Question After the dam was removed, the flow of the river increasedrapidly in the immediate area downstream for a short period.(e)Explain why the number of migratory birds visiting areas downriverfrom the former dam site increased the year after dam removal.Farmers in the region depend heavily on an aquifer for cropirrigation. The aquifer recharge zone is marked on the diagram.(f)Describe one way that farmers could protect the aquifer rechargezone shown in the diagram.The local people are engaged in a variety of agriculturalpractices in the watershed of the river. Agriculture uses a varietyof methods to produce meat for human consumption.(g) Describe howthe planting of a variety of native grasses in grazing pasturesthat grow in different conditions is a sustainable approach forgrazing beef cattle.(h) Describe one environmental problem wetland ecosystems mayexperience because of the increased need for agricultural land forcrops or beef production Write your answers in the spaces provided. Refer to the figure or diagram to answer the question. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. Sea trout are a fish species that migrate annually between spawning grounds in rivers and the sea. The data show the population of sea trout spawning at two different sites along the river. Two changes occurred through the years. In 1998 a fish ladder was installed allowing fish to pass over the dam, and in 2008 the dam was removed. 2 3 Open Sea Aquifer Recharge Zone Flow of River Dam Population of Trout per Kilometer Trout 0-1 year old Year 1988 1992 1999 2011 2016 Location A 0 0 75 3760 9270 Location B 1320 380 2440 4960 8110 Trout older than 1 year Year 1988 1992 1999 2011 2016 Location A 0 200 360 340 Location B 260 670 440 430 400

E. The dam removal impacts on the migratory due to , when tere is dam removal ,there is increase of water turbidity and sediment build uo downstream from releasing large amounts of sediment from the reservoir and water quality  imapcts from sudden release of water from the reservoir and it is vey important that there is change in temperature, which affwct the migratory birds living style very much.The environment created by the removal of dam in downstream creats a suitable environment for the birds so they migrate down river .So here temperature plays a vital role. When a dam is removed ,the rivers natural hydrology that is movement of water is restored .Above the dam ,habitat for native river species is restabilished as the reservoir disappears and below the dam ,the natural flow patterns that native plants and animals are accustomed to are returned to their original configuration. F. Definition of recharge zone of aquifer : an aquifer is a layer of underground rock or sand which stores and carries water. A recharge area is the place where water is able to seep into the ground and refill an aquifer because no confining layer is present.Recharge area is necessary for a healthy aquifer. how fast the aquifer can recharge we should look into it by the following way depending on its permeability ,aquifer can gain water at a rate of 50 feet per year to 50 inches per century.They have both recharge and discharge zone .A recharge zone should occur at a hihg elevation where rain ,snowmelt,lake,or river water seeps into the ground to replenish the auifer.We also concerned about the pollutant in the recharge area beacuse recharge area are environmentally sensitive areas because any pollution in the recharge zone can enter the aquifer .So by dispose of chemicals properly,limit the fertilizer use on plants,by avoiding human construction of building and parkings lots can act as impermeable layers and limit the amount of water that reaches the aquifer . the main things in some agricultural area flood irrigation is the primary method ofe recharge . G. Things to do in prepartion of native grass for grazing propose Before buying seed,by researching about the species that you want to plant, make sure thata the species is adapted to your area for the intended use.match the species to the location,soil type, and grazing amnagement to make the right species slection.Nitrogrn is the best fertilizer ,by application of it to the grass pastures ,grasses increase per annum.By choosing the bset seed like Bermuda grass , the most widely adapted warm season grass.It sis very easy to grow in most soils and is drought-tolerant and durable.Bermudagrass requires very little maintenance and Centipedegrass , a good low maintenence warm season grass.. By adapting a good method to increase production is by sparying out weeds using selective herbicide leaving the pasture behind.Broadcasting of legume seeds  which is a cost effective way of increasing the quality of the pasture.   H.    we know that due to rising carbon dioxide levels affect bith detrimental and beneficial on crop yields. At the same time ,agriculture have significant effects on climate change primarily through the production  and release of gases like carbon dioxide, methane , and nitrous oxide.agricultural practices have negative impact on water quality .Improper agricultural methods may elevate concetrations of nutrients ,fecal coliforms and sediment loads .Increased nutrients loading from animal waste can lead to eutrophication of water bodies which may damage aquatic ecosysyem and wetland ecosystem. Grazing animals and pasture production can negatively affect water quality through erosion and sediemnt production and transport into surface water through nutrients from urine and feces dropped by the animals and fertility practices associated with the production of high quality patures and pathogens from waste. Livestock farming have a vast environmental imact.It contributes tp land and water degradation,biodiversity loss,acid rain,coral reef degeneration and deforestation.livestock contributes 18% of human producrd greenhouse gas emmissions ,which is a great problem in the ecosystem.   ...