File:Wrc.svg

此SVG文件的PNG预览的大小：600 × 450像素。其他分辨率：320 × 240像素 | 640 × 480像素 | 1,024 × 768像素 | 1,280 × 960像素 | 2,560 × 1,920像素。

原始文件 ‎（SVG文件，尺寸为600 × 450像素，文件大小：11 KB）

本文件并非来自中文维基百科，而是来自维基共享资源。请参阅维基共享资源上的详细描述、讨论页、页面历史、日志。

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摘要

描述Wrc.svg	English: calculated diagram of soil with model formula (van Genuchten, 1980) ^[1] Deutsch: Der Saugdruck von Sand, Schluff, Lehm und Ton. Neu berechnetes Diagramm verschiedener Bodenarten mit Modelldaten gemäß van Genuchten, 1980
日期	2015年8月13日
来源	自己的作品
作者	FMoeckel, DufterKunde
授权 (二次使用本文件)	http://de.wikipedia.org/wiki/Datei:Wrc.svg
其他版本	Wrc.jpg

W3C-validity not checked.

Van Genuchten model of soil water retention ( $\theta$ – relative soil water content, $\Psi _{\mathrm {m} }$ – soil matric potential):

\theta =\theta _{r}+{\frac {\theta _{s}-\theta _{r}}{\left(1+\left(\alpha \,{\frac {\left|\Psi _{\mathrm {m} }\right|}{\mathrm {hPa} }}\right)^{n}\right)^{m}}}

with

m=1-{\frac {1}{n}}\;.

Parameter List
Soil	Soil	$\theta _{r}$	$\theta _{r}$	$\alpha$	$n$	$m$
Ss	Sand	0.043019	0.370687	0.087424	1.57535	0.36522
Uu	Silt	0	0.421256	0.003405	1.34475	0.25637
Lu	Loam-Silt	0	0.421217	0.013345	1.12614	0.11201
Tt	Clay	0	0.550541	0.006812	1.08155	0.07540

GNU Octave source code

function van_genuchten()
	%* Encdoing: UTF-8.
	%* Written by DufterKunde
	%  https://de.wikipedia.org/wiki/Benutzer:DufterKunde
	%  to produce a corrected version of
	%  https://commons.wikimedia.org/wiki/File:Wrc.svg .
	%  It is supposed to be run in GNU octave 4.0,
	%  but it should also work with older versions of octave as well.
	%  Only minor changes are needed to make it run with Matlab.
	%* The plot shows the matric potential Psi_m
	%  of different types of soil as a function of the
	%  relative soil water content theta.
	%  It is based on the equation and parameters from
	%  {{cite web
	%  | url=https://www.bgr.bund.de/DE/Themen/Boden/Netzwerke/Adhocag/Downloads/Ergaenzungsregel_1_18.pdf
	%  | title=Verknüpfungsregel 1.18 – Parameter für das Modell einer stetigen Funktion der θ(ψ)-Beziehung
	%  | accessdate=2015-07-29
	%  | author=Ad-hoc-AG Boden
	%  | coauthors=
	%  | date=2004-09-17
	%  | format=PDF, 242 KiB
	%  | publisher=Staatlichen Geologischen Dienste und BGR
	%  | language=German
	%  }}
	%  theta = theta_r + (theta_s - theta_r)/(1 + (alpha*(-psi))^n)^m
	%  with
	%  m     = 1 - 1/n .
	%* Ss = Sand, Uu = Silt, Lu = Loam-Silt, Tt = Clay.
	%* Compliance of the output with the svg-standard validated by:
	%  https://validator.w3.org/
	%  and practical functionality tested with
	%  - Mozilla Firefox for Ubuntu 40.0,
	%  - Chromium 43.0.2357.130 Ubuntu 15.04 (64-bit)
	%  - eog (“Eye of Gnome”) 3.14.4,
	%  - Inkscape 0.91 r13725, and
	%  - SVG Check: https://tools.wmflabs.org/svgcheck/ (rsvg 2.36.1).
	
