Application of Fuzzy-hierarchal Integrated Evaluation Method on. the Oasis Ecosystem Stability

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1 The Jounal o Ameican Science, 2(3), 2006, Zhang, et al, Application o Fuzzy-hieachal Integated Evaluation Application o Fuzzy-hieachal Integated Evaluation Method on the Oasis Ecosystem Stability Jinping Zhang 1, Bingtuo Guo 2, Zhichao Yan 3 1. Depatment o Wate Resouces o China Institute o Wate Resouces & Hydopowe Reseach, Being , China, jinping2000_zh@163.com 2. Yellow Rive Engineeing Consulting Co., Ltd., Zhengzhou, Henan Povince , China 3. Being Shingshan Distict Sanitation Administation Cente, Being , China Abstact: The actos inluenced on the oasis ecosystem stability involve many aspects and the elationships among actos have the chaacteistic o uncetain and hieachal. This pape takes the iigation aea o the noth o Ningxia (that daws wate om the Yellow Rive) as an example to compae the oasis ecosystem stability o ten calculated units with the method o uzzy-hieachal integated evaluation. The esults show that this method is scientiic and ational, and is also an eective method to evaluate the oasis ecosystem stability. [The Jounal o Ameican Science. 2006;2(3):41-47]. eywods: uzzy; hieachal; oasis; ecosystem; stability 1. Intoduction The oasis ecosystem stability ees to the situation in which the enegy low, mateial low, human low and inomation low o the oasis ecosystem can be kept in a good cycle, the existing suoundings o lives in oasis ae optimized continuously, and the unctions o oasis can also be kept to develop sustainable. Because the basic chaacte o stability is to pomote the sustainable development and sustain a good cycle o system, the essence connotation o oasis stability is the sustainable development o oasis ecosystem. [1] Fom the deinition o the oasis ecosystem stability, we can know that the actos inluenced on the oasis ecosystem stability involve many aspects and these actos have the chaacteistics o dynamic and continuous because o they will change themselves in dieence time and space. The oasis is a place with centalized human activities and high developed poductivity. The pimodial oasis is the long evolutive esult o natue, and vaious species, esouces depends on each othe on a hamonious state. But this pimodial natue balance is boke down by the moden human beings. Because o the limitations o knowledge and technologies, some iational development and utilization o esouces in oasis ae appeaed, especially wate esouces, which plays a key ole on the subsistence and development o oasis. As a esult, the ecosystem o oasis begins to degade gadually, and uthe to eect on the pospeity and sustainable development o oasis. Theeoe, it is ugent to study the cucial actos that inluence on the stability o oasis ecosystem om the view o natue and human, then to make out the coesponding evaluation standad to diect the human activities and make sue the healthy stability and sustainable development o oasis ecosystem. 2. The Establishment o Evaluation Indexes Because the involved eatues o oasis ecosystem stability ae vey complex, the evaluation system 41

2 The Jounal o Ameican Science, 2(3), 2006, Zhang, et al, Application o Fuzzy-hieachal Integated Evaluation must ollow the pinciples o science, hieachy, integated and pedication. Wate, land, biology and envionment ae the ou main basic eathes to om the oasis system. Moeove, they ae the key eathes who have an impotant eect on the sustainable development o the oasis ecosystem stability. The human activities ae all elated to these ou eathes and the changes o these eathes ae also the elections and esults o human intevention. Theeoe, we can make them as the ist contol es o the oasis ecosystem stability evaluation, then to classiy them uthe accoding to thei impotance degee. The es system is shown in Figue Fuzzy-hieachal integated evaluation model Fom the evaluation es system o oasis ecosystem stability, we can know that the system can be decomposed, so it has the chaacteistic o hibeachy. The es ae elated and depended on each othe and the elationships among them have uncetain and uzzy chaacteistics. This pape evaluates the oasis ecosystem stability by establishing the uzzy-hieachal integated evaluation model. The ollowing is the pocess o the whole evaluation: u (1) Constuct judge matix [ ] k k accoding to the impotance degee uj o each level ( ui) o each. Table 1 is the judge value o the impotance degee o each. The oasis system Wate esouces Land esouces Biology esouces Wate esouces pe unit aea in amland (+) Wate esouces pe unit aea in non-amland (+) The wate shotage ate in agicultue (-) The wate shotage ate in ecosystem, (-) Plantation (-) Plantation salinization (-) Wasteland (-) Woodland (+) Woodland cove degee (+) Gassland (+) Gassland cove degee (+) Wetland (+) Gassland cove ate o ecosystem geen equivalent (+) Envionment esouces Wate pollution situation (-) Undegound wate level depth (eects on salinization +) Undegound wate level depth (eects on non-salinization -) Figue 1. Evaluation es system o oasis ecosystem stability Notes: + means the positive and means the negative 42

