LU500972B1 - Spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverages - Google Patents
Spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverages Download PDFInfo
- Publication number
- LU500972B1 LU500972B1 LU500972A LU500972A LU500972B1 LU 500972 B1 LU500972 B1 LU 500972B1 LU 500972 A LU500972 A LU 500972A LU 500972 A LU500972 A LU 500972A LU 500972 B1 LU500972 B1 LU 500972B1
- Authority
- LU
- Luxembourg
- Prior art keywords
- forest
- fed
- rain
- monthly
- irrigated
- Prior art date
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 165
- 239000013589 supplement Substances 0.000 title claims abstract description 63
- 238000000034 method Methods 0.000 title claims abstract description 38
- 239000010410 layer Substances 0.000 claims description 28
- 238000011160 research Methods 0.000 claims description 28
- 239000002344 surface layer Substances 0.000 claims description 12
- 230000008569 process Effects 0.000 claims description 11
- 238000012545 processing Methods 0.000 claims description 11
- 230000008859 change Effects 0.000 claims description 9
- 235000006629 Prosopis spicigera Nutrition 0.000 claims description 4
- 240000000037 Prosopis spicigera Species 0.000 claims description 4
- 238000012937 correction Methods 0.000 claims description 4
- 238000007781 pre-processing Methods 0.000 claims description 4
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 230000004907 flux Effects 0.000 claims description 3
- 230000010354 integration Effects 0.000 claims description 3
- 230000005855 radiation Effects 0.000 claims description 3
- 230000009467 reduction Effects 0.000 claims description 3
- 230000001932 seasonal effect Effects 0.000 claims description 3
- 239000002689 soil Substances 0.000 claims description 3
- 230000002262 irrigation Effects 0.000 abstract description 8
- 238000003973 irrigation Methods 0.000 abstract description 8
- 230000002950 deficient Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000002028 Biomass Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q50/00—Information and communication technology [ICT] specially adapted for implementation of business processes of specific business sectors, e.g. utilities or tourism
- G06Q50/02—Agriculture; Fishing; Forestry; Mining
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q10/00—Administration; Management
- G06Q10/06—Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V20/00—Scenes; Scene-specific elements
- G06V20/10—Terrestrial scenes
- G06V20/188—Vegetation
Landscapes
- Engineering & Computer Science (AREA)
- Business, Economics & Management (AREA)
- Theoretical Computer Science (AREA)
- Economics (AREA)
- General Physics & Mathematics (AREA)
- Strategic Management (AREA)
- Physics & Mathematics (AREA)
- Human Resources & Organizations (AREA)
- Entrepreneurship & Innovation (AREA)
- General Health & Medical Sciences (AREA)
- Health & Medical Sciences (AREA)
- Marketing (AREA)
- Tourism & Hospitality (AREA)
- General Business, Economics & Management (AREA)
- Mining & Mineral Resources (AREA)
- Agronomy & Crop Science (AREA)
- Marine Sciences & Fisheries (AREA)
- Primary Health Care (AREA)
- Life Sciences & Earth Sciences (AREA)
- Development Economics (AREA)
- Educational Administration (AREA)
- Animal Husbandry (AREA)
- Game Theory and Decision Science (AREA)
- Operations Research (AREA)
- Quality & Reliability (AREA)
- Multimedia (AREA)
- Management, Administration, Business Operations System, And Electronic Commerce (AREA)
Abstract
Disclosed is a spatial distribution method for ecological water supplement considering rain- fed and irrigated forests with different coverage. By identifying land use type and coverage, daily, monthly and yearly actual water demand and ecological water supplement of rain-fed forest and irrigated forest with different coverage can be calculated, and spatial distribution and display can be conducted, so as to make forest managers be clear about the water demand and ecological water supplement of forestland in an area, and know which part of forestland needs irrigation, in which month does the forestland need irrigation and how much water is needed, thus to formulate a more reasonable irrigation regime. The present invention is of great significance to ensure the integrity of vegetation ecosystem.
Description
SPATIAL DISTRIBUTION METHOD FOR ECOLOGICAL WATER SUPPLEMENT
CONSIDERING RAIN-FED AND IRRIGATED FORESTS WITH DIFFERENT COVERAGE 9500972
The present invention belongs to the technical field of water demand and supplement calculation and display of vegetation ecosystem, and particularly relates to a spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage.
Ecological water demand of vegetation refers to the minimum amount of water consumed to ensure the normal growth and development of vegetation or to maintain the health and function of vegetation ecosystem, which is considered to be the key to the restoration and reconstruction of degraded ecosystem. Foreign researches on ecological water demand mainly focus on the relationship between the growth of aquatic organisms and river flow and the relationship between river flow and the maintenance of ecosystem integrity, while the existing researches in
China mainly focus on the arid, semi-arid and semi-humid areas in northwest and north China.