	% parameters:
	pF         = [  0     6];
	N          = 10*diff(pF) + 1;
	psi        = -logspace(pF(1),pF(2),N);
	x          = [  0     0.55];
	y          = pF;
	X          = [ 70   550   ];
	Y          = [390   30   ];
	DY         = diff(Y)/diff(y);
	Tick       =   8;
	tick       =   6;
	lgnd_wdth  =  95;
	lgnd_hght  = 120;
	lgnd_strk  =  35;
	lgnd_pad   =   4;
	lgnd_Pad   =  12;
	today      = clock();
	
	% Sand:
	theta_r_ss = 0.043019;
	theta_s_ss = 0.370687;
	alpha_ss   = 0.087424;
	n_ss       = 1.57535;
	theta_ss   = theta_vg(psi, theta_r_ss, theta_s_ss, alpha_ss, n_ss);
	
	% Silt:
	theta_r_uu = 0;
	theta_s_uu = 0.421256;
	alpha_uu   = 0.003405;
	n_uu       = 1.34475;
	theta_uu   = theta_vg(psi, theta_r_uu, theta_s_uu, alpha_uu, n_uu);
	
	% Loam-Silt:
	theta_r_lu = 0;
	theta_s_lu = 0.421217;
	alpha_lu   = 0.013345;
	n_lu       = 1.12614;
	theta_lu   = theta_vg(psi, theta_r_lu, theta_s_lu, alpha_lu, n_lu);
	
	% Clay:
	theta_r_tt = 0;
	theta_s_tt = 0.550541;
	alpha_tt   = 0.006812;
	n_tt       = 1.08155;
	theta_tt   = theta_vg(psi, theta_r_tt, theta_s_tt, alpha_tt, n_tt);
	
