Land Use versus Stream Water Health - Literature review Example

Literature Review Client Inserts His/her Name Client Inserts Grade Course Client Inserts Tutor’s Name 19/05/2012 ABSTRACT It is a fact that various human activities are the major cause of alterations in the environmental health status, particularly the health status of various water bodies. Water, a basic need for life, makes rivers among other water bodies a natural resource of paramount importance. Methods for assessing the status of the water in streams and rivers exist and it is the role of human to inquire into river water health status and always attempt to restore the appropriate status. TABLE OF CONTENTS ABSTRACT 2 TABLE OF CONTENTS 3 INTRODUCTION 4 LAND USE VERSUS STREAM WATER HEALTH. 4 VARIOUS CONTAMINANTS 5 Nitrates and Other Salts 5 Calcium and Sodium 6 Fluorine 6 Bacteria 7 Pesticides and Herbicides 7 Volatile Organic Compounds and Other Toxic Wastes in Urban Settings 7 Harmful Mining Releases 8 Urbanization 9 Storm Water Management 10 Promoting the General Awareness of the Public 10 REALITY OF VARIOUS CONTAMINANTS PATHWAYS 11 CONCLUSION 13 LIST OF REFERENCES 15 INTRODUCTION There are currently major concerns on the heightened degradation of river water health condition (Kathleen 2011). Various studies have concluded that the health condition of river water is directly or indirectly affected by the human activities happening within a particular river’s watershed (Allan 2004). This study focuses on examining the linkage between the human land use practices and the health condition dynamics of nearby river water; examine these linkages and the possibility of restoring the original health status of river water. The study is a literature review of the work of Allan (2004) on the same subject. Allan (2004) argues that despite the public’s recognition of the occurrence of adverse effects on water bodies, there have been ineffective strategies to counter this situation. Instead the issue in question is taken lightly while deterioration of these waters gains momentum. He however suggests that there is still some haziness in the reality of the effect of various contamination pathways. The analysis of Allan’s (2004) arguments is looked into hereunder. LAND USE VERSUS STREAM WATER HEALTH. It is widely accepted that various land use practices including agricultural activities (Allan 2004; Näreaho et al. 2006; Kathleen 2011) mining, road works and urbanization; and deforestation among others introduce adverse effects on the condition and/or the quality of river water. The aspects of river water that are of ultimate importance and that are affected include reduction in the flow rates of water and poisoning or intoxicating of water. The latter automatically results to unhealthy water for domestic use and for recreation by humans; and for supporting life of aquatic animals and plants (Kathleen 2011). The land use practices that affect the health status of stream water are mostly those related to agriculture where all agricultural activities taking place within a particular stream’s watershed (Näreaho et al. 2006) are given ultimate significance in this context. Mining activities especially within such a watershed may also result in water contamination when harmful elements such as heavy metals, ammonia, nitrogen and phosphorus among others. The entire process of river or stream water contamination is gradual and complex in the sense that it is well understood by understanding the various pathways of different contaminants including their sources (Allan 2004). A typical farmer for example may not know the potential harm he or she may be causing to the health of water in a stream that is one kilometre away but within the watershed (Näreaho et al. 2006). All in all, the whole process involves the movement of these contaminants from their initiation site to the river through surface runoffs or through infiltration and hence underground transportation (through flow). This means that the rate of contamination of a stream or a river is directly proportional to the watershed’s gradient towards the river. The various pathways of contaminants are described below which expose the effects of some of activities that are insensitively conducted by humans. VARIOUS CONTAMINANTS Nitrates and Other Salts Nitrogen is a highly important element and a requirement for nutrition of both plants and animals including humans and thus it is highly considered in the process of enriching the soil matter in agriculture and also in the manufacture of human foods. In agriculture it is applied in the form of fertilizers. Nitrogen may also drain from domestic animals’ septic tanks and/or manure (Kathleen 2011). Many nitrogenous compounds used are highly soluble salts and therefore significant amounts of nitrogen are deposited in rivers through surface run off (Näreaho et al. 2006). The result is accumulation of nitrogenous salts in rivers. These excesses of nitrogen become poisonous on use/intake and have been known to cause methemoglobinemia in infants (Näreaho et al. 2006). Excesses of nitrogen in water also cause high growth of aquatic plants which occupies large amount of the living space of aquatic animals. Calcium and Sodium Calcium and sodium salts are constantly applied on surfaces of roads so as in cold countries like Green Land to counter the