A number of methods are used for estimating the ecological water demand of vegetation, and the commonly used methods are: area quota method, water balance method, remote sensing estimation method, biomass estimation method and so on. Although some scholars have calculated ecological water supplement, the calculation results are not distinguished between rain-fed forest and irrigated forest, which may result in higher water demands, and can only reflect the overall water demand and ecological water supplement of vegetation in a research area; in addition, the calculation results cannot be used to determine the spatial distribution of the ecological water demand and ecological water supplement, and cannot be used to tell managers which specific part of forestland is short of water. However, how to make efficient use of water resources is the key to the sustainable development of water-deficient areas.
Therefore, considering the differences between the rain-fed forest and the irrigated forest, calculating the ecological water demand and ecological water supplement of vegetation in such areas, and conducting spatial distribution have important reference functions for forest managers to formulate a reasonable irrigation regime, ensure the integrity of vegetation ecosystem, and utilize water resources more efficiently.
Aiming at the above deficiencies in the prior art, the present invention provides a spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage, which solves the problem in the existing water supplement estimation methods that the spatial distribution of the ecological water demand and ecological water LU500972 supplement cannot be determined.
To achieve the above purpose, the present invention adopts the following technical solution: a spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage, including the following steps:
S1. identifying rain-fed forest and irrigated forest with different coverage, and numbering the forests;
S2. creating Thiessen polygons of meteorological stations in a research area based on the meteorological stations involved in the research area, and numbering the Thiessen polygons;
S3. obtaining Grid_Code data through data integration based on forestland type data, vegetation coverage information of different forestland types, and numbering information of the
Thiessen polygons of the meteorological stations in the research area;
S4. determining vegetation coefficients corresponding to different months based on coverage information of the rain-fed forest and the irrigated forest in the Grid_Code data;
S5. calculating daily and monthly potential evapotranspiration, actual water demand and effective rainfall based on the coverage information of the rain-fed forest and the irrigated forest, the numbering information of the Thiessen polygons of the meteorological stations, and the vegetation coefficients in the Grid_Code data;
S6. correcting the actual water demand of the rain-fed forest based on the coverage information of the rain-fed forest and the irrigated forest and the numbering information of the
Thiessen polygons of the meteorological stations in the Grid_Code data, as well as the daily and monthly potential evapotranspiration, actual water demand and effective rainfall;
S7. calculating monthly and yearly actual water demand, effective rainfall and ecological water supplement of forestland based on the corrected actual water demand; and
S8. determining ecological water demand and ecological water supplement of the rain-fed forest and the irrigated forest based on the monthly and yearly actual water demand, effective rainfall and ecological water supplement of the forestland, thus to realize spatial distribution of the ecological water supplement of the forestland.
Further, the step S1 is specifically as follows:
S11. using an Intersect tool in ArcGIS to identify historical land use data and identify units that has always been forestland in history; wherein data type of the identified forestland units is vector surface layer data;
S12. selecting two groups of high-resolution remote sensing image data of the same seasonal period based on the identified forestland units, and conducting pre-processing and object-oriented fuzzy logic classification processing to the data, thus to identify area change of each forestland unit in the two groups of data;
S13. taking the forestland units without area change as the rain-fed forest and taking the 500972 forestland units with area reduction or area increase as the irrigated forest based on the identified area change of each forestland unit;
S14. using the Intersect tool to process the identified rain-fed forest data and irrigated forest data, thus to obtain a distribution map of the rain-fed forest and the irrigated forest;
Wherein data type of the distribution map of the rain-fed forest and the irrigated forest is vector polygon layer data;
S15. adding Type_ID attributes of the rain-fed forest and the irrigated forest to the vector polygon layer data respectively;
Wherein Type_ID for the rain-fed forest is 1, and Type_ID for the irrigated forest is 2; and
S16. using a normalized difference vegetation index to calculate vegetation coverage of the rain-fed forest and the irrigated forest respectively based on the Type_ID attributes of the vector surface layer data, and numbering the vegetation coverage based on calculation results thereof.
Further, in the step S16, a formula for calculating the vegetation coverage Fveg is as follows:
Fveg=(NDVI-NDVImin)/(NDVImax-NDVImin)
Where NDVI is the normalized difference vegetation index, NDVImin is the minimum value of the normalized difference vegetation index, and NDVImax is the maximum value of the normalized difference vegetation index;
Fveg = 75% indicates a high coverage, 75%>Fveg>45% indicates a medium coverage, and Fveg<45% indicates a low coverage,
In the step S16, a method for numbering the vegetation coverage based on the calculation results thereof is specifically as follows:
Adding Fveg_ID attributes to data of each vegetation coverage, and numbering the
Fveg_ID attributes as 1, 2 and 3 respectively for the high coverage, the medium coverage and the low coverage.
Further, the step S2 is specifically as follows:
S21. using a Create Thiessen tool in ArcGIS to create a vector polygon layer of the
Thiessen polygons based on n meteorological stations in and around the research area;
S22. using a Clip tool in ArcGIS to clip the created vector surface layer of the Thiessen polygons and obtain a vector polygon layer of the Thiessen polygons in the research area based on the vector polygon layer within the research area, and adding therein corresponding
Station_ID attributes for each meteorological station; and
S23. assigning 1, 2, 3 ... n to the Station_ID attributes according to codes of the meteorological stations in a descending order, thus to realize the numbering of the Thiessen polygons in the research area.