	% generate svg-file:
	fid        = fopen ("Wrc.svg","w");
	fprintf(fid,["<?xml version=\"1.0\" encoding=\"utf-8\"?>\n", ...
	             "<svg\n", ...
	             "xmlns=\"http://www.w3.org/2000/svg\"\n", ...
	             "width=\"600\" height=\"450\"\n", ...
	             ">\n",...
	             "\t<title>Water Retention Curves</title>\n"]);
	fprintf(fid,["\t<desc>\n",...
	             "\t\t* This is a corrected version of\n",...
	             "\t\t  https://commons.wikimedia.org/wiki/File:Wrc.svg\n",...
	             "\t\t  generated by DufterKunde\n",...
	             "\t\t  https://de.wikipedia.org/wiki/Benutzer:DufterKunde\n",...
	             "\t\t  on %i-%02i-%02i.\n",...
	             "\t\t* The plot shows the matric potential Psi_m\n",...
	             "\t\t  of different types of soil as a function of the\n",...
	             "\t\t  relative soil water content theta.\n",...
	             "\t\t  It is based on the equation and parameters from\n",...
	             "\t\t  {{cite web\n",...
	             "\t\t  | url=https://www.bgr.bund.de/DE/Themen/Boden/Netzwerke/Adhocag/Downloads/Ergaenzungsregel_1_18.pdf\n",...
	             "\t\t  | title=Verknüpfungsregel 1.18 – Parameter für das Modell einer stetigen Funktion der θ(ψ)-Beziehung\n",...
	             "\t\t  | accessdate=2015-07-29\n",...
	             "\t\t  | author=Ad-hoc-AG Boden\n",...
	             "\t\t  | coauthors=\n",...
	             "\t\t  | date=2004-09-17\n",...
	             "\t\t  | format=PDF, 242 KiB\n",...
	             "\t\t  | publisher=Staatlichen Geologischen Dienste und BGR\n",...
	             "\t\t  | language=German\n",...
	             "\t\t  }}\n",...
	             "\t\t  theta = theta_r + (theta_s - theta_r)/(1 + (alpha*(-psi))^n)^m\n",...
	             "\t\t  with\n",...
	             "\t\t  m     = 1 - 1/n .\n",...
	             "\t\t* Ss = Sand, Uu = Silt, Lu = Loam-Silt, Tt = Clay.\n",...
	             "\t\t* This svg-file has been generated line-by-line\n",...
	             "\t\t  by a GNU Octave function.\n",...
	             "\t\t* Compliance with the svg standard validated by:\n",...
	             "\t\t  https://validator.w3.org/\n",...
	             "\t\t  and practical functionality tested with\n",...
	             "\t\t  - Mozilla Firefox for Ubuntu 40.0,\n",...
	             "\t\t  - Chromium 43.0.2357.130 Ubuntu 15.04 (64-bit)\n",...
	             "\t\t  - eog (“Eye of Gnome”) 3.14.4,\n",...
	             "\t\t  - Inkscape 0.91 r13725, and\n",...
	             "\t\t  - SVG Check: https://tools.wmflabs.org/svgcheck/ (rsvg 2.36.1).\n",...
	             "\t</desc>\n"],today(1),today(2),today(3));
	fprintf(fid,"\t<g shape-rendering=\"geometricPrecision\" stroke=\"black\" stroke-width=\"2\">\n");
	fprintf(fid,"\t\t<!-- horizontal grid lines: -->\n");
	fprintf(fid,"\t\t<g stroke=\"#c0c0c0\">\n");
	for k = (pF(1) + 1) : (pF(2) - 1)
		Y_grid = Y(1) + k * DY
		fprintf(fid,"\t\t\t<polyline points=\"%i,%i %i,%i\"/>\n",...
		        X(1),Y_grid,X(2),Y_grid);
	endfor
	fprintf(fid,"\t\t</g>\n");
	fprintf(fid,"\t\t<!-- actual graph data: -->\n");
	fprintf(fid,"\t\t<g fill=\"none\" stroke-width=\"3\">\n");
	write_svg_dat(fid,psi(1:end-10),theta_ss(1:end-10),x,y,X,Y,"0000ff","Ss = Sand");
	write_svg_dat(fid,psi,theta_uu,x,y,X,Y,"ff0000","Uu = Silt");
	write_svg_dat(fid,psi,theta_lu,x,y,X,Y,"00ff00","Lu = Loam-Silt");
	write_svg_dat(fid,psi,theta_tt,x,y,X,Y,"b000b0","Tt = Clay");
	fprintf(fid,"\t\t</g>\n");
	fprintf(fid,"\t\t<!-- ticks on x-axis: -->\n");
	for k = [0.1 : 0.1 : 0.5]
		X_grid = X(1) + k * diff(X)/diff(x)
		fprintf(fid,"\t\t<polyline points=\"%5.2f,%i %5.2f,%i\"/>\n",...
		        X_grid,Y(1),X_grid,Y(1)-Tick);
		fprintf(fid,"\t\t<polyline points=\"%5.2f,%i %5.2f,%i\"/>\n",...
		        X_grid,Y(2)+Tick,X_grid,Y(2));
	endfor
	fprintf(fid,"\t\t<!-- major ticks on y-axis: -->\n");
	for k = (pF(1) + 1) : (pF(2) - 1 )
		Y_grid = Y(1) + k * DY;
		fprintf(fid,"\t\t<polyline points=\"%i,%i %i,%i\"/>\n",...
		        X(1),Y_grid,X(1)+Tick,Y_grid);
		fprintf(fid,"\t\t<polyline points=\"%i,%i %i,%i\"/>\n",...
		        X(2)-Tick,Y_grid,X(2),Y_grid);
	endfor
	fprintf(fid,"\t\t<!-- minor log-ticks on left y-axis: -->\n");
	for k = pF(1) : (pF(2) - 1)
		for m = 2 : 9
			y_grid = Y(1) + ( k + log10(m) ) * DY;
