Study on the Countermeasures of Drought Control and Disaster Release Based on Humanland Relationship— ——A Case Study in Yunnan Province

Baoshun WANG, Xianguang MA, Min FENG, Lei WEI, Yan YANG

1. Institute of Land Resources and Sustainable Development, Yunnan University of Finance and Economics, Kunming 650221,China;

2. Planning and Design Institute of Land and Resources of Yunnan, Kunming 650216, China

Southern China is always impressed on Chinese people as"a land abundant with water".Nevertheless, confronted by severe droughts in Yunnan and Guizhou provinces, both of governments and Chinese people seem to be at a loss what to do, for the concerning area and influence are so extensive that has exceeded drought-related researches available. Therefore,drought-prevention and disaster-reduction has become a key strategic problem guaranteeing crop,eco-environment, water resources, and even national securities[1].It is obvious that a serious review and research on drought becomes necessary.

Meanwhile, a conclusion has been made on drought causes in Yunnan Province that global warming and El Niño are dominant factors[2],but ecological unbalance caused by ecoenvironment destruction should be considered as well.What’s more, besides natural factors, eco-environment deterioration by human activities, including deforestation, blind construction of water conservancy project, and overdevelopment of resources, is a major cause based on further exploration on destruction of eco-environment in Yunnan Province[2].

Nevertheless, it is a tradition that people excessively rely on constructing diversion works or conducting artificial rainfall at drought, which would possibly result in secondary destruction on eco-environment if misused,forming a new ecological unbalance,deteriorating drought, and leading to a vicious circle (Fig.1). Hence, it is necessary and urgent to reduce ecological pressure and restore eco-balance,from the perspective of the effects of man-earth relationship on drought, in order to reduce/prevent disasters basically and advance the change from drought relief after disasters to drought prevention before disasters.

With consideration of researches available on control and reduction of drought and other disasters in China,highlights are given to regional drought-occurrence rules[3-5]and causes[6], technology in preventing disasters[7-9],risk management of agricultural drought[10]and evaluation on drought prevention, which provides scientific references and methods in terms of drought prevention and disaster reduction, especially in prevention of agricultural drought. In the long run,less attention is paid to disaster prevention from man-earth relationship of these researches, and therefore, the problem can not be resolved fundamentally. It can be concluded that to consider and explore thoughts and countermeasures on drought and disaster prevention in terms of man-earth relationship becomes an irreversible trend for construction of ecological civilization and drought prevention and disaster reduction.

Man-earth Relationship and Droughts Occurring Recently in Yunnan Province

Definition and evolution of manearth relationship

Man-earth relationship refers to the relationship between human activity and geographical environment, on the premise of appearance of human beings, with human labor as a means and material technology as an intermediary[12]. Based on a specific territory,the man-earth system is a dynamicstructure physical system formed in a specific region in the process of interplay[3].Hence,the man-earth system is a synthesis of society and natural environment integrating geographical environment and human activities.

It should be recognized that both of connotation and denotation of manearth relationship is developing upon time. In early stage, for instance, because of a small population and undeveloped economy, people highly rely on nature. As population increases,and social, economy and technology advances, natural resources are increasingly exploited and developed,which reduces absolute quantity of natural resources, as well as relative quantity compared with social development, leading to destruction of ecology,pollution on environment,and conflict between human being and environment.Hence, a coordinated development of people and earth appears accordingly. However, during the history process, the recognition on human-earth relationship tends to be volatile upon schools,covering ancient man-earth relationship, determinism theory of geographical environment,dualism, environment probabilism,adaptation theory,human ecology,determination theory of productive relations,voluntarism,and sustainable development[13].

Currently, although droughts can not be completely prevented, it is necessary to recognize the occurrence and development of drought, as well as the concerning damages on environment in order to take countermeasures and reduce loss. After all, human beings should learn how to coexist with the natural disasters and keep away from timely to minimize loss of life and property. As for prevention of drought disaster,it is an important part to explore the fundamental way from the perspective of coordination of man-earth relationship.