Further, the step S3 is specifically as follows:
Obtaining Grid_Code data by calculating Type_ID, Fveg_ID and Station_ID according to 21500972 formula Grid_Code=Type_ID x 100 + Fveg_ID x 10+Station_ID;
Wherein the Grid_Code data is an array of three-digit numbers, with the hundreds digits representing the codes of different forestland types, the tens digits representing the codes of vegetation coverage, and the units digits representing the codes of the Thiessen polygons of the meteorological stations in the research area.
Further, in the step S5, the daily potential evapotranspiration D_ET,, is: 0408AR, ~G) +7 —— Male.)
D_ET,, = __—_ mean FFF
A+y(1+0.34u,)
The daily actual water demand D _ ET, is:
D_ET,, = Free D _ ET oÿk
The daily effective rainfall D _ Pe, is:
P P< D_ET,,
D Pe, = - D ET, D ET SP — aij — aij
The monthly potential evapotranspiration M _ ET, is:
M _ET,,=> D_ET,,
The monthly actual water demand M _ ET, is:
M ET, => D_ET,,
The monthly effective rainfall A _ Pe, is:
M _Pe,=>D_Pe, where D_ ET, D ET, and D _ Pe, respectively represent the daily potential evapotranspiration, daily actual water demand and daily effective rainfall when Type_ID is i,
Fveg_ID is jand Station_ID is k; M _ET,,, M ET, and M _ Pe, respectively represent the monthly potential evapotranspiration, monthly actual water demand and monthly effective rainfall when Type_ID is i, Fveg_ID is / and Station_ID is k; R, is surface net radiation, G is soil heat flux, y is a psychrometric constant, 7; Is daily average temperature, x, is wind speed at a height of 2 meters, e, is saturation vapor pressure, e, is actual water pressure, A is slope of saturation vapor pressure curve, Lo is a vegetation coefficient corresponding to different vegetation coverage of forestland in each month, and P is daily rainfall.
Further, the corrected actual water demand M _ ET, of the rain-fed forest in the step S6 is:
M Elan = KM Pay LU500972
Where M _ Pe, „ is the monthly effective rainfall of the rain-fed forest when Fveg_ID is / and Station_ID is k, and Æ, is a water demand correction coefficient of the rain-fed forest obtained based on the coverage information of the rain-fed forest and the numbering 5 information of the Thiessen polygons of the meteorological stations.
Further, the step S7 is specifically as follows:
S71. using Grid_code as a medium to connect the corrected monthly actual water demand and monthly effective rainfall to the vector surface layer of the Grid_code by ArcGIS, and taking the actual water demand and effective rainfall of each month as conversion fields to convert the vector surface layer of the Grid_code into a raster layer by a Feature to Raster tool in ArcGIS, thus to obtain raster data of the monthly actual water demand and monthly effective rainfall in 12 months;
S72. converting the raster data of the monthly actual water demand and monthly effective rainfall in 12 months into a volume unit by a Field Calculator tool;
S73. using a Raster Calculator tool in ArcGIS to calculate the differences of the raster data of the monthly actual water demand and monthly effective rainfall in 12 months under the volume unit respectively, thus to obtain the monthly ecological water supplement in 12 months; and
S74. summing up the monthly actual water demand, monthly effective rainfall and monthly ecological water supplement in 12 months respectively, thus to obtain the yearly actual water demand, yearly effective rainfall and yearly ecological water supplement.
Further, the step S8 is specifically as follows:
Using a Zonal Statistics as Table tool in ArcGIS and taking Grid_Code as a statistical classification basis to conduct statistics on the raster data of the monthly and yearly actual water demand, effective rainfall and ecological water supplement of the forestland, and obtain the ecological water demand and ecological water supplement of the rain-fed forest and the irrigated forest in each month and each year, thus to realize the spatial distribution of the ecological water supplement of the forestland.
The present invention has the following beneficial effects: (1) Input data of the present invention can be downloaded from the existing websites, so no field observation test is needed; (2) Calculation process of the present invention can be realized by Matlab and ArcGIS
Workstation, so no manual processing step by step is needed, which is time-saving and labor- saving, and the processing process can be applied to other research areas; (3) In the present invention, the rain-fed forest and the irrigated forest with different coverage is distinguished, so the calculated ecological water demand is more reasonable, and the principle of giving priority to water saving is practiced, which can provide a better guidance 500972 for the water-deficient areas to rationally allocate water resources; (4) The present invention realizes the spatial distribution and display of the monthly and yearly ecological water demand and ecological water supplement of vegetation, which makes the managers clear at a glance, and can provide a reliable reference for the formulation of a more reasonable irrigation regime; and (5) The present invention identifies degraded natural forest, and the distribution map of ecological water demand and ecological water supplement can be remotely viewed, which can provide technical support for superior leaders to perform real-time supervision and management.
Fig. 1 is a flow chart of a spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage provided by the present invention.