			fprintf(fid,"\t\t<polyline points=\"%i,%5.2f %i,%5.2f\"/>\n",...
			        X(1),y_grid,X(1)+tick,y_grid);
		endfor
	endfor
	fprintf(fid,"\t\t<!-- legend: -->\n");
	fprintf(fid,["\t\t<rect x=\"%i\" y=\"%i\" width=\"%i\" " ,...
	             "height=\"%i\" stroke=\"black\" fill=\"white\"/>\n"],...
	        X(2)-lgnd_wdth-lgnd_Pad,Y(2)+lgnd_Pad,lgnd_wdth,lgnd_hght);
	Y_lgnd = Y(2)+1.5*Tick + [0.5 1.5 2.5 3.5]/4*lgnd_hght
	X_lgnd = [X(2)-lgnd_wdth-lgnd_pad X(2)-lgnd_wdth-lgnd_pad+lgnd_strk];
	fprintf(fid,"\t\t<g fill=\"none\" stroke-width=\"3\">\n");
	fprintf(fid,"\t\t\t<polyline stroke=\"#0000ff\" points=\"%i,%i %i,%i\"/>\n",...
	        X_lgnd(1),Y_lgnd(1),X_lgnd(2),Y_lgnd(1));
	fprintf(fid,"\t\t\t<polyline stroke=\"#ff0000\" points=\"%i,%i %i,%i\"/>\n",...
	        X_lgnd(1),Y_lgnd(2),X_lgnd(2),Y_lgnd(2));
	fprintf(fid,"\t\t\t<polyline stroke=\"#00ff00\" points=\"%i,%i %i,%i\"/>\n",...
	        X_lgnd(1),Y_lgnd(3),X_lgnd(2),Y_lgnd(3));
	fprintf(fid,"\t\t\t<polyline stroke=\"#b000b0\" points=\"%i,%i %i,%i\"/>\n",...
	        X_lgnd(1),Y_lgnd(4),X_lgnd(2),Y_lgnd(4));
	fprintf(fid,"\t\t</g>\n");
	fprintf(fid,"\t\t<!-- axis-box: -->\n");
	fprintf(fid,["\t\t<polygon points=\"%i,%i %i,%i %i,%i %i,%i\" ",...
	             "fill=\"none\" stroke=\"black\" stroke-width=\"2\"/>\n"],...
	        X(1),Y(2),X(2),Y(2),X(2),Y(1),X(1),Y(1));
	fprintf(fid,"\t\t<!-- text: -->\n");
	fprintf(fid,"\t\t<g stroke-width=\"0\" fill=\"black\" font-family=\"Helvetica\" font-size=\"24\">\n");
	fprintf(fid,"\t\t\t<!-- x-axis annotation: -->\n");
	fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" text-anchor=\"middle\" font-style=\"italic\">θ</text>\n",...
	        mean(X)-10,445);
	fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" text-anchor=\"middle\">0</text>\n",...
	        X(1),420);
	for k = [0.1 : 0.1 : 0.5]
		X_grid = X(1) + k * diff(X)/diff(x);
		fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" text-anchor=\"middle\">%3.1f</text>\n",...
		X_grid,420,k);
	endfor
	fprintf(fid,"\t\t\t<!-- y-axis annotation: -->\n");
	fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" transform=\"rotate(-90)\" text-anchor=\"end\">p</text>\n",...
	        -mean(Y)+ 7,593);
	fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" transform=\"rotate(-90)\" text-anchor=\"start\" font-style=\"italic\">F</text>\n",...
	        -mean(Y)+ 7,593);
	fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" transform=\"rotate(-90)\" text-anchor=\"end\" font-style=\"italic\">–ψ</text>\n",...
	        -mean(Y)-20,19);
	fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" transform=\"rotate(-90)\" text-anchor=\"start\" font-size=\"18\">m</text>\n",...
	        -mean(Y)-20,26);
	fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" transform=\"rotate(-90)\" text-anchor=\"start\">/ hPa</text>\n",...
	        -mean(Y)   ,19);
	for k = pF(1) : pF(2)
		Y_grid = Y(1) + k * DY;
		if ( k < 0 )
			fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" text-anchor=\"end\">–</text>\n",...
			        X(2)+8,Y_grid+10);
		endif
		fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" text-anchor=\"start\">%i</text>\n",...
		        X(2)+8,Y_grid+10,abs(k));
		fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" text-anchor=\"end\">10</text>\n",...
		        X(1)-15,Y_grid+10);
		if ( k >= 0 )
			fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" text-anchor=\"start\" font-size=\"18\">%i</text>\n",...
			        X(1)-15,Y_grid-2,k);
		else
			fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" text-anchor=\"start\" font-size=\"18\">–%i</text>\n",...
			        X(1)-15,Y_grid-2,-k);
		endif
	endfor
	fprintf(fid,"\t\t\t<!-- legend: -->\n");
	fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" text-anchor=\"start\">Ss</text>\n",...
	        X_lgnd(2)+lgnd_Pad,Y_lgnd(1)+8);
	fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" text-anchor=\"start\">Uu</text>\n",...
	        X_lgnd(2)+lgnd_Pad,Y_lgnd(2)+8);
	fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" text-anchor=\"start\">Lu</text>\n",...
	        X_lgnd(2)+lgnd_Pad,Y_lgnd(3)+8);
	fprintf(fid,"\t\t\t<text x=\"%i\" y=\"%i\" text-anchor=\"start\">Tt</text>\n",...
	        X_lgnd(2)+lgnd_Pad,Y_lgnd(4)+8);
	fprintf(fid,["\t\t</g>\n",...
	             "\t</g>\n",...
	             "</svg>"]);
	fclose(fid);
	