Recent droughts occurring in Yunnan Province

Drought is one of natural disaster the most serious in Yunnan Province,with a high frequency and an extensive coverage. For example, average 50 counties suffer drought yearly in Yunnan Province[14]. The research made by Huang[15]based on drought information during 1950 -2002 indicated that average influential area of drought reached 354 500 hm2in Yunnan, of which over 30% crops in farmlands at 170 400 hm2were affected.In general,crop loss in the province averaged 306 400 t yearly. Since the 1980s, in particular, average area under influence of drought increased to 560 000 hm2,and even over 700 000 hm2in the year with serious drought[16]. For instance,from November 2009 to March 2010, Yunnan experienced the most serious drought and direct economic loss achieved 12 billion yuan[17]. According to disaster classification proposed by Shi et al.[18], the drought occurring in spring in Yunnan has reached severe disaster in terms of occurrence frequency, and direct economic loss. From the research conducted by Huang and Zhang[19]on the area influenced by drought from 2000 to 2008 in Yunnan, the drought areas tended to be volatile, of which the minimum was 206 000 hm2, and the area changed the most significantly in 2005 by 1.189 million hm2. In addition to that,as shown in Fig.1, the affected area by drought in Yunnan Province kept increasing in the 16 years, and the growth reached the peak in 2010 at 2.295 7 million hm2.

It is obvious that successive droughts have caused great loss on Yunnan Province. In accordance withstatistics, since October 2009, 16 prefecture-level divisions as well as 129 county-level divisions all suffered drought disasters in terms of forestry.Specifically, the withered forests reached 1.88 million hm2, and shrubs in karst regions withered in large areas. What’s worse, pest disaster in forests is deteriorating. The affected area in 4 years reached 1.311 3 million hm2, with the area suffering 30% crop loss at 450 700 hm2and direct economic loss at 3.3 billion yuan.Additionally, forest fire becomes more frequently due to drought.In 2012,for example, totaling 299 forest fires occurred in Yunnan Province,and affected forests reached 2 500 hm2, which grew by 160%and 260%.Since winter in 2012,782 000 hm2crops have been affected in Yunnan Province, the area with 30% crop affected reached 358 000 hm2, and the area with 80%crops affected at 85 300 hm2. On the other hand, the affected forest area reached 1.554 1 million hm2,and direct economic loss reached about 10 billion yuan. According to data in Water Resources Department of Yunnan Province,until April 17, 2013, 11 cities in Yunnan were hit by droughts, of which some suffered severe drought,resulting in dry-up of 323 rivers and 331 reservoirs.Consequently,12.448 9 million people are affected, and dysdipsia became popular among 3.423 8 million people and 1.689 1 domestic animals, so that 2.697 7 populations are in need of help[20].

According to information above, it can be concluded that drought disaster is not a short-term or an extreme small-probability event, but a high-frequency and strong disaster with a large area[6]. Therefore, it is of importance and significance for social and economic sustainable development in Yunnan Province to Prevent drought and reduce disasters in a scientific way.

Dialectic Analysis on Drought Prevention and man-earth Relationship Coordination

Regional ecological changes in Yunnan Province

Under influence of human activities, such as forest destruction, farming in steep slopes, over grazing, irrational development of resources, ecosystem is deteriorating, and environment quality is degrading. Because natural geographical environment is a complete complex,ecological changes occur in the environment system, and it is necessary to analyze ecological changes in Yunnan Province in the context of southwest region.

Sharp decline of forest, destruction of natural vegetations, and degradation of regional ecosystem

Since the 1950s, forest resources have undergone excessively exploitation,resulting in serious destruction on forests and sharp decline of forest coverage[21].On basis of statistics[22],in western regions, natural forests in Sichuan and Yunnan boundary are the most seriously damaged and unit stock volume of forest decreases over 2.5% yearly. In Xishuangbanna Dai Autonomous Prefecture, forest area reduced by 230 000 hm2during 1959-1980 and forest coverage rate dropped from 54% to 29%[23]. The decreasing of forests, however, poses a threat on biodiversity and eco-environment(Table 1)[11].

Deterioration of water and soil loss

Resulting from low forest coverage,excessive exploitation of forests and reclamation of lands, surface vegetation of soils drop substantially, and the function of mountain regions declines in terms of water conservancy and adjustment, deteriorating water and soil loss. According to statistics[24], water and soil loss became prominent. For example, the area of water and soil loss reached 134 000 km2, representing 35% of provincial area and the eroded soils totaled 510 million ton yearly, accounting for 1/10 of national loss. Water and soil loss caused by slope cropland proves the severest,taking up to 30%of water and soil loss areas and 40% of water and soil loss quantity. Generally speaking, water and soil loss has caused deterioration of eco-environment destruction and living conditions.