Fig. 2 is a schematic diagram of a realization process of ecological water supplement spatial distribution provided by the present invention, figure 2 A showing the interrelation between models 1, 2 and 3; figures 2B, 2C and 2D being more detailed schematic diagrams of models 1, 2 and 3, respectively. The processing process of Models 1 and 3 are realized by
ArcGIS Workstation programming, whereas the calculation process of model 2 is realized by
MATAlab programming.
Specific embodiments of the present invention are described below to facilitate those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those ordinary skilled in the art, as long as various changes are within the spirit and scope of the present invention defined and determined by the attached claims, these changes are obvious. All inventions which utilize the conception of the present invention are protected.
As shown in Fig. 1, a spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage, including the following steps:
S1. identifying rain-fed forest and irrigated forest with different coverage, and numbering the forests;
S2. creating Thiessen polygons of meteorological stations in a research area based on the meteorological stations involved in the research area, and numbering the Thiessen polygons;
S3. obtaining Grid_Code data through data integration based on forestland type data, vegetation coverage information of different forestland types, and numbering information of the
Thiessen polygons of the meteorological stations in the research area;
S4. determining vegetation coefficients corresponding to different months based on LU500972 coverage information of the rain-fed forest and the irrigated forest,
S5. calculating daily and monthly potential evapotranspiration, actual water demand and effective rainfall based on the coverage information of the rain-fed forest and the irrigated forest, the numbering information of the Thiessen polygons of the meteorological stations, and the vegetation coefficients in the Grid_Code data;
S6. correcting the actual water demand of the rain-fed forest based on the coverage information of the rain-fed forest and the irrigated forest and the numbering information of the
Thiessen polygons of the meteorological stations in the Grid_Code data, as well as the daily and monthly potential evapotranspiration, actual water demand and effective rainfall,
S7. calculating monthly and yearly actual water demand, effective rainfall and ecological water supplement of forestland based on the corrected actual water demand in the Grid_Code data; and
S8. determining ecological water demand and ecological water supplement of the rain-fed forest and the irrigated forest based on the monthly and yearly actual water demand, effective rainfall and ecological water supplement of the forestland, thus to realize spatial distribution of the ecological water supplement of the forestland.
The step S1 of the embodiment is specifically as follows:
S11. using an Intersect tool in ArcGIS to identify historical land use data and identify units with a land nature always being forestland in history;
Wherein data type of the identified forestland units is vector polygon layer data;
S12. selecting two groups of high-resolution remote sensing image data of the same seasonal period based on the identified forestland units, and conducting pre-processing and object-oriented fuzzy logic classification processing to the data, thus to identify area change of each forestland unit in the two groups of data;
Wherein the pre-processing of the remote sensing image data includes image orthorectification, fusion, geometric correction and clipping;
S13. taking the forestland units without area change as the rain-fed forest and taking the forestland units with area reduction or area increase as the irrigated forest based on the identified area change of each forestland unit;
S14. using the Intersect tool to process the identified rain-fed forest data and irrigated forest data, thus to obtain a distribution map of the rain-fed forest and the irrigated forest;
Wherein data type of the distribution map of the rain-fed forest and the irrigated forest is vector polygon layer data;
S15. adding Type_ID attributes of the rain-fed forest and the irrigated forest to the vector surface layer data respectively;
Wherein Type_ID for the rain-fed forest is 1, and Type_ID for the irrigated forest is 2; and
S16. using a normalized difference vegetation index to calculate vegetation coverage of LU500972 the rain-fed forest and the irrigated forest respectively based on the Type_ID attributes of the vector surface layer data, and numbering the vegetation coverage based on calculation results thereof.
Specifically, using the data of the normalized difference vegetation index (NDVI) to calculate the vegetation coverage (Fveg) by a Field Calculator tool in ArcGIS, and a formula for calculating the vegetation coverage Fveg in the step S16 is as follows:
Fveg=(NDVI-NDVImin)/(NDVImax-NDVImin)
Where NDVI is the normalized difference vegetation index, NDVImi is the minimum value of the normalized difference vegetation index, and NDVImax is the maximum value of the normalized difference vegetation index;
Fveg = 75% indicates a high coverage, 75%>Fveg>45% indicates a medium coverage, and Fveg<45% indicates a low coverage,
A method for numbering the vegetation coverage based on the calculation results thereof is specifically as follows:
Adding Fveg_ID attributes to data of each vegetation coverage, and numbering the
Fveg_ID attributes as 1, 2 and 3 respectively for the high coverage, the medium coverage and the low coverage, thus to create a distribution map of vegetation coverage (which is vector surface layer data).
The step S2 of the embodiment is specifically as follows:
S21. using a Create Thiessen tool in ArcGIS to create a vector surface layer of the
Thiessen polygons based on n meteorological stations in and around the research area;
S22. using a Clip tool in ArcGIS to clip the created vector surface layer of the Thiessen polygons and obtain a vector polygon layer of the Thiessen polygons in the research area based on the vector polygon layer within the research area, and adding therein corresponding
Station_ID attributes for each meteorological station; and
S23. assigning 1, 2, 3 ... n to the Station_ID attributes according to codes of the meteorological stations in a descending order, with the data obtained being vector polygon layer data, thus to realize the numbering of the Thiessen polygons in the research area.