endfunction

function theta = theta_vg(psi, theta_r, theta_s, alpha, n)
	% van Genuchten equation
	m = 1 - 1/n
	theta = theta_r + (theta_s - theta_r)./(1 + (alpha*(-psi)).^n).^m;
endfunction

function write_svg_dat(fid,psi,theta,x,y,X,Y,cl,name)
	Y_dat = ( log10(-psi) - y(1) )*diff(Y)/diff(y) + Y(1);
	X_dat = ( theta       - x(1) )*diff(X)/diff(x) + X(1);
	fprintf(fid,"\t\t\t<polyline stroke=\"#%s\" points=\"",cl);
	for	k = 1 : (length(psi) - 1)
		fprintf(fid,"%4.2f,%i ",X_dat(k),Y_dat(k));
	endfor
	fprintf(fid,["%4.2f,%i\">\n",...
	             "\t\t\t\t<title>%s</title>\n",...
	             "\t\t\t</polyline>\n"],X_dat(end),Y_dat(end),name);
endfunction

Reference

↑ Ad-hoc-AG Boden (2004-09-17). Verknüpfungsregel 1.18 – Parameter für das Modell einer stetigen Funktion der θ(ψ)-Beziehung (in German) (PDF, 242 KiB). Staatlichen Geologischen Dienste und BGR. Archived from the original on 2016-03-04. Retrieved on 2015-07-29.

许可协议

我，本作品著作权人，释出本作品至公有领域。这适用于全世界。
在一些国家这可能不合法；如果是这样的话，那么：
我无条件地授予任何人以任何目的使用本作品的权利，除非这些条件是法律规定所必需的。

文件历史

点击某个日期/时间查看对应时刻的文件。

	日期/时间	大小	用户	备注
当前	2015年8月17日 (一) 13:18	600 × 450（11 KB）	DufterKunde	Minor source code clean-up.
	2015年8月14日 (五) 13:44	600 × 450（10 KB）	DufterKunde	Restricted to a more realistic range of matric potential / pF-values. (Unfortunately, the original source does not mention in which intervals the model is valid.)
	2015年8月13日 (四) 15:17	600 × 450（14 KB）	DufterKunde	The original file was based on a wrong equation due to a typo (see File talk:Wrc.svg#Plots seem to be based on wrong equation). This has been discussed with and confirmed by the original author User:FMoeckel~commonswiki via e-mail. The new SVG...
	2011年4月7日 (四) 05:22	512 × 405（27 KB）	Trex2001	resized font
	2011年4月6日 (三) 11:41	512 × 404（26 KB）	Trex2001	redone in SVG (was embedded bitmap before)
	2011年4月6日 (三) 11:25	512 × 724（179 KB）	Trex2001	Reverted to version as of 16:07, 9 January 2010
	2011年4月6日 (三) 11:16	512 × 378（180 KB）	Trex2001	cropped
	2010年1月9日 (六) 16:07	512 × 724（179 KB）	FMoeckel~commonswiki	{{Information \|Description={{en\|1=calculated diagram of soil with model formula (van Genuchten, 1980) <ref>[www.bgr.de/saf_boden/adhocag/Ergaenzungsregel_1_18.pdf]</ref>}} {{de\|1=neu berechnetes Diagramm verschiedener Bodenarten mit Modelldaten gemäß va