Excessive exploitation of mineral resources and destruction on ecoenvironment With social and economic development, humans’ demands on mineral resources are growing, and excessively exploitation on mineral resources in Yunnan Province has led to destruction on ground vegetation, landslide and debris flow. For example, unscientific construction of mining engineering possibly causes landside and irrational piling of mineral wastes would shape unstable slopes, providing materials for natural disasters, such as debris flow.

Irrational construction of projects and change of eco-environment

Yunnan Province is generally a mountainous province, and most lands should be leveled at road construction or pipeline paving, so that original shape or structure of slopes has been changed, possibly resulting in landslide and collapse. Meanwhile, hydroelectric development projects are much more in Yunnan,and water level might undergo sharp growth or decline due to improper site selection,producing uplift pressure and dynamic water pressure, which would lead to landslide[11].In addition to that,construction of roads and reservoir would produce construction wastes, contaminating environment and causing ecosystem imbalance.

The dialectical relationship between drought prevention and manearth relationship

Ecosystem is a dynamic system in a development process. Given abundant time and stable supply of energy, the ecosystem would develop oriented by a specific trend in terms of species diversity, structure complication, and function perfection until a mature state. Actually, an ecosystem is able to maintain a stable and balance state, with self-adjustment capacity.However,it is notable that such self-adjustment is allowed only within acertain extent, which would be limited or even disappear once the system change exceeds ecological threshold.

Basically, discordant man-earth relationship results in unbalance of original geographical environment,forming a new balance, which actually intensifies, instead of limiting, the changes caused by factors, and deteriorates ecological destruction.

Because of long-term irrational development of natural resources in Yunnan Province, ecological disasters increase, with a high frequency, and high risks, leading to destruction on eco-environment and unbalance of ecosystem. When drought occurs, the adjustment of an ecosystem would weaken due to ecological unbalance,which actually exacerbating adverse effects of droughts. After the disaster,what’s worse, secondary disasters are prone to occur, including debris flow, water and soil loss, desertification,biohazard and life loss, causing a vicious circle. Such a vicious circle would inevitably break original ecobalance, changing climate components in a region and affecting human existence and development(Fig.2).

Countermeasures and Suggestions on Preventing Droughts and Disaster Reduction based on Manearth Relationship

To establish a harmonious coexistence concept of man and water to protect eco-environment

It is important to promote coexistence concept of man and water among people and rectify irrational idea and action of water. Water is rare resource and every drop of water should be made full use of, which should be propagandized, laying foundation for drought prevention and disaster reduction.

To increase vegetation area, enhance forest coverage and improve climate

It is recommended to plant trees or grasses on gentle slopes and return farmlands to forests, and strictly control felling to guarantee forest coverage, in order to improve ecosystem function in terms of water conservancy and adjustment, reduce water and soil loss,and to improve dry climate.

To protect soil reservoir and improve regulation function

It is crucial to protect farmlands,improve soils by deep tillage, increase soil permeability,and enhance regulation of sol reservoir in order to reduce water loss and relieve drought damages. Because of special soil properties in plateau in Yunnan Province,soil reservoir in Yunnan is characterized by large storage capacity and strong regulation, which plays a key role in drought prevention for Yunnan Province[26].

To advance natural rainfall recycling and improve use and transform rates of rainfall

It is notable that to develop and adopt rainfall accumulation system to intensify accumulation and use of rainfalls and snows to transform into water resources for drinking, which provides a new water source. What’s more, the method has little effects on eco-environment and plays an active role in maintaining eco-balance and advance virtuous circle of ecosystem.

To restrict development of waterconsuming industry to guarantee rational use of water resources

With advancement of urbanization and industrialization, water-consuming industries are much popular in different regions,deteriorating water risks in China[27].Hence,it becomes necessary to restrict iron and steel industry, flood irrigation, and high-consumption service industry of water. For example,the industries above should be restricted or forbidden at approving to control water from economy, politic and law constructions and to guarantee rational use of water.

To adjust water actively and promote intensive use of water resources

In the long run,it is urgent and effective to improve water resource into a part of national strategic resources for further use and management from macro-perspective. For instance, water price can be adjusted as per market mechanism, involving ladder water price and taxation on waste water,and index-based control can be used if necessary to guarantee strict use of water and make dynamic management on regional water.

Conclusions

On basis of man-earth relationship, it is important to well consider harmony development between man and nature, establish the thoughts of respecting nature and protect nature and make full use of water oriented byman-earth relationship.