Grid_Code data containing different types (rain-fed forest and irrigated forest), coverage and numbering information of the Thiessen polygons of the meteorological stations shall be prepared before subsequent data calculation based on the data obtained in the steps S1-S2, and the step S3 above is specifically as follows: conducting Intersect processing to the distribution map of the forestland and the distribution map of vegetation coverage in the step S1 as well as the Thiessen polygons in the research area in the step S2 by ArcGIS, thus a vector polygon layer with an attribute list containing Type_ID, Fveg_ID and Station_ID will be obtained; adding Grid_Code attributes to this layer; using a Field Calculator tool in ArcGIS and inputting a calculation formula "Grid_Code=Type_IDx100+Fveg_IDx10+Station_ID" to conduct calculation,
thus to finally obtain Grid_Code; using a Dissolve tool in ArcGIS and taking Grid_Code as a LU500972
Dissolve Field to conduct processing; and merging duplicate Grid_Code, thus to obtain vector surface layer data of the Grid_Code, i.e., the Grid_Code data.
The steps S1-S3 above are the contents of Model 1 in the dotted box on the left in Fig. 2; the input data includes land use, high-resolution remote sensing image and NDVI data; the output data includes the vector polygon layer data of the Grid_Code and a Grid_Code.txt file; and automatic processing can be realized by ArcGIS Workstation programming during the processing process.
The vegetation coefficients in the step S4 of the embodiment is used to convert potential evapotranspiration into actual water demand of vegetation, and the vegetation coefficients of major vegetation types can be obtained by consulting literature or provided by local agriculture and forest departments.
In the step S5 of the embodiment, the daily potential evapotranspiration D_ET,, is: 0.408A(R, -G) + yr u(e,.-e,)
D ET, = __—_ mean FFF ” A+y(1+0.3444,)
The daily actual water demand D_ ET, is:
D_ET,, = Free D _ ET oÿk
The daily effective rainfall D _ Pe, is:
P P< D_ET,,
D Pe, = - D ET, D ET SP — aij — aij
The monthly potential evapotranspiration M _ ET, is:
M _ET,,=> D_ET,,
The monthly actual water demand M _ ET, is:
M ET, => D_ET,,
The monthly effective rainfall A _ Pe, is:
M _Pe,=>D_Pe,
Where D ET, D_ET,, and D_ Pe, respectively represent the daily potential evapotranspiration, daily actual water demand and daily effective rainfall when Type_ID is 7,
Fveg_ID is jand Station_ID is k, which are in mm; M _ ET, M _ET,, and M _ Pe, respectively represent the monthly potential evapotranspiration, monthly actual water demand and monthly effective rainfall when Type_ID is i, Fveg_ID is jand Station_ID is k, which are in mm; R, is surface net radiation, which is in MJ-m*-d", G is soil heat flux, which is in MJ-m™"-d"
', 7 is a psychrometric constant, which is in kpa-°C™", 7 is daily average temperature, which 500972 is in °C, 4, is wind speed at a height of 2 meters, which is in m/s, e, is saturation vapor pressure, which is in kPa, e, is actual water pressure, which is in kPa, A is slope of saturation vapor pressure curve, which is in kpa-°C”*, Lo is a vegetation coefficient corresponding to different vegetation coverage of forestland in each month, which is dimensionless, and P is daily rainfall, which is in mm.
The corrected actual water demand M _ ET. of the rain-fed forest in the step S6 of the embodiment is:
M _ET,, =k;-M _Pe,,
Where M _ Pe, „ is the monthly effective rainfall of the rain-fed forest when Fveg_ID is / and Station_ID is k, which is in mm, and Æ, is a water demand correction coefficient of the rain- fed forest obtained based on the coverage information of the rain-fed forest and the numbering information of the Thiessen polygons of the meteorological stations.
The steps S4-S6 above are the contents of Model 2 in the dotted box on the right in Fig. 2, and automatic calculation can be conducted by Matlab programming, wherein the Grid_Code.txt file obtained in the steps 1-2 provides loop parameters i, j and k, latitudes and altitudes of the meteorological stations, and meteorological data such as precipitation, temperature, humidity, wind speed and sunshine duration for Matlab calculation, which are used as input data during calculation, thus to obtain excel data of the daily potential evapotranspiration, daily actual water demand, daily effective rainfall, monthly actual water demand and monthly effective rainfall of different Grid_Code, which are all in mm.
The step S7 of the embodiment is specifically as follows:
S71. using Grid_code as a medium to connect the corrected monthly actual water demand and monthly effective rainfall to the vector polygon layer of the Grid_code by ArcGIS, and taking the actual water demand and effective rainfall of each month as conversion fields to convert the vector polygon layer of the Grid_code into a raster layer by a Feature to Raster tool in ArcGIS, thus to obtain raster data of the monthly actual water demand and monthly effective rainfall in 12 months;
Wherein the Feature to Raster tool can be used to set a raster size as R with a unit of m according to different requirements;
S72. converting the raster data of the monthly actual water demand and monthly effective rainfall in 12 months into a volume unit by a Field Calculator tool;
S73. using a Raster Calculator tool in ArcGIS to calculate the differences of the raster data of the monthly actual water demand and monthly effective rainfall in 12 months under the volume unit respectively, thus to obtain the monthly ecological water supplement in 12 months; 500972 and
S74. summing up the monthly actual water demand, monthly effective rainfall and monthly ecological water supplement in 12 months respectively, thus to obtain the yearly actual water demand, yearly effective rainfall and yearly ecological water supplement.
