hydrometeorological natural disasters and water resources ...
HYDROMETEOROLOGICAL NATURAL DISASTERS AND WATER RESOURCES MANAGEMENT IN EVROTAS RIVER BASIN (PELOPONNESUS, GREECE) Andreadakis Emm., Fountoulis I., Mariolakos I., Kapourani E. National and Kapodistrian University of Athens, Faculty of Geology and Geoenvironment, Department of Dynamic, Tectonic, Applied Geology, Panepistimiopoli, Zografou 15784 Athens, [email protected], [email protected], [email protected], [email protected] ABSTRACT Hydrometeorological disasters include rapid onset types, such as floods and wildfires, as much as slow disaster types, such as droughts and desertification. These types of phenomena are closely connected to each other, and in some cases they may be induced, triggered or amplified by human activities, the impact on which defines the phenomena as disasters. Climate change (imminent or evolving) may alter the hydrometeorological patterns of an area, favoring such disaster incidents, which in turn may affect each other in terms of domino effects. Evrotas River basin (Laconia, Peloponnesus, Greece) is a relatively small basin in a Mediterranean region with semi arid characteristics. A large part of the basin is considered as area of high desertification risk, while droughts and floods have repeatedly stroke during the last decades. On top of that, a large scale wildfire in August 2007 burnt a large percentage of the basin, in all altitude and all vegetation zones. Under the circumstances, Evrotas River as a hydrological, hydrogeological and ecological system is facing a complex challenge. Once the local economy is based on agriculture and tourism, both water-costly activities, water resources efficiency is critical for development, while quantity, chemical and ecological deficiency problems have been observed in recent years and local antagonism has been increasing for the assertion of rights over water use and resource exploitation among settlements and municipalities. At the same time, recent annual precipitation data, though not dramatically reduced, show a tendency towards less and more intense rainfalls in expense of longer and milder ones. As a result, flood phenomena are increased and recharge time of aquifers is reduced. In this framework, flood water should no longer be considered unwelcome and drained rapidly to the sea. On the contrary, flood water should be considered a critical natural resource, and it should be an object of systematic exploitation. Flood risk management, burnt area recovery measures and water resources management have to be considered as closely connected activities, and interdisciplinary projects seem to be the safest way to success. 1. AIM OF THE STUDY Hydrometeorological disasters (floods, droughts, desertification, extreme weather phenomena, wildfires, wet mass movements etc) tend to increase in frequency and damage, as a result of the increasing interaction between human and a changing environment. In the framework of climatic change, this tendency is expected to be enhanced in the future[1]. At the same time, water resources are subject to strong pressure, as a result of unsustainable management practices. In fact, water resources failure (in quality and quantity needs and standards as well as ecosystem preservation) is considered a “slow disaster” itself. However, hydrometeorological (H/M) disasters and water resources (WR) management seem to be dealt with separately, in quite the same way that surface water was dealt with separately to groundwater, for some time in the recent past decades. As a result, measures and policies to mitigate H/M disasters are often conflicting with measures and policies applied to achieve sustainable water resources management in the same areas. The hydrological cycle involves all forms and expressions of water, which cannot be separated into “good” (as a resource) or “bad” (as a disaster). Water
management involves both resources and disasters, so common ground and interdisciplinary action is required for managers, engineers and scientists. This study attempts to propose directions for integration of H/M disaster management and WR management, through the example of Laconia prefecture (Peloponnesus, Greece) and more specifically Evrotas River basin. CLIMATE HYDROLOGICAL CYCLE
DROUGHTS HEATWAVES
EXTREME WEATHER
STORMS
HUMAN WATER RESOURCES
H/M DISASTERS
WILDFIRES
FLOODS WET MASS MOVEMENTS HYDROLOGICAL IMPACT
DIRECT IMPACT
GEOMORPHOLOGICAL IMPACT DESERTIFICATION