3 The Jounal o Ameican Science, 2(3), 2006, Zhang, et al, Application o Fuzzy-hieachal Integated Evaluation Table 1. The judge value o the impotance degee o u (ui) uj equal a little moe obvious stong absolute between each impotant impotant impotant impotant impotant impotant degee λ (2) Compute the lagest eigenvalue max and eigenvecto ξ o each judge matix, and to check up the consistent o matix[ u ]. k k (3) I the matix is consistent, we can calculate the uzzy weight vecto A o each in the lowest level. (4) Ascetain the uzzy matix o scheme level Suppose the decision scope V is a collection o schemes (oasis stability evaluation egion). V {egion 1,egion 2,, egion m}{ v, v,..., v } The es collection which has an impotant eect on the oasis ecosystem stability is that: u {,,, 1 2 n So, the vecto o each egion is as ollows: T v (,,, ), j 1,2,, n j 1 j 2 j I the value o egions and n es: F n1 n2 } nj [2] 1 2 m i in the scheme j is consideed as, we can get the value matix with 1 m 2m nm When the can be calc ulated, the is calculated as: F m i max d d i min,, when when is a negative is a positive In which, d is the gade dieence value and can be calculated as evaluation value o the i in the egion j max min i d i, is the

4 The Jounal o Ameican Science, 2(3), 2006, Zhang, et al, Application o Fuzzy-hieachal Integated Evaluation An evaluation uzzy matix is omed by n evaluation values o m egions R n n2 1 m 2m nm (5) The integated uzzy integated evaluation esults can be got by weighted aveage model M (, + ): Ao R C ( c, c, c 1 2 m ) 4. Model application The iigation aea o dawing wate om the Yellow Rive in Ningxia is located in the nothwest o China with ew ain and stong evapoation, and its ecosystem is vey agility. Fo ecent yeas, the contadiction between wate supply and demand is becoming moe seious, and the human activities ae moe equent and stong which esult in the degadation o oasis ecosystem stability. Theeoe, it is necessay to apply the model into this egion so as to sustain the hamonious development o oasis soc-economy and eco-envionment. In the model application, the iigation aea is divided into ten calculated units accoding to the administative disticts. Unde the condition o 50 pecent o inlow equent o the Yellow Rive in 2000, the ecosystem stability o ten units is evaluated and compaed. 4.1 Compute uzzy weight vecto Aiming at the actual situation o iigation aea, the impotant degee among es is compaed to as: A constuct a judge matix. With the sotwae o Matlab, the eigenvalue and eigenvecto o coesponding matix ae calculated, and then the matix s consistence is checked up. At last, the uzzy weight vecto A is got A( 0.116, 0.088, 0.116, 0.17, 0.075, 0.013, 0.027, 0.036, 0.036, 0.023, 0.023, 0.057, 0.057, 0.097, 0.041, 0.026) 4.2 Constuct the uzzy matix o scheme level The values o each single unit in iigation aea ae as Table 2 and Table 3 [3]-[5] : 44

5 The Jounal o Ameican Science, 2(3), 2006, Zhang, et al, Application o Fuzzy-hieachal Integated Evaluation Table 2. The value o each calculated unit in iigation unde the condition o 50 pecent o inlow equent o the Yellow Rive in 2000 Unit Wate Wate e souces pe unit esouces pe Wate unit aea in aea in p Plantation Plantation Woodland Woodland Wetland ollution non-amland (t/a) salinization cove degee amland (m 3 /mu) (m 3 /mu) Zhongwei Zhongning Qintongxia Yongxing Yinchuan Helan Pingluo S hizuishan Wuzhong Lingwu Table 3. The value o each calculated unit in iigation unde the condition o 50 pecent o inlow equent o the Yellow Rive in 2000 unit Zhongwei Zhongning Qintongxia Yongxing Yinchuan Helan Pingluo S hizuishan Wuzhong Lingwu Gassland cove degee The uzzy matix Wetland Wasteland Gassland cove ate o ecosystem geen equivalent The wate shotage ate in agicultue The wate shotage ate in ecosystem Undegound wate level depth (m) Undegound wate level depth (m) R is got with the method o the uzzy matix o scheme level calculation. 45