The step S8 of the embodiment is specifically as follows:
Using a Zonal Statistics as Table tool in ArcGIS and taking Grid_Code as a statistical classification basis to conduct statistics on the raster data of the monthly and yearly actual water demand, effective rainfall and ecological water supplement of the forestland, and obtain the ecological water demand and ecological water supplement of the rain-fed forest and the irrigated forest in each month and each year, thus to realize the spatial distribution of the ecological water supplement of the forestland.
The steps S7-S8 above are the contents of Model 3 in the dotted box on the left in Fig. 2, and can be realized by automatic processing on ArcGIS Workstation programming; the input data includes the vector polygon layer data of the Grid_Code obtained in Model 1 and the excel data of the monthly actual water demand and monthly effective rainfall obtained in Model 2; and the output data includes the raster data (distribution map) of the monthly and yearly actual water demand, monthly and yearly effective rainfall, and monthly and yearly ecological water supplement, as well as the txt format data file summing up the total monthly and yearly actual water demand, monthly and yearly effective rainfall, and monthly and yearly ecological water supplement in the area.
The land type data, high-resolution remote sensing image data, NDVI data and meteorological data used in the present invention can be downloaded from the existing websites, so no field observation test is needed; the calculation process involved can be realized by Matlab and ArcGIS Workstation, so no manual operation step by step is needed, and the calculation process can be used for calculating the actual water demand of forestland in other areas; daily, monthly and yearly actual water demand as well as daily, monthly and yearly ecological water supplement of rain-fed forest and irrigated forest with different coverage can be calculated, and spatial distribution and display can be conducted, so as to make forest managers be clear about the water demand and ecological water supplement of forestland in an area, and know which part of forestland needs irrigation, in which month does the forestland need irrigation and how much water is needed, thus to formulate a more reasonable irrigation regime. The present invention is of great significance to ensure the integrity of vegetation ecosystem.
Claims (9)
1. À spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage, including the following steps:
S1.identifying rain-fed forest and irrigated forest with different coverage, and numbering the forests;
S2. creating Thiessen polygons of meteorological stations in a research area based on the meteorological stations involved in the research area, and numbering the Thiessen polygons;
S3. obtaining Grid_Code data through data integration based on forestland type data, vegetation coverage information of different forestland types, and numbering information of the Thiessen polygons of the meteorological stations in the research area;
S4. determining vegetation coefficients corresponding to different months based on coverage information of the rain-fed forest and the irrigated forest in the Grid_Code data;
S5. calculating daily and monthly potential evapotranspiration, actual water demand and effective rainfall based on the coverage information of the rain-fed forest and the irrigated forest, the numbering information of the Thiessen polygons of the meteorological stations, and the vegetation coefficients in the Grid_Code data;
S6. correcting the actual water demand of the rain-fed forest based on the coverage information of the rain-fed forest and the irrigated forest and the numbering information of the Thiessen polygons of the meteorological stations in the Grid_Code data, as well as the daily and monthly potential evapotranspiration, actual water demand and effective rainfall;
S7. calculating monthly and yearly actual water demand, effective rainfall and ecological water supplement of forestland based on the corrected actual water demand;
S8. determining ecological water demand and ecological water supplement of the rain-fed forest and the irrigated forest based on the monthly and yearly actual water demand, effective rainfall and ecological water supplement of the forestland, thus to realize spatial distribution of the ecological water supplement of the forestland.
2. The spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage according to claim 1, wherein the step S1 is as follows:
S11. using an Intersect tool in ArcGIS to identify historical land use data and identify units that has always been forestland in history; wherein data type of the identified forestland units is vector polygon layer data;
S12. selecting two groups of high-resolution remote sensing image data of the same LU500972 seasonal period based on the identified forestland units, and conducting pre- processing and object-oriented fuzzy logic classification processing to the data, thus to identify area change of each forestland unit in the two groups of data;
S13. taking the forestland units without area change as the rain-fed forest and taking the forestland units with area reduction or area increase as the irrigated forest based on the identified area change of each forestland unit;
S14. using the Intersect tool to process the identified rain-fed forest data and irrigated forest data, thus to obtain a distribution map of the rain-fed forest and the irrigated forest: wherein data type of the distribution map of the rain-fed forest and the irrigated forest is vector polygon layer data;
S15. adding Type_ID attributes of the rain-fed forest and the irrigated forest to the vector polygon layer data respectively; wherein Type_ID for the rain-fed forest is 1, and Type_ID for the irrigated forest is 2; and
S16. using a normalized difference vegetation index to calculate vegetation coverage of the rain-fed forest and the irrigated forest respectively based on the Type_ID attributes of the vector surface layer data, and numbering the vegetation coverage based on calculation results thereof.