Figure 1: Water resources and Hydrometeorological disasters interaction with human, in the framework of the hydrological cycle and the climate. 2. WATER SYSTEMS AND MANAGEMENT IN EVROTAS RIVER BASIN The hydrogeological system of the area defined by Taygetos and Parnon mts is a complex structure consisting of karstic aquifers (limestone and marble of Pindos, Tripolis and Mani geotectonic units), porous aquifers (Plio-Quaternary and alluvial deposits) and hard rock aquifers (phyllites-quartzites formations). The hydrological function of the system is realized by three groups of basins, which are hydrogeologically open (they are connected to water bodies of adjacent basins). Evrotas River basin covers the most of this area, while a number of minor basins outflow directly to the Laconic gulf, or in the plain of Evrotas delta. Although this is a rather small area (Evrotas basin is roughly 1700km2) the tectonic structure and evolution of the region has resulted in great spatial differentiation of hydrological and hydrogeological functions, with a significant impact on water resources availability and the type, distribution and frequency of H/M disasters. As a result, water management has evolved accordingly in different ways for different parts of the area. At the north and northwest part of the region (Taygetos eastern margin) water resources are more abundant, due to the number of important spring outlets discharging the karstic aquifers that extend over the most of the mountain, which is richly fed by the rain and the winter snow cover. Aquiclude formations isolate some of the limestone tectonic nappes and at the same time force leakage towards the interior of the basin. Moreover, the fans on the foot of the margin host porous aquifers fed by the adjacent karstic ones, and they are exploited by very productive drills. On the contrary, the eastern part of the region (central Parnon, western margin) suffers from water shortage, increasingly from the axis of Evrotas valley to the east. The tectonic setting is different from Taygetos, and groundwater escapes to great depth (almost down to the sealevel), and then to the east (Myrtoon sea). Moreover, rainfall and snow cover are lighter in this area. As a result, settlement development is sparser and in smaller units, while agriculture is based on the
river alluvial deposit aquifer (hydraulically connected to the river) and on deep drills, located near the valley, and facing the problem of imminent exhaustion. Spring outlets are mainly small, while the most productive ones are in great altitudes to the north. The basin of Sparta is highly productive because spring outlets, fan drills and alluvial deposit wells are complementary to this area. On the other hand, the increased and intense development in this area, has led to problems of mainly organic pollution (nitrates, BOD) in both the river and the porous aquifers. The composite delta area of Evrotas River hosts, apart from a number of settlements (Skala, Elos, Asteri etc) a large intensely cultivated field, irrigated by both channeling of Vasilopotamos karstic spring outlets and productive drills exploiting the porous coastal aquifer. As a result, sea intrusion problems have intensified, especially after poor wet seasons, mainly towards the east. The south of the region (Mani peninsula and Voion peninsula), outside Evrotas basin suffers from severe water shortage as a result of the poor rainfall, the lack of snow cover and the direct connection of karstic and porous aquifers to the sea. Water needs are met by rather poorly productive wells and drills with sea intrusion or Fe-Mn pollution problems, water transport from the basin of Evrotas (especially for Mani area) and lately, water processing and desalination. 3. HYDROMETEOROLOGICAL DISASTERS IN THE AREA 3.1 Floods and extreme weather Laconia prefecture has repeatedly suffered from flood phenomena during the last decade [2]. It has been pointed out that floods are a diachronic and altogether natural feature of the area in geological time [3], [4]. Nevertheless, in the human time scale, it is evident that recently, the frequency and damage of floods have increased. In other words, both hazard and risk are increasing in the area and such times call for measures. Hazardous areas defined by both historical and analytical data are mainly focused in both the main riverbed of Evrotas River and the tributaries primarily from Taygetos Mt. and secondarily of Parnon Mt. As much as the tributaries are concerned, the type of phenomenon is almost exclusively flash flood. Outside the basin, other flood hazardous areas are located in the entrance of streams coming from mountainous areas into plains (Molaoi basin, Sminos basin etc). Unfortunately, flood risk management for most of these areas is focused in embankments (before or during the flood) along the river and quick channeling of water straight to the sea, while post disaster phase includes only compensations. It has been evident, during almost all events, that little can be done to avoid the disaster, once the floodwater is concentrated into the single streams that enter the