presence of ice pellets during winter. These lead to the formation of salts which are later swept away or drain into the nearby water bodies an accumulation of which alter the chemical balance of the water. Calcium in particular forms basic salts that may heighten the level of water PH and serve to destroy habitat for fish which are hypersensitive to chemical changes. Similarly, addition of sodium also leads to the formation of basic caustic of soda. In the water solution and with higher accumulations, the water PH is increased and the effect is similar to that of calcium. Sodium ions also lead to dehydration of various organisms by creating external environment of hypertonic solution that threatens the life of fish. Excesses of these two cations are also harmful to human health on intake. The worst condition is when they combine with halogens to form salts that make the water saline with time. Fluorine Excess of fluorine in water is as well detrimental to human health. The formation of fluorides in the water leads to major diseases of teeth. Bacteria The major sources of bacteria and other disease causing agents in this context can either be inappropriately disposed human sewage or domestic animals manure (Kathleen 2011). Their release into the rivers may cause a wide array of illnesses to human when the river water is ingested or during related recreational activities in the river. This has been observed in many of the developing countries where the society mostly uses the river water directly for drinking, bathing and simultaneously for watering the animals. Here, many outbreaks of waterborne diseases such as cholera and dysentery have been evident (Kathleen 2011). Pesticides and Herbicides Various pesticides and herbicides are differently used to kill different pests and weeds which are unwontedly thriving in specific areas of importance such as areas around homes, lawns, roadsides and more significantly, farmlands. Most of these occur in chemicals which are not easily biodegraded. These chemicals are also known to persistently retain their virulence for lengthened periods of time. A good example of a persistent pesticide is the DDT which is commonly known for its recurring harmful effects on the surrounding living organisms in the area of its application (Allan 2004). These chemicals, with time, are transported into the nearby water bodies through surface run offs (Kathleen 2011). They threaten not only life of aquatic animals, but also that of humans. Various herbicides have also been known to extend their effects to aquatic plants and animals by killing them, for example, fish and some aquatic invertebrates (Daughton 2011). Volatile Organic Compounds and Other Toxic Wastes in Urban Settings Urbanization has led to degradation of the nearby water bodies. Among the various detrimental activities in a typical urban centre is the release of harmful chemicals and toxics wastes in rivers. These include volatile organic compounds such as petroleum products. Many of these organic compounds are known to be carcinogenic, an example being benzene (Brierley & Fryirs 2005). Benzene, toluene, ethyl-benzene and xylenes are examples of releases from leaking fuel tanks and garages. Used medical wastes such as drug containers and syringes among other toxic wastes from industries have been in the past, thrown into nearby rivers in developing countries (Daughton. 2011). Municipal sewage effluents are not to forget. Treated sewage is mostly higher in ammonia content and on release into the nearby water bodies, the oxygen levels in such waters reduce drastically, resulting in a deadly condition for benthic life in such water bodies (Daughton. 2011). Many urban settings are characterized by bare land spaces which indicate presence of runoff regimes that wash away various wastes into the nearby water bodies and definitely contaminate them. Such wastes are directly a threat to the life of the surrounding communities as well as to the life of aquatic animals and plants in such a river. Coincidentally, urban settings are a home to a large number of people who are in a great danger of such contaminations. Harmful Mining Releases Mining activities are a major source of harmful minerals depending on the kind of minerals that is being mined. Heavy metals such as lead and mercury plus highly toxic metals such as arsenic and polonium among others may be released in a particular mining process (Brierley & Fryirs 2005). If they occur within a watershed of a particular stream or a river, there are high chances of contamination of its water with the metals. These kinds of metals are deadly on intake. Arsenic in particular accumulates in bony fishes which are later eaten by humans (Brierley & Fryirs 2005). Such a pathway is not easy to detect and therefore it becomes important if such water health qualities are assessed time after time (Brierley & Fryirs 2005). Urbanization It is an acceptable fact that the world’s population today is becoming urban day-in-day-out (Emily & Margaret 2007). Incidentally, vast land spaces have been turned by human into urban settings. Be as it may, urban settings remain the most complex places to manage (Earth Tech 2007). The management of these settings requires gifted hands especially when it comes to the control of the usage of a public utility. Rivers, whether near urban settings