3. The spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage according to claim 2, wherein in step S16, the formula for calculating the vegetation coverage Fveg is as follows: Fveg=(NDVI-NDVImin)/(NDVImax-NDVImin) where NDVI is the normalized difference vegetation index, NDVImin is the minimum value of the normalized difference vegetation index, and NDVImax is the maximum value of the normalized difference vegetation index; Fveg = 75% indicates a high coverage, 75%>Fveg>45% indicates a medium coverage, and Fveg<45% indicates a low coverage, in step S16, the method for numbering the vegetation coverage based on the calculation results thereof is specifically as follows: adding Fveg_ID attributes to data of each vegetation coverage, and numbering the Fveg_ID attributes as 1, 2 and 3 respectively for the high coverage, the medium coverage and the low coverage.
4. The spatial distribution method for ecological water supplement considering rain-fed and LU500972 irrigated forests with different coverage according to claim 3, wherein the step S2 is as follows:
S21. using of the Create Thiessen tool in ArcGIS to create a polygon layer of the Thiessen polygons based on n meteorological stations in and around the research area;
S22. using a Clip tool in ArcGIS to clip the created vector polygon layer of the Thiessen polygons and obtain a vector polygon layer of the Thiessen polygons in the research area based on the vector polygon layer within the research area, and adding therein corresponding Station_ID attributes for each meteorological station;
S23. assigning 1, 2, 3... n to the Station_ID attributes according to codes of the meteorological stations in a descending order, thus to realize the numbering of the Thiessen polygons in the research area.
5. The spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage according to claim 4, wherein the step S3 is as follows: obtaining Grid_Code data by calculating Type_ID, Fveg_ID and Station_ID according to a formula Grid_Code=Type_ID x 100 + Fveg_ID x 10 + Station_ID; wherein the Grid_Code data is an array of three-digit numbers, with the hundreds digits representing the codes of different forestland types, the tens digits representing the codes of vegetation coverage, and the units digits representing the codes of the Thiessen polygons of the meteorological stations in the research area.
6. The spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage according to claim 5, wherein in the step S5, the daily potential evapotranspiration D _ ET; , is:
0.408A(R, -G) + yr u(e,.-e,) D ET, = __—_ mean FFF ” A+y(1+0.3444,) the daily actual water demand D_ ET, is: D_ET,, = Free D _ ET oÿk the daily effective rainfall D _ Pe, is: P P< D_ET,, D Pe, = - D ET, D ET SP — aij — aij the monthly potential evapotranspiration M _ ET, is:
M ET, XD Etam LU500972 the monthly actual water demand M _ ET, is: M _ET, =>, D__ET the monthly effective rainfall M _ Pe, is: M _Pe,=>D_Pe, where D_ ET, D ET, and D_Pe,, respectively represent the daily potential evapotranspiration, daily actual water demand and daily effective rainfall when Type_ID is 7, Fveg_ID is jand Station_ID is k; M _ET,,, M ET, and M _ Pe, respectively represent the monthly potential evapotranspiration, monthly actual water demand and monthly effective rainfall when Type_ID is i, Fveg_ID is / and Station_ID is k; R, is surface net radiation, G is soil heat flux, y is a psychrometric constant, 7; Is daily average temperature, x, is wind speed at a height of 2 meters, e, is saturation vapor pressure, e, is actual water pressure, A is slope of saturation vapor pressure curve, Lo is a vegetation coefficient corresponding to different vegetation coverage of forestland in each month, and P is daily rainfall.
7. The spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage according to claim 6, wherein the corrected actual water demand M _ ET, of the rain-fed forest in the step S6 is: M ET an =k M_Pe, where M _ Pe, „ is the monthly effective rainfall of the rain-fed forest when Fveg_ID is / and Station_ID is k, and Æ, is a water demand correction coefficient of the rain-fed forest obtained based on the coverage information of the rain-fed forest and the numbering information of the Thiessen polygons of the meteorological stations.
8. The spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage according to claim 7, wherein the step S7 is as follows:
S71. using Grid_code as a medium to connect the corrected monthly actual water demand and monthly effective rainfall to the vector polygon layer of the Grid_code by ArcGIS, and taking the actual water demand and effective rainfall of each month as conversion fields to convert the vector polygon layer of the Grid_code into a raster layer by a Feature to Raster tool in ArcGIS, thus to obtain raster data of the monthly LU500972 actual water demand and monthly effective rainfall in 12 months;
S72. converting the raster data of the monthly actual water demand and monthly effective rainfall in 12 months into a volume unit by a Field Calculator tool;
S73. using a Raster Calculator tool in ArcGIS to calculate the differences of the raster data of the monthly actual water demand and monthly effective rainfall in 12 months under the volume unit respectively, thus to obtain the monthly ecological water supplement in 12 months; and
S74. summing up the monthly actual water demand, monthly effective rainfall and monthly ecological water supplement in 12 months respectively, thus to obtain the yearly actual water demand, yearly effective rainfall and yearly ecological water supplement.