floodplains. In November 2005, when the whole of the basin was saturated and activated during extreme weather conditions, flash floods burst out in several tributaries and a riverine flood finally took place along the main riverbed of Evrotas at a number of sites. On the basis of calculations made for the site of the bridge of Evrotas at Sparta (where a hydrometric station is settled [5]) it was figured out that during this extreme event alone, more than 18 million m3 of water flowed through, and most of it ended into the sea within 48 hours. To make a sharp comparison, it is noted that for the whole period November 2006-October 2007, the same station recorded a calculated runoff of approximately 21 million m3. In the case of November 2005 water was a disaster, while during the next (hydrologically poor) period it was an exhausted resource. 3.2 Wildfires A significant part of the recharge area of Evrotas basin in the mountainous areas of the region (Taygetos and Parnon), is covered by mainly coniferous forests, which is a very favourable factor for water retention and detention during the wet season, thus favoring infiltration in expense of runoff. Moreover, it effects microclimatic and soil conditions blocking the expansion of desertification phenomena, in which the region is particularly vulnerable. During the summer
Total Runoff (millions m3)
of 2007, and after the poor wet season mentioned also above, severe wildfires burnt out 15% of the basin, which is a proportion too large to let unaffected the hydrological function of the area [6], not to mention that some of the sub-basins have been affected in much greater extent. As a result, erosion and runoff are expected to increase both as average pace and during extreme weather phenomena [7], [8], [9], [10]. The hydrometric station at Sparta Bridge recorded the signs of the impact. Two days after the outburst of the wildfires, a complete dry out of the riverbed was recorded due to extensive use of water for fire extinction uphill. A month later, during the first rainstorm on Parnon Mt., sudden hyperconcentrated flow (flash/debris flood) phenomena took place at Oinous river (Parnon main tributary to Evrotas), was recorded at Sparta bridge as sudden and sharp rise of waterlevel. Another phenomenon of the kind took place in October farther north, near the fire-affected area of the north part of the basin (in Arcadia), and was recorded by the hydrometric station at Vivari. It is well evident that wildfires, affected by both human and climate, have an immediate impact on the hydrological function of a fire affected basin [11], [12]. Moreover, runoff is expected to increase on expense of evaporotranspiration and infiltration in the fire affected areas, so impact will not only be immediate, but also persistent. After the fire, soil erosion is enhanced, so desertification is intensified. Researchers agree that the duration of this impact depends on the recovery pace of the area. In this framework, it has to be pointed out that forest management should be considered as an important sector of environmental management, not only for the preservation of forests, but because of the impact on water resources and other H/M disasters (floods, wet mass movements, desertification etc). Runoff through Sparta Bridge (Evrotas River) 25 20
29-8-2007, 18:00 Wildfire
15
20-9-2007, 21:39 Flash Flood
10 5 0 November 24th - November 2006November 26th October 2007 2005
Figure 2: Comparison between runoff under Sparta Bridge during floods (Nov. ΄05) and the whole next season (Nov.΄06 - Oct.΄07).
Figure 3: Water level monitoring at Sparta Bridge (Evrotas). Total dryout during the wildfires, “flash flood”-like impact during extreme weather conditions (Source: http://www.evrotas.gr).
4. CONCLUSIONS - DISCUSSION The water resources of Laconia depend greatly on the hydrogeological conditions and the hydrology of Evrotas River basin. In the same area, a number of hydrometeorological hazards coexist with seasonal or permanent water shortage. Drought events are increasing, rains are becoming less and more intense, evaporotranspiration is high, desertification is present, in the fire affected areas infiltration is reduced in favor of runoff and seawater intrusion affects the coastal areas. Any measure for any of these problems should not ignore the impact on the others. In fact, in a region threatened by drought and desertification, flood water should be considered a valuable resource, rather than a hazard, and be treated as such [13]. Sending floodwaters straight to the sea the quickest possible, mitigates flood hazard near the delta, but does not help with water shortage in the continental areas or seawater intrusion near
the coast. Embankments cannot hold all floods and cannot be applied all along the drainage network.