The research analyzed causes of secondary disasters of droughts and proposed countermeasures,such as harmony coexistence and development of man and water, protection of eco-environment and water adjustment. Furthermore, the adverse effects from droughts minimized on basis of coordinated manearth relationship.

It is notable that the research explored the relationship of man-earth coordination and drought prevention from the perspective of logical relationship and further exploration is requiring on the effects of man-earth relationship coordination on drought prevention.

Acknowledgement

We thank the communication chances provided by Cross-strait Water Treatment and Sustainable Development Seminar and amendments proposed by experts in 2013.

[1]YU RC(宇如聪).A major strategic problem of drought prevention in guaranteeing crop, eco-environment and water resource safety(防旱减灾已成为确保粮食安全、生态环境安全、水资源安全等的重大战略问题)[DB/OL].http://news.xinmin.cn/rollnews/2012/03/19/14090160.html,2012-03-19.

[2]YANG YC (杨迎春). Protection of ecoenvironment from the perspective of drought in Yunnan Province (从云南干旱看生态环境保护问题)[J].Western Development(西部大开发),2012(1):41-56.

[3]YANG ZS (杨子生), LIU YS (刘彦随).Temporal and spatial changes of droughts during 1950-2010 in China(中国1950～2010 年旱灾的时空变化特征分析)[A]. Yunnan University of Finance and Economics(云南财经大学)National Chengchi University (台湾政治大学).Water treatment and sustainable development in China (中国水治理与可持续发展研究)[C]. Yunnan University of Finance and Economics(云南财经大学)?National Chengchi University(台湾政治大学).2012:12.

[4]ZHAN C(詹存),LIANG C(梁川),ZHAO L(赵璐).Temporal and spatial distribution characteristics and causes analysis of seasonal drought in hilly area of central Sichuan(川中丘陵区季节性干旱时空分布特征及成因分析)[J]. Transactions of the Chinese Society of Agricultural Engineering (农业工程学报),2013,21:82-90+301.

[5]ZHU JQ(朱建强),HE KP(何开平),TIAN XH (田小海),LU BL (卢碧林),SHEN H( 沈 浩). Prevention of agricultural droughts and emergency countermeasures in fields of Hubei Plain (湖北平原湖区农业防旱抗旱与应急施救研究)[J].Journal of Irrigation and Drainage (灌溉排水学报),2011,05:1-6.

[6]ZHANG GJ(张光军).Causes and countermeasures of agricultural droughts in north Hubei Province (鄂北地区农业旱灾的成因与对策研究)[D].Central China Normal University(华中师范大学),2008.

[7]YANG AR (杨爱荣).Drought prevention assistant decision-making system in a pasturing area based on GIS (基于GIS技术的牧区防旱减灾辅助决策系统研建)[D]. Beijing Forestry University(北京林业大学),2004.

[8]LI YZ (李玉中), WANG CY (王春乙),CHENG YN (程延年). Agricultural drought prevention and resistance technology and application(农业防旱抗旱减灾工程技术与应用)[J].Engineering Science (中国工程科学),2012,09:85-88,95.

[9]WANG LC (王龙昌), JIA ZK (贾志宽),WANG LX (王立祥).Application of gray system theory in the drought climate forecast in southern Ningxia (灰色灾变理论在宁南山区干旱气候预测中的应用)[J]. Journal of Arid Land Resources and Environment (干旱区资源与环境),2003,01:60-64.

[10]XI MH (郗蒙浩),ZHAO QH (赵秋红),YAO Z ( 姚忠). Risk evaluation on drought based on fuzzy theory with a case of Yangquan City, Shanxi Province (基于模糊理论的农业旱灾风险评估——以山西省阳泉市为例)[J].Journal of Natural Disasters(自然灾害学报),2013,01:153-158.

[11]GU Y(顾颖),NI SH(倪深海),WANG HR(王会容). Comprehensive evaluation on ability of coping with agriculture drought in China(中国农业抗旱能力综合评价)[J].Advance in Water Science(水科学进展),2005,05:700-704.

[12]YE DF (叶岱夫).The interactive mechanism of man-earth areal system and the sustainable development(人地关系地域系统与可持续发展的相互作用机理初探)[J].Geographical Research(地理研究),2001,20(3):307-314.