文件用途

以下2个页面使用本文件：

全域文件用途

以下其他wiki使用此文件：

de.wikipedia.org上的用途
en-two.iwiki.icu上的用途
- Water retention curve
ja-two.iwiki.icu上的用途
- 水分保持曲線
nl.wikipedia.org上的用途
- Veldcapaciteit
- Zuigspanning
pl.wikipedia.org上的用途
- Roztwór glebowy
ru.wikipedia.org上的用途
- Основная гидрофизическая характеристика
sv.wikipedia.org上的用途
- Vattenbindningskurva

元数据

此文件中包含有扩展的信息。这些信息可能是由数码相机或扫描仪在创建或数字化过程中所添加。

如果此文件的源文件已经被修改，一些信息在修改后的文件中将不能完全反映出来。

简短标题	Water Retention Curves
图像标题	* This is a corrected version of -{R\|https://commons.wikimedia.org/wiki/File:Wrc.svg}- generated by DufterKunde -{R\|https://de.wikipedia.org/wiki/Benutzer:DufterKunde}- on 2015-08-17. * The plot shows the matric potential Psi_m of different types of soil as a function of the relative soil water content theta. It is based on the equation and parameters from Ad-hoc-AG Boden. -{R\|Verknüpfungsregel 1.18 – Parameter für das Modell einer stetigen Funktion der θ(ψ)-Beziehung}- (PDF, 242 KiB). Staatlichen Geologischen Dienste und BGR. 2004-09-17 [2015-07-29] （German）. theta = theta_r + (theta_s - theta_r)/(1 + (alpha(-psi))^n)^m with m = 1 - 1/n . Ss = Sand, Uu = Silt, Lu = Loam-Silt, Tt = Clay. * This svg-file has been generated line-by-line by a GNU Octave function. * Compliance with the svg standard validated by: -{R\|https://validator.w3.org/}- and practical functionality tested with - Mozilla Firefox for Ubuntu 40.0, - Chromium 43.0.2357.130 Ubuntu 15.04 (64-bit) - eog (“Eye of Gnome”) 3.14.4, - Inkscape 0.91 r13725, and - SVG Check: -{R\|https://tools.wmflabs.org/svgcheck/}- (rsvg 2.36.1).
宽度	600
高度	450

[1] Ad-hoc-AG Boden (2004-09-17). Verknüpfungsregel 1.18 – Parameter für das Modell einer stetigen Funktion der θ(ψ)-Beziehung (in German) (PDF, 242 KiB). Staatlichen Geologischen Dienste und BGR. Archived from the original on 2016-03-04. Retrieved on 2015-07-29.

[1]

File:Wrc.svg

摘要

Reference

许可协议

说明

此文件中描述的项目

描繪內容

創作作者

某些值没有维基数据项目

著作權狀態

保有知識產權並由其所有者公開於公有領域

许可协议

著作权持有者释出至公有领域 ^{简体中文（已转写）}

成立或建立時間

13 8 2015

文件来源

上传者的原创作品

多媒體型式

image/svg+xml

文件历史

文件用途

全域文件用途

元数据

摘要

Reference

许可协议

说明

此文件中描述的项目

某些值没有维基数据项目

著作权持有者释出至公有领域 简体中文（已转写）

13 8 2015

image/svg+xml

文件历史

文件用途

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著作权持有者释出至公有领域 ^{简体中文（已转写）}