Figure 4: Integrated map of flood risk priority areas, fire affected areas (August 2007) and immediate post fire hydrological impact for Laconia (Autumn 2007). The complex interaction among drought-wildfire-flood takes each disaster as an amplifying factor for the others. This takes place in a changing climatic environment, favoring extreme weather, disturbing the basin’s hydrology and enhancing desertification, while water need is constantly increasing. Hydrometeorological hazards and water resources cannot be managed independently, and it will take multidisciplinary action and holistic point of view, to cope with these problems. The context should be “environment management” rather than “disaster management” or “water resources management”. This “environment management” should start from the mountain areas towards the plains, and not otherwise, with small scale actions, applied in large scale:
• • • •
Forest protection and management, and protection and restoration of the fire affected area with anti-erosion and vegetation restoration measures. Water retention works along the drainage network, combined with karstic aquifer recharge works, to mitigate floods and enhance infiltration. Institutional measures and application of land use zonation, for the protection of watershed areas and flood hazardous areas. Protection of watershed areas from inappropriate farming and husbandry practices, especially in areas with desertification phenomena and fire affected areas.
REFERENCES [1] IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 pp. [2] Manolakos, P. And Papadoulakis, V. (2007) Record of flood disasters in Laconia Prefecture. App. 1 in: Nikolaieds et al. (2007) “Antiflood Protection Master Plan for Laconia Prefecture”. (LIFE-Environment 2005, ENVIFRIENDLY http://www.envifriendly.tuc.gr). [3] Pope, R. & Millington, A. (2000) Unravelling The Patterns of Alluvial Fan Development Using Mineral Magnetic Analysis: Examples From The Sparta Basin, Lakonia, Southern Greece. Earth Surf. Process. Landforms 25, 601-615. [4] Fountoulis, I., Mariolakos, I., Andreadakis, Emm., Sambaziotis, E., Karagiozi, E., (2007) Strategic Planning of Anti-Flood protection for Laconia Prefecture, App.2 in : Nikolaides et al. (2007) “Antiflood Protection Master Plan for Laconia Prefecture”. (LIFE-Environment 2005, ENVIFRIENDLY). [5] http://www.evrotas.gr. [6] Bosch J.M. and Hewlett J.D. (1982) A review of catchment experiments to determine the effect of vegetation changes on water yield and evapotranspiration. Journal of Hydrology, 55 (1982) 3—23, Elsevier. [7] DeBano, L.F., Osborne, J.F., Krammes, J.F. & Letey, J. (1967) Soil wettability and wetting agents. Our current knowledge of the problem. USDA, For. Serv., Res. Pap, PSW-43, Berkeley, USA. [8] Brown, J.A.H. (1972): Hydrologic effects of a bushfire in a catchment in south-eastern new South Wales, Journal of Hydrology. 15, 77-96. [9] Bosch J.M. and Hewlett J.D. (1982) A review of catchment experiments to determine the effect of vegetation changes on water yield and evapotranspiration. Journal of Hydrology, 55 (1982) 3—23, Elsevier. [10] Batalla R.J. & Sala M. (1998): Changes on sediment and dissolved load after wildland fire in a Mediterranean river basin. XXIII General Assembly of the European Geophysical Society, Nice, France, April 1998. [11] Doerr S.H., Shakesby R.A., Blake W.H., Chafer C.J., Humphreys G.S., Wallbrink P.J. (2006) Effects of differing wildfire severities on soil wettability and implications for hydrological response. Journal of Hydrology, 319, 295–311, Elsevier. [12] Mayor A.G., Bautista S., Llovet J., Bellot J. (2007) Post-fire hydrological and erosional responses of a Mediterranean landscape: Seven years of catchment-scale dynamics. Catena, 71, 68–75, Elsevier. [13] Guiraud R. (1990) Small dams and subsurface dams in arid and semi-arid areas: The example of Saharan and Sahelian Africa. In: R. Paepe et al. (eds), Greenhouse Effect, Sea Level and Drought, 513-522. Kluwer Academic Publishers. Netherlands.