or not are public utilities in view of many. The general understanding is that every person living in such an urban setting is entitled to the use of such a river (Emily & Margaret 2007). The only negative image of this motive is that mostly the public cannot well manage such a utility due to various reasons related to interests in favour of the self. This makes thriving of such a utility impossibility (Emily & Margaret 2007). However, with the respective municipal council in proper form, and the intervention of the government through various projects and civic education on the importance of safeguarding natural resources, Emily and Margaret (2007) finds it safer to say that restoration of rivers is possible. There is a call for each member of the society to first conceptualize the significance of the presence of such rivers just for the natural beauty of the urban landscape and for the service to the future generation (Allan 2004). The need to use the services of a nearby river for everyone in an urban setting makes most of such rivers to be highly sensitive to changes in its surrounding (Stanton 2007). Some of these changes include the clearing of the vegetation around the rivers for the construction of various structures and this leads deprivation of the river’s micro catchments (Davies et al. 2008). On the contrary, the new catchments become effluents from the municipal sewage, disposal of waste materials into the river, industrial effluents and intermittent run offs which may disfigure river banks for example (Emily & Margaret 2007). The change of both the chemical and physical conditions of the river water is thus given. The end effect is instability in the river water’s life supporting systems and thus the death of plants and aquatic animals (Meng et al. 2009). River restoration is among the mostly debated environmental management and development issues basically in respect to the evident clearance of riparian vegetation for construction or for cultivation (Earth Tech 2007). There are various strategies that can be employed in an attempt to ameliorate the problem as discussed below. Storm Water Management Massive runoff regimes after strong rains are known to occur wherever land is bare (Stanton 2007). Such runoffs may lead to overflowing of river banks, a condition that can lead to deterring of human activities, transit services among others. The major cure for this problem is the establishment floods control measures (Allan 2004) especially as related to agricultural use of lands near the rivers. Avoidance of cultivation of lands close to the river banks and the application of various soil erosion control measures serve as the best examples. Planting of trees and all other processes that may promote the growth of vegetation for cover along river banks and for the retention of almost original nature of the river catchment base are other strategies that enhance sustenance of a typical river or stream’s life. Promoting the General Awareness of the Public The establishment of civic education on the importance of protecting natural resources can serve a great role in the overall efforts to restoring various resources to their original form. What is needed is a win-win policy that enhances awareness of the public that these efforts are for catering of their welfare (Stanton 2007) as well as that of future generation. In fact, most of the degradation of natural resources occurs due to lack of this awareness that otherwise would efficiently counter the destructive habits. REALITY OF VARIOUS CONTAMINANTS PATHWAYS According to Allan (2004), there are a number of pathways that various contaminants follow before coming into contact with river water. Soil erosion, aided by surface runoff, is the key process that leads to contamination of surface waters. Various contaminants hold stiffly on soil particles while others dissolve in the water and are transported to the rivers in the process (Kathleen 2011). Underground water transport of the infiltrated water also serves as another route especially for the soluble contaminants for example, nitrogenous compounds and pesticides used to serve various agricultural purposes (Meng et al. 2009). Some other pathways are direct including the releases of toxic wastes and bacteria into the river when sewages pipes burst and when industrial wastes are discharged into the rivers (Meng et al. 2009). In addition, the rain water pathway is yet a significant one. Some of gases released into the atmosphere from mining, road works and to some extent from agricultural activities such as spraying of various chemicals on crops later combine with water and fall back to the ground in form of compounds and/or solution accumulations of which may lead to establishment of harmful concoctions in the rivers (Allan 2004). The release of sulphur dioxide into the atmosphere has been known to produce acid rain which alters the level of water PH which may negatively affect the living conditions of various aquatic animals and plants. Allan (2004) finds out that different pathways’ influences are not directly visualized and that it is not quite certain that the rate of alteration of river water health condition will correctly match the expected effects of observed activities around the water source. Similarly, the timeline between the initiation of the suspected harmful land