction coefficient for the coverage and vegetation factor, the soil erosion has been calculated in the same area, for the two situations. By analyzing the entire studied perimeter of the Cojocna Didactic Experimental Station with an area of 404 ha, we can notice (Fig. 5) that the average annual soil erosion rate for the Cojocna Didactic Experimental Station has values which range between 0 and 4 t/ha/year. The largest area presents erosion values between 0 and 0.5t/ha/year, which is 74.57% in the first case (before land reclamations) and 73.63% in the second case (after land reclamations) from the total surface. 8.71 4.86 Eroziune S (ha) 4.88 21.97 0-0.5 11.69 27.54 Eroziune actual S (ha) 4.75 5.04 0-0.5 61.44 298.57 0.5-1 1-1.5 1.5-2 57.12 296.40 0.5-1 1-1.5 1.5-2 2-3 2-3 Fig. 5. Erosion values in the two cases (case 1 and 2).
It should be noted that the surfaces percentage with annual erosion soil loss higher than 2 t/ha/year represent only 2.43% of the total area in both cases. The differences resulted from the calculation of erosion soil loss in terms of areas sizes can be seen in the graphic below (Fig. 6) without noticing obvious values between the two periods which were analyzed. 350 300 250 200 150 100 50 Eroziune Eroziune actual 0 Eroziunea t/ha/an 0-0.5 0.5-1 1-1.5 1.5-2 2-3 > 3 Fig.6. Comparing the results of erosion. 3D modelling is increasingly used for the representation and exploitation of the results because it has several advantages compared to the 2D modelling. Thereby, the 3D model of the land reclamations objectives from Cojocna area was generated from the graphical base presented above, through the ArcGIS 9.3 software, using the ArcMap module. The ArcScene application of the ArcGIS program allows the data visualization in 3D (Fig. 7). Since the land reclamations objectives have a relatively small surface compared to the studied perimeter surface, we have built these 3D objectives using Google SketchUp software for a more detailed view (Fig. 8).
Fig.7. 3D view with ArcScene application. Fig.8. Representing 3D the terrain and the concret fall in ArcScene application. The longitudinal and transversal profiles of land reclamation works (terraces) were made using the AutoCAD Civil 3D software, specially designed by AutoCAD for topographical data processing, surfaces generation, volumetric calculations and for construction plans designing in two (2D) or three (3D) dimensions.
a. b. Fig.9. a. Generating the longitudinal profile. b. The longitudinal profile. Along the alignment profiles can be cut in any section of interest of the study. These points will define the cut profiles along the alignment and in transversal section. The generation of the long profile (Fig. 9) and the transversal profiles (Fig.10) is made from the Road menu (a specific lisp loaded in the program). a. b. Fig.10. a. Generating the transversal profile. b. The transversal profiles. Along the alignment profiles can be cut in any section of interest of the study. These points will define the cut profiles along the alignment and in transversal section. The generation of the long profile (Fig. 9) and the transversal profiles (Fig.10) is made from the Road menu (a specific lisp loaded in the program).