management involves both resources and disasters, so common ground and interdisciplinary action is required for managers, engineers and scientists. This study attempts to propose directions for integration of H/M disaster management and WR management, through the example of Laconia prefecture (Peloponnesus, Greece) and more specifically Evrotas River basin. CLIMATE HYDROLOGICAL CYCLE
DROUGHTS HEATWAVES
EXTREME WEATHER
STORMS
HUMAN WATER RESOURCES
H/M DISASTERS
WILDFIRES
FLOODS WET MASS MOVEMENTS HYDROLOGICAL IMPACT
DIRECT IMPACT
GEOMORPHOLOGICAL IMPACT DESERTIFICATION
Figure 1: Water resources and Hydrometeorological disasters interaction with human, in the framework of the hydrological cycle and the climate. 2. WATER SYSTEMS AND MANAGEMENT IN EVROTAS RIVER BASIN The hydrogeological system of the area defined by Taygetos and Parnon mts is a complex structure consisting of karstic aquifers (limestone and marble of Pindos, Tripolis and Mani geotectonic units), porous aquifers (Plio-Quaternary and alluvial deposits) and hard rock aquifers (phyllites-quartzites formations). The hydrological function of the system is realized by three groups of basins, which are hydrogeologically open (they are connected to water bodies of adjacent basins). Evrotas River basin covers the most of this area, while a number of minor basins outflow directly to the Laconic gulf, or in the plain of Evrotas delta. Although this is a rather small area (Evrotas basin is roughly 1700km2) the tectonic structure and evolution of the region has resulted in great spatial differentiation of hydrological and hydrogeological functions, with a significant impact on water resources availability and the type, distribution and frequency of H/M disasters. As a result, water management has evolved accordingly in different ways for different parts of the area. At the north and northwest part of the region (Taygetos eastern margin) water resources are more abundant, due to the number of important spring outlets discharging the karstic aquifers that extend over the most of the mountain, which is richly fed by the rain and the winter snow cover. Aquiclude formations isolate some of the limestone tectonic nappes and at the same time force leakage towards the interior of the basin. Moreover, the fans on the foot of the margin host porous aquifers fed by the adjacent karstic ones, and they are exploited by very productive drills. On the contrary, the eastern part of the region (central Parnon, western margin) suffers from water shortage, increasingly from the axis of Evrotas valley to the east. The tectonic setting is different from Taygetos, and groundwater escapes to great depth (almost down to the sealevel), and then to the east (Myrtoon sea). Moreover, rainfall and snow cover are lighter in this area. As a result, settlement development is sparser and in smaller units, while agriculture is based on the
river alluvial deposit aquifer (hydraulically connected to the river) and on deep drills, located near the valley, and facing the problem of imminent exhaustion. Spring outlets are mainly small, while the most productive ones are in great altitudes to the north. The basin of Sparta is highly productive because spring outlets, fan drills and alluvial deposit wells are complementary to this area. On the other hand, the increased and intense development in this area, has led to problems of mainly organic pollution (nitrates, BOD) in both the river and the porous aquifers. The composite delta area of Evrotas River hosts, apart from a number of settlements (Skala, Elos, Asteri etc) a large intensely cultivated field, irrigated by both channeling of Vasilopotamos karstic spring outlets and productive drills exploiting the porous coastal aquifer. As a result, sea intrusion problems have intensified, especially after poor wet seasons, mainly towards the east. The south of the region (Mani peninsula and Voion peninsula), outside Evrotas basin suffers from severe water shortage as a result of the poor rainfall, the lack of snow cover and the direct connection of karstic and porous aquifers to the sea. Water needs are met by rather poorly productive wells and drills with sea intrusion or Fe-Mn pollution problems, water transport from the basin of Evrotas (especially for Mani area) and lately, water processing and desalination. 3. HYDROMETEOROLOGICAL DISASTERS IN THE AREA 3.1 Floods and extreme weather Laconia prefecture has repeatedly suffered from flood phenomena during the last decade [2]. It has been pointed out that floods are a diachronic and altogether natural feature of the area in geological time [3], [4]. Nevertheless, in the human time scale, it is evident that recently, the frequency and damage of floods have increased. In other words, both hazard and risk are increasing in the area and such times call for measures. Hazardous areas defined by both historical and analytical data are mainly focused in both the main riverbed of Evrotas River and the tributaries primarily from Taygetos Mt. and secondarily of Parnon Mt. As much as the tributaries are concerned, the type of phenomenon is almost exclusively flash flood. Outside the basin, other flood hazardous areas are located in the entrance of streams coming from mountainous areas