use activities and the response of the river water condition is not clear. In other words, it is not easy to conclude that certain activities are causes of particular effects on the water (Allan 2004). Different activities occur in different areas that bear different sloping indices. It becomes difficult to conclude that the activities happening say close to the river banks have more effects on the dynamics of the health conditions of the water than the activities happening far off the river banks (Allan 2004). There also occur difficulties in distinguishing the effects caused by the current activities from those that were caused during past times (Stoddard et al. 2006). If for example one finds water having saline conditions, he or she may as well face difficulties in relating this to the past, to the present and to a particular source of influence. The saline condition may be closely related to the geological characteristics of the rock or soil matter underlying the river bed and thus many conclusions may be incorrect. Most of these observations are avoided during analysis and therefore the conclusions are only being well described as estimations (Allan 2004). The assessment of the health of the river water is however a crucial undertaking regardless of the method employed (Stoddard et al. 2006; Meng et al. 2009). Of ultimate importance is the ability to locate the problems if any and to make relevant recommendations in response (Davies et al. 2008). Various indicators of unhealthy river water are many (Stoddard et al. 2006). First is the chemical composition of the water. In other words, if the chemical composition of the water is altered, the number of fish that can survive the changed condition for example also changes proportionally either directly or inversely. For a better chemical balance, the fish number increases and the opposite is true (Davies et al. 2008). CONCLUSION Various human land use practices are the main cause of detrimental effects on the riparian ecosystems including the health status of river water (Allan 2004). The land use practices that affect the health status of stream water are mostly those related to agriculture where all agricultural activities taking place within a particular stream’s watershed are given ultimate significance in this context. Mining activities especially within such a watershed may also result in water contamination when harmful elements such as heavy metals, ammonia, nitrogen and phosphorus among others. There is thus a call to examine human practice and recommend on the best strategies for restoring the healthy conditions of river water for use by humans and for meeting the requirements of aquatic life (Earth Tech 2007). This can be enhanced by the use of various methods including the use of a reference condition that accurately reflects the effects of human activities on the health conditions of the river water. The establishment of civic education on the importance of protecting natural resources can serve a great role in the overall efforts to restoring various resources to their original form (Meng et al. 2009). What is needed is a condition that enhances awareness of the public that the rehabilitative efforts are for catering of their welfare as well as that of future generation What with planning in advance (Earth Tech 2007), enhancing awareness of the public and giving the issues of the environmental health the first priority by the respective government, restoration of the original status of natural resources is achievable. LIST OF REFERENCES Allan, J. D. 2004. Landscapes and Riverscapes: The influence of land-use on stream ecosystems. Annual Review of Ecology and Systematics 35(1): 257-284. Brierley, G.J., and Fryirs, K.A., 2005. Geomorphology and river management - applications of the River Styles framework. Carlton, VIC.: Blackwell Publishing. Daughton, C.G., ed. 2011. Pharmaceuticals and Personal Care Products (PPCPs) as Environmental Pollutants: Pollution from Personal Actions, Activities, and Behaviours. U.S. Environmental Protection Agency. 3-12. Davies, P., Harris J. J. et al., 2008. Sustainable rivers audit: river health check. A Report on the Ecological Health of Rivers in the Murray–Darling Basin 2004-2007, SRA Report 1. 11-33. Earth Tech. 2007. Sydney Metropolitan CMA Waterways Health Strategy. Earth Tech Pty. Ltd. for Sydney Metropolitan CMA, Sydney, NSW. 125-128. Emily, S.B., and Margaret, A.P. 2007. Restoring streams in an urbanizing world. A Journal of Freshwater Biology, 52(4): 738-751. Kathleen, H.B., 2011. Water resource protection in Australia: Links between land use and riverhealth with a focus on stubble farming systems. Journal of Hydrology, 403(1-2), 176-183. Meng, W., Zhang, N. et al., 2009. Integrated assessment of river health based on water quality, aquatic life and physical habitat. Journal of Environmental Sciences 21, 1017–1027. Näreaho, T., Jormola, J. et al., 2006. Environmental maintenance of cleaned ditches in agricultural areas. (In Finnish). The Finnish Environment. Finnish Environment Institute, Helsinki. 52, 61-63. Stanton, P., 2007. Rivertown. Rethinking urban rivers, Massachusetts: The MIT Press. Stoddard, J. L., Larsen, D. P. et al. 2006. Setting expectations for the ecological condition of streams: the concept of reference conditions. Ecological Applications 16: 1267–1276. Read More