[13]FENG DX (冯德显), ZHAG L (张莉),YANG RX (杨瑞霞), et al. A study of planning the main functional regions based on the man-nature relationship theory of Hainan Province(基于人地关系理论的海南省主体功能区规划研究)[J].Areal Research and Development(地域研究与开发),2008,27(1):1-5.

[14]FAN BJ (范宝俊). Disaster management library:the sixth volume,study of disaster prevention countermeasures(灾害管理文库:第六卷 灾害防御对策研究) [M]. Beijing:Contenmporary China Publishing House(北京:当代中国出版社),1999.

[15]BAI SM(白树明),HUANG ZY(黄中艳).Drought characteristics in Yunnan Province and prediction on the development trend in following ten years(云南旱灾特点和未来10 年干旱趋势预测)[J].People(人民珠江),2003(6):4-6.

[16]WEN KG (温克刚), LIU JH (刘建华).China meteorological disasters (Yunnan)(中国气象灾害大典, 云南卷)[M].Beijing:Meteorological Press (北京:气象出版社),2006.

[17]WANG JJ (王佳津),MENG YB (孟耀斌),ZHANG C(张 朝),et al.Establishment of Palmer drought severity model for Yunnan Province analysis of characteristics of drought disaster in 2010(云南省Palmer 旱度模式的建立——2010 年干旱灾害特征分析)[J].Journal of Natural Disasters (自然灾害学报),2012,21(1):190-197.

[18]SHI PJ (史培军). Theory and practice on disaster system research in a fourth time(四论灾害系统研究的理论与实践)[J].Journal of Natural Disasters (自然灾害学报),2005,14(6):8-9.

[19]HUANG Y(黄雨),ZHANG DL(张德亮).Analysis of influence factors of drought in Yunnan Province and preliminary exploration of disaster reduction strategy (云南省干旱成灾因素分析及减灾对策初探)[J].Journal of Yunnan Agricultural University(云南农业大学学报),2011,5(2):37-40.

[20]WANG Y (王云).Moderate or high degree droughts in 11 prefecture-level divisions in Yunnan, causing 10 billion yuan losses( 云南11 州市出现中度以上气象干旱， 损失近百亿元)[DB/OL].http://www.yn.xinhuanet.com/newscenter/2013-04/26/c_132341204.htm,2013-04-26.

[21]QIN Q (秦趣), FENG WB (冯维波).Earthquake resistance and hazardous reduction in western mountains based on man-earth relationship(基于人地关系的西部山区抗震减灾对策研究)[J].World Earthquake Engineering(世界地震工程),2009,25(1):160-161.

[22]WANG SM(王苏民), LIN ED(林而达),SHE ZX (佘之祥). Effects of environment evolution on China development and countermeasures (环境演变对中国本部发展的影响及对策)[J]. Beijing:Science Press (北京:科学出版社),2002:47-49.

[23]MENG GC(孟国才), WANG SG(王士革),XIE H(谢洪).Present situation and restoration of agriculture ecological environment in western mountain of China(我国西部山区农业生态环境现状与恢复对策)[J]. Research of Agricultural Modernization(农业现代化研究),2005,26(3):182-185.

[24]LI DD(李丹丹).Afforestation of 30 million mu and amelioration of mediumand low-yielding lands at 20 million muwithin two years in Yunnan (云南2 年内要造林超3000 万亩, 改造中低产林2000 万亩)[DB/OL].http://www.yn.xinhuanet.com/newscenter/2013 -04/09/c_132294268.htm,2013-04-09.

[25]WU GH(伍光和),WANG NA(王乃昂),HU SX (胡双熙),et al.Physical geography(自然地理学)[M].The 4th edition(第四版). Beijing:Higher Education Press(北京:高等教育出版社),2008.

[26]WU ZL(邬志龙),YANG ZS(杨子生).To protect soil reservoir and recycling of rainfall—an important way of drought prevention in Yunnan Province (保护“土壤水库” 与雨水资源化——云南省防旱减灾的重要途径之一.) Research on water governance and sustainable development of China (中国水治理与可持续发展研究)[C]. Beijing:Social Sciences Academic Press(北京:社会科学文献出版社),2012:264-272.

[27]YUAN BX (原碧霞). Water risks close to "red lines" and the transformation close to base line (水危机逼近红线,转型逼向底线)[DB/OL].http://news.xinhuanet.com/politics/2011-07/06/c_121628203.htm,2011-07-06.