into plains (Molaoi basin, Sminos basin etc). Unfortunately, flood risk management for most of these areas is focused in embankments (before or during the flood) along the river and quick channeling of water straight to the sea, while post disaster phase includes only compensations. It has been evident, during almost all events, that little can be done to avoid the disaster, once the floodwater is concentrated into the single streams that enter the floodplains. In November 2005, when the whole of the basin was saturated and activated during extreme weather conditions, flash floods burst out in several tributaries and a riverine flood finally took place along the main riverbed of Evrotas at a number of sites. On the basis of calculations made for the site of the bridge of Evrotas at Sparta (where a hydrometric station is settled [5]) it was figured out that during this extreme event alone, more than 18 million m3 of water flowed through, and most of it ended into the sea within 48 hours. To make a sharp comparison, it is noted that for the whole period November 2006-October 2007, the same station recorded a calculated runoff of approximately 21 million m3. In the case of November 2005 water was a disaster, while during the next (hydrologically poor) period it was an exhausted resource. 3.2 Wildfires A significant part of the recharge area of Evrotas basin in the mountainous areas of the region (Taygetos and Parnon), is covered by mainly coniferous forests, which is a very favourable factor for water retention and detention during the wet season, thus favoring infiltration in expense of runoff. Moreover, it effects microclimatic and soil conditions blocking the expansion of desertification phenomena, in which the region is particularly vulnerable. During the summer
Total Runoff (millions m3)
of 2007, and after the poor wet season mentioned also above, severe wildfires burnt out 15% of the basin, which is a proportion too large to let unaffected the hydrological function of the area [6], not to mention that some of the sub-basins have been affected in much greater extent. As a result, erosion and runoff are expected to increase both as average pace and during extreme weather phenomena [7], [8], [9], [10]. The hydrometric station at Sparta Bridge recorded the signs of the impact. Two days after the outburst of the wildfires, a complete dry out of the riverbed was recorded due to extensive use of water for fire extinction uphill. A month later, during the first rainstorm on Parnon Mt., sudden hyperconcentrated flow (flash/debris flood) phenomena took place at Oinous river (Parnon main tributary to Evrotas), was recorded at Sparta bridge as sudden and sharp rise of waterlevel. Another phenomenon of the kind took place in October farther north, near the fire-affected area of the north part of the basin (in Arcadia), and was recorded by the hydrometric station at Vivari. It is well evident that wildfires, affected by both human and climate, have an immediate impact on the hydrological function of a fire affected basin [11], [12]. Moreover, runoff is expected to increase on expense of evaporotranspiration and infiltration in the fire affected areas, so impact will not only be immediate, but also persistent. After the fire, soil erosion is enhanced, so desertification is intensified. Researchers agree that the duration of this impact depends on the recovery pace of the area. In this framework, it has to be pointed out that forest management should be considered as an important sector of environmental management, not only for the preservation of forests, but because of the impact on water resources and other H/M disasters (floods, wet mass movements, desertification etc). Runoff through Sparta Bridge (Evrotas River) 25 20
29-8-2007, 18:00 Wildfire
15
20-9-2007, 21:39 Flash Flood
10 5 0 November 24th - November 2006November 26th October 2007 2005
Figure 2: Comparison between runoff under Sparta Bridge during floods (Nov. ΄05) and the whole next season (Nov.΄06 - Oct.΄07).
Figure 3: Water level monitoring at Sparta Bridge (Evrotas). Total dryout during the wildfires, “flash flood”-like impact during extreme weather conditions (Source: http://www.evrotas.gr).
4. CONCLUSIONS - DISCUSSION The water resources of Laconia depend greatly on the hydrogeological conditions and the hydrology of Evrotas River basin. In the same area, a number of hydrometeorological hazards coexist with seasonal or permanent water shortage. Drought events are increasing, rains are becoming less and more intense, evaporotranspiration is high, desertification is present, in the fire affected areas infiltration is reduced in favor of runoff and seawater intrusion affects the coastal areas. Any measure for any of these problems should not ignore the impact on the others. In fact, in a region threatened by drought and desertification, flood water should be considered a valuable resource, rather than a hazard, and be treated as such [13]. Sending floodwaters straight to the sea the quickest possible, mitigates flood hazard near the delta, but does not help with water shortage in the continental areas or seawater intrusion near
the coast. Embankments cannot hold all floods and cannot be applied all along the drainage network.
Figure 4: Integrated map of flood risk priority areas, fire affected areas (August 2007) and immediate post fire hydrological impact for Laconia (Autumn 2007). The complex interaction among drought-wildfire-flood takes each disaster as an amplifying factor for the others. This takes place in a changing climatic environment, favoring extreme weather, disturbing the basin’s hydrology and enhancing desertification, while water need is constantly increasing. Hydrometeorological hazards and water resources cannot be managed independently, and it will take multidisciplinary action and holistic point of view, to cope with these problems. The context should be “environment management” rather than “disaster management” or “water resources management”. This “environment management” should start from the mountain areas towards the plains, and not otherwise, with small scale actions, applied in large scale:
• • • •
Forest protection and management, and protection and restoration of the fire affected area with anti-erosion and vegetation restoration measures. Water retention works along the drainage network, combined with karstic aquifer recharge works, to mitigate floods and enhance infiltration. Institutional measures and application of land use zonation, for the protection of watershed areas and flood hazardous areas. Protection of watershed areas from inappropriate farming and husbandry practices, especially in areas with desertification phenomena and fire affected areas.
REFERENCES [1] IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 pp. [2] Manolakos, P. And Papadoulakis, V. (2007) Record of flood disasters in Laconia Prefecture. App. 1 in: Nikolaieds et al. (2007) “Antiflood Protection Master Plan for Laconia Prefecture”. (LIFE-Environment 2005, ENVIFRIENDLY http://www.envifriendly.tuc.gr). [3] Pope, R. & Millington, A. (2000) Unravelling The Patterns of Alluvial Fan Development Using Mineral Magnetic Analysis: Examples From The Sparta Basin, Lakonia, Southern Greece. Earth Surf. Process. Landforms 25, 601-615. [4] Fountoulis, I., Mariolakos, I., Andreadakis, Emm., Sambaziotis, E., Karagiozi, E., (2007) Strategic Planning of Anti-Flood protection for Laconia Prefecture, App.2 in : Nikolaides et al. (2007) “Antiflood Protection Master Plan for Laconia Prefecture”. (LIFE-Environment 2005, ENVIFRIENDLY). [5] http://www.evrotas.gr. [6] Bosch J.M. and Hewlett J.D. (1982) A review of catchment experiments to determine the effect of vegetation changes on water yield and evapotranspiration. Journal of Hydrology, 55 (1982) 3—23, Elsevier. [7] DeBano, L.F., Osborne, J.F., Krammes, J.F. & Letey, J. (1967) Soil wettability and wetting agents. Our current knowledge of the problem. USDA, For. Serv., Res. Pap, PSW-43, Berkeley, USA. [8] Brown, J.A.H. (1972): Hydrologic effects of a bushfire in a catchment in south-eastern new South Wales, Journal of Hydrology. 15, 77-96. [9] Bosch J.M. and Hewlett J.D. (1982) A review of catchment experiments to determine the effect of vegetation changes on water yield and evapotranspiration. Journal of Hydrology, 55 (1982) 3—23, Elsevier. [10] Batalla R.J. & Sala M. (1998): Changes on sediment and dissolved load after wildland fire in a Mediterranean river basin. XXIII General Assembly of the European Geophysical Society, Nice, France, April 1998. [11] Doerr S.H., Shakesby R.A., Blake W.H., Chafer C.J., Humphreys G.S., Wallbrink P.J. (2006) Effects of differing wildfire severities on soil wettability and implications for hydrological response. Journal of Hydrology, 319, 295–311, Elsevier. [12] Mayor A.G., Bautista S., Llovet J., Bellot J. (2007) Post-fire hydrological and erosional responses of a Mediterranean landscape: Seven years of catchment-scale dynamics. Catena, 71, 68–75, Elsevier. [13] Guiraud R. (1990) Small dams and subsurface dams in arid and semi-arid areas: The example of Saharan and Sahelian Africa. In: R. Paepe et al. (eds), Greenhouse Effect, Sea Level and Drought, 513-522. Kluwer Academic Publishers. Netherlands.