9. The spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverage according to claim 8, wherein the step S8 is as follows: using a Zonal Statistics as Table tool in ArcGIS and taking Grid_Code as a statistical classification basis to conduct statistics on the raster data of the monthly and yearly actual water demand, effective rainfall and ecological water supplement of the forestland, and obtain the ecological water demand and ecological water supplement of the rain-fed forest and the irrigated forest in each month and each year, thus to realize the spatial distribution of the ecological water supplement of the forestland.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| LU500972A LU500972B1 (en) | 2021-12-09 | 2021-12-09 | Spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverages |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| LU500972A LU500972B1 (en) | 2021-12-09 | 2021-12-09 | Spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverages |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| LU500972B1 true LU500972B1 (en) | 2023-02-16 |
Family
ID=80448610
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| LU500972A LU500972B1 (en) | 2021-12-09 | 2021-12-09 | Spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverages |
Country Status (1)
| Country | Link |
|---|---|
| LU (1) | LU500972B1 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107886444A (en) * | 2017-10-11 | 2018-04-06 | 南京大学 | A kind of distribution Runoff calculation method in region of no relief under urbanization |
| CN108399577A (en) * | 2018-03-27 | 2018-08-14 | 南京信息工程大学 | A kind of forest land vegetation ecological based on evapotranspiration needs the Quantizing Method of water |
| CN112418154A (en) * | 2020-12-07 | 2021-02-26 | 中国水利水电科学研究院 | Ecological water supplement amount space distribution method considering rain-fed and irrigated forests with different coverage degrees |
-
2021
- 2021-12-09 LU LU500972A patent/LU500972B1/en active IP Right Grant
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107886444A (en) * | 2017-10-11 | 2018-04-06 | 南京大学 | A kind of distribution Runoff calculation method in region of no relief under urbanization |
| CN108399577A (en) * | 2018-03-27 | 2018-08-14 | 南京信息工程大学 | A kind of forest land vegetation ecological based on evapotranspiration needs the Quantizing Method of water |
| CN112418154A (en) * | 2020-12-07 | 2021-02-26 | 中国水利水电科学研究院 | Ecological water supplement amount space distribution method considering rain-fed and irrigated forests with different coverage degrees |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112418154B (en) | Ecological water supplementing quantity space spreading method considering different coverage degree of rain-fed and irrigated forests | |
| Sahle et al. | Quantifying and mapping of water-related ecosystem services for enhancing the security of the food-water-energy nexus in tropical data–sparse catchment | |
| CN110689173A (en) | Irrigation area agricultural irrigation water demand decision method and system | |
| Yang et al. | Assessment of changes in oasis scale and water management in the arid Manas River Basin, north western China | |
| CN102779391B (en) | Drought early-warning method and drought early-warning system | |
| CN113407897B (en) | Design method of distributed water circulation model based on multi-source mutual-aid water supply mode | |
| CN107807598A (en) | Internet of Things+water saving, the fertile Precision Irrigation system and method for section | |
| CN108958329B (en) | Drip irrigation water and fertilizer integrated intelligent decision-making method | |
| CN107330804A (en) | A kind of wisdom water conservancy management and control cloud platform and method | |
| Xu et al. | Evaluating the ecological benefits of plantations in arid areas from the perspective of ecosystem service supply and demand-based on emergy analysis | |
| CN104951986A (en) | Estimation method for load of watershed agricultural non-point source pollutants into lake | |
| CN115630802A (en) | Ecological restoration space planning method combining with ecological system service supply and demand | |
| CN111899126A (en) | Three red line control index dividing method based on water circulation simulation | |
| CN109002946B (en) | Water resource optimization scheduling method for 'two-reservoir-two-station' system for replenishing water in rivers and lakes | |
| LU500972B1 (en) | Spatial distribution method for ecological water supplement considering rain-fed and irrigated forests with different coverages | |
| Lei et al. | Spatial-temporal evolution and driving factors of water yield in three major drainage basins of Hainan Island based on land use change | |
| Savoskul et al. | Water, climate, food, and environment in the Syr Darya Basin | |
| Medeiros et al. | Diagnosis of the accelerated soil erosion in Sao Paulo State (Brazil) by the soil lifetime index methodology | |
| Phue et al. | Existing Water Balance in the Bago River Basin, Myanmar | |
| Zadsar et al. | Using SWAT model to investigate the impact of Rangeland management practices on water conservation (case study: Gorganroud Watershed, Golestan, Iran) | |
| Pan et al. | Perspectives of human–water co‐evolution of blue–green water resources in subtropical areas | |
| Allani et al. | A contribution to an advisory plan for integrated irrigation water management at Nebhana dam system: from research to operational support | |
| Nishina et al. | Historical trends of riverine nitrogen loading from land to the East China Sea: a model-based evaluation | |
| Zhai et al. | Decision-making technology based on knowledge engineering and experiment on the intelligent water-fertilizer irrigation system | |
| Fipps et al. | Implementation of a district management system in the Lower Rio Grande Valley of Texas |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FG | Patent granted |
Effective date: 20230216 |