6 The Jounal o Ameican Science, 2(3), 2006, Zhang, et al, Application o Fuzzy-hieachal Integated Evaluation 4.3 Fuzzy integated evaluation By the above omulation: Ao R C ( c, c, c 1 2 m )( 0.106, 0.12, 0.09, 0.09, 0.10, 0.124, 0.079, 0.092, 0.098, 101) So, the pioity ode o oasis ecosystem stability o ten calculated units in iigation aea is: Helan > Zhongning > Zhongwei > Lingwu > Yinchuan > Wuzhong > Shizuishan > Yongning > Qingtong > Pingluo. 5. Oasis ecosystem stability evaluation in each calculated unit With the method o uzzy integated evaluation, we can compae the oasis ecosystem stability o each unit in iigation aea o Ningxia. Howeve, the ecosystem stability o each unit is still not be ensued, so it is need to intoduce the coesponding tansomation unction to tansom the evaluation value o each calculated unit, and compae it with the integated evaluation standad o oasis ecosystem stability. On these esults, the oasis ecosystem stability o each unit in iigation aea can be detemined. The integated evaluation standad o oasis ecosystem stability is as Table 4 [6]-[7]. In the pocess o model calculation, all expets ae think the ecosystem stability o Ningxia is in a good situation in So the tansomation unction y x 66x can be constucted as:. Combing with the uzzy integated evaluation esults, the oasis ecosystem stability o each unit in iigation aea can be detemined as Table 5. 2 Table 4. The integated evaluation standad o oasis ecosystem stability The oasis ecosystem stability The integated evaluation standad Best >0.8 Bette Medioc e Wose Wost <0.2 Table 5. The oasis ecosystem stability o each unit in iigation aea o Ningxia Zhongwei Zhongning Qingtongxia Yongning Yinchuan Helan Pingluo Shizuishan Unit Integated Wuzhong Lingwu evaluation value Stability situation Bette Bette Bette Bette Bette Bette Medioce Bette Bette Bette 46

7 The Jounal o Ameican Science, 2(3), 2006, Zhang, et al, Application o Fuzzy-hieachal Integated Evaluation Fom the esults, we know that in 2000, when the inlo w equent o the Yellow Rive is 50 pecent, expect Pingluo, the ecosystem stability o othe Counties o Cites in Ningxia iigation ae all bette, but ae all at the lowe limit o good state. 6. Conclusions The oasis ecosystem stability is a complex poblem involving vaious eathes o vaious aspects and the stability pesents dieence changes along with the dieence o time and space. With the method o uzzy-hieachal integated evaluation, this pape discusses the oasis ecosystem stability and gets the scientiic and ational esults, so this method can be adopted and populaized. In moden days, human activities have become the dominant acto to detemine whethe o not the development o the oasis ecosystem stability is healthy. Theeoe, the utue study on the oasis ecosystem stability shall be paid moe attention to the human activities and thei eects on the oasis stability. Acknowledgement: Ou eseach is kindly suppoted by the ey pojects o West o China in Ministy o Science and Technology Study on Rational Wate Resouces Allocation o Economy and Ecosystem in Ningxia (Numbe: 2004BA901A17). Coespondence to: Jinping Zhang Room 513 o Depatment o Wate Resouces o China Institute o Wate Resouces & Hydopowe Reseach 20 Chegongzhuang,West Road Being , China jinping2000_zh@163.com Received: May 24, Reeences [1] Deling Han. Discuss on the Oasis Stability[J]. Jounal o Ningxia Univesity. 1999:6. [2] Jian Xie, Chengping Liu. The Method and Application o Fuzzy Math. Wuhan: Science and Engineeing Publishing Company in Cente China. 2002:5. [3] Yuansheng Pei, jianhua Wang, Luo Lin. Analysis o eect o South-to-Noth Wate Tanse Poject on Aquatic Ecosystems o Haihe Rive Basin[J]. Acta Ecologica Sinica 2004;24(10): [4] Jinping Zhang, Zhangjing, Suyan Sun. Application o Gey Coelation Analysis in Oasis Ecosystem Stability Evaluation[J]. Resouces Science 2006;28(4): [5] Yuansheng Pei, Suyan Sun Chuiyu Lu. Study on Oasis [6] [7] Ecosystem Stability Pediction[J]. Jounal o Hydaulic Engineeing 2006; 38(4): Shishen Yang g. Study on the model o gade division o natual disaste and compaison o disastous conditions[j]. Jounal o Natual Disastes 1997;6(1):9-12. Yaning Chen, Siquan Yang. The application and model o gey association o evaluation o natual disaste[j].pogess in Geogaphy 1999; 18(2)