Post by L Roebuck on Sept 23, 2006 9:10:24 GMT -5
NATURE FOR LIFE
By Anabelle E. Plantilla
The value of karst formations
The sight of the Chocolate Hills is truly majestic—tiny little dots of green and brown as far as the eye can see. The inscription says that they are karst formations. What? During a visit to Bohol, Bill Granert and Jun-G Madronero of the Soil and Water Conservation Foundation (SWCF) gave Haribon a very good explanation of cone karst formations, an example of which are the Chocolate Hills, and their ecological importance. Incidentally, cone karst formations only form in wet tropical climates.
The term “karst” is derived from the geographical name “kras” from part of the karst terrain of Slovenia, Eastern Europe. Karst terrain is best known for its underground drainage systems or cave systems that often form there.
Approximately 10 percent of the earth’s surface is composed of karst and approximately 25 percent of the world’s population live on these areas. In the Philippines, eight percent or approximately 35,000 sq km is karst. The hollow nature of karst terrain results in very high pollution potential. Stream and surface runoff directly enter sinkholes, cracks and caves and thus, bypass natural filtration through soil and sediment. Groundwater can travel quite rapidly through these underground networks, with speeds of up to hundreds of meters, or even kilometers, per day, transmitting contaminants to wells and springs in the vicinity.
In our country, karst formations can be found in Luzon and Mindanao, and 23 of these, representing 10,000 sq km, are protected by law through the National Integrated Protected Areas System and the National Caves and Cave Resources Management Acts. They are protected largely because of their aesthetic and, therefore, tourism value. Some examples are Callao Cave in Cagayan, Hundred Islands in Pangasinan, Mount Banahaw-Mount Cristobal in Laguna and Quezon, Mount Isarog in Camarines Sur, Saint Paul Subterranean River in Palawan, Chocolate Hills, Mount Kitanglad in Bukidnon and Sohoton Natural Bridge in Samar.
Having abundant and easily accessible water resources is one of the advantages of karst environments. They cause faster recharging of aquifers and are the main sources of springs. Another advantage is that they record history. In most caves can be found burial grounds of ancient tribes, artifacts and even drawings. They also have good soils as they trap weathered parent materials and organic matter and neutralize acidic soil. They are good sources of building materials for producing cement, filling material and commercial lime. Their economic value for tourism, food sources (birds’ nests), guano, medicines, irrigation and potable water and as a gene bank for endemic species has not yet even been determined.
On the other hand, inappropriate human activities have contributed to the degradation of these environments. Although karst soils are fertile, they are frequently very shallow, thus prone to erosion. The hydrological system of karst areas is also very sensitive to pollution which can directly enter the groundwater and rapidly flow to areas where water is consumed by humans where serious health consequences can occur.
The SWCF works for the protection of the Rajah Sikatuna Protected Landscape, another karst formation found in Bohol. Haribon’s site provides a very good opportunity for further learning and exchange. The SWCF provides technical assistance to people organizations found within the protected landscape and is continuously raising local awareness on the importance of karst formations given their very delicate makeup and requirements for management. But Bill and Jun-G are hopeful as their organization has made very good strides in engaging the local governments and communities in conserving their very life support systems. More on karst environments next week
Article
By Anabelle E. Plantilla
The value of karst formations
The sight of the Chocolate Hills is truly majestic—tiny little dots of green and brown as far as the eye can see. The inscription says that they are karst formations. What? During a visit to Bohol, Bill Granert and Jun-G Madronero of the Soil and Water Conservation Foundation (SWCF) gave Haribon a very good explanation of cone karst formations, an example of which are the Chocolate Hills, and their ecological importance. Incidentally, cone karst formations only form in wet tropical climates.
The term “karst” is derived from the geographical name “kras” from part of the karst terrain of Slovenia, Eastern Europe. Karst terrain is best known for its underground drainage systems or cave systems that often form there.
Approximately 10 percent of the earth’s surface is composed of karst and approximately 25 percent of the world’s population live on these areas. In the Philippines, eight percent or approximately 35,000 sq km is karst. The hollow nature of karst terrain results in very high pollution potential. Stream and surface runoff directly enter sinkholes, cracks and caves and thus, bypass natural filtration through soil and sediment. Groundwater can travel quite rapidly through these underground networks, with speeds of up to hundreds of meters, or even kilometers, per day, transmitting contaminants to wells and springs in the vicinity.
In our country, karst formations can be found in Luzon and Mindanao, and 23 of these, representing 10,000 sq km, are protected by law through the National Integrated Protected Areas System and the National Caves and Cave Resources Management Acts. They are protected largely because of their aesthetic and, therefore, tourism value. Some examples are Callao Cave in Cagayan, Hundred Islands in Pangasinan, Mount Banahaw-Mount Cristobal in Laguna and Quezon, Mount Isarog in Camarines Sur, Saint Paul Subterranean River in Palawan, Chocolate Hills, Mount Kitanglad in Bukidnon and Sohoton Natural Bridge in Samar.
Having abundant and easily accessible water resources is one of the advantages of karst environments. They cause faster recharging of aquifers and are the main sources of springs. Another advantage is that they record history. In most caves can be found burial grounds of ancient tribes, artifacts and even drawings. They also have good soils as they trap weathered parent materials and organic matter and neutralize acidic soil. They are good sources of building materials for producing cement, filling material and commercial lime. Their economic value for tourism, food sources (birds’ nests), guano, medicines, irrigation and potable water and as a gene bank for endemic species has not yet even been determined.
On the other hand, inappropriate human activities have contributed to the degradation of these environments. Although karst soils are fertile, they are frequently very shallow, thus prone to erosion. The hydrological system of karst areas is also very sensitive to pollution which can directly enter the groundwater and rapidly flow to areas where water is consumed by humans where serious health consequences can occur.
The SWCF works for the protection of the Rajah Sikatuna Protected Landscape, another karst formation found in Bohol. Haribon’s site provides a very good opportunity for further learning and exchange. The SWCF provides technical assistance to people organizations found within the protected landscape and is continuously raising local awareness on the importance of karst formations given their very delicate makeup and requirements for management. But Bill and Jun-G are hopeful as their organization has made very good strides in engaging the local governments and communities in conserving their very life support systems. More on